JP6032883B2 - Welding unit and packaging apparatus provided with the welding unit - Google Patents

Description

  The present invention relates to a welding unit of a packaging apparatus that covers a packaged object with a film strip and packages the package by thermally welding the film strip around the packaged object, and a packaging apparatus including the welding unit. .

  A film strip is folded around the left and right sides of the package, such as paper or booklet, and the folded portion where the side edges of the film strip are overlapped on one side of the package is heated. A package body which is welded and is further sealed by heat-cutting a film strip before and after the packaged object is widely used for physical distribution, mailing and the like.

  FIG. 9 is a diagram showing an example of such a package. As shown in FIG. 9, the package 900 has a flat-shaped article 91 wrapped with a film strip 92. The film strip 92 has a front-end sealing portion 92a and a rear-end sealing portion 92b that are heat-welded, and is further folded in the vicinity of the side end 92c on one side and the side end 92d on the other side. A mating portion 92e is provided. And in the vertical seal part 92f of the folding part 92e, the side ends of the film strip 92 are heat-welded.

  And the heat welding of the side ends of a film strip is performed when the heated welding member presses a film strip. Here, in the configuration in which the welding member presses the film strip, Patent Literature 1 discloses a configuration in which the pressing force is adjusted while being detected by the load cell. In Patent Literature 2, the pressing force can be adjusted. The structure is disclosed.

JP 2002-264205 A JP 2009-143600 A

  Here, in order to stably perform the thermal welding of the side ends of the film strip (welded member), it is necessary that the pressing force with which the welding member presses the welded member is constant. In Patent Document 1, since the pressing force is detected by the load cell, the device becomes expensive. Moreover, in the structure of patent document 2, although pressing force can be increased / decreased, since thickness differs for every kind of film strip, it is difficult to keep pressing force constant.

  Accordingly, an object of the present invention is to provide a welding unit in which a welding member can apply a constant pressing force to a member to be welded with a simple configuration, and a packaging device including the welding unit.

  According to a first aspect of the present application, a welding unit includes a welding member that thermally welds a welding member, a support member that supports the welding member via an elastic member, and the welding member is in contact with the welding member. Detection means for detecting this, drive means for moving the support member so that the welding member moves in the direction of contact with and separation from the welded member, control means for controlling the operation of the drive means, And when the detecting means detects that the welding member is in contact with the welded member, the control means moves the support member by a predetermined distance toward the welded member. It is characterized by controlling.

  According to the first aspect, after the welding member contacts the member to be welded, the support member is moved by a predetermined distance toward the member to be welded, so that the elastic member is compressed by a certain distance. As a result, the welding member presses the member to be welded by the reaction force of the elastic member compressed for a certain distance, and the welding member can apply a constant pressing force to the member to be welded with a simple configuration.

The first invention preferably further comprises the following configuration.
(1) The movable member includes a movable piece that is displaced when the welding member comes into contact with the member to be welded, and the detection unit detects that the welding member is in contact with the member to be welded by detecting the displacement of the movable piece. Detect.
(2) The support member includes a first frame and a second frame, the driving means is attached to the first frame, and the elastic member and the detection means are attached to the second frame. The second frame is moved with respect to the first frame by the driving means.
(3) In the configuration (2), the welding member is movable with respect to the second frame in a direction orthogonal to the conveying direction of the welding member.

  According to the configuration (1), the detection means does not directly detect that the welding member has contacted the member to be welded, but detects that the welding member has contacted the member to be welded via the movable piece. Further, it is possible to prevent the welding member having a high temperature from being affected by heat.

  According to the configuration (2), since all the components that give a constant pressing force are attached to the second frame, the entire second frame must be replaced when the welding member that is a replacement part is replaced. As a result, replacement work can be facilitated. Further, by exchanging the entire second frame, the position adjustment of the elastic member and the detection means with respect to the welding member can be made unnecessary.

  According to the configuration (3), since the welding member is movable in a direction orthogonal to the conveying direction of the welding member, the welding member can be moved to an appropriate welding site of the welding member. it can.

  2nd invention of this application is a packaging apparatus provided with the welding unit of the said 1st invention.

  According to the second invention, it is possible to provide a packaging device in which the welding member can apply a constant pressing force to the member to be welded with a simple configuration.

  In short, according to the present invention, it is possible to provide a welding unit and a packaging device in which the welding member can apply a constant pressing force to the member to be welded with a simple configuration.

