JPH0930504A - Packaging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively prevent defective solvent welding and unexpected accident due to a foreign matter in a packaging film by detecting the entrance of the foreign matter by a foreign matter detecting body and stopping movements of horizontal solvent welding members when the foreign matter enters between the horizontal solvent welding members. SOLUTION: A barrel-shaped packaging film F is fed crossly prior to one member 3 out of a pair of horizontal solvent welding members 2 and 3 which weld with solvent the barrel-shaped packing film F in the cross direction. There is provided a foreign matter detecting body 5 which is biased by a support spring 4 in a cross-feed direction and supported elastically in a retractable manner against the support spring 4. When the foreign matter detecting body 5 butts against a foreign matter and retracts against the support spring 4, a detection signal is produced.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a packaging device for hermetically packaging fresh food and the like.

[0002]

2. Description of the Related Art Conventionally, as this type of device, a bottomed cylindrical synthetic resin packaging film has been sent outward along a predetermined length in the longitudinal direction along the outer peripheral surface of a cylindrical chute for loading articles to be packaged. The object to be packaged is charged through the tubular chute, and the packaging film is hermetically sealed with a pair of welding members provided so as to move closer to each other in a direction orthogonal to the longitudinal direction of the tubular chute, After that, there is one in which a bottomed tubular packaging film is formed by the same procedure, and the objects to be packaged in the tubular chute are sequentially sealed and packaged.

[0003]

In the above-mentioned conventional apparatus,
When a foreign matter such as a plurality of objects to be packaged is mistakenly introduced into the vertical or horizontal cylindrical chute, the mistakenly introduced foreign matter is provided with a pair of welding members provided orthogonally to the cylindrical chute. There is a possibility that it will be incompletely welded and the other parts will be damaged due to the interposition during the counter interval.

In such a case, the present invention provides a packaging device which detects, when a foreign substance, which has been mistakenly introduced, is present in the opposing interval of a pair of welding members, by detecting this, for example, preventing the welding member from operating. The purpose is to do.

[0005]

The structure of the present invention for achieving the above object will be described with reference to the drawings corresponding to the embodiments. In the invention according to claim 1, the packaging film F has a cylindrical shape. The film F is sent to the longitudinal direction along the outer peripheral surface of the tubular chute 1 at the outside of one end of the cylindrical chute 1 in a direction orthogonal to the longitudinal direction. A pair of moving welding members 2 and 3 are provided, and a tubular packaging film F that is sent outward from one end of the tubular chute 1 by the mutual movement of these welding members 2 and 3 is orthogonal to the feeding direction. In the packaging apparatus configured to package the article S to be packaged, which is welded in the direction, and is thereby put into the tubular packaging film F through the interior of the tubular chute 1, the pair of welding members 2, 3 One of Of the foreign matter detection body that is moved closer to the member 3 in advance of the member 3 and is urged by the support spring 4 in the approaching movement direction, and is elastically supported so as to be retractable against the support spring 4. 5 is the welding member 2,
3, a detection signal is not transmitted at all times, but a detection signal is transmitted when the foreign matter detection body 5 retracts against the support spring 4. It is a thing.

Further, in the invention according to claim 2, the foreign matter detecting body 5 is made of a conductive material, and a detecting circuit 6 for transmitting the detection signal through the foreign matter detecting body 5 is formed. It has the structure according to claim 1.

Further, in the invention according to claim 3, a sensor 6a for detecting the backward movement of the foreign matter detecting body 5 is provided at a fixed position so as to face the detecting body 5, and the foreign matter detecting body 5 retreats. The detection signal is transmitted by the sensor 6a at this time.

