JP2017165428A - Welding mold and package apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a welding mold and a package apparatus comprising the welding mold in which a failure, such as interposition of a packaging object in a heat welding part, may be detected upon heat welding, so as to solve a problem that it is required to remove a product in which the packaging object is interposed in the heat welding part by visual examination after packaging when the packaging object, such as a food, is packaged in a package container.SOLUTION: There is provided a welding mold for welding a thermoplastic film, in which an optical fiber sensor in which a bragg grating is formed is arranged on a contacting projecting part of a welding mold contacting to the thermoplastic film. By virtue of the welding mold, no noise effect due to electric power applied to the welding mold is provided and thus deformation in the welded part may be measured at a high-accuracy.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a welding mold and a sealing device. More specifically, the present invention relates to a welding mold capable of detecting a defect in the welded portion when a thermoplastic film is welded, and a sealing device having the welding mold.

  Thermoplastic films are used in various forms to enclose an object to be encapsulated such as food. For example, thermoplastic films are used in encapsulating bags that enclose solids such as potato chips, retort pouches that enclose colloidal foods such as curry roux and jelly, and in non-food encapsulating containers for drugs and chemical products It is used. In order to ensure hermeticity in these enclosures, many enclosures employ a method in which heat is applied to the entrance / exit portion of the enclosure by a heater bar, and the thermoplastic film constituting the enclosure is dissolved and bonded. .

  For example, Patent Document 1 discloses a heater bar that welds its end portion to a cylindrical thermoplastic sheet. In this enclosing apparatus using the heater bar, after the sheet is welded by the heater bar, food that is a predetermined object to be encapsulated is charged, and only a predetermined length is secured from the end portion, and the heater bar is again formed. The inside is hermetically sealed by welding, and then the welded portion is cut with a heater bar. In this way, the food inside is not exposed to the outside air before reaching the final consumer.

  When an object to be encapsulated is charged, the object to be encapsulated material insertion means inserts an object into the back side of the enclosure of the object to be encapsulated and inputs the object to be encapsulated. However, there may be a problem in that the charged encapsulated material jumps between the portions where the enclosing object entrance / exit is welded. When a conventional heater bar is used, the object to be encapsulated in this way is welded and then removed from the shipping line by visual inspection or inspection by a displacement sensor using a laser, for example. I had to remove it. However, it is difficult to perform the inspection accurately and stably due to the level difference of the inspector and the sensitivity of the displacement sensor, and it is necessary to perform multiple inspections in order to completely remove the defect. There is a problem that the time for the inspection work increases.

  In addition, as described in Patent Document 2, it is conceivable that a strain gauge is provided on the heater bar for welding and the inspection is performed at the same time as the welding. However, in the strain gauge using an electric signal, noise is large and realistic. It was difficult to make measurements. In addition, when a strain gauge is provided, it is necessary to provide a strain gauge at a predetermined interval in the welded portion, which causes a problem that wiring becomes complicated.

Japanese Patent Laying-Open No. 2015-63329 JP 2012-66870 A

  In view of the above circumstances, an object of the present invention is to provide a welding mold capable of detecting a defect in the welded portion when a thermoplastic film is welded, and a sealing device having the welding mold.

The welding mold of the first invention is a welding mold for welding a thermoplastic film, and an optical fiber sensor in which a Bragg grating is formed on a contact convex portion of the welding mold that contacts the thermoplastic film. It is characterized by being installed.
The welding mold of the second invention is characterized in that, in the first invention, an optical fiber sensor is installed along the contact convex portion.
The welding mold of the third invention is characterized in that, in the second invention, a groove for installing the optical fiber sensor is provided on a side surface reaching the top of the contact convex portion.
The welding mold of the fourth invention is characterized in that, in the second invention, a groove for installing the optical fiber sensor is provided at the top of the contact convex portion.
In the welding mold of the fifth invention, in the third or fourth invention, the optical fiber sensor is installed in the two grooves provided in the contact convex portion, and the temperature measuring unit is arranged in one groove. The other groove is provided with a strain measuring unit.
A sealing device according to a sixth aspect of the invention includes the welding mold according to the first to fifth aspects of the invention.