It is a perspective view of the packaging apparatus which concerns on this invention. It is II-II sectional drawing of FIG. It is the schematic explaining the action | operation of a packaging part. It is the schematic following the state of FIG. 3A explaining the action | operation of a packaging part. It is the schematic following the state of FIG. 3B explaining the action | operation of a packaging part. It is the schematic following the state of FIG. 3C explaining the action | operation of a packaging part. It is the schematic following the state of FIG. 3D explaining the action | operation of a packaging part. It is the schematic following the state of FIG. 3E explaining the action | operation of a packaging part. It is the schematic following the state of FIG. 3F explaining the action | operation of a packaging part. It is the schematic following the state of FIG. 3G explaining the action | operation of a packaging part. It is the schematic following the state of FIG. 3H explaining the action | operation of a packaging part. It is the schematic following the state of FIG. 3I explaining the action | operation of a packaging part. It is the schematic following the state of FIG. 3J explaining the action | operation of a packaging part. It is the schematic following the state of FIG. 3K explaining the action | operation of a packaging part. It is the schematic following the state of FIG. 3L explaining the action | operation of a packaging part. It is the schematic following the state of FIG. 3M explaining the action | operation of a packaging part. It is the schematic following the state of FIG. 3N explaining the action | operation of a packaging part. It is a perspective view of a welding unit. It is a front view which shows the welding unit in the state which removed a part of support frame in FIG. It is an enlarged view of the welding roller part of FIG. It is VII-VII sectional drawing of FIG. It is VIII-VIII sectional drawing of FIG. It is a figure which shows an example of a package body.

  FIG. 1 is a perspective view of a packaging device 10 according to the present invention. For convenience of explanation, the following description will be made assuming that the upstream side in the conveyance direction X of the package is “front” and the downstream side is “rear”.

  As shown in FIG. 1, a sheet roll 100 around which a resin film strip (welded member) 101 that wraps an article to be packaged is placed is placed on the lower portion of the packaging device 10. A placement unit 11 is arranged. In the upper part of the packaging device 10, the supply unit 12 on which the article to be packaged is placed, the packaging part 13 in which the article to be packaged is wrapped with a film strip, and the article to be packaged are packaged in order from the front to the rear. A discharge portion 14 for discharging the package is disposed. In the packaging device 10, control means (not shown) for controlling the operation of each unit constituting the packaging device 10 is arranged.

  That is, a CPU (Central Processing Unit) as a control means is a ROM (Read Only Memory) that stores an operation panel on which an input operation unit and an output display unit are arranged, a control program for controlling the operation of each unit, and the like. : Flash ROM), RAM (random access memory or hard disk) that temporarily stores various data, and various input / output devices are controlled.

  The roll placement unit 11 includes a support roller 111 and a support roller 112. Each of the support roller 111 and the support roller 112 has a cylindrical shape and is rotatably supported by the frame 10 a of the packaging device 10. The support roller 111 is linked to a support roller 112 as a driving roller by a timing belt, and is supported by the frame 10a so as to rotate in the same direction in conjunction with the rotation of the support roller 112. The sheet roll 100 is rotatably supported by a support roller 111 and a support roller 112, and a single strip-shaped film strip 101 is drawn upward from behind the support roller 112.

  The supply unit 12 includes a supply stand 121 on which the article to be packaged is placed, and a side plate 122 that regulates both side edges of the article to be packaged. The side of the article to be packaged placed on the supply stand 121 is regulated by the side plate 122 and sent to the packaging unit 13. In the present embodiment, the article to be packaged is manually sent to the packaging unit 13, but may be provided with an automatic supply mechanism. The supply unit 12 is configured to be detachable from the frame 10 a of the packaging device 10.

  The discharging unit 14 includes a discharging table 141 on which the package formed in the packing unit 13 is placed, and a holding member 142 that holds the discharging table 141 horizontally. The holding member 142 can be changed between a state of holding the paper discharge table 141 and a state of not holding the paper discharge table 141. When the holding member 142 does not hold the paper discharge table 141, the lower surface of the paper discharge table 141 is The frame 10a is folded so as to be in contact with the frame 10a.