Further, in the invention according to claim 4, a tubular chute 1 in which the packaging film F is formed in a tubular shape and is fed in the longitudinal direction along the outer peripheral surface thereof.
A pair of welding members 2 and 3 that move toward and away from each other outside the one end of the cylindrical chute 1 in a direction orthogonal to the longitudinal direction of the cylindrical chute 1 are provided. The tubular packaging film F, which is fed outward from one end of the tubular chute 1, is welded in a direction orthogonal to the feeding direction thereof, so that the tubular packaging film F passes through the inside of the tubular chute 1 and enters the tubular packaging film F. In a packaging device adapted to wrap an object to be packaged S, a foreign matter detection body 5 is elastically supported by being biased by a support spring 4 during a facing interval between the pair of welding members 2 and 3, and the foreign matter detection is performed. When a foreign matter is sandwiched between the body 5 and any one of the pair of welding members 2 and 3, the foreign matter detector 5 is pushed by the foreign matter and resists the urging force of the support spring 4. When the foreign matter detector 5 moves backward, Those having the structure which is adapted to detect that the intervening serial in opposing distance between the pair of welding members 2 and 3.

Further, in the invention according to claim 5, a tubular chute 1 in which the packaging film F is formed in a tubular shape and is fed in the longitudinal direction along the outer peripheral surface thereof.
A pair of welding members 2 and 3 that move toward and away from each other outside the one end of the cylindrical chute 1 in a direction orthogonal to the longitudinal direction of the cylindrical chute 1 are provided. A tubular packaging film F, which is fed outward from one end of the tubular chute 1, is welded in a direction orthogonal to the feeding direction, whereby the tubular packaging film 1 passes through the inside of the tubular chute 1 and enters the tubular packaging film 1. Item S to be packed
In the packaging apparatus for packaging the above-mentioned welding device, the supporting spring 4 is moved integrally with any one of the pair of welding members 2 and 3 and ahead of the member 3.
The foreign matter detection body 5 which is urged by the approaching movement direction and elastically supported so as to be able to retreat against the support spring 4 is provided in parallel with the welding members 2 and 3, and a detection signal is not always transmitted. A configuration is adopted in which a detection signal is transmitted when the foreign matter detection body 5 retracts against the support spring 4 within a range in which the welding member 3 moves a certain distance. is there.

Further, in the invention according to claim 6, the support spring 4 for urging the foreign matter detecting body 5 in the direction preceding the welding member 3 is one or both of the pair of welding members 2 and 3. The spring force is set to be weaker than that of the buffer spring 7 for urging the springs toward each other toward each other.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a vertical hermetically-sealed packaging device according to an embodiment of the present invention. In the following examples, a so-called vertical type packaging device in which the tubular chute 1 is a vertical type and the pair of welding members 2 and 3 are orthogonal to the chute 1 will be described. On the contrary, the tubular chute is a horizontal type. Next to
Needless to say, the present invention is also applicable to so-called horizontal type package leaving in which a unitary welding member orthogonal to this is a vertical type. A vertical tubular chute 1 for loading an article to be packaged is arranged in the front part of the apparatus main body 8, a forming plate 9 is loosely fitted on the upper portion of the vertical tubular chute 1, and a vertical tubular chute is also provided. 1. A vertical welding roll 10a for welding the longitudinal overlapping portion of the packaging film F formed in a tubular shape by the tubular chute 1 so as to face the center of the packaging film F to form the tubular welding of the packaging film F. A pair of horizontal welding members 2 is provided with a feed roll 10b, and a packaging film F formed by welding in a tubular shape on the lower portion of the vertical tubular chute 1 is welded and cut at predetermined intervals along the longitudinal direction thereof. , 3 are provided opposite to each other with the vertical cylindrical chute 1 interposed therebetween.

The forming plate 9 is formed by bending a single metal plate in a downwardly spread shape, and has a roll-like shape which is rotatably arranged on the upper portion of the apparatus main body 8 by an inner peripheral edge portion 9a thereof. From the packaging film F to the guide rollers 11, 1
Sheet-like wrapping film F pulled out through 1 ...
Is bent downward to form a cylindrical shape along the outer peripheral surface of the vertical cylindrical chute 1, and the side edges of the cylindrically formed packaging film F are polymerized with each other.

