Bag opening machine

Abstract

To provide a bag opening machine that can open bags properly.SOLUTION: A bag opening machine 1 includes: a cassette 10 for setting multiple bags F; a pair of first suction pads 20 that reciprocate between a first suction position, which is the position that sucks the set bags F, and a first holding position, which is the position that holds the bag F in an opened state after sucking one surface side; and a second suction pad 30 that reciprocates between a retracted position, which is a position deviated from the movement path of each first suction pad 20 in accordance with the movement of each first suction pad 20; and a second holding position, which is the position that holds the bag F in an opened state after sucking the other surface side. During the time each first suction pad 20 moves the bag F from the first suction position to the first holding position, the second suction pad 30 sucks the other surface side of the upper edge portion of the bag F while pinching the upper edge portion of the bag F between it and each first suction pad 20, and each first suction pad 20 is separated from the second suction pad 30, thereby opening the opening part of the bag F.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a bag opening machine. [Background technology]

[0002] Patent Document 1 discloses a conventional bag opening machine. This bag opening machine includes a first suction pad and a second suction pad. The first suction pad adheres to one side of a bag near the opening when the bag is folded flat and placed face down, and then gradually changes its orientation to horizontal as it moves upward. This causes the bag to move upward while being raised so that the opening is facing upward. The second suction pad moves upward together with the first suction pad, sandwiching the area near the opening of the bag between itself and the horizontally oriented first suction pad, and adheres to the other side near the opening of the bag. Then, the first and second suction pads rise while maintaining the same height, and the second suction pad gradually moves away from the first suction pad. This allows the bag opening machine to open the opening of the bag. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2023-144739 Summary of the Invention [Problem to be solved by the invention]

[0004] The first suction pad of the bag opening machine in Patent Document 1 faces downward when adsorbing a bag placed flat, and faces horizontally so as to face the second suction pad when it and the second suction pad clamp the bag near the opening. Because this bag opening machine changes the orientation of the first suction pad while lifting the first suction pad while adsorbing the bag, there is a risk that the bag may fall off while the first suction pad is being lifted. Furthermore, if the orientation or angle of the first suction pad is misaligned when adsorbing a bag placed flat, or if the orientation or angle of the first suction pad is misaligned when facing the second suction pad, there is a risk that the first suction pad or second suction pad may not be able to properly adsorb the bag.

[0005] The present invention has been made in consideration of the above-mentioned conventional circumstances, and an object to be achieved is to provide a bag opening machine that can open the opening of a bag well. [Means for solving the problem]

[0006] The bag opening machine of the present invention comprises: a cassette into which a plurality of flattened bags are set with their openings facing upward; a first suction unit that reciprocates horizontally between a first suction position and a first holding position; a second suction unit that reciprocates between a retracted position and a second holding position in association with the movement of the first suction unit so as not to interfere with the movement of the first suction unit; It is equipped with the first suction position is a position where one side of an upper edge of the bag that is folded flat and set in the cassette is suctioned; the first holding position is a position where the bag is held in an open state by suction on one side of the upper edge portion, the retreated position is a position that is out of the movement path of the first suction unit, the second holding position is a position facing the first suction portion and holding the other surface side of the upper edge of the bag in a suction state, As the first suction portion suctions one side of the upper edge of the bag and moves from the first suction position to the first holding position, the second suction portion, which moves from the retracted position to the second holding position, suctions the other side of the upper edge of the bag, sandwiching the upper edge of the bag between itself and the first suction portion, and the opening of the bag opens as the first suction portion moves away from the second suction portion.

[0007] Because the first suction unit of this bag opening machine only moves back and forth horizontally between the first suction position and the first holding position, the orientation and angle of the first suction unit are always constant. Therefore, the first suction unit can reliably suction one side of the upper edge of a bag folded flat at the first suction position. Furthermore, this bag opening machine can properly clamp the upper edge of the bag between the first suction unit and the second suction unit, and the second suction unit can reliably suction the other side of the upper edge of the bag. Thus, when the first suction unit suctions one side of the upper edge of the bag and when the upper edge of the bag is clamped between the first suction unit and the second suction unit, the orientation and angle of the first suction unit do not shift, and the first and second suction units can reliably suction the upper edge of the bag to open the opening of the bag.