  2 is a cross-sectional view taken along the line II-II in FIG. The packaging unit 13 includes a film folding member 21, a welding unit 30, a first conveyance unit 40, a fusing unit 50, and a second conveyance unit 60 in order from the front to the rear. The film folding member 21 folds the left and right side end portions of the film strip 101 and forms a folded portion in which the side end portions are overlapped. The welding unit 30 is bonded in the X direction by pressing the heated welding roller (welding member) 31 against the folded portion of the film strip 101 and melting the film strip 101 of the folded portion. . The 1st conveyance unit 40 conveys the film strip 101 by which the folding part was welded back, and sends it to the fusing unit 50. FIG. The fusing unit 50 uses the heated fusing member 51 to break and weld the film strip 101 on which the folded portion is welded in a direction (Y direction) perpendicular to the X direction, and the rear end portion and the front end portion are A sealed package is formed. The second transport unit 60 is configured to send the sealed package to the discharge unit 14.

  3A to 3O are schematic diagrams for explaining the operation of the packaging unit 13 excluding the film folding member 21. FIG. Hereinafter, the outline | summary of the action | operation of the packaging part 13 is demonstrated using FIG. 3A-FIG. 3O. FIGS. 3A to 3F are diagrams illustrating a preparatory operation before packaging an object to be packaged with the film strip 101, and FIGS. 3G to 3O illustrate a packaging operation of packaging the package with the film strip 101. FIGS. It is a drawing.

  As shown in FIG. 3A, the film strip 101 in which the side ends are overlapped by the film folding member 21 to form a folded portion is disposed on the transport surface 131 of the packaging portion 13.

  Next, as shown in FIG. 3B, the first driven roller 41 of the first transport unit 40 moves downward, and the film strip 101 is sandwiched between the first driven roller 41 and the first drive roller 42. Thereafter, in order to weld the folded portion, the welding roller 31 of the welding unit 30 moves downward and contacts the film strip 101. At the same time as the welding roller 31 welds the folded portion, the film strip 101 to which the folded portion is welded is sandwiched by the first driven roller 41 and the first drive roller 42 and conveyed backward.

  When the film strip 101 is transported backward by a certain amount, the driven roller 61 of the second transport unit 60 moves downward as shown in FIG. 3C, and the film strip 101 is separated from the second driven roller 61 and The first driven roller 41 is moved upward after being sandwiched by the second drive roller 62. The film strip 101 is sandwiched between the second driven roller 61 and the second drive roller 62 and conveyed backward.

  Next, when the welding of the folded portion is completed, as shown in FIG. 3D, the welding roller 31 moves upward, and the second driven roller 61 and the second drive roller 62 stop conveying the film strip 101. To do. Then, the fusing member 51 of the fusing unit 50 moves downward, fusing the film strip 101, and the rear end sealing portion of the film strip 101 is formed.

  Next, as shown in FIG. 3E, the fusing member 51 moves upward, and then, as shown in FIG. 3F, the second driven roller 61 and the second drive roller 62 are blown behind the film strip 101. The side portion (unnecessary film strip) is removed backward by conveying, and the second driven roller 61 moves upward. This completes the preparation before packaging an article to be wrapped with the film strip 101.

  Next, as shown in FIG. 3G, the package object 110 is inserted into the film strip 101. When the sensor 52 detects the object to be packaged 110, as shown in FIG. 3H, the first driven roller 41 moves downward, and the film strip 101 with the object to be packaged 110 inserted is the first It is sandwiched between the driven roller 41 and the first drive roller 42.

  Next, as shown in FIG. 3I, the welding roller 31 moves downward and contacts the film strip 101. At the same time as the welding roller 31 welds the folded portion, the film strip 101 into which the packaging body 110 is inserted and the folded portion is welded is sandwiched between the first driven roller 41 and the first drive roller 42 and is moved backward. Be transported.

  As shown in FIG. 3J, when the film strip 101 into which the article to be packaged 110 is inserted is fed backward by a certain amount, the second driven roller 61 moves downward as shown in FIG. The belt-like body 101 is sandwiched between the second driven roller 61 and the second drive roller 62, and then the first driven roller 41 moves upward. And the film strip 101 in which the package 110 was inserted is pinched by the 2nd driven roller 61 and the 2nd driving roller 62, and is conveyed back.

  Next, when the sensor 52 detects the front end portion of the article to be packaged 110, as shown in FIG. 3L, the film strip 101 into which the article to be packaged 110 is inserted has the second driven roller 61 and the second drive roller 62. Therefore, the front end portion of the article to be packaged 110 is positioned behind the fusing member 51. At the same time, the welding roller 31 moves upward.

