Pillow packaging machine

Abstract

To provide a pillow packaging machine capable of further shortening a package as a product to be packaged becomes shorter CONSTITUTION: The pillow packaging machine 10 for packaging a manually supplied commodity includes a bag making device 20 for making a belt-like packaging material 15 into a cylindrical bag, a center sealing device 21 for joining both side edges of the packaging material together, and a top sealing device 22 for sealing and cutting the packaging material in the width direction. The conveying path of the cylindrically formed packaging material is arranged in a downward inclined state along the conveying direction. A commodity detecting sensor 27 is provided for detecting the height of the commodity reaching the tip of the cylindrically formed packaging material and moving together with the packaging material in the reached state, and the cutting position of the packaging material is adjusted based on the length of the commodity and the height of the commodity.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a pillow packaging machine. [Background technology]

[0002] A pillow packaging machine continuously supplies a strip of packaging film, for example, wound on a roll, to a bag former on the inlet side of the packaging machine body, where it is formed into a tubular bag as it passes through the bag former. A center seal device located downstream of the bag former seals the overlapping portions of the packaging film, forming the tubular bag. A product conveying / feeding device is located upstream of the bag former, and products conveyed from the product conveying / feeding device at predetermined intervals are fed into the bag former. As a result, as the products pass through the bag former, they are placed in the tubular packaging film at predetermined intervals. The products are conveyed along with the tubular packaging film. An end seal device located on the outlet side of the pillow packaging machine seals and cuts the tubular packaging film horizontally at predetermined intervals to produce a pillow package containing the product.

[0003] As disclosed in Patent Document 1 and other publications, in a typical pillow packaging machine, the transport path of the packaging film after passing through the product conveying / supplying device and the bag former is arranged to extend horizontally. A plurality of products are placed at intervals of a packaging pitch in the front and rear of the cylindrically formed packaging film, and the products are packaged sequentially starting from the leading product. In the pillow packaging machine disclosed in Patent Document 1, an inner tube is arranged inside the bag former. The packaging film passes through the space between the outer periphery of the inner tube and the inner periphery of the bag former, and is formed into a cylindrical bag. Therefore, the packaging film can be formed into a cylindrical bag by matching it to the outer shape of the inner tube, regardless of the dimensions and shape of the product. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] U.S. Patent No. 4,715,166 Summary of the Invention [Problem to be solved by the invention]

[0005] When using the pillow packaging machine disclosed in Patent Document 1 to handle randomly supplied products with different front-to-rear lengths, it is possible to adopt a configuration in which the products are conveyed at equal intervals, for example, at a pitch that matches the maximum dimension of the products. In such a case, if the product size is small, the packaging body becomes long compared to the product, which looks bad and wastes packaging film.

[0006] Furthermore, when the cutting position is adjusted according to the length of the product, the product is detected by a sensor located upstream of the bag making machine, and the product is detected before it is fed to the bag making machine. As a result, the product must travel a certain distance after its length is detected before it actually reaches the top sealing device, during which time it must package products of different sizes that are in front of it, making control complicated and, if errors accumulate, there is a risk that the product will get caught in the top sealing device.

[0007] The above-mentioned problems are described as being independent of each other, and the present invention does not necessarily have to solve all of the problems described, but it is sufficient if it can solve at least one of the problems. Furthermore, we intend to obtain rights to the configurations for solving these problems separately through divisional applications, amendments, etc. [Means for solving the problem]

[0008] In order to solve the above-mentioned problems, the pillow packaging machine of the present invention is (1) a pillow packaging machine equipped with a bag making machine that makes a strip-shaped packaging material into a tubular bag, a center sealing device that joins both side edges of the packaging material made into a tubular bag by the bag making machine, and a top sealing device that seals and cuts the packaging material in the width direction, and the top sealing device is equipped with a height detection device that detects the height of a product located inside the tubular made packaging material, and the cutting position of the packaging material is set based on the length of the product and the height of the product detected by the height detection device.