[0008] Therefore, the bag opening machine of the present invention can open the opening of the bag well. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view showing a bag opening machine of a first embodiment. [Figure 2] 1 is a front view showing a bag opening machine of Example 1. FIG. [Figure 3] 1 is a front view showing the bag opening device of Example 1 with the insertion unit removed. FIG. [Figure 4] FIG. 1 is a plan view showing a bag opening machine of a first embodiment. [Figure 5] FIG. 2 is a bottom view showing the main parts of the bag opening machine of the first embodiment. [Figure 6] FIG. 2 is a rear view showing the main parts of the bag opening machine of the first embodiment. [Figure 7]1 is a front view showing a state in which a first suction section of the bag opening device of the first embodiment is in the middle of moving from a first holding position to a first suction position. FIG. [Figure 8] 1 is a bottom view showing the main parts of the bag opening device of the first embodiment in a state in which the first suction unit is in the middle of moving from the first holding position to the first suction position. FIG. [Figure 9] 1 is a rear view showing the main parts of the bag opening device of the first embodiment in a state in which the first suction unit is in the middle of moving from the first holding position to the first suction position. FIG. [Figure 10] 10 is a bottom view showing a state in which the convex portion of the moving unit main body of the bag opening device of Example 1 passes in front of the front end corner portion of the protruding portion of the support plate. FIG. [Figure 11] 1 is a front view showing a state in which each first suction pad of the bag opening device of the first embodiment is sucking a bag at a first suction position. FIG. [Figure 12] 1 is a bottom view showing a state in which the support part of the bag opening machine of Example 1 supports the insertion part located in the raised position. FIG. [Figure 13] 1 is a rear view showing a state in which the support part of the bag opening machine of Example 1 supports the insertion part located in the raised position. FIG. [Figure 14] 1 is a front view showing a state in which the upper edge of a bag is sandwiched between each of the first suction pads and the second suction pads of the bag opening device of the first embodiment. FIG. [Figure 15] This is a bottom view showing the main parts of the bag opening machine of Example 1, with the upper part of the bag sandwiched between each of the first and second suction pads. [Figure 16] 1 is a front view showing a state in which the bag opening machine of Example 1 has opened the opening of the bag. [Figure 17] 1 is a bottom view showing the main parts of the bag opening machine of the first embodiment when the bag opening device has opened the opening of the bag. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0010] A preferred embodiment of the present invention will now be described.

[0011] The second suction unit of the bag opening machine of the present invention can move back and forth on an arc centered on a horizontal axis perpendicular to the movement path of the first suction unit. In this case, the space above the movement path of the first suction unit can be used for the movement path of the second suction unit, thereby making the bag opening machine more compact.

[0012] The bag opening machine of the present invention may include a moving unit that moves together with the first suction unit, a drive unit that moves the moving unit, and a linking unit that moves the second suction unit in linkage with the movement of the moving unit. In this case, the bag opening machine can reciprocate the first suction unit and the second suction unit using a single drive unit.

[0013] The moving unit of the bag opening machine of the present invention may support and push up the interlocking unit while moving the first suction unit from the first holding position to the first suction position, thereby positioning the second suction unit at the retracted position, and may stop supporting the interlocking unit while moving the first suction unit from the first suction position to the first holding position, thereby positioning the second suction unit at the second holding position. In this case, when moving the second suction unit from the second holding position to the retracted position, the bag opening machine pushes up the second suction unit together with the interlocking unit by the driving force of the drive unit. That is, in this bag opening machine, the second suction unit moves from the second holding position to the retracted position by the driving force of the drive unit. On the other hand, in this bag opening machine, when moving the second suction unit from the retracted position to the suction position, the moving unit is moved to a position where it does not support the interlocking unit by the driving force of the drive unit, and the interlocking unit and the second suction unit descend by gravity and move to the suction position. This allows the bag opening machine to reduce the power required for the drive unit.