According to the first invention, the FBG sensor is installed on the contact convex portion of the welding mold that comes into contact with the thermoplastic film, so that it is not affected by noise caused by the electric power applied to the welding mold, The distortion of the welded portion can be measured with high accuracy. When this mold is used for a sealing device, it is possible to detect whether there is a foreign substance at the welded portion at the same time as the thermoplastic film is welded, and the inspection after welding can be omitted.
According to the second invention, since the FBG sensor is installed along the contact convex portion, the strain and temperature of the welded portion can be measured over a wide range of the contact convex portion by one FBG sensor. When this mold is used in a sealing device, measurement can be performed by a single FBG sensor over a wide range of the opening of the sealing container.
According to the third invention, the groove for installing the FBG sensor is provided on the side surface reaching the top of the contact convex portion, thereby determining at which position of the welding die the FBG sensor is installed, The initial setting time of the strain amount for each welding mold is reduced. Further, since the groove is provided on the side surface reaching the top of the contact convex portion, the FBG sensor can be easily installed.
According to the fourth aspect of the present invention, the groove for installing the FBG sensor is provided at the top of the contact convex portion, so that the position of the FBG sensor to be installed is determined, and the welding mold The initial setting time of each strain amount is reduced. Moreover, the groove | channel is provided in the top part of the contact convex part, and the distortion and temperature of the part nearer to the part which welds can be measured.
According to the fifth invention, the optical fiber sensor is installed in the two grooves provided in the contact convex portion, the temperature measuring unit is arranged in one groove, and the strain measuring unit is arranged in the other groove. By being arranged, both strain and temperature of the welded part can be measured by the FBG sensor, and the state of the welded part can be known with high accuracy.
According to the sixth invention, the sealing device has the welding mold of the first invention to the fifth invention, so that the foreign matter is caught in the welded portion of the thermoplastic film with high accuracy and stability, and It can be easily distinguished. Thereby, the work time required for the inspection process of the thermoplastic film welded portion can be reduced.

It is a front view of the welding metal mold | die which concerns on 1st Embodiment of this invention. It is a side view of the welding metal mold | die of FIG. It is a top view of the welding metal mold | die of FIG. 1 is an overall configuration diagram of a sealing device according to an embodiment of the present invention. It is use explanatory drawing of the welding metal mold | die of FIG. It is a front view of the welding metal mold | die which concerns on 2nd Embodiment of this invention. It is a front view of the welding metal mold | die which concerns on 3rd Embodiment of this invention. (A) It is a front view of the welding metal mold | die which concerns on 4th Embodiment of this invention. (B) It is a partial side view of the welding metal mold | die which concerns on 4th Embodiment of this invention. (A) It is a schematic explanatory drawing of the optical fiber F in which FBG was formed. (B) It is the figure which showed the spectrum of the incident light LB0 which injected into FBG, the spectrum of the reflected light LB1 reflected by FBG, and the spectrum of the transmitted light LB2 reflected by FBG.

  Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 4 is an overall configuration diagram of the food enclosing apparatus 1 that is an enclosing apparatus using the welding mold 25 according to the first embodiment of the present invention, and FIG. In the present specification, the direction perpendicular to the surface with which the welding mold 25 contacts in the food container 15 having a quadrangular prism-like outer shape as shown in FIG. Moreover, although the food enclosure device 1 was taken up as an enclosure device, this invention is not limited to this, It can apply also about the apparatus which encloses another to-be-enclosed thing.

  As shown in FIG. 4, the food enclosing apparatus 1 has a function of enclosing a food that is one of the objects to be encapsulated in an enclosing container through a plurality of steps A to I. The processes performed in the food enclosure device 1 are a bag making process A, a bag supplying process B, an opening process C, a preliminary process D, a charging process E, a shaping process F, a sealing process G, a discharging process H, and a preliminary process I. Hereinafter, each process excluding the preliminary process will be described. In addition, the enclosure device represented by the food enclosure device 1 does not need to include all of these steps, and includes an apparatus constituted by only a part thereof. However, the sealing device always includes a sealing step G described below.

