Bag-making and packaging apparatus

Abstract

A bag-making and packaging apparatus creates one product per cycle by packaging articles in a bag made from a film. The bag-making and packaging apparatus includes a longitudinal sealing mechanism, a guide, an article sensor, a transverse sealing mechanism, a cutting mechanism, and a prediction unit. The guide guides the articles which fall from above into a film tube. The transverse sealing mechanism forms a transversely sealed part in the film tube with each cycle. The cutting mechanism cuts the film tube in the transversely sealed part with each cycle. The prediction unit predicts whether or not jamming of the articles could occur in the transverse sealing mechanism on the basis of an output of the article sensor with each cycle. When the prediction unit has predicted that the jamming could occur in a certain cycle, the cutting mechanism does not cut the film tube in the certain cycle.

Claims

1. A bag-making and packaging apparatus that creates one product per cycle by packaging articles falling from a weighing machine in a bag made from a film, the bag-making and packaging apparatus comprising: a longitudinal sealing mechanism that forms a film tube from the film; a guide that guides the articles which fall from the weighing machine into the film tube; an article sensor disposed at a location below the weighing machine, the article sensor configured to sense the articles which fall from the weighing machine; a transverse sealing mechanism that forms a transversely sealed part in the film tube with each cycle; a cutting mechanism that cuts the film tube in the transversely sealed part with each cycle; and a prediction unit that predicts whether or not jamming of the articles occurs in the transverse sealing mechanism based on a fall timing of each of the articles which falls from the weighing machine to pass by the location of the article sensor with each cycle, wherein when the prediction unit has predicted that the jamming occurs in a certain cycle, the cutting mechanism does not cut the film tube in the certain cycle.

2. The bag-making and packaging apparatus according to claim 1, wherein when the prediction unit has predicted that the jamming occurs in the certain cycle, the transverse sealing mechanism does not form the transversely sealed part in the certain cycle.

3. The bag-making and packaging apparatus according to claim 1, further comprising: a setting storage unit that stores an offset time beginning at the starting point of the cycle and a permission time beginning at the ending point of the offset time, wherein a sum of the offset time and the permission time is shorter than the cycle, and when the article sensor detects the articles outside of the permission time, the prediction unit predicts that the jamming occurs.

4. The bag-making and packaging apparatus according to claim 3, further comprising: a processing unit; and a jamming sensing unit that senses an occurrence of the jamming; wherein when the jamming sensing unit does not sense an occurrence of the jamming, the processing unit updates the permission time stored by the setting storage unit to a longer time.

5. The bag-making and packaging apparatus according to claim 1, further comprising: a warning unit that issues a warning when the jamming has occurred at least a predetermined number of times within a predetermined time duration.

6. The bag-making and packaging apparatus according to claim 1, wherein the length of the bag of the product is a first length, and when the prediction unit has predicted that the jamming occurs, a second bag having a second length greater than the first length is created due to the cutting mechanism not cutting the film tube.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a schematic drawing showing a product P manufactured by a bag-making and packaging apparatus 20 according to the present disclosure;

(2) FIG. 2 is a schematic drawing showing the configuration of the bag-making and packaging apparatus 20;

(3) FIG. 3 is a block diagram of a processing unit 27;

(4) FIG. 4 is a schematic drawing showing a film F;

(5) FIG. 5 is a schematic drawing showing a film tube FT;

(6) FIG. 6 is a schematic drawing showing a film tube FT;

(7) FIG. 7 is a schematic drawing showing a transverse sealing mechanism 24;

(8) FIG. 8 is a timing chart of various signals of the bag-making and packaging apparatus 20;

(9) FIG. 9 is a schematic drawing showing an example of an ejected unsatisfactory product Q;

(10) FIG. 10 is a schematic drawing showing an example of an ejected unsatisfactory product Q;

(11) FIG. 11 is a block diagram of the processing unit 27 of the bag-making and packaging apparatus 20 according to a modification of the present disclosure; and

(12) FIG. 12 is a block diagram of the processing unit 27 of the bag-making and packaging apparatus 20 according to another modification of the present disclosure.

DETAILED DESCRIPTION OF EMBODIMENTS

(13) Below is a description, made with use of the drawings, of an embodiment of a bag-making and packaging apparatus according to the present disclosure. The specific configuration of the bag-making and packaging apparatus according to the present advancement is not limited to the following embodiment, and can be altered as appropriate within a range that does not deviate from the scope of the advancement.

(14) (1) Overall Configuration

(15) FIG. 1 shows a product P manufactured by a bag-making and packaging apparatus according to the present disclosure. The product P is articles packaged by a bag B made from a film F. A longitudinally sealed part XL and a transversely sealed part XT are formed in the bag B.