[0009] In this way, the cutting position of the packaging material can be adjusted according to the height as well as the length of the product. Therefore, for example, the thinner the product, the shorter the length of the package can be, reducing the amount of packaging material consumed. Furthermore, in this invention, since the height detection device is located on the top seal device side, the impact of product misalignment on the packaging material can be reduced compared to when it is located upstream of the bag making machine. In addition, since the cutting position can be set taking into account the position and orientation of the product inside the packaging material, it is possible to prevent the use of more packaging material than necessary.

[0010] (2) The conveying path for the cylindrical packaging material may be arranged at a downward incline along the conveying direction. In this way, the orientation of the inserted products varies, and they slide down the downward incline conveying path in this varied orientation. For example, the products may be parallel to the conveying surface or tilted with the front end raised, and the angles at which they slide may also vary. The height detection device detects the height of the product when it reaches the leading edge of the packaging material, as well as the height of the product moving along with the packaging material. Therefore, for products with varying orientations as described above, the cutting position is adjusted based on the height of the product when it reaches the leading edge.

[0011] (3) The height detection device preferably detects the height of the product as it moves along with the packaging material when it reaches the leading edge of the cylindrically formed packaging material. In this way, the product inserted into the bag making machine slides down the downwardly inclined conveying path until it reaches the leading edge. Since the height of the product moving along with the packaging material is detected when it reaches the leading edge, the height of the product when it has settled inside the bag can be detected. This reduces the impact of product misalignment relative to the packaging material. Furthermore, since the product reaches the leading edge of the packaging material, the amount of packaging material used is reduced.

[0012] (4) The cutting position of the packaging material may be the portion of the packaging material that is positioned at the top seal device when the packaging material is transported a predetermined length after the height detection device detects the rear end of the product, and the predetermined length may be the sum of the distance from the height detection device to the top seal device and the rear end cutting length based on the height of the product detected by the height detection device. In this way, the appropriate cutting position is determined according to the length and height of the product, and the pillow packaging machine can top seal the product without it getting caught in the top seal device, reducing packaging material consumption.

[0013] (5) The rear end cut length may be set to a first cut length at the maximum height detected by the height detection device and a second cut length at the minimum height, the second cut length being shorter than the first cut length, and the length between the maximum height and the minimum height being proportional to the height between the first cut length and the second cut length. In this way, the pillow packaging machine can top seal at an appropriate cutting position with simple control.

[0014] (6) The rear end cut length may be set to a first cut length at the maximum height detected by the height detection device, a second cut length at the minimum height, and a third cut length at a predetermined height between the maximum height and the minimum height, the third cut length being shorter than the first cut length and the second cut length being equal to or greater than the third cut length, the length between the maximum height and the predetermined height being proportional to the height between the first cut length and the third cut length, and the length between the minimum height and the predetermined height being proportional to the height between the second cut length and the third cut length. In this way, the pillow packaging machine can minimize the risk of thin products being caught in the top seal device.

[0015] (7) A support member may be provided between the bag former and the top seal device to support the cylindrically formed packaging material from the inside, and the height detection device may be comprised of a plurality of product detection sensors attached to the support member. In this way, the product detection sensors are positioned within the internal space of the cylindrically formed packaging material. Therefore, the product detection sensors can more accurately detect the height based on the product's orientation. As a result, even if the packaging material is made of an opaque material such as paper, the product detection sensors can detect the height based on the product's orientation.

