JP2001004759A - Metal detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a simple, compact metal detector for performing the manual single-pass detection inspection of the presence or absence of a metal foreign object being mixed into a mass-shaped specimen represented by square bread at the inspection passage of a middle-folded passage that is composed of a group of electromagnetic coils being provided three-dimensionally. SOLUTION: An enclosure for inspection with an inspection passage for detecting the presence or absence of a metal foreign object in a specimen by a known principle for capturing the change in an electromagnetic field for the metal foreign object that crosses the electromagnetic field of magnetization coils is formed where a plurality of coil groups 5a, 5b, and 5c are sealed to the three required locations at a middle-folded passage in reverse mountain shape at a central part 4 in that one surface with a U-shaped section is open. As a result, since an inspection passage where the electromagnetic coil groups are arranged three-dimensionally is formed at the required part of the middle- folded passage utilizing human engineering, human habits, a specimen can be inspected securely with a single pass even if the specimen is a number of surfaces to be inspected relatively with mass.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal detector suitable for inspecting and detecting metal foreign matter which must not be mixed in non-metal products such as loaf food such as bread.

[0002]

2. Description of the Related Art As a conventional metal detector, as a typical example, a conveying means of a belt conveyor 31 and a detecting means of a tunnel-like search coil 32 as shown in FIG. Fig. 6 is a mechanical type that detects a contaminant metal foreign matter when the laser beam passes through the search coil.
(2) A manual work type having no transport means for contacting a thin subject such as clothing with a flat test case 41 having a plurality of electromagnetic coils 42 embedded therein such that an induction magnetic field is converged upward as shown in FIG. A stationary metal detector or the like is typically known.

[0003]

The conventional metal detector as described above has no problem in terms of performance in the case of a conveyor type, but has a problem in that it has a relatively large size and a high cost. Suitable for line installation, but not suitable for small places such as retail stores.

[0004] The manual detector of the above-mentioned flat type inspection housing is inexpensive and small, but its original function is that it is suitable for a subject such as thin clothing, and generally the inspection magnetic field is flat. Since only one surface of the housing is converged and the reach distance is limited, when inspecting a large mass such as bulk food, it is necessary to change the surface to be inspected and repeatedly inspect it, which is efficient. is not.

[0005]

Means for Solving the Problems In order to solve the above problems, the present invention mainly has the following configuration. (1) It has a U-shaped cross section of katakana whose one side is open, whose inner dimension is sufficiently larger than the outer dimensions of the massive subject, the open side is the front, and the upper and lower two sides of the U are gentle at the center. An angled, bent, straight, inverted, mountain-shaped passage is formed, and an inspection housing is formed for manually detecting metal foreign matter from the left end to the right outer end of the passage while holding the subject by hand. That you did. (2) A predetermined point as close as possible to the center of the inverted mountain-shaped passage of the inspection housing, that is, a center of the upper side plate located to the left of the center-folding contact, and a corner as close as possible to the outer end of the passage. Detecting means for fixing a plurality of groups of electromagnetic coils such that the induced magnetic field converges inside the passage at a predetermined position of the lower side plate of the U-shape and at a predetermined position of the U-shaped side plate substantially at the intermediate position between the two positions. That it was provided. (3) adjusting the magnetic strength of the plurality of electromagnetic coil groups;
Or, in the case where a metallic foreign substance is mixed in the subject, control such as transmitting a detection signal as a warning based on a known principle that captures disturbance of the magnetic field due to the mixed metallic foreign substance crossing a magnetic field converging from any of the electromagnetic coil groups. The circuit was provided.
(4) In contrast to the above, the open side of the test housing is shifted upward by 90 ° and in other words, the test object is held by the hand in the folded path in the lateral direction by hand. The configuration was changed to a configuration in which the subject was inspected while suspended in a folded path, and all other details were exactly the same as above. (The contents of Claim 2 above)

[0006]