As shown in FIG. 1, the vertical welding member roll 10a and the feed roll 10b are attached to a horizontal rotary shaft 12 projecting forward from the apparatus main body 8 and are provided at the center of the vertical cylindrical chute 1. Horizontal axis of rotation 1 provided facing each other
By rotating 2 horizontally, the vertical welding member roll 10
a and the feed roll 10b are sandwiched between the pair of rolls 10a, 10a through the side edges of the packaging film F which are overlapped with each other, and the longitudinal side edges of the film F are welded to each other to form a tubular package. The film F is formed by welding.

As shown in FIG. 1, a cutting blade 13 is attached to the upper and lower intermediate portions of the horizontal welding member 2 on one side of the left and right horizontal welding members 2 and 3, and the left and right horizontal welding members 2 and 3 are attached.
When the packaging film F is welded in the lateral direction, the cutting blade 13 divides the packaging film F into upper and lower portions at the upper and lower central portions thereof.

FIG. 2 is a plan view showing an essential part of the present invention. As shown in FIG. 2, one of the pair of horizontal welding members 2 and 3 is provided with the horizontal welding member 2 on one side. Lateral feed rod 15, on which the bosses 14, 14 are slidably fitted
15 is elastically supported by buffer springs 7 and 7, and the horizontal welding member 3 on the other side is a holding rod 17 for holding this horizontally.
Is fixed to a lateral feed drive rod 16 which is driven in the lateral feed direction in synchronization with the lateral feed rods 15 and 15. However, although not shown, the horizontal welding member 3 may be elastically supported by the lateral feed drive rod 16 by a buffer spring having a spring force equivalent to that of the buffer springs 7, 7.

Through-holes 18 are provided at both ends of a holding rod 17 for holding the horizontal welding member 3 in the lateral feed direction.
A mounting rod 19 penetrates through 8 and extends forward, and a conductive foreign matter detector 5 is attached to the horizontal welding member 3 at the front end thereof.

As shown in FIG. 4, the foreign matter detecting body 5 comprises a metal frame 5a having a horizontally long rectangular front shape, through holes 20, 20 provided at both ends thereof, and a metal wire 5b at the front surface thereof. ，
5b is stretched laterally in a net-like manner, so that the lines 5b, 5b
It is composed of meshes 5c, 5c formed therebetween, and the attachment rods 19, 19 are penetrated through the through holes 20, 20.
In the above structure, the metal filaments 5b, 5b are not particularly necessary, and only the frame 5a may be used.

Between the through holes 18 at both ends of the holding rod 17 of the horizontal welding member 3 and the mounting rod 19 through which the through holes 18 pass,
Rings 21 and 22 made of an insulating material such as a synthetic resin are interposed between the through holes 20 provided at both ends of the foreign matter detecting body 5 and the mounting rod 19 penetrating therethrough. The horizontal welding member 3 and the foreign matter detecting body 5 and the mounting rods 19, 19 are mounted in an insulating state, and the insulating ring 2 made of a synthetic resin material is also used.
3 is fitted to the attachment rods 19 and 19 and is abutted on one surface side of the holding rod 17, and the holding rod is provided via the collar portion 21a of the flanged ring 21 abutted on the other side, the insulating ring 23 and the washer 24. Attach the nuts 25 and 26 from both sides of 17 to the rods 19 and 1
The horizontal welding member 3 is fixed to the holding rods 17 on both sides in a fixed position by screwing it into the foreign body detecting member 5
Between the nut 26 and the flange portion 22a of the flanged ring 22 that is placed on the one surface side of the foreign matter detecting body 5 through the through holes 20 at both ends of the buffer spring 7. A weak coil-like support spring 4 is interposed, and the foreign matter detection body 5
A conductive metal washer 27 is abutted on the other surface side of the foreign object detection body 5 by screwing a conductive metal nut 28 into the tips of the conductive metal mounting rods 19 and 19 in this state. The washer 27 is biased by the spring 4 to come into contact with the metal washer 27, and is attached to the washer 27, the metal nut 28, and the metal mounting rods 19 and 19 in a conductive state, and the foreign matter detection body 5 is biased by the support spring 4. Against the mounting rod 19,19
When the foreign matter detection body 5 moves backward, the detection body 5 and the metal washer 27 can be moved backward.
Since the abutting state with is released, conduction between the detection body 5 and the metal washer 27 is cut off.