  Next, as shown in FIG. 3M, the fusing member 51 moves downward to melt the film strip 101 into which the article to be packaged 110 is inserted, and the front end sealing portion of the film strip 101 is formed. . As a result, a package body in which the package object 110 is packaged with the film strip 101 is formed. At the same time, a rear end sealing portion of the film strip 101 into which the article to be packaged 110 is not inserted is also formed.

  Next, as shown in FIG. 3N, the package is sandwiched between the second driven roller 61 and the second drive roller 62 and conveyed backward. Then, as shown in FIG. 3O, the second driven roller 61 moves upward.

  Thereafter, the packaging body is formed by repeating the operations of FIGS. 3G to 3O.

  Hereinafter, the configuration of the welding unit 30 will be described more specifically.

  FIG. 4 is a perspective view of the welding unit 30. The welding unit 30 includes a welding roller 31 and a support member 32 that supports the welding roller 31. The support member 32 includes a first frame 321 and a second frame 322. The welding roller 31 is covered at its upper side and side by a welding roller support member 33, and the welding roller support member 33 is attached to the second frame 322.

  The first frame 321 is fixed to the frame 10a of the packaging device 10 at both ends 321a in the Y direction. A motor (drive means) 34 is attached to the upper portion of the first frame 321. The operation of the motor 34 is controlled by control means.

  5 is a front view showing the welding unit 30 with a part of the welding roller support member 33 removed in FIG. 4, and FIG. 6 is an enlarged view of the portion of the welding roller 31 in FIG. 7 is a cross-sectional view taken along the line VII-VII in FIG. 5, and FIG. 8 is a cross-sectional view taken along the line VIII-VIII in FIG. The motor 34 rotates the drive shaft 342 via the drive belt 341, and eccentric members 343 are attached to both ends of the drive shaft 342, respectively. The eccentric portion 343 a of the eccentric member 343 is connected to the Y-direction side portion of the second frame 322 via the connecting member 344. The first frame 321 has rails 321b formed on both sides in the Y direction, and the second frame 322 can move up and down along the rails 321b. As a result, when the motor 34 rotates and the drive shaft 342 rotates, the eccentric member 343 rotates, and the second frame 322 moves up and down along the rail 321b with respect to the first frame 321. Yes.

  As shown in FIG. 6, the welding roller 31 is fixed to the washer 35 with a screw. A spring (elastic member) 36 is provided on the top of the washer 35, and the shaft 351 through which the washer 35 and the spring 36 are inserted is fixed to the welding roller support member 33 at the upper and lower ends thereof. The upper end of the spring 36 is in contact with the welding roller support member 33, and the lower end of the spring 36 is in contact with the washer 35. Therefore, when the welding roller 31 moves toward the welding roller support member 33, the washer 35 also moves toward the welding roller support member 33, and the washer 35 compresses the spring 36.

  As shown in FIG. 5, a long hole 322a extending in the Y direction is formed in the second frame 322, and the welding roller support member 33 is fixed to the long hole 322a by a screw 322b. Yes. Therefore, the welding roller 31 and the washer 35 are supported by the second frame 322 via the spring 36 and the welding roller support member 33. Further, the welding roller support member 33 can move in the Y direction in the elongated hole 322a by loosening the screw 322b, and as a result, the welding roller 31 can move in the Y direction with respect to the second frame 322. It has become.

  A sensor (detection means) 37 is attached to the welding roller support member 33, and the sensor 37 detects the displacement of the movable piece 38. Specifically, the sensor 37 is an optical sensor and includes a light emitting unit and a light receiving unit. Then, when the movable piece 38 is displaced and the light emitted from the light emitting unit is blocked by the movable piece 38 and the light emitted from the light emitting unit cannot be received by the light receiving unit, the sensor 37 detects the displacement of the movable piece 38. Detect. The movable piece 38 is fixed to the washer 35. When the washer 35 compresses the spring 36 and is displaced upward, the movable piece 38 is displaced upward.

  When the sensor 37 detects the displacement of the movable piece 38, the control means rotates the motor 34 by a predetermined amount in the direction in which the second frame 322 descends.