(1) According to the metal detector of the present invention as described above, when the mass object is manually passed through the bent path of the inspection housing while holding the mass object by hand, Even if you try to trace the path along a half-fold path, the higher the traveling speed naturally, the closer the short-circuit and the trajectory close to a straight line will follow. The surface to be inspected is closer to the electromagnetic coil group fixed to each of the lower plates, or passes through the contact, so that there is an effect of reliably crossing the magnetic field. (2) Regarding the work of detecting the inspection surface in front of the subject,
The electromagnetic coil group fixed to the side plate is responsible, but if possible, as a method of use for test personnel, it is recommended to use handbooks to lightly touch the side plate at the back of the test passage and proceed while using the instruction manual etc. By doing so, reliable detection accuracy is still achieved. (3) Thus, the metal detector of the stationary type, which does not require any special transporting means, can provide a reliable and inexpensive metal detector with one-passing of the subject, which requires less labor.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 3 are views showing a first embodiment of a metal detector according to the present invention. FIG.
FIG. 2 is a diagram showing the relationship between the front of a center-fold passage having a U-shaped cross section and a predetermined fixing position of each electromagnetic coil group, and an assumed dynamic posture when a subject passes through this passage. , FIG.
FIG. 4 is a cross-sectional view of the center portion of the center-fold path as viewed in the direction of arrow B in FIG.
Fig. 3 is a perspective view of a resin-packed square bread as the most typical handling unit among the massive subjects.

In FIG. 1, reference numerals 1, 2, and 3 denote side plates, upper plates, and lower plates constituting a U-shaped cross section of katakana, respectively, and are accurately refracted at a central portion 4 as shown in FIG. It is formed in the shape of an upside-down straight angled bent passage at a gentle angle.

Electromagnetic coil groups 5a, 5b, and 5c are fixed in a direction in which an electromagnetic field converges on one side of each plate forming the passage in the inside of the passage. The electromagnetic coil group 5c of the lower plate 3 is located at a predetermined position as close as possible to the center bending refraction section 4, the electromagnetic coil group 5b of the side plate 1 is at a predetermined position as close as possible to the outer end of the right side of the center folding passage. And 5c are fixed at predetermined positions substantially intermediate between the respective plate surfaces.

Reference numeral 6 in FIG. 1 denotes a control circuit housing of the present invention.
A switch 7, an alarm buzzer 8 and an alarm lamp 9 are externally provided. In the housing, the magnetic field strength of each of the above-mentioned electromagnetic coils is adjusted, and the foreign metal contaminant in the subject converges from any of the above-mentioned electromagnetic coils. A series of control circuits for outputting a predetermined alarm by inputting a detection signal to the alarm buzzer or the alarm lamp according to a known principle by traversing the electromagnetic field to be generated. Reference numeral 11 denotes a support.

Next, the function of the metal detector according to the present invention will be described. A specific example of the subject that is easy to understand will be described by performing an inspection for the presence or absence of metal foreign matter in the bread slice shown in FIG. Switch on switch 7,
After the control circuit is energized, the inspection worker holds the binding portion 21 of the resin packaging bag of the subject 20 by hand while holding the binding surface 21 opposite to the binding portion on the side plate 1 having the U-shaped cross section. It is slightly pressed against the surface and is advanced into the U-shaped cross section in the direction of arrow A shown in FIG.

When the subject 20 is caused to travel along the upside-down path of the center-fold path, the higher the traveling speed, considering the habits of humans, the higher the speed at which the test object 20 travels. Move in the horizontal direction slightly like a short circuit, and proceed as shown in the dynamic diagram assumed for the subject 20 shown in FIG.

Therefore, according to the dynamic movement tendency described above, the subject 20 in the passage moves first while the upper surface of the surface to be inspected approaches the electromagnetic coil group 5a in a posture as shown in 20a in FIG. When approaching the outer end, the lower surface of the surface to be inspected moves in a posture as shown in FIG. 20c while approaching the electromagnetic coil group 5c. In addition, since the test object 20 is slightly pressed against the side plate 1, each test surface crosses any electromagnetic field of the electromagnetic coil group in a standby state, and if there is a mixed metal foreign substance, A disturbance of the electromagnetic field is induced, a change in current in the control circuit is detected, a detection signal of a metal foreign matter is transmitted as an alarm, and a series of inspection cycles is completed.