Lead wires 29 are appropriately connected to the rear ends of the mounting rods 19, 19. Therefore, a detection circuit 6 as shown in FIG. 9 is provided between the foreign matter detection body 5 and the mounting rods 19, 19.
Is formed. That is, the detection circuit 6 sends a detection signal to the detection device 30 connected to the lead wire 29 when the foreign matter detection body 5 is biased by the support spring 4 and is connected to the mounting rods 19 and 19 in a conductive state. In addition to preventing the transmission, the foreign matter detecting body 5 resists the urging force of the support spring 4 and moves backward by the metal washer 27 as shown by the alternate long and short dash line.
When it is in a non-conduction state with 9, the detection signal is transmitted to the detection device 30. The lead wire is properly connected to a power supply 31 for transmitting a detection signal.

FIG. 3 is a side view of the state of FIG. 2, in which the disposition state of the foreign matter detection body 5 is well shown, and is formed in a tubular shape by the vertical tubular chute 1. A pair of horizontal welding members 2 and 3 are opposed to each other with the packaging film F sandwiched therebetween, and the foreign matter detector 5 is arranged on the front side of the horizontal welding member 3 on one side.

In the above structure, the lateral feed rod 15 and the lateral feed drive rod 16 are synchronously driven from the state shown in FIGS. 2 and 3 to the state shown in FIGS. The horizontal welding member 2 on one side and the horizontal welding member 3 on the other side, which are biased by the buffer spring 7, laterally sandwich the tubular packaging film F, and the film F is welded.

At this time, when the horizontal welding members 2 and 3 are in contact with each other and the packaging film F sandwiched between the two is welded, the foreign body detecting member 5 is first preceded by the horizontal welding member 3 on one side. Horizontal welding members 2 facing each other via the packaging film F
Therefore, as shown in FIG. 5 or FIG. 6, the foreign matter detection body 5 retracts to the side of the other horizontal welding member 3 and, as shown in FIG.
As shown in FIG. 4, the horizontal welding member 3 has an appropriately convex and concave end portion, and therefore the convex portion 3a passes through the meshes 5c, 5c (see FIG. 4) of the foreign matter detector 5 and faces each other. It is adapted to abut the member 2. As described above, when the foreign matter detecting body 5 is simply the frame body 5a, it is not necessary to form the tip of the horizontal welding member 3 in a concavo-convex shape. At this time, the cutting blade 13 provided in the central portion of the horizontal welding member 2 is fitted into the concave portion 3b of the facing horizontal welding member 3 to cut the welding portion of the packaging film F at the central portion thereof. There is.

However, as shown in FIGS. 7 and 8, the packaging film F fed downward along the vertical cylindrical chute 1 is sandwiched, and the left and right horizontal welding members 2 and 3 are aligned with each other. When the packaging film F is moved closer to each other and thus the packaging film F is welded in the lateral direction, a plurality of articles S to be packaged are erroneously inserted into the vertical cylindrical chute 2 or foreign matter K is continuously attached to the articles S to be packaged. If it is inserted by mistake, the foreign matter detector 5 comes into contact with the foreign matter K via the packaging film F before the two horizontal welding members 2 and 3 come into contact with each other, and the foreign matter is detected by the contact pressure. The body 5 retracts against the biasing force of the support spring 4.

As shown in FIG. 7, the foreign matter detector 5 detects the foreign matter K.
When the foreign matter detector 5 comes into contact with the metal washer 27 that receives the metal nut 28 at the tip of the mounting rod 19, the foreign matter detector 5 is released from the contact state, and a gap C is generated between the two.

That is, as shown in FIG. 9, a conductive foreign matter detector 5, a metal washer 27 with which both ends thereof are in contact with each other, a lead wire 29 at the rear end of the metallic mounting rods 19, 19 and a power source 3
When the foreign substance detecting body 5 moves backward as shown by the alternate long and short dash line, the detecting circuit 6 including the detector 1 and the detecting device 30 is brought into the non-conducting state by generating the void C. By detecting the non-conduction state in this way by the detection device 30, this detection signal is sent to the drive sources of the horizontal welding members 2 and 3 and the lateral feed movement of these members 2 and 3 is stopped. At the same time, it is designed to move backward to the original position.

