JP2893287B2 - Article inspection equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field of the Present Invention> The present invention relates to an article inspection apparatus that inspects an article while transporting the article on a conveyor.

<Prior Art> In a production line, various inspections are performed before product shipment.

In particular, weight inspections and metal contamination inspections are often performed on all products. For this reason, metal detectors and weight sorters should be placed on the line to automatically reject and sort out defective products. I have to.

However, the separate installation of the metal detector and the weight sorter is disadvantageous in terms of the installation area. Therefore, the weight sorter shown in FIG. 9 has been used conventionally (J.
41822).

The weight sorter 1 includes a run-up conveyor 3 placed on a base 2, a weighing conveyor 4 that receives and conveys articles from the run-up conveyor 3, and a weighing device according to the weight of the articles carried into the weighing conveyor 4. A measuring device 5 for outputting a signal is provided, and the approaching conveyor 3 is provided with a detection head 6 formed in a frame shape surrounding the transport path.

FIG. 10 schematically shows the internal configuration of the detection head 6, in which a magnetic flux from a transmission coil 7 excited by an AC or DC power supply is opposed to the transmission coil 7 and aligned in the transport direction. The receiving coils 8 and 9 receive the signals.

The number of interlinkage magnetic fluxes between the two receiving coils 8 and 9 is determined by the passage 6a.
Is determined in advance so as to be equal in the absence of an article, and when there is the passage of the article W containing metal, the difference in the number of interlinkage magnetic fluxes between the two receiving coils 8 and 9 becomes more remarkable than when passing a good article. Become.

Reference numeral 10 denotes a detection / judgment circuit for judging the presence or absence of metal contamination based on voltages induced in the receiving coils 8 and 9.

The article that has passed through the run-up conveyor 3 in this way is carried into the weighing conveyor 4 and weighed by the weighing device 5, and the results of metal detection and weight selection judgment for the article are displayed on the instruction unit 11, and A selection signal corresponding to the selection determination result is transmitted to a subsequent selection line (not shown).
To remove defective articles and sort the articles.

<Problem to be Solved> However, the run-up conveyor 3 provided with the detection head 6 formed so as to cover the periphery of the article conveying path as described above.
In this case, there is a problem that the height or width of an article that can be conveyed is greatly restricted, and a problem that the detection sensitivity of metal contained in the lower part of the article is insufficient.

In addition, when various inspection functions (for example, a function of automatically performing a pattern check on the appearance of a product, etc.) are added in addition to the metal detection function, detection that covers a part of the article transport path as described above is performed. Since a large space is occupied by the head 6, it is difficult to add another inspection function.

These problems are also the same when a detection head having a transmission coil and a reception coil arranged coaxially with an article conveying path is provided on a run-up conveyor or a weighing conveyor, and a conventional weight sorter provided with such a conveyor. Then, it was difficult to realize multiple types and multiple inspection functions.

An object of the present invention is to provide an article inspection device that solves this problem.

<Means for Solving the Problems> In order to solve the above problems, an article inspection apparatus according to a first aspect of the present invention comprises: An article inspection device that has a conveyor that conveys articles conveyed on the roller-side conveyor belt to the other roller side, and that inspects articles conveyed on the conveyor during conveyance. An upper plate disposed between the two rollers and the conveyor belt for supporting the conveyor belt for receiving the articles conveyed on the conveyor on the upper surface side, and an upper portion formed by a member for preventing transmission of lines of magnetic force. A head frame formed in an open bottomed box shape and attached to a lower surface side of the upper plate so that the opened upper portion is closed; and a transport belt disposed in the head frame, A magnetic flux generating means for generating a magnetic flux intersecting with the article conveying path; and a plurality of magnetic flux generating means arranged in the head frame at a position close to the magnetic flux generating means in a direction in which the article is conveyed, and linked from the magnetic flux generating means A detection head including a plurality of magnetic sensors that outputs a signal corresponding to a magnetic flux is provided on the conveyor, and based on signals output from the plurality of magnetic sensors, metal contamination of articles carried on the conveyor is determined. Metal determination means for determining the presence or absence is provided.