[0016] Furthermore, the configurations shown in (1) to (7) above can be configured by combining them as appropriate, and based on such combined configurations, it is advisable to combine the components described in the embodiments and drawings. [Effects of the Invention]

[0017] The present invention allows the cutting position to be adjusted based on the product height as well as the product length, making it possible to shorten the package even more for thinner products. The present invention reduces the amount of packaging material consumed and reduces the environmental impact. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a diagram showing a preferred embodiment of a pillow packaging machine according to the present invention; [Figure 2] FIG. [Figure 3] 10A and 10B are diagrams illustrating an example of how a trailing edge cut length is set relative to the height of a product. [Figure 4] 10A and 10B are diagrams illustrating an example of how a trailing edge cut length is set relative to the height of a product. DETAILED DESCRIPTION OF THE INVENTION

[0019] Preferred embodiments of the present invention will be described in detail below with reference to the drawings. However, the present invention is not limited to these embodiments, and various changes, modifications, and improvements can be made based on the knowledge of those skilled in the art without departing from the scope of the present invention.

[0020] Fig. 1 shows a preferred embodiment of a pillow packaging machine according to the present invention. The pillow packaging machine 10 of this embodiment is configured to pillow-package products 13 of different sizes. The pillow packaging machine 10, which sequentially packages various products 13, includes a packaging machine main body 11 and a packaging material supply device 12 that continuously supplies strip-shaped packaging material 15 to the packaging machine main body 11. The packaging material 15 may be made of various materials, such as a resin film or paper. In this embodiment, the packaging material 15 is paper.

[0021] The packaging material supply device 12 supplies the packaging machine main body 11 with a strip-shaped packaging material 15 for wrapping the product 13. The pillow packaging machine 10 of this embodiment operates intermittently. Accordingly, the packaging material supply device 12 repeatedly conveys and pauses the packaging material 15.

[0022] The packaging material supply device 12 continuously supplies strip-shaped packaging material 15 for wrapping products 13 to the packaging machine main body 11. This packaging material supply device 12 includes a rotating shaft 17 that supports a raw roll 16 on which the strip-shaped packaging material 15 has been wound into a roll, a plurality of rollers 18 that form a conveying path that guides the packaging material 15 that is continuously unwound from the raw roll 16 to the packaging machine main body 11, and a drive motor (a speed-controllable motor such as a servo motor) (not shown) that applies a conveying force to the packaging material 15.

[0023] The packaging material 15 is passed over rollers 18 arranged at appropriate positions, and is guided through a predetermined path to the packaging machine main body 11. These rollers 18 include drive rollers that apply drive to the strip-shaped packaging material 15, tension rollers that apply tension, dancer rollers that eliminate slack, and free rollers that change the conveying direction of the strip-shaped packaging material 15 and guide its conveyance. In this example, the output of the drive motor is linked to the drive rollers to draw out the packaging material 15, but various configurations are possible, such as linking the output of the drive motor to the rotary shaft 17 to unwind the packaging material 15.

[0024] The packaging machine main body 11 has a conveying path that slopes diagonally downward toward the front in the traveling direction. The packaging machine main body 11 is equipped with a bag former 20 that makes cylindrical bags out of packaging material 15 supplied to its inlet side. The bag former 20 passes strip-shaped packaging material 15, which is continuously supplied from the packaging material supply device 12, through the bag former 20, bringing both side edge portions 151 of the packaging material 15 into contact with or close to each other and making cylindrical bags.

[0025] Furthermore, the packaging machine main body 11 is equipped with a center seal device 21 that joins both side edges of the packaging material 15 and is located downstream of the bag maker 20, a top seal device 22 that is located downstream of the bag maker 20, and an output conveyor 23 that is located downstream of the top seal device 22.

[0026] The bag former 20 is equipped with a support member 28 that supports a film with openings at the front and rear ends from the inside, and the packaging material 15 passes through the space between the bag former 20 and the support member 28 to form a tubular bag. In this way, even if the width or height of the product 13 is shorter than the internal shape of the bag former 20, the packaging material 15 will not move toward the center of the outer periphery of the support member 28, and can be formed into a neat tubular shape with a space around the product 13. Although not specifically shown in the drawings, the support member 28 is connected to a predetermined position on the packaging machine main body 11 with a portion of it inserted inside the bag former 20 by a predetermined mounting member. As a result, the support member 28 is installed at a predetermined position within the bag former 20 and can support the packaging material 15 from the inside as it passes through the bag former 20.