  The bag making process A is a process in which individual food enclosures 15 are created from the bag material 15a. The film-like bag material 15a wound around the raw roll 15b is fed out by the take-out roll 2 and the feed roll 4b, and the fed bag material 15a passes through the guide roll 4a at the position of the take-out roll 2 at the bottom of the bag. The bottom portion of the bag is sealed by the welding mold 3, and the bag material is cut to a predetermined length by the cutter 5 to form a food enclosure 15.

  The bag supply process B is a process of supplying the food enclosure 15 to the table. The food enclosing container 15 cut to a predetermined length in the bag making process A is sucked and held on both sides by a suction cup 6 of a bag feeding device (not shown) and delivered to the table 7. The food enclosure 15 supplied to the table 7 is gripped by a gripper 8 of a bag gripping device (not shown) on the table 7 side. As shown in FIG. 4, the gripper 8 is composed of a pair of front and rear of the food enclosure 15 with the food enclosure 15 interposed therebetween, and grips the front and rear of the food enclosure 15 by vacuum suction. A receiving base 9 for supporting the bag bottom is provided on the table 7 side below the gripper 8.

  The opening process C is a process in which the food enclosure 15 is made into a form in which an object to be encapsulated can be easily put. The gripper 8 and the cradle 9 provided on the table 7 side move to the position of the opening process C when the table 7 rotates in the direction of the arrow in FIG. By operating each other in a direction away from 15, the opening of the food enclosure 15 is opened. In that state, after the sealing plate 10 a having the air nozzle 10 is placed above the food enclosure 15 by an elevating device (not shown), air is blown into the food enclosure 15 from the air nozzle 10. Thus, the food enclosure 15 is expanded, and the bag bottom of the food enclosure 15 becomes a square bottom according to the shape of the cradle 9. By becoming a square bottom, it is supported by the cradle 9 and is sent to the next process in a stable state.

  The charging process E is a process in which an object to be sealed is charged into the food sealing container 15. The food enclosure 15 that has been opened in the opening process C is moved to the position of the charging process E where the filling nozzle 11 is located by rotating the table 7 in the direction of the arrow in FIG. In the charging step E, the tip of the filling nozzle 11 serving as a food charging means is inserted into the food enclosure 15, and then an object to be filled is introduced into the food enclosure 15 from the filling nozzle 11.

  The shaping process F is a process in which the opening of the food enclosure 15 is folded into a predetermined shape and the opening is shaped. When the table 7 rotates in the direction of the arrow in FIG. 4, the food enclosure 15 is moved to the shaping step F. At the position of the shaping step F, the shaping guide 13 is inserted into the opening of the food enclosure 15 enclosing the object to be encapsulated, and the folded portions are press bars provided before and after the food enclosure 15. By being pressed by 12, the opening is folded into a predetermined shape and shaped.

  The sealing step G is a step of closing the opening of the food enclosure 15 by pressing the welding mold 25 as a sealing means against the opening of the food enclosure 15. When the table 7 rotates in the direction of the arrow in FIG. 4, the food enclosure 15 is moved to the position of the sealing step G. At that place, in the enclosing apparatus according to the present embodiment, the welding mold 25 described below is used, the opening of the food enclosing container 15 is closed, and the food enclosing container 15 is sealed. That is, the welding mold 25 as a sealing means is pressed against the food enclosure 15 and a predetermined amount of heat is applied, so that the sheet constituting the food enclosure 15 is welded and the food enclosure 15 is sealed.

  The discharge process H is a process of discharging the food enclosure 15 in a state sealed by the sealing process G and enclosing the object to be sealed from the table 7. The food enclosure 15 whose opening is sealed in the sealing process G is conveyed in accordance with the rotation of the table 7 in the sealed state, and is sent to the next process such as boxing by the discharge conveyor 14 or the like.