It should be noted here that, as shown in FIGS. 5 and 6, no foreign matter K has entered the inside of the packaging film F, and the two horizontal welding members 2 and 3 are completely in contact with each other. Even in the state, the foreign matter detection body 5 comes in contact with the horizontal welding member 2 facing the both sides of the horizontal welding members 2 and 3 and retracts, and a gap L is formed between the foreign matter detection body 5 and the metallic washer 27. When this happens, the detection circuit 6 is opened, but when the detection circuit 6 is opened just before the horizontal welding members 2 and 3 completely contact each other in this way, the detection device 30 does not transmit a detection signal. Just take the timing.

That is, the movement of the two horizontal welding members 2 and 3 of this kind is generally performed by the rotating disc cam and the crank mechanism, and the rotation of the disc cam is converted into the linear movement of the two horizontal welding members 2 and 3. Since it is converted, for example, both horizontal welding members 2,
When the amount of linear movement of 3 or the amount of rotation of the rotating cam is within a certain amount, when the detection circuit 6 is opened, a foreign matter intrusion detection signal is transmitted to stop or reverse the driving portions of both horizontal welding members 2 and 3. In this way, when the detection circuit 6 is opened at a point when a certain amount is exceeded, it is considered that the operation is normal and control is performed so that the detection signal is not transmitted. That is, since the linear movement amount of the horizontal welding members 2 and 3 and the rotation amount of the rotary cam can be easily detected by a limit switch, a proximity switch, an optical sensor or a rotary encoder, these detection signals and the detection circuit 6 are provided. The detection signal may be transmitted by an AND circuit with the opening of the.

Further, although the above-mentioned detection circuit 6 utilizes electrical conductivity, as shown in FIG. 7, the sensor 6a is attached to the portion opposed to the above-mentioned void portion C so as to extend from the holding rod 17. It may be attached by the rod 32. For example, a light-emitting diode (LED) and a phototransistor or a light-emitting element such as a photodiode and a light-receiving element are interposed, and the light-emitting element of the sensor 6a is normally reflected by the foreign matter detector 5 and is received by the light-receiving element. When the void C is generated, the light emitting element is not reflected and the light of the light emitting element is not input to the light receiving element. Therefore, the state may be detected. Alternatively, an infrared sensor may be interposed in the void portion C so that the electromagnetic wave of the foreign matter detecting body 5 is always detected, and when an abnormal void occurs, the infrared sensor detects a state caused by the different electromagnetic wave. In addition,
In these embodiments, the foreign matter detector 5 need not be conductive. The sensor 6a may be a proximity switch or a limit switch that detects the backward movement of the foreign matter detection body 5.

Further, since the support spring 4 which elastically biases the foreign matter detecting body 5 has a weaker spring force than the buffer spring 7 which elastically biases the horizontal welding member 2, the foreign matter K is kept between the horizontal welding members 2 and 3.
When the foreign matter detector 5 enters, the support spring 4 contracts first to retract the foreign matter detector 5 and then the buffer spring 7 appropriately shrinks, so that the foreign matter detector 5 does not malfunction.

Incidentally, in FIG. 3 or FIG. 8, 32 is
A pair of packaging film pressing plates, which are arranged on the upper portions of both the horizontal welding members 2 and 3 so as to be movable within a certain range, and are urged toward each other by a spring 33. The tubular wrapping film F is sandwiched so as to have a flat shape to facilitate welding and cutting, and also has a function of receiving the object S to be packaged that falls from inside the tubular film F from above.

In FIG. 1, reference numeral 34 denotes a packaging film feed roller which is pressed against the vertical cylindrical chute 2 through the packaging film F and is synchronized with the horizontal welding members 2 and 3 in the same manner as the feed roll 10b. Is driven to rotate intermittently,
The packaging film F is intermittently fed downward by a predetermined length.