[0027] The support member 28 may be, for example, a rectangular tubular shape with openings at the front and rear, or may have a shape in which at least one of the four faces (both side faces, bottom face, and top face) of the rectangular tubular shape is partially or entirely open. A configuration in which one face is entirely open may, for example, be a configuration in which there is no bottom face. The front end on the downstream side of the support member 28 is located immediately adjacent to the top seal device 22.

[0028] The support member 28 has a shape in which a part or all of a predetermined surface is open, and is provided with left and right side surface portions 281 at least at the front end side in the traveling direction, and an upper surface portion 282 that connects the left and right side surface portions 281 at their upper ends. As a result, the two side surface portions 281 are spaced apart at a predetermined distance and are in an upright position. The side surface portions 281 are located near the top seal device 22. A predetermined number of product detection sensors 27 are attached to each of the left and right side surfaces 281. The product detection sensors 27 are, for example, transmission type sensors, and each set consists of a light-emitting element provided on one side surface 281 and a light-receiving element provided on the other side surface 281, with multiple sets arranged vertically. The multiple sets of product detection sensors 27 are arranged in a line upward, perpendicular to the conveying plane of the products 13 and packaging material 15 inside the bag making machine 20. The number of multiple sensors is, for example, 16.

[0029] As a result, when a product 13 is positioned between the product detection sensors 27, the light emitted from the light-emitting unit is blocked by the product 13. This causes the product detection sensors 27 to output a detection signal for the product 13. Furthermore, in this embodiment, 16 product detection sensors 27 are arranged in a row in a direction perpendicular to the conveyance surface, so the position of the top edge of a product 13 passing the sensor installation position can be determined from the presence or absence of a detection signal output from each product detection sensor 27.

[0030] Of the multiple merchandise detection sensors 27, the lowest one is positioned at a height of, for example, 6 mm from the bottom, and the top one is positioned lower than the bottom surface of the upper surface portion 282, for example, at a height 10 mm lower than the top surface of the upper surface portion 282. The remaining merchandise detection sensors 27 are then positioned at equal intervals between them.

[0031] As described above, the packaging material 15 is conveyed with both side edge portions 151 protruding downward from the bag former 20. The bag former 20 has two upper plates arranged on the left and right at a predetermined distance downstream. These upper plates form the conveying surface from the bag former 20 to the top sealing device 22. The packaging material 15 is conveyed with both side edge portions 15a protruding downward from the gap between the left and right upper plates. The center sealing device 21 is disposed below the upper plates and includes a pair of left and right bar sealers 211 that heat the both side edge portions 151 of the packaging material 15, a pair of left and right first pinch rollers 212 disposed upstream of the bar sealers 211, and a pair of left and right second pinch rollers 213 disposed downstream of the bar sealers 211. The pair of bar sealers 211 are configured to open and close so that the opposing heating surfaces move closer to and away from each other.

[0032] The first pinch roller 212 and the second pinch roller 213 pinch both side edge portions 151 of the packaging material 15 that have come into contact with each other via the bag former 20 with a predetermined pressure, and rotate synchronously. As a result, the first pinch roller 212 and the second pinch roller 213 apply a conveying force to the both side edge portions 151 and ultimately to the packaging material 15. The second pinch roller 213 also functions as a pressure roller that applies pressure to and cools the both side edge portions 151 of the packaging material 15 that have been heated by the bar sealer 211, thereby heat-sealing them. This sealed area becomes the center seal portion of the package 26.