(16) The bag-making and packaging apparatus 20 according to the present advancement is installed below a weighing machine 10, as shown in FIG. 2. The weighing machine 10 drops articles A in predetermined weights into the bag-making and packaging apparatus 20. The bag-making and packaging apparatus 20 receives the articles A and manufactures a product P by packaging the articles A in a film F. In one operation cycle of the bag-making and packaging apparatus 20, one product P is manufactured.

(17) (2) Detailed Configuration

(18) The bag-making and packaging apparatus 20 has a conveying mechanism 21, a film-shaping mechanism 22, a longitudinal sealing mechanism 23, a transverse sealing mechanism 24, a cutting mechanism 25, an article sensor 26, and a processing unit 27, as shown in FIG. 2.

(19) (2-1) Conveying Mechanism 21

(20) The conveying mechanism 21 conveys the film F extracted from a film roll FR, and the products P. The conveying mechanism 21 has rollers 21a, 21b, 21c, a pull-down belt 21d, and a conveyor belt 21e.

(21) (2-2) Film-Shaping Mechanism 22

(22) The film-shaping mechanism 22 rounds the flat film F into the form of a tube. The film-shaping mechanism 22 has a former 22a and a tube 22b. The former 22a deforms the flat film F so that the film encircles the tube 22b.

(23) (2-3) Longitudinal Sealing Mechanism 23

(24) The longitudinal sealing mechanism 23 forms a film tube FT from the film F. The film tube FT has a longitudinally sealed part XL. The longitudinal sealing mechanism 23 has a heater, and temporarily softens two longitudinal edges of the film F. The two softened longitudinal edges bond together, forming the longitudinally sealed part XL. The tube 22b of the film-shaping mechanism 22 functions as a guide that guides articles A falling from above to the inside of the film tube FT.

(25) (2-4) Transverse Sealing Mechanism 24

(26) With each cycle, the transverse sealing mechanism 24 forms one transversely sealed part XT in the film tube FT. The transverse sealing mechanism 24 has a first sealing jaw 24a and a second sealing jaw 24b. The first sealing jaw 24a and the second sealing jaw 24b both have a heater, and temporarily soften part of the film tube FT. The softened parts bond together, forming a transversely sealed part XT.

(27) (2-5) Cutting Mechanism 25

(28) With each cycle, the cutting mechanism 25 cuts the film tube FT at the transversely sealed part XT. The cutting mechanism 25 is provided to the transverse sealing mechanism 24. The cutting mechanism 25 includes a knife 25a and a receiving part 25b. The knife 25a is provided to the first sealing jaw 24a. The receiving part 25b is provided to the second sealing jaw 24b. The knife 25a can extend and retract. When extended, the knife 25a is accommodated in the receiving part 25b.

(29) (2-6) Article Sensor 26

(30) The article sensor 26 senses the articles A falling from above. The article sensor 26 is, for example, an optical sensor, but this example is not provided by way of limitation. The location where the article sensor 26 is attached is, for example, above the tube 22b and below the weighing machine 10, but this example of a location is not provided by way of limitation.

(31) For example, the article sensor 26 can be provided to a spot 26a where the film F encircles the tube 22b. In this case, an opening is provided in the tube 22b at a location adjacent to the spot 26a. Light emitted from a light projector of an optical sensor of the article sensor 26 permeates through the film F and then passes through the opening of the tube 22b to be radiated onto the articles A.

(32) (2-7) Processing Unit 27

(33) The processing unit 27 coordinates the operations of the bag-making and packaging apparatus 20. The processing unit 27 is a computer including a CPU and a storage device. FIG. 3 shows the configuration of the processing unit 27. The processing unit 27 has a central processing unit 100, a product setting storage unit 111, a jamming setting storage unit 112, a jamming prediction unit 113, a conveying mechanism control unit 121, a longitudinal sealing mechanism control unit 123, a transverse sealing mechanism control unit 124, a cutting mechanism control unit 125, and a weighing machine communication unit 130.

(34) The central processing unit 100 performs various calculations and controls. The product setting storage unit 111 stores the sizes of bags B for products P that are to be manufactured, the types of films F, and other settings. The jamming setting storage unit 112 stores settings pertaining to article A fall timings that are regarded as normal or abnormal. With each cycle, the jamming prediction unit 113 compares an output signal of the article sensor 26 with a setting stored in the jamming setting storage unit 112, and predicts whether or not jamming could occur in that cycle of the bag-making and packaging apparatus. The conveying mechanism control unit 121, the longitudinal sealing mechanism control unit 123, the transverse sealing mechanism control unit 124, and the cutting mechanism control unit 125 respectively control the conveying mechanism 21, the longitudinal sealing mechanism 23, the transverse sealing mechanism 24, and the cutting mechanism 25. The weighing machine communication unit 130 conducts communication with the weighing machine 10.