Explaining the procedure of the hermetically sealed packaging, the packaging film feeding roller 34 descends the packaging film F along the vertical cylindrical chute 1 by a predetermined length, and the packaging film F is fed.
The side edges of the packaging film F are welded by a vertical welding roll 10a to form a tubular packaging film F, and the lower end portion of the packaging film F is welded by both lateral welding members 2 and 3 to form a bottomed tubular film. The packaging film F is formed.

Next, the object S to be packaged is placed in the vertical cylindrical chute 1.
, The packaged object S passes through the vertical cylindrical chute 1 and is put into the bottomed cylindrical packaging film F.

Subsequently, the packaging film F is welded by both the horizontal welding members 2 and 3, and the space between the two welding portions is cut by the cutting blade 13 (see FIG. 6).

If a foreign matter K is mistakenly put into the bottomed cylindrical packaging film F following the article S to be packaged, the foreign matter detector 5 comes into contact with the foreign matter K and the foreign matter detector 5 is attached to the support spring 4. When the two horizontal welding members 2, 3 are moved backward against the power, the detection signal due to the backward movement is compared with the movement amounts of the two horizontal welding members 2, 3 and if the two meet a certain condition, the detection signal is output. Of the horizontal welding members 2 and 3 to stop and reverse the lateral feeding of the horizontal welding members 2 and 3 to prevent the occurrence of welding defects and unexpected situations.

[0036]

According to the first aspect of the invention, when the tubular packaging film delivered from one longitudinal end of the tubular chute is welded by the pair of welding members in the direction orthogonal to the feeding direction. When a foreign substance enters the inside of the packaging film or between the two welding members on the outside of the packaging film, this foreign substance detector detects the intrusion state and stops the movement of both welding members. Therefore, it is possible to effectively prevent defective welding or an unexpected situation due to the presence of foreign matter in the packaging film.

According to the invention of claim 2, the foreign matter detector is made of a conductive material, and the detection circuit is formed through the foreign matter detector, so that the detector circuit can be manufactured easily and at low cost. In addition, it is possible to ensure reliable operability.

According to the invention of claim 3, a sensor for detecting the backward movement of the foreign matter detector is provided facing a fixed position, and when the foreign matter detector moves backward, a detection signal is transmitted by the sensor. Since it is supposed to be
The configuration is simple and good operability can be guaranteed.

According to the invention of claim 4, claim 1
Similarly, when the tubular packaging film delivered from one longitudinal end of the tubular chute is welded by the pair of welding members in the direction orthogonal to the feeding direction, inside the packaging film or the packaging film. When a foreign substance enters between the two welding members on the outside of the package, the foreign substance detector detects the intrusion state and stops the movement of both welding members. Defects and unexpected situations can be effectively prevented. At this time, the foreign matter detector need not necessarily be electrically conductive.

According to the fifth aspect of the present invention, when the tubular packaging film delivered from one end portion in the longitudinal direction of the tubular chute is welded by the pair of welding members in the direction orthogonal to the feeding direction, If no foreign matter has entered the inside of the packaging film or between the two welding members on the outside of the packaging film, the welding work can be reliably performed and the occurrence of malfunction can be effectively prevented. .

Further, in the invention according to claim 6, the foreign matter detector provided integrally with either one of the pair of welding members and so as to move prior to the welding member is provided in the leading direction. The spring force of the support spring that urges the pair of welding members is set to be weaker than that of the buffer spring that urges one or both of the pair of welding members toward each other. In this case, a foreign matter may be pressed by a buffer spring having a strong spring force, which may cause an unexpected situation. The welding work can be stopped without damage, and a cutting blade for cutting the packaging film is provided in the center between the two welding members. But Since that will retract against the urging force of have the support spring, it is possible to protect the or cut foreign matter, does not or damage the cutting edge of the cutting blade.

[Brief description of drawings]

FIG. 1 is a partially cutaway side view of a packaging device according to an embodiment of the present invention.

FIG. 2 is a horizontal enlarged cross-sectional view of the main part.