  FIG. 1 is a front view of a welding mold 25 according to the first embodiment of the present invention, FIG. 2 is a side view of the welding mold 25, and FIG. 3 is a plan view of the welding mold 25. The figure is shown. As described above, the welding mold 25 constitutes a sealing means in the sealing process G.

  The welding mold 25 includes a contact convex portion 25a having a length capable of welding the entire upper edge of the food enclosure 15 on a base portion 25e serving as a base. The contact convex part 25a protrudes from the upper surface of the base part 25e, and makes the top part 25b which is a plane contact the food enclosure 15. That is, when the welding mold 25 is used as a sealing means in the sealing step G, the welding mold 25 in FIG. 1 is rotated 90 degrees to the left or right on the paper surface of FIG. 1, that is, as shown in FIG. Used. In this embodiment, the contact convex part 25a is located in the center of the transversal direction of the base part 25e, and the longitudinal direction is made the same as the length of the base part 25e. The welding mold 25 has pressing parts 25f for fixing the welding mold 25 to both ends in the longitudinal direction of the pedestal part 25e.

  The pedestal 25e of the welding mold 25 is provided with a heat generating wire and a heat pipe (not shown) for making the temperature distribution uniform, and the operator of the enclosing device determines the temperature of the contact convex portion 25a. The temperature is set so that the thermoplastic film constituting the food enclosure 15 can be melted and sealed. In addition, although the welding die 25 in this embodiment was the structure provided with the heating wire, it is not limited to this, and there is no particular problem as long as it is a structure that can melt the thermoplastic film. For example, an ultrasonic generator for melting a thermoplastic film can be provided inside.

  The contact convex part 25a is comprised by the top part 25b which contacts the food enclosure 15, and the both side surfaces 25c until it reaches the top part. Each side surface 25c of the welding mold 1 according to this embodiment is provided with a groove 25d, and the groove 25d is provided with an FBG sensor 26, that is, an optical fiber sensor in which a Bragg grating is formed. . In consideration of ease of processing, the cross section of the groove 25d is triangular, but is not particularly limited thereto.

  Here, the FBG sensor 26 will be described with reference to FIG. FIG. 9A is a schematic explanatory diagram of the optical fiber F in which the FBG is formed. FIG. 9B is a spectrum of the incident light LB0 incident on the FBG sensor 26 and a spectrum of the reflected light LB1 reflected by the FBG. It is the figure which showed the spectrum of the transmitted light LB2 reflected by FBG. As shown in FIG. 9A, the FBG is a portion CB in which the refractive index of the core C of the optical fiber F is periodically changed along the axial direction, and the core C has a high refractive index. And a portion CA having a low refractive index of the core C are alternately formed at a constant stripe interval Λ. For this reason, as shown in FIG. 9B, the optical fiber F in which the FBG is formed reflects light of a certain wavelength as reflected light LB1 and transmits light of other wavelengths among the incident light LB0. The light LB2 can be transmitted. At this time, the center wavelength of the spectrum of the reflected light LB1 is 2nΛ. Here, n is the effective refractive index of the optical fiber F.

  Further, as shown in FIG. 9B, the reflected light LB1 reflected by the FBG has a substantially trapezoidal spectrum centered on the center wavelength. The reflection characteristics of the FBG are evaluated by a wavelength band W (hereinafter referred to as -3 dB bandwidth W) in which the signal intensity reduction rate with respect to the signal intensity at the center wavelength of the reflected light LB1 is suppressed to -3 dB or less. Specifically, the −3 dB bandwidth W substantially matches the bandwidth of the ITU-T standard (for example, 0.4 nm or 0.8 nm), and the intensity of the signal within the −3 dB bandwidth in the reflected signal is attenuated. Bragg gratings that can be significantly reduced and that can significantly reduce the intensity of signals at wavelengths outside the -3 dB bandwidth are evaluated as good quality filters.