(35) (3) Film F

(36) FIG. 4 shows the film F used in the packaging of the articles A. The film F extends in a longitudinal direction L, and has a constant width along a transverse direction T perpendicular to the longitudinal direction L. A design corresponding to packaging of one product P is printed at each distance of length D.

(37) FIG. 5 shows the film tube FT formed in the longitudinal sealing mechanism 23. The longitudinally sealed part XL is formed in the film tube FT.

(38) FIG. 6 shows the transversely sealed part XT formed in the transverse sealing mechanism 24. A cut position CP, where a cut is made by the cutting mechanism 25, is in the transversely sealed part XT.

(39) (4) Basic Operation of Transverse Sealing Mechanism 24

(40) FIG. 7 shows the details of the transverse sealing mechanism 24. In addition to the pair of sealing jaws 24a, 24b, the transverse sealing mechanism 24 has a pair of arms 242a, 242b and a pair of rotating shafts 243a, 243b. The pair of arms 242a, 242b rotate about the respective rotating shafts 243a, 243b. The rotating shafts 243a, 243b are able to move horizontally as indicated by the arrows. The movement of the rotating shafts 243a, 243b is synchronized with the rotation of the arms 242a, 242b, whereby the sealing jaws 24a, 24b move in D-shaped paths, indicated by the double-dashed lines. The D-shaped paths each have a straight-line portion R1 and a curved-line portion R2. In the straight-line portions R1, the sealing jaws 24a, 24b descend at the same speed as the conveying speed of the film F. The transversely sealed part XT is thereby formed. In the final stage of the straight-line portions R1, the cutting mechanism 25 cuts the transversely sealed part XT.

(41) (5) Jamming Countermeasures

(42) (5-1) Jamming Prediction

(43) FIG. 8 is a timing chart of various signals of the bag-making and packaging apparatus 20. A cycle time Tc is the length of the cycle during which the bag-making and packaging apparatus 20 creates one product P. An ejection request signal ER is a signal from the bag-making and packaging apparatus 20 to the weighing machine 10 to eject articles A, and is generated once per cycle. In one example, the ejection request signal ER is treated as a starting point of the cycle, but the cycle starting point is not limited to this example. An ejection completion signal EC is a signal that reports to the bag-making and packaging apparatus 20 that the weighing machine 10 has ejected articles A in response to the ejection request signal ER. An article detection signal AD is a signal representing detection of falling articles A by the article sensor 26.

(44) A permission time signal PT indicates the timing during which articles A are permitted to pass by the location of the article sensor 26. The waveform of the permission time signal PT is determined by two parameters. The first is an offset time T1. The second is a permission time T2. The offset time T1 begins at the starting point of the operation cycle. The permission time T2 begins at the ending point of the offset time T1. The offset time T1 and the permission time T2 are set so that the sum thereof is shorter than the cycle time Tc. These parameters are stored in the jamming setting storage unit 112 of the processing unit 27.

(45) A sealing jaw state SJ represents the sealing jaws 24a, 24b as being either in the straight-line portions R1 or the curved-line portions R2. A cut signal CT causes the cutting mechanism 25 to cut the transversely sealed part XT.

(46) When articles A are detected by the article sensor 26 while the permission time signal PT is at a high level, the jamming prediction unit 113 regards the articles A as falling at the proper fall timing. When articles A are detected by the article sensor 26 while the permission time signal PT is at a low level, the jamming prediction unit 113 predicts that the articles A could cause jamming. For example, the jamming prediction unit 113 predicts the occurrence of jamming in that cycle on the basis of the presence of a pulse AD1 in the article detection signal AD.

(47) (5-2) Operation During Jamming Prediction (Cutting Stops)

(48) In a certain cycle, when the jamming prediction unit 113 predicts the occurrence of jamming, the transverse sealing mechanism control unit 124 stops the cutting mechanism 25 in that cycle. The transversely sealed part XT is thereby not cut in that cycle.

(49) (5-3) Ejected Unsatisfactory Product Q

(50) Due to the stopping of the cutting mechanism 25, the bag-making and packaging apparatus 20 ejects an unsatisfactory product Q of the products P. An unsatisfactory product Q is two bags B joined at the transversely sealed part XT, as shown in FIG. 9. A second length D2, which is the length of the unsatisfactory product Q, is longer than a first length D1, which is the length of a product P.