[0033] The top sealing device 22 seals and cuts the cylindrical packaging material 15 containing the product 13 in a direction perpendicular to the conveying direction, parallel to the conveying surface, and transverse to the material. The top sealing device 22 has an upper top sealer 24 and a lower top sealer 25 above and below the packaging material 15, sandwiching it between them. The upper top sealer 24 and the lower top sealer 25 each have a built-in heater, which heats the sealing surfaces at their respective tips to a predetermined temperature. Furthermore, a cutter blade is built into the sealing surface 241 of the upper top sealer 24, for example, in the center in the front-to-back direction. Furthermore, the sealing surface 251 of the lower top sealer 25 has a cutter groove in the center in the front-to-back direction.

[0034] In this embodiment, the upper top sealer 24 and the lower top sealer 25 approach and move away from each other with their sealing surfaces 241, 251 facing each other. As they approach each other, the upper and lower sealing surfaces 241, 251 sandwich and heat the packaging material 15 from above and below, and the cutter blades enter the cutter grooves to cut it. Thus, the top sealing device 22 seals and cuts a predetermined position (a portion where no product 13 is present) of the center-sealed packaging material 15 laterally, forming a top seal portion that extends laterally. As a result, the leading end of the packaging material 15 (the portion containing the leading product 13) is separated from the following packaging material 15, and package 26 is produced.

[0035] The products 13 to be packaged vary in type and number each time, such as mail-order products. Therefore, the products 13 may consist of a single product or multiple products. Furthermore, the size of the products 13 varies from product to product, with respect to the length along the conveying direction and the height.

[0036] In this embodiment, an operator manually supplies products 13 from a waiting area to the packaging machine main body 11, or a supply device such as a robot supplies the products 13 to the packaging machine main body 11. The pillow packaging machine 10 then packages the supplied products 13 to produce packages 26. Because the pillow packaging machine 10 automatically packages products one by one in this manner, it operates intermittently, pausing once the packaging process for one product 13 is complete to wait for the next product 13 to be supplied.

[0037] That is, the control device of the pillow packaging machine 10 performs a top sealing process on the packaging material 15 using the top sealing device 22. As a result, the leading end of the packaging material 15 where the product 13 is present is cut off from the packaging material 15 to produce a package 26. Accordingly, the leading end of the packaging material 15 is sealed and closed.

[0038] In this state, the worker supplies the product 13 into the bag former 20. Because the conveying path inside the bag former 20 is configured to slope diagonally downward toward the front of the direction of travel, the product 13 inserted into the bag former 20 slides down inside the bag former 20 and stops when it reaches the tip of the tubular packaging material 15. The product 13 that has reached the tip of the packaging material 15 in this way is detected by the product detection sensor 27.

[0039] Next, the worker operates an operation unit for giving an instruction to restart operation that is provided in the pillow packaging machine 10. This operation may be performed by pressing a predetermined button or touching a screen.

[0040] The control device of the pillow packaging machine 10 performs predetermined control to resume operation when it receives both an operation restart instruction signal output from the operation unit and a detection signal output from the product detection sensor 27. In this way, the control device resumes operation based on two signals, which prevents, for example, the product 13 not being inserted all the way into the packaging material 15, leaving extra space between the front end of the product 13 and the front end of the packaging material 15, or the creation of an empty bag when the operation unit is mistakenly operated without a product 13 being supplied.

[0041] Furthermore, the pillow packaging machine 10 of this embodiment has a function of controlling the top sealing device 22 to seal and cut the packaging material 15 to a cut length that matches the product size when packaging products 13 of different sizes.

[0042] The control device performs the following control based on the output of the product detection sensor 27, producing packages 26. When operation resumes, the control device conveys the packaging material 15 at a predetermined constant speed. As a result, the products 13 inside the packaging material 15 are conveyed along with the packaging material 15. When the detection output of the product detection sensor 27 turns off, that is, when the rear end of the product 13 passes the installation position of the product detection sensor 27, the control device conveys the packaging material 15 a predetermined length and then temporarily halts conveyance. The control device then controls the top sealing device 22 to sandwich, seal, and cut the packaging material 15 between the upper top sealer 24 and lower top sealer 25.