  If such an FBG is used, crosstalk between adjacent channels can be greatly reduced, and a signal having a desired wavelength can be accurately extracted.

  The FBG sensor 26 is fixed in the groove 25d by a welding agent, and is installed along the contact convex portion 25a as shown in FIGS. Here, “along the contact protrusion 25a” means along the longitudinal direction of the contact protrusion 25a. In the FGB sensor 26, locations where the Bragg grating is applied are provided at predetermined intervals (intervals between two strain measuring units 26a in FIG. 2). In the present embodiment, the places where the Bragg grating is applied are provided at intervals of 50 mm. In the present embodiment, the groove 25d is provided outside the contact convex portion 25a. However, the present invention is not limited to this. For example, it is possible to divide the welding mold 25 into the left and right halves of the paper surface of FIG. 1 along the longitudinal direction of the welding mold 25 and to provide a groove 25d on the joint surface of these two members.

  The FGB sensor 26 is manufactured from one optical fiber in this embodiment, and both ends thereof are connected to a sensor amplifier (not shown) provided on the right side of the paper surface of FIG. The FBG sensor 26 is fixed so as to be wound around the side surface 25c of the welding mold 25. There are nine temperature measuring units 26b for measuring the temperature on the upper side of the sheet of FIG. Nine strain measuring sections 26a for measuring the above are provided.

  Since the FBG sensor 26 is installed on the contact convex portion 25a of the welding mold 25 that contacts the thermoplastic film of the welding mold 25, the influence of noise caused by the electric power applied to the welding mold 25 is reduced. The distortion of the welded portion can be measured with high accuracy. When this welding mold 25 is used for a sealing device, it is possible to detect whether there is a foreign substance at the welded portion at the same time as the thermoplastic film is welded, and the inspection after welding can be omitted. Further, by using the FBG sensor 26, it is possible to constantly monitor the sealing conditions (temperature and pressure) together with the detection of the foreign matter.

  By installing the FBG sensor 26 along the contact convex portion 25a of the welding mold 25, the strain and temperature of the welded portion can be measured over a wide range of the contact convex portion 25a. When this welding mold 25 is used in a sealing device, measurement can be performed by one FBG sensor 26 over a wide range of the opening of the sealing container.

  Since the groove 25d for installing the FBG sensor 26 is provided on the side surface reaching the top of the contact convex portion 25a of the welding mold 25, where the FBG sensor 26 is installed in the welding mold 25. As a result, the initial setting time of the strain amount for each welding mold 25 is reduced. Further, since the groove 25d is provided on the side surface 25c reaching the top 25b of the contact convex portion 25a, the FBG sensor 26 can be easily installed.

  The FBG sensor 26 is installed in the two grooves 25d of the contact convex portion 25a, the temperature measuring unit 26b is arranged in one groove 25d, and the strain measuring unit 26a is arranged in the other groove 25d. Thus, both the strain and temperature of the welded portion can be measured by the FBG sensor 26, and the state of the welded portion can be known with high accuracy.

  Since the sealing device has the welding mold 25, it is possible to accurately, stably and easily determine that a foreign object has been caught in the welded portion of the thermoplastic film. Thereby, the operation | work required for the test | inspection process of a thermoplastic film welding part can be eliminated.

  A method of welding the upper side of the food enclosure 15 using the welding mold 25 in the sealing step G will be described. The operator of the enclosing device sets the temperature of the top portion 25b of the welding mold 25 in advance to a temperature at which the food enclosing container 15 can be welded. When the food enclosure 15 whose opening has been shaped in the shaping process F stops at a predetermined position in the sealing process G, the control unit of the food enclosure 1 is provided with a welding mold provided before and after the food enclosure 15. 25 is brought into contact with the food enclosure 15 by the actuator, and the food enclosure 15 is sandwiched by the welding mold 25. By holding this sandwiched state for a predetermined time, the food enclosure 15 is sealed. At this time, the control unit of the food enclosure device 1 measures the strain and temperature generated at the top portion 25 b of the welding mold 25 by the FBG sensor 26. For example, when a foreign substance is caught in the welded portion, the strain amount of the portion becomes large, so that the control unit of the food enclosure device 1 can remove the food enclosure 15 with the increased strain amount as a defective product.