(51) (6) Characteristics

(52) (6-1)

(53) In a cycle in which jamming could occur, the cutting mechanism 25 does not cut the film tube FT. Therefore, instances of articles A coming out through the cut position CP of the film tube FT are minimized.

(54) (6-2)

(55) When articles A are detected outside of the permission time T2, the jamming prediction unit 113 predicts that jamming could occur. Therefore, the possibility of jamming is assessed by a simple configuration that uses the article sensor 26.

(56) (6-3)

(57) In a case in which jamming could occur, the bag-making and packaging apparatus 20 creates a bag that is longer than the length of a product P. Therefore, it is easy to identify an unsatisfactory product Q including a spot where jamming has occurred.

(58) (7) Modifications

(59) Modifications of the above embodiment are presented below. A plurality of modifications can be combined.

(60) (7-1) Operation During Jamming Prediction (Transverse Sealing Operation Stopped)

(61) In the above embodiment, when the jamming prediction unit 113 predicts the occurrence of jamming, the transverse sealing mechanism control unit 124 stops the cutting mechanism 25 in that cycle. In addition, the transverse sealing mechanism control unit 124 can stop the transverse sealing mechanism 24 in that cycle.

(62) Specifically, the transverse sealing mechanism control unit 124 stops the sealing jaws 24a, 24b at points V in the curved-line portions R2 of the D-shaped paths in FIG. 7. The sealing jaws 24a, 24b thereby do not come into contact with the film tube FT in that cycle.

(63) The ejected unsatisfactory product Q is two joined bags B with no transversely sealed part XT, as shown in FIG. 10.

(64) With this configuration, the transverse sealing mechanism 24 does not form a transversely sealed part XT in the film tube FT in a cycle in which jamming could occur. Therefore, damage to the film F by the transverse sealing operation is minimized, and instances of articles A coming out from the film tube FT are therefore further minimized.

(65) (7-2) Jamming Sensing Unit

(66) The transverse sealing mechanism 24 can further have a jamming sensing unit 126 that senses an actual determination of jamming, as shown in FIG. 11. The jamming sensing unit 126 is configured as, for example, an electric current monitoring unit that monitors electric currents of motors that drive the arms 242a, 242b of the transverse sealing mechanism 24. In this case, when an electric current exceeding a predetermined threshold value flows to a motor, the jamming sensing unit 126 assesses that jamming is occurring.

(67) Furthermore, when the jamming sensing unit 126 does not sense jamming, the central processing unit 100 can update the length of the permission time T2 to a length increased by a predetermined amount, and can write the updated length into the jamming setting storage unit 112.

(68) With this configuration, the permission time T2 is extended when the jamming sensing unit 126 does not actually sense jamming. Therefore, the permission time T2 is automatically optimized.

(69) (7-3) Warning Unit

(70) As shown in FIG. 12, the bag-making and packaging apparatus 20 can be further provided with a warning unit 28 that issues a warning when the jamming has occurred at least a predetermined number of times within a predetermined time duration.

(71) With this configuration, a warning is issued when the frequency of jamming occurrences is high. Therefore, the user has an opportunity to reexamine the set value of the permission time T2.

(72) (7-4) Structure of Transverse Sealing Mechanism 24

(73) In the above embodiment, the sealing jaws 24a, 24b of the transverse sealing mechanism 24 move through the D-shaped paths in FIG. 7. As an alternative, the sealing jaws 24a, 24b can move horizontally back and forth.

(74) With this configuration, the structure of the transverse sealing mechanism 24 is simple.

(75) (7-5) Structure of Cutting Mechanism 25

(76) In the above embodiment, the cutting mechanism 25 cuts the transversely sealed part XT with the knife 25a. As an alternative, the cutting mechanism 25 can be configured to thermally cut the transversely sealed part XT with the heat of the heaters of the sealing jaws 24a, 24b.

(77) With this configuration, there are few mechanical components, which is advantageous from the standpoint of the maintenance of the bag-making and packaging apparatus 20.

REFERENCE SIGNS LIST

(78) 10 Weighing machine 20 Bag-making and packaging apparatus 21 Conveying mechanism 22 Film-shaping mechanism 22a Former 22b Tube 23 Longitudinal sealing mechanism 24 Transverse sealing mechanism 25 Cutting mechanism 26 Article sensor 27 Processing unit 100 Central processing unit 111 Product setting storage unit 112 Jamming setting storage unit 113 Jamming prediction unit A Articles AD Article detection signal B Bag CP Cut position CT Cut signal EC Ejection completion signal ER Ejection request signal F Film FR Film roll FT Film tube P Product PT Permission time signal R1 Straight-line portion R2 Curved-line portion T1 Offset time T2 Permission time Tc Cycle time XL Longitudinally sealed part XT Transversely sealed part