  The welding roller 31 has a cylindrical shape, and a heater 311 is provided inside the welding roller 31 as shown in FIGS. 7 and 8. The heater 311 is heated by a current flowing through the heater wire 312. By heating the heater 311, the outer surface of the welding roller 31 is also heated to a temperature at which the film strip 101 is melted. On the outer surface of the welding roller 31, three convex portions 31 a having an enlarged outer diameter are formed, and each convex portion 31 a presses the folded portion of the film strip 101. That is, three welding lines are formed at the folded portion of the film strip 101.

  Hereinafter, an outline of an operation in which the control unit presses the welding roller 31 against the film strip 101 will be described.

  When the film strip 101 is welded by the welding roller 31 shown in FIG. 3B or FIG. 3I, the control means starts from the state where the welding roller 31 is separated from the film strip 101 to the film strip 101. The second frame 322 is lowered with respect to the first frame 321 by rotating the motor 34 until it is pressed with a predetermined pressure. When the second frame 322 is lowered, the welding roller 31 supported by the welding roller support member 33 is also lowered together with the welding roller support member 33 fixed to the second frame 322.

  When the convex portion 31 a of the welding roller 31 comes into contact with the film strip 101, the welding roller 31 receives an upward reaction force from the film strip 101, and as a result, the washer 35 fixed to the welding roller 31 compresses the spring 36. Let When the washer 35 compresses the spring 36, the movable piece 38 is displaced upward, and the sensor 37 detects the displacement of the movable piece 38. Therefore, after the welding roller 31 comes into contact with the film strip 101, the spring 36 is slightly compressed (first stage compression) until the sensor 37 detects the displacement of the movable piece 38. Here, since the displacement distance of the movable piece 38 to be detected by the sensor 37 is constant, the compression amount (first step compression amount) in the first step compression of the spring 36 is the thickness of the film strip 101. Regardless, it is constant.

  When the sensor 37 detects the displacement of the movable piece 38, the control means recognizes that the welding roller 31 has contacted the film strip 101, and further rotates the motor 34 by a predetermined amount from this state. Then, as the motor 34 rotates by a predetermined amount, the second frame 322 is further lowered by a predetermined distance. Here, before the motor 34 is rotated by a predetermined amount, the welding roller 31 has already been in contact with the film strip 101. From this state, the second frame 322 is lowered by a predetermined distance, so that the spring 36 is In addition to the one-stage compression, the predetermined distance is further compressed (second-stage compression). Here, since the descending distance of the second frame 322 is constant, the compression amount (second step compression amount) in the second step compression of the spring 36 is constant regardless of the thickness of the film strip 101. Yes. As a result, the welding roller 31 presses the film strip 101 by the reaction force of the spring 36 compressed by the total compression amount of the first step compression amount and the second step compression amount.

  According to the packaging device 10 configured as described above, the following effects can be exhibited.

(1) After the sensor 37 detects that the welding roller 31 has contacted the film strip 101, the control means rotates the motor 34 and lowers the second frame by a predetermined distance. Therefore, the spring 36 is caused by the lowering of the predetermined distance of the second frame 322 in addition to the first stage compression until the sensor 37 detects the displacement of the movable piece 38 after the welding roller 31 contacts the film strip 101. Only the second stage compression is further compressed. Here, the first-stage compression amount and the second-stage compression amount of the spring 36 are respectively constant. As a result, the welding roller 31 presses the film strip 101 by the reaction force of the spring 36 compressed by a certain amount, and the welding roller 31 can apply a constant pressing force to the film strip 101 with a simple configuration. . Since the first stage compression amount is usually a small amount and a constant amount, the pressing force with which the welding roller 31 presses the film strip 101 is normally managed by the second stage compression amount. In addition, since the spring 36 is compressed in two stages by the first stage compression and the second stage compression, characteristics other than the thickness of the film strip 101 (for example, melting characteristics resulting from the stretching ratio). Etc.) can be adjusted by the second-stage compression amount, which is the second stage, on the pressing force with which the welding roller 31 presses the film strip 101.

(2) The sensor 37 does not directly detect that the welding roller 31 is in contact with the film strip 101, but detects that the welding roller 31 is in contact with the film strip 101 via the movable piece 38. It can prevent receiving the heat influence of the welding roller 31 which is high temperature.

(3) Since the welding roller support member 33 and the members attached to the welding roller support member 33 (the welding roller 31, the washer 35, the spring 36, the sensor 37, and the movable piece 38) are all attached to the second frame 322, When replacing the welding roller 31 that is a replacement part, the welding roller support member 33 or the entire second frame 322 to which the welding roller support member 33 is attached can be replaced as a unit. Easy and possible. Further, by exchanging the welding roller support member 33 or the entire second frame 322, the position adjustment of each member with respect to the welding roller 31 can be made unnecessary.