  In FIG. 6, the front view of the welding metal mold | die 25 which concerns on 2nd Embodiment of this invention is shown. The difference from the welding mold 25 according to the first embodiment is only the installation position of the FBG sensor 26 in the welding mold 25.

  In the second embodiment, the FBG sensor 26 is installed in a groove 25 d provided in the top portion 25 b of the welding mold 25. The depth of the groove 25d is set such that the FBG sensor 26 does not protrude upward from the plane of the top portion 25b.

  Since the groove 25d for installing the FBG sensor 26 is provided in the welding mold 25, it is determined in which position of the welding mold 25 the FBG sensor 26 is installed, and the strain amount for each welding mold 25 The initial setting time of is reduced. In addition, since the groove 25d is provided in the top portion 25b of the contact convex portion 25a, the strain at a portion closer to the portion to be welded can be measured.

  In the above description, the groove 25d for installing the FBG sensor 26 is provided in the welding mold 25. However, when the FBG sensor 26 is installed particularly on the side surface, the groove 25d may not be provided.

  In FIG. 7, the front view of the welding metal mold | die 25 which concerns on 3rd Embodiment of this invention is shown. The difference from the welding mold 25 according to the first embodiment is that a sensor hole 27 a for accommodating the FBG sensor 26 is provided along the longitudinal direction of the welding mold 25. Two sensor holes 27a are provided at positions close to the top portion 25b of the contact convex portion 25a. The sensor hole 27a is provided so as to pass through the contact convex portion 25a. The FBG sensor 26 is fixed to the sensor hole 27a by the welding agent poured into the sensor hole 27a.

  FIG. 8 shows a welding mold 25 according to the fourth embodiment of the present invention. FIG. 8A is a front view of the welding mold 25, and FIG. 8B is a partial side view of the welding mold 25. The difference from the welding mold 25 according to the first embodiment is that a sensor press 27b is provided in the welding mold 25, and the sensor press 27b forms an upper portion of the contact convex portion 25a. Grooves 25d for accommodating the FBG sensor 26 are provided on the pedestal 25e side of the sensor press 27b and on the sensor press 27b side of the pedestal portion 25e, respectively. 8A is provided with a temperature measurement unit 26b. In order to fix the FBG sensor 26 having the temperature measurement unit 26b, a groove 25d of the sensor press 27b and The groove 25d of the pedestal portion 25e is provided with a plurality of fixed protrusions 27c, and the FBG sensor 26 is fixed to the welding mold 25 without using a welding agent by the fixed protrusions 27c.

1 Food Enclosing Device 11 Filling Nozzle 15 Food Enclosing Container 25 Welding Mold 25a Contact Protrusion 25b Top 25c Side 25d Groove 26 FBG Sensor 26a Strain Measurement Unit 26b Temperature Measurement Unit

Claims (6)

A welding mold for welding a thermoplastic film,
An optical fiber sensor in which a Bragg grating is formed is installed on the contact convex portion of the welding mold that comes into contact with the thermoplastic film.
A welding mold characterized by that. The optical fiber sensor is installed along the contact convex portion,
The welding mold according to claim 1. On the side surface leading to the top of the contact projection,
A groove for installing the optical fiber sensor is provided,
The welding mold according to claim 2, wherein: At the top of the contact projection,
A groove for installing the optical fiber sensor is provided,
The welding mold according to claim 2, wherein: In the two grooves provided in the contact convex portion, the optical fiber sensor is installed,
A temperature measurement unit is arranged in one groove, and a strain measurement unit is arranged in the other groove.
The welding mold according to claim 3 or 4, wherein the welding mold is provided. The welding mold according to any one of claims 1 to 5,
A sealing device characterized by that.

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