[0043] In this case, the predetermined length is X+Y. As shown in FIG. 2, X is the distance from the product detection sensor 27 to the top sealing device 22 and is a fixed value. The distance from the product detection sensor 27 to the top sealing device 22 may be, for example, the distance to the center of the upper top sealer 24 and the lower top sealer 25 in the front-to-rear direction. Y is the length from the rear end of the product 13 in the package 26 to the tip of the top seal portion (rear end cut length). In this embodiment, Y is a variable that corresponds to the height of the product 13. Note that the support member 28 is not shown in FIG. 2.

[0044] As shown in FIG. 3 , the rear-end cut length is defined as a first cut length Y1 when all product detection sensors 27 output detection signals, and a second cut length Y2 when only the lowest product detection sensor 27 outputs a detection signal. The interval between these lengths is proportional to the number of product detection sensors 27 that detected the product 13. In the illustrated example, the first cut length Y1 is 105 mm, and the second cut length Y2 is 52 mm. The first cut length Y1 is defined as the length that allows the packaging material 15 to be sandwiched between the upper and lower top sealers 24 and 25 of the top sealing device 22 when a product 13 of the maximum height that can be supplied into the tubular packaging material 15 is supplied. The second cut length Y2 is defined as the necessary and sufficient length to allow the packaging material 15 to be sandwiched between the upper and lower top sealers 24 and 25 of the top sealing device 22 when a product 13 of the maximum height that can be supplied into the tubular packaging material 15 is supplied. The second cut length Y2 is shorter than the first cut length Y1 and is defined as the necessary and sufficient length to allow the packaging material 15 to be sandwiched between the upper and lower top sealers 24 and 25 of the top sealing device 22 when a product 13 of the maximum height that can be detected by only the lowest product detection sensor 27 is supplied.

[0045] In this way, the pillow packaging machine 10 detects the rear end position of the product 13, moves the packaging material 15 a predetermined distance, and then performs the top sealing process. This allows the packaging material 15 to be cut to a cutting length that corresponds to the length of the product 13. Furthermore, if the height of the product 13 is short, and the packaging material 15 is conveyed so that the rear end cutting length is the first cutting length Y1, there will be a small amount of excess length from the rear end of the product 13 to the top sealing portion. In other words, if the height of the product 13 is short, the pillow packaging machine 10 can top seal the packaging material 15 to produce the package 26 even if the rear end cutting length is shorter than the first cutting length Y1. In this embodiment, the control device changes the rear end cutting length based on the height of the product 13, and if the height is short, it sets it to a length shorter than the first cutting length Y1. This allows the pillow packaging machine 10 to reduce the amount of packaging material 15 used.

[0046] Furthermore, the height of the products 13 that determines the trailing edge cutting length is the maximum value, i.e., if the thickness varies in the front-to-back direction, it is adjusted to the sensor output of the highest part. In other words, after a product detection sensor 27 outputs a detection signal, the control device monitors which product detection sensor 27 outputs a detection signal until the detection signal is no longer output, and determines the trailing edge cutting length based on the highest product detection sensor 27 that output a detection signal. For example, if only the first product detection sensor 27 outputs a detection signal in many sections, and the third product detection sensor 27 outputs a detection signal in some sections, the control device controls the conveying distance of the packaging material 15 using the trailing edge cutting length based on the third height, regardless of the length of those sections.

[0047] Furthermore, if the simultaneously output detection signals are such that, for example, no detection signal is output from the first product detection sensor 27 but only from the second product detection sensor 27, the control device controls the conveyance distance of the packaging material 15 using the trailing edge cut length based on the second height. Even if no detection signals are output from the intermediate product detection sensors 27, the detection signal from the highest product detection sensor 27 is considered valid and the trailing edge cut length is determined. This shortens the trailing edge cut length, minimizing the risk of the top seal device 22 getting the products 13 caught.