The article inspection apparatus according to a second aspect of the present invention is the article inspection apparatus according to the first aspect, wherein the conveyor provided with the detection head is supported from below by a weighing machine, and the metal contamination inspection of the article is performed. And weight detection can be performed on the same conveyor.

<Operation> In this way, according to the first aspect, the article shape is not restricted by the detection head, the article conveying path is not covered, and the transmission of the magnetic flux generated by the magnetic flux generating means to the lower surface side of the conveyor is prevented. It is possible to carry out metal contamination inspection of articles carried into the conveyor while being blocked by the head frame,
Other inspection functions can be easily added.

Further, in the second invention, the metal contamination inspection and the weight inspection of the article can be performed on the same conveyor in a state in which the magnetic flux generated by the magnetic flux generating means of the detection head is prevented from being transmitted to the measuring instrument.

<Example of the present invention> Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 shows a weight sorter as an article inspection apparatus according to one embodiment.
FIG. 2 is a front view, FIG.
It is the side view which looked at the figure from the A direction.

In these figures, 21 is a base, 22 is a conveyor support plate erected so as to face the base 21, and 23 is a run-up conveyor screwed on both sides to the upper part of the conveyor support plate 22. The base 21 is supported so that its transport direction is parallel to the longitudinal direction of the base 21.

Reference numeral 24 denotes a U-shaped conveyor frame having an upper opening, 25 denotes a drive roller rotatably supported by a center shaft 25a at one end of both sides 24a and 24b of the conveyor frame 24, 26
Is a driving device that rotationally drives the driving roller 25.

27 is a driven roller having a center shaft 27a rotatably supported on the other end of both sides 24a and 24b of the conveyor frame 24;
Is a transport belt stretched between the driving roller 25 and the driven roller 27.

Reference numeral 30 denotes a detection head for detecting metal contained in an article conveyed on the conveyor belt 28 of the run-up conveyor 23.

This detection head 30 is formed in a substantially rectangular flat plate shape,
It is arranged in a gap between the conveyor belts 28.

FIG. 4 is a plan view showing only the detection head 30, and FIG.
The figure is a sectional view thereof.

In these figures, reference numeral 31 denotes an upper plate of the detection head 30, which also serves as a belt support function for preventing the transport belt 28 from being loosened due to the load of the conveyed article, and a back surface 28a of the transport belt 28.
It is made of a synthetic resin, such as plastic, which has little friction with respect to and transmits magnetic lines of force.

Reference numeral 32 denotes a head frame, which is made of aluminum for the purpose of preventing transmission of lines of magnetic force to the lower surface side. The head frame 32 is supported by screws on both sides 24a and 24b of the conveyor frame 24.

33 is a transmitting coil (magnetic flux generating means) wound on the outermost circumference in the head frame 32, and 34 and 35 are receiving coils (magnetic sensors) of the same diameter arranged inside the transmitting coil 33 along the conveyor conveyance direction. And the magnetic flux generated from the transmission coil 33 interlinks the two reception coils 34 and 35 with an equal amount.

Reference numerals 36, 37, and 38 denote coil frames of the transmission coil 33 and the two reception coils 34, 35.

Numeral 40 (FIGS. 1 to 3) is a weighing conveyor constructed in the same manner as the run-up conveyor 23 except for the detection head 30, and a driving roller 42 and a driven roller 43 are rotatably supported on both sides of a conveyor frame 41. Then, the transport belt 44 stretched between the rollers is rotated by the driving force of the driving device 45.

Reference numeral 46 denotes a weighing device that supports the weighing conveyor 40 from below, and outputs a weighing signal corresponding to the weight of the conveyed article with respect to the weighing conveyor 40.

50, 51 are opposite ends 52a, 52b of the connecting member 52 so as to face each other.
The transmitter and receiver are mounted on the conveyor 23 and the weighing conveyor from a position slightly higher than the belt transport surface.
The light receiver 50 is formed so as to be able to receive light from the light projector 50 passing through the gap with the light receiver 40, and the carrying in of the article is detected by the light receiving signal of the light receiver 51.