FIG. 3 is a longitudinal sectional view of the main part.

FIG. 4 is a perspective view of a foreign matter detector, which is a main part of the same.

FIG. 5 is a plan view showing a normal operating state of the device.

FIG. 6 is a side view of the same.

FIG. 7 is a plan view showing an operating state of the apparatus when there is an abnormality.

FIG. 8 is a side view of the same.

FIG. 9 is a circuit diagram schematically showing a main part of the present invention.

[Explanation of symbols]

 1 Cylindrical chute 2 Welding member 3 Welding member 4 Support spring 5 Foreign matter detector 6 Detection circuit 6a Optical sensor 7 Buffer spring F Packaging film S Packaged object K Foreign matter

Claims (6)

[Claims] 1. A longitudinal direction in which a tubular chute is sandwiched outside one end of a tubular chute in which the packaging film is formed in a tubular shape and is fed along the outer peripheral surface in the longitudinal direction. Is provided with a pair of welding members that move toward and away from each other in a direction orthogonal to each other, and a tubular packaging film that is fed outward from one end of the tubular chute by the movement of these welding members toward each other is orthogonal to the feeding direction. In the packaging device, which is configured to package the article to be packaged, which is welded to the inside of the tubular chute by way of the inside of the tubular chute, with one of the pair of welding members. The foreign matter detection body is integrally moved ahead of the member, is biased in the approach movement direction by a support spring, and is elastically supported so as to be retractable against the support spring. A packaging device which is provided in parallel with the welding member and which does not send a detection signal at all times, but which sends a detection signal when the foreign matter detector moves backward against the support spring. 2. The packaging device according to claim 1, wherein the foreign matter detector is formed of a conductive material, and a detection circuit is formed through the foreign matter detector. 3. A sensor for detecting the backward movement of the foreign matter detector is provided at a fixed position facing the foreign matter detector so that a detection signal is transmitted by the sensor when the foreign matter detector moves backward. The packaging device according to claim 1, wherein 4. A tubular chute, wherein the packaging film is formed in a tubular shape and is fed in the longitudinal direction along the outer peripheral surface of the tubular chute, with the tubular chute interposed therebetween in the longitudinal direction. Is provided with a pair of welding members that move toward and away from each other in a direction orthogonal to each other, and a tubular packaging film that is fed outward from one end of the tubular chute by the movement of these welding members toward each other is orthogonal to the feeding direction. In the packaging device configured to package an article to be packaged by being welded to the inside of the tubular packing film by way of the inside of the tubular chute, the foreign matter detection body has a facing space between the pair of welding members. When a foreign matter is sandwiched between the foreign matter detector and any one of the pair of welding members, the foreign matter detector is pushed by the foreign matter and elastically supported by the support spring. If you support A packaging device that is retracted against the force of the knee and detects that a foreign substance is present in the opposing interval between the pair of welding members by the backward movement of the foreign substance detector. 5. A tubular chute in which the packaging film is formed in a tubular shape and is fed in the longitudinal direction along the outer peripheral surface of the tubular chute, the longitudinal direction being sandwiched between the tubular chutes. Is provided with a pair of welding members that move toward and away from each other in a direction orthogonal to each other, and a tubular packaging film that is fed outward from one end of the tubular chute by the movement of these welding members toward each other is orthogonal to the feeding direction. In the packaging device, which is configured to package the article to be packaged, which is welded to the inside of the tubular chute by way of the inside of the tubular chute, with one of the pair of welding members. The foreign matter detection body is integrally moved ahead of the member, is biased in the approach movement direction by a support spring, and is elastically supported so as to be retractable against the support spring. It is provided in parallel with the welding member, and the detection signal is not transmitted at all times, but the detection signal is transmitted when the foreign matter detector moves backward against the support spring within the range in which the welding member moves a certain distance. Packaging equipment. 6. The support spring for urging the foreign matter detector in a direction preceding the welding member has a spring force higher than that of a buffer spring for urging one or both of the pair of welding members in the approaching direction. The packaging device according to any one of claims 1 to 5, wherein is set weakly.