[0048] In the above-described embodiment, the trailing edge cut length is determined as a first cut length Y1 and a second cut length Y2, and the interval between them is proportional to the number of commodity detection sensors 27 that detect the commodities 13. However, the present invention is not limited to this, and various patterns can be used. For example, as shown in FIG. 4, a trailing edge cut length (third cut length Y3) is set when the number of commodity detection sensors 27 that output detection signals is a predetermined value N between 2 and 15 (for example, 3). Here, Y2 is set to a value equal to or greater than Y3.

[0049] When the first through Nth merchandise detection sensors 27 detect the merchandise 13, the trailing edge cut length is set to a value proportional to the line connecting the second cut length Y2 and the third cut length Y3. On the other hand, when the Nth through 16th merchandise detection sensors 27 detect the merchandise 13, the trailing edge cut length is set to a value proportional to the line connecting the third cut length Y3 and the first cut length Y1. As shown in FIG. 4, when N=3, if a detection signal is output only from the first merchandise detection sensor 27, the trailing edge cut length is Y2, and when detection signals are output up to the third merchandise detection sensor 27, the trailing edge cut length is Y3. Furthermore, when detection signals are output up to the second merchandise detection sensor 27, the trailing edge cut length is an intermediate value between Y2 and Y3.

[0050] Y3 should be a value on the proportional line between the two points shown in Figure 4. In this way, the control device of the pillow packaging machine 10 can control the rear end cutting length based on the proportional value between the two points shown in Figure 4 for products 13 above a certain height, which causes detection signals to be output from the Nth or subsequent product detection sensors 27. This allows the cutting dimensions of the packaging material 15 to be an appropriate length that takes into account the length and height of the products 13.

[0051] Furthermore, in the case of thin products (such as clear files, notebooks, card cases, diaries, and IC memory sticks), the rear end position of the product 13 may not be reliably detected. That is, normally, when the product 13 passes through the detection area of ​​the product detection sensors 27 as the packaging material 15 is transported, a predetermined product detection sensor 27 is shielded from light depending on the height of the packaging material 15 in the detection area, and a detection signal is output. Then, when the rear end of the product 13 passes through the detection area of ​​the product detection sensors 27, none of the product detection sensors 27 are shielded from light and do not output a detection signal. Therefore, the control device recognizes the passage of the product 13 when, after a detection signal has been output from one of the product detection sensors 27, none of the product detection sensors 27 output a detection signal.

[0052] On the other hand, if the product 13 is positioned at an angle with its front side raised and at the leading edge of the packaging material 15, the rear end of the top surface of the product 13 will be lower than when it moves along the conveying surface. If the product 13 is thin, the top surface of the rear end of the product 13, which has its front side raised, may be located at the installation position of the product detection sensors 27 but may be located below the detection area of ​​the first product detection sensor 27 from the bottom. In such a case, detection signals are not output from all product detection sensors 27, and the control device erroneously recognizes that the rear end of the product 13 has passed. If the control device then temporarily stops after conveying the packaging material 15 a predetermined length based on this erroneous recognition, the product 13 may be between the upper top sealer 24 and the lower top sealer 25, potentially causing it to become caught.

[0053] This is because the conveying surface of the pillow packaging machine 10 in this embodiment is inclined downward, and because the products 13 are manually fed by an operator. For example, if a thin product 13 that can only be detected by the lowest product detection sensor 27 is fed into the bag former 20 while moving along the conveying surface, the product 13 will encounter air resistance as it falls, sliding down the packaging material 15 with its front end raised, and its front end will come into contact with the leading edge of the packaging material 15 and stop. Because the front end of the product 13 is raised, the lowest product detection sensor 27 will reliably detect the product 13 and output a detection signal. On the other hand, if the product 13 is in an oblique position, its rear end will be positioned below the lowest product detection sensor 27, and the position of the rear end may not be accurately detected.

[0054] Therefore, in this embodiment, the rear end cut length is set longer when the product 13 can only be detected by the first product detection sensor 27 or at a low position, such as the second product detection sensor 27. This minimizes the risk of the product 13 getting caught even when the product 13 is present but cannot be detected by the product detection sensor 27.