(4) Since the welding roller 31 is movable in the Y direction, the welding roller 31 can be moved to an appropriate welding site (the folding portion of the film strip 101) of the film strip 101. In the above embodiment, since the welding roller support member 33 that supports the welding roller 31 is movable in the Y direction, members attached to the welding roller support member 33 (welding roller 31, washer 35, spring) 36, the sensor 37, and the movable piece 38) can be moved together in the Y direction. Therefore, when the welding roller 31 is moved to an appropriate welding position of the film strip 101, the position adjustment of each member with respect to the welding roller 31 can be made unnecessary.

  In the above embodiment, the sensor 37 indirectly detects that the welding roller 31 has come into contact with the film strip 101 due to the displacement of the movable piece 38. For example, a sensor that directly detects contact with 101, for example, a sensor that is directly attached to the welding roller 31 may be used.

  In the above embodiment, the welding roller support member 33 can be moved in the Y direction within the elongated hole 322a by loosening the screw 322b, but the control means automatically moves the welding roller support member 33 in the Y direction. You may be allowed to.

  In the above embodiment, the three convex portions 31a are formed on the welding roller 31, but the number of convex portions is not limited to three, and one or more convex portions may be formed. In addition, it is preferable that two or more convex portions are formed.

  In the above embodiment, the folded portion of the film strip 101 is formed in the horizontal direction, and the welding roller 31 is pressed from the upper side to the lower side with respect to the folded portion. It is also possible to apply to a configuration in which the mating portion is formed in the vertical direction and the welding roller is pressed from the side against the folding portion.

  The present invention is not limited to the configuration described in the above embodiment, and can include various modifications that can be considered by those skilled in the art without departing from the content described in the claims.

  In the present invention, since the welding member can provide a welding unit that can apply a certain pressing force to the member to be welded with a simple configuration, and a packaging device including the welding unit, the industrial utility value is great.

DESCRIPTION OF SYMBOLS 10 Packaging apparatus 10a Frame 11 Roll mounting part 111 Support roller 112 Support roller 12 Supply part 121 Supply stand 122 Side plate 13 Packaging part 131 Conveying surface 14 Discharge part 141 Discharge base 142 Holding member 21 Film folding member 30 Welding unit 31 Welding roller 31a Convex portion 311 Heater 312 Heater wire 32 Support member 321 First frame 321a Both ends 321b Rail 322 Second frame 322a Long hole 322b Screw 33 Fusing roller support member 34 Motor 341 Drive belt 342 Drive shaft 343 Eccentric member 343a Eccentric member 344 35 Washer 36 Spring 37 Sensor 38 Movable piece 40 First transport unit 41 First driven roller 42 First drive roller 50 Fusing unit 51 Fusing member 60 Second transport unit 61 Second driven b La 62 second drive roller 101 film strip 110 to be packaged 900 package 91 to be packaged 92 film strip 92a forward sealing portion 92b rear sealing portion
92c One side end 92d The other side end 92e Folding part 92f Vertical seal part

Claims (5)

A welding member for thermally welding the welding member;
A supporting member for supporting the welding member via an elastic member;
Detecting means for detecting that the welding member is in contact with the welding member;
Driving means for moving the support member so that the welding member moves in a direction in which the welding member comes in contact with and separates from the welding member;
Control means for controlling the operation of the drive means,
When the detecting means detects that the welding member contacts the welding member, the control means moves the support member toward the welding member by a predetermined distance regardless of the thickness of the welding member. The welding unit is controlled so as to press the member to be welded. A movable piece that is displaced when the welding member contacts the member to be welded;
The welding unit according to claim 1, wherein the detection unit detects that the welding member is in contact with the member to be welded by detecting a displacement of the movable piece. The support member includes a first frame and a second frame,
The driving means is attached to the first frame,
The elastic member and the detection means are attached to the second frame,
The welding unit according to claim 1 or 2, wherein the second frame is moved with respect to the first frame by the driving means.   The welding unit according to claim 3, wherein the welding member is movable with respect to the second frame in a direction orthogonal to a conveyance direction of the welding member.   A packaging device comprising the welding unit according to any one of claims 1 to 4.

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