The central portion 52c of the connecting member 52 is supported by a supporting member 53 erected from the base 21 so that the vertical position and the light projecting / receiving angle can be arbitrarily set.

55, based on the signals from the detection head 30 and the measuring device 46, performs the determination of the presence / absence of metal mixed in the carried-in article and the weight selection determination, displays the determination result on the display unit 56, and displays the determination result. Is a determination instructing unit that outputs a selection signal according to the following to a subsequent selection drive line.

Reference numeral 57 denotes a switch key for setting parameters (permissible weight range, reference amount for metal detection, excitation frequency, and the like) necessary for these determinations, a transfer speed, and the like.

FIG. 6 is a block diagram showing a schematic configuration of the determination instruction unit 55.

In FIG. 6, reference numeral 60 denotes a transmission coil 33 of the detection head 30.
An excitation circuit for exciting the current with an alternating current (or a direct current) of a predetermined frequency, a balance 61 for outputting a differential component of the two receiving coils 34 and 35, and a detector 62 for detecting the differential component Metal determination means for determining the presence or absence of a mixed metal based on the output.

63 is a weighing device after a predetermined time has elapsed (after the weighing signal is stabilized) after the light to the light receiver 51 is blocked by the carry-in of the article.
Weight determination means for determining the weight of the article based on the weighing signal from 46.

64 is a judgment result display means for displaying the two judgment results on the display unit 56, 65 is a selection signal output means for outputting a selection signal corresponding to the judgment result to the subsequent stage, and 66 is an excitation circuit
60 is a parameter setting means for setting various parameters for the metal determination means 62 and the weight determination means 63 by operating the switch key 57.

 Next, the operation of the weight sorter 20 will be described.

When the article is carried onto the run-up conveyor 23, the two receiving coils 34 of the detection head 30
Although 35 magnetic flux changes occur, when there is no mixed metal, the magnetic flux change is relatively small, and the detection output does not exceed a predetermined reference amount.

When the article is conveyed from the run-up conveyor 23 to the weighing conveyor 40, a determination based on the weight value of the article is made, and the weight determination result and the metal determination result are displayed on the display unit 56.

If incoming goods contain mixed metal, two receiving coils 3
Since significant magnetic flux changes occur in 4 and 35, metal determination means 6
2 outputs a determination signal indicating the mixing of metal.

FIG. 7 is a diagram showing a comparison of sensitivity between the flat-type detection head 30 and the conventional opposed-type detection head.
When a metal with a radius of 1 mm (relative permeability 20) is within a predetermined distance range (for example, 60 mm) from the receiving coil surface, the differential voltage output is lower than that of the opposed type under the same conditions (coil diameter, number of turns, excitation frequency, etc.) It is calculated (omitted) that the detection can be performed with a remarkably high sensitivity especially in the lower part (the part near the receiving coil) from 3 times to 15 times, and the actual detection sensitivity shows the same tendency as this result. Thus, mixed metal that easily sinks below the article can be detected with high sensitivity.

In this way, the articles for which the metal mixing determination and the weight determination have been performed are subjected to the sorting process according to the determination result by the subsequent sorting drive line.

<Other embodiments of the present invention> Note that, in the above-described embodiment, the current is caused to flow through the transmission coil 33 as the magnetic flux generating means included in the detection head 30, but a permanent magnet may be used. Further, Hall elements or the like may be used instead of the receiving coils 34 and 35 as the magnetic sensors.

Further, the transmitting coil 33 and the receiving coils 34 and 35 may be patterned on a printed board.

Further, in the above-described embodiment, the case where the flat type detection head 30 is mounted in the run-up conveyor 23 has been described. However, the detection head 30 may be mounted in the weighing conveyor 40.

In this case, the run-up conveyor 23 and the weighing conveyor 40 of the above embodiment have almost the same shape except for the presence or absence of the detection head, and the run-up conveyor 23 and the weighing conveyor 40 may be replaced as they are.