[0055] On the other hand, if the product 13 is thick enough to be detected by the third product detection sensor 27, the product 13 can be detected if it is present, and the trailing edge cut length is returned to the normal length.

[0056] In addition, in this embodiment, the packaging material 15 is made of paper, but it may be made of a resin film.

[0057] In the above-described embodiment, the conveying path for the bag former 20 and the packaging material 15, etc. downstream thereof, is inclined downward, but the present invention is not limited to this and may be horizontal. In this case, it is preferable to arrange a conveying device such as a product transport conveyor upstream of the bag former 20, and to configure the conveying device to supply the products 13 into the bag former 20.

[0058] While various aspects of the present invention have been described above using embodiments thereof, it should be noted that these embodiments and descriptions are provided to aid in understanding the present invention, and are not intended to limit the scope of the present invention. The scope of the present invention is not limited to the structures and manufacturing methods explicitly described in the specification, but also encompasses combinations of various aspects of the present invention disclosed herein. While the structures of the present invention that are sought to be patented are specified in the appended claims, it is hereby expressly stated that structures not currently specified in the claims may be claimed in the future as disclosed herein. [Explanation of symbols]

[0059] 10: Pillow packaging machine 11: Packaging machine body 12: Packaging material supply device 13: Product 15: Packaging material 16: Raw roll 20: Bag making machine 21: Center seal device 22: Top seal device 24: Upper top sealer 25: Lower top seal 26: Packaging 27: Product detection sensor 28: Support member 151: Both side edges

Claims

1. a bag making device that makes a cylindrical bag from a strip-shaped packaging material; a center seal device that joins and seals both side edges of the packaging material formed into a cylindrical bag by the bag forming device; A pillow packaging machine equipped with a top sealing device that seals and cuts the packaging material in the width direction, a height detection device for detecting the height of the product located inside the cylindrically formed packaging material is provided on the top sealing device side; The cutting position of the packaging material is set based on the length of the product and the height of the product detected by the height detection device. Pillow packaging machine.

2. The pillow packaging machine according to claim 1 , wherein a conveying path for the cylindrically formed packaging material is arranged at a downward incline along the conveying direction.

3. The pillow packaging machine according to claim 2, wherein the height detection device detects the height of the product when the product reaches the tip of the cylindrically formed packaging material and moves together with the packaging material.

4. the cutting position of the packaging material is the portion of the packaging material that is positioned in the top seal device when the packaging material is conveyed a predetermined length after the rear end of the product is detected by the height detection device, A pillow packaging machine as described in any one of claims 1 to 3, wherein the specified length is the distance from the height detection device to the top seal device plus the rear end cut length based on the height of the product detected by the height detection device.

5. The rear end cut length is a first cut length at the maximum height detected by the height detection device and a second cut length at the minimum height detected by the height detection device are set; The second cut length is shorter than the first cut length, 5. The pillow packaging machine according to claim 4, wherein the distance between the maximum height and the minimum height is a length proportional to the height between the first cut length and the second cut length.

6. The rear end cut length is a first cut length at a maximum height detected by the height detection device, a second cut length at a minimum height detected by the height detection device, and a third cut length at a predetermined height between the maximum height and the minimum height detected by the height detection device; The third cut length is shorter than the first cut length, The second cut length is equal to or greater than the third cut length, The length between the maximum height and the predetermined height is proportional to the height between the first cut length and the third cut length, 5. The pillow packaging machine according to claim 4, wherein the distance between the minimum height and the predetermined height is a length proportional to the height between the second cut length and the third cut length.

7. a support member that supports the packaging material formed into the cylindrical shape from the inside between the bag former and the top seal device, The pillow packaging machine according to any one of claims 1 to 3, wherein the height detection device is composed of a plurality of product detection sensors attached to the support member.

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