[0014]

As described above, a conventional stationary plate-shaped metal detector is used for detecting a metallic foreign object by allowing a massive object to pass through an inspection passage having a U-shaped cross section while holding it by hand. On the other hand, (1) the three-dimensional configuration of the electromagnetic coil group on each of the three sides of the U-shaped cross section enables efficient one-pass inspection work even for a massive subject. (2) From the point of view of ergonomics utilizing human habits, the U-shaped cross-section passage is an upside-down inverted mountain-shaped passage, and an electromagnetic coil group is arranged at a key point, so that there is more room than the size of the subject In spite of the cross section of the normal size, the subject passes through the plurality of three-dimensional surfaces to be inspected sufficiently close to the waiting electromagnetic coil group, which is smaller than that of the linear inspection passage. High detection accuracy. (3) Also, in the example of the surface to be inspected of the loaf of square loaf bread, the front and rear surfaces in the traveling direction and the surface at hand do not directly face the electromagnetic coil group, but the depth of the U-shaped cross section is particularly large relative to the external dimensions of the object. In addition, the three-dimensional configuration of the electromagnetic coil group provided on the three surfaces allows the metal in the wide range of the inner part of the subject to be determined by contriving the dimensions of the subject to be deep, and selecting an electromagnetic coil with a long reach of the electromagnetic flux. Foreign matter can be sufficiently captured and detected. (4) In the above example, the passage of the inspection housing has a configuration in which the open surface of the U-shaped cross-section passage faces the front. The difference is that the test path is advanced while the sample is suspended and the test is performed. However, the test accuracy, function, etc. can be regarded as exactly the same as in the case of the front configuration.

[Brief description of the drawings]

FIG. 1 is an external explanatory view showing a first embodiment of a metal detector according to the present invention.

FIG. 2 is a diagram showing a correlation between a bent inspection path and a group of electromagnetic coils fixed to each part of the inspection housing of the metal detector according to the present invention, and a case where a massive subject passes through the bent path. Assumed dynamic diagram.

FIG. 3 is a sectional view taken along the line BB in FIG. 2;

FIG. 4 is a perspective view of a bread wrapped in resin as an example of a subject;

FIG. 5 is a diagram of a mechanical metal detector combined with a conveyor.

FIG. 6 is a diagram of a stationary flat-plate type manual metal detector.

[Explanation of symbols]

1. Side plate forming a U-shaped cross section 2, Upper plate forming a U-shaped cross section 3, Lower plate forming a U-shaped cross section 4, Refraction point of middle bent path 5, Electromagnetic coil group 6, Control circuit 7 , Switch 8, alarm buzzer 9, alarm light 10, relative relationship diagram between the center bent path and the position where the electromagnetic coil group is fixed, and expected dynamic diagram of the subject at the time of inspection 11, support stand 20, subject 21, binding Part 22, inspection surface 31, belt conveyor 32, tunnel-like search coil 41, stationary plate-type metal detector flat plate inspection housing 42, electromagnetic coil

Claims (2)

[Claims] 1. A katakana-shaped U-shaped cross-section (1, 2, 3) having only one side open and having an inner dimension sufficiently larger than the outer shape of the subject (20), The inspection housing (10), which has a straight bent path in a mountain shape inverted upside down at a gentle angle to the left and right from the central part (4) in the longitudinal direction with the open surface of the cross section facing the front, and the magnetic field induced by the electromagnetic coil. A plurality of predetermined positions of the upper plate (2) forming the cross section on the left side as close as possible to the bent central portion (4) of the housing (10) fixed so as to converge toward the inside of the passage. An electromagnetic coil group (5a); a plurality of electromagnetic coil groups (5c) at predetermined positions on a lower plate (3) as close as possible to the outer end of the passage away from the bending position to the right; and the two electromagnetic coil groups (5a) and (5c) the side plate at the substantially central part A) controlling the magnetic force of the induced magnetic field of the plurality of electromagnetic coil groups (5b) at the predetermined position in (1), and responding to a change in the magnetic field due to disturbance of the magnetic field by a metal foreign matter passing through the magnetic field; Alarm means (8,
And a control circuit (6) having a U-shaped cross-section from the left end of the folded path of the inspection housing (10) by hand while holding the subject (20) by hand. Detecting the presence or absence of metal foreign matter by a well-known principle that captures the change of the induced magnetic field due to the mixed metal foreign matter in the subject (20) by passing the inside of the subject (20) to the outside of the right end while maintaining a sufficient depth. A metal detector. 2. The method according to claim 1, wherein the open face of the U-shaped cross section of the katakana is a front face, but the open face is turned upward by 90 °. The metal detector as described.