Further, in the above-described embodiment, the two receiving coils 34, 35 which are almost equally affected by the magnetic flux generated from the transmitting coil 33 and have substantially the same shape along the article transport direction are connected to the transmitting coil 33.
Although arranged on the same plane as 33, the transmitting coil and the receiving coil may be arranged so as to face each other with a slight separation.

Further, as shown in a detection head 30 'shown in FIG. 8, three pairs of receiving coils 34a to 34c and 35a to 35c are arranged in the article transport direction B.
May be arranged along the inside of the transmission coil 33.

In this case, the position of the mixed metal in the article can be known more accurately, and the tendency of the mixed metal can be grasped.

<Effects of the present invention> As described above, the article inspection device of the present invention includes a gap between two rollers of a conveyor and a gap surrounded by a conveyor belt.
An upper plate supporting the conveyor belt from below, a head frame formed of a member having a bottom for preventing transmission of lines of magnetic force and formed in a box shape with a bottom and attached so that the opened upper surface is closed by the lower surface of the upper plate; Providing a detection head constituted by magnetic flux generating means and a magnetic head provided inside the frame,
The detection head performs a metal contamination inspection of the articles carried on the conveyor. Therefore, there is no need to limit the width and height of the conveyed article by the detection head, and the metal under the article can be detected with extremely high sensitivity.

Further, it is not necessary to cover the article transport path, and it is possible to easily add another inspection function in addition to the metal detection function.

[Brief description of the drawings]

FIG. 1 is a perspective view showing the appearance of one embodiment of the present invention, and FIG.
The figure is a front view of FIG. 1, and FIG. 3 is a side view of FIG. FIG. 4 is a plan view of a main part of one embodiment, and FIG.
It is sectional drawing. FIG. 6 is a functional block diagram of one embodiment, FIG. 7 is a diagram showing characteristics of a detection head, and FIG. 8 is a diagram showing a main part of another embodiment of the present invention. FIG. 9 is a front view showing the structure of a conventional apparatus, and FIG. 10 is a schematic view showing the main part thereof. 20 ... weight sorter, 23 ... running conveyor, 24 ... conveyor frame, 25 ... drive roller, 27 ... driven roller, 28
…… Conveyor belt, 30… Detection head, 31 …… Upper plate, 32…
... Head frame, 33 ... Transmission coil, 34, 35 ... Reception coil, 40 ... Measurement conveyor, 46 ... Measuring instrument, 55 ... Determination instruction section.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B07C 5/344 G01V 3/10-3/11

Claims (2)

(57) [Claims] 1. A conveyor for driving an article conveyed on a conveyor belt on one roller side to another roller side by driving a conveyor belt stretched between two rollers arranged in parallel. An article inspection apparatus for inspecting articles conveyed on the conveyor while conveying the article, comprising a member that transmits magnetic force lines, and supporting a conveyor belt for receiving the articles conveyed on the conveyor on an upper surface side. An upper plate disposed between the two rollers and the conveyor belt, and a box having a bottom and an upper portion opened by a member for preventing transmission of lines of magnetic force so that the opened upper portion is closed. A head frame attached to the lower surface side of the upper plate, a magnetic flux generating means disposed in the head frame, and generating a magnetic flux intersecting a conveyance path of an article on the conveyance belt; A detection head comprising a plurality of magnetic sensors arranged in parallel in the conveying direction of the article at a position close to the magnetic flux generating means in the system and outputting a signal corresponding to a linkage magnetic flux from the magnetic flux generating means. Provided on the conveyor, based on signals output from the plurality of magnetic sensors,
An article inspection apparatus, comprising: a metal determination unit that determines whether or not an article conveyed on the conveyor is mixed with metal. 2. The apparatus according to claim 1, wherein the conveyor provided with the detection head is supported by a weighing machine from below, so that the metal contamination inspection and the weight detection of the articles can be performed on the same conveyor. 2. The article inspection apparatus according to claim 1, wherein