[0014] The moving section of the bag opening machine of the present invention may have an inclined surface that slopes from the top to the bottom, from the first holding position side of the first suction section to the first suction position side, and the interlocking section may have a contact section that moves while making contact with the inclined surface. In this case, the bag opening machine can smoothly raise and lower the second suction section in conjunction with the moving section, because the contact section of the interlocking section moves while making contact with the inclined surface of the moving section. Furthermore, by changing the inclination angle of the inclined surface, the bag opening machine can adjust the movement speed of the second suction section relative to the first suction section, and the second suction section can sandwich the upper edge of the bag between itself and the first suction section to effectively suction the other side of the upper edge of the bag.

[0015] The bag opening machine of the present invention is equipped with an insertion unit that has a tubular portion that forms an insertion port and moves up and down between an insertion position and a raised position to insert the packaged item into the bag, the insertion position being a position where the tubular portion is inserted into the bag from the upper end of the bag with the opening opened, and the raised position being a position that does not interfere with the movement of the first suction unit. In this case, the bag opening machine moves so as not to interfere with the movement of the first suction unit, and the tubular portion of the insertion unit can be smoothly inserted into the bag from the opening of the opened bag.

[0016] The feeding section of the bag opening machine of the present invention can start rising from the feeding position toward the raised position when the first suction section starts moving from the first holding position to the first suction position, and can descend from the raised position to the feeding position while the first suction section moves to the first holding position after the second suction section moves from the retracted position to the second holding position. In this case, the bag opening machine can insert the tubular section of the feeding section into the bag while opening the opening of the bag, thereby shortening the cycle time.

[0017] The bag opening machine of the present invention may include a moving unit that moves together with the first suction unit, and a support unit that moves in conjunction with the movement of the moving unit and supports the input unit positioned in the raised position. In this case, the bag opening machine can have the support unit support the input unit in the raised position or not support it in accordance with the movement of the first suction unit, which is moved by the drive unit. In other words, the support unit also moves back and forth between a position where it supports the input unit and a position where it does not support it, due to the driving force of the drive unit.

[0018] Example 1 Next, a first embodiment of the bag opening machine of the present invention will be described with reference to the drawings. In the following description, the up-down direction refers to the up-down direction when the bag opening machine 1 is installed on a horizontal surface. The left-right direction refers to the direction in which the pair of first suction pads 20 move back and forth when the bag opening machine 1 is installed on a horizontal surface, with the direction from the first holding position to the first suction position being the leftward direction and the opposite direction being the rightward direction. The front-rear direction refers to the direction from the moving unit 50 to each first suction pad 20 in a plan view when the bag opening machine 1 is installed on a horizontal surface, with the direction opposite being the rearward direction. In each drawing, the positive direction of the X axis shown in the drawing is the leftward direction, the negative direction of the X axis is the rightward direction, the positive direction of the Y axis is the forward direction, the negative side of the Y axis is the rearward direction, the positive direction of the Z axis is the upward direction, and the negative direction of the Z axis is the downward direction.

[0019] As shown in FIGS. 1 to 4, the bag opening machine 1 of the first embodiment includes a cassette 10, a pair of first suction pads 20, one second suction pad 30, a drive unit 40, a moving unit 50, a first interlocking unit 60, an insertion unit 70, and a support unit 80. The pair of first suction pads 20 correspond to the first suction unit. The second suction pad 30 corresponds to the second suction unit. The bag opening machine 1 is placed on a base plate 3 with its upper surface horizontally disposed. The base plate 3 is flat. In a plan view, the base plate 3 has a rectangular shape that is long in the left-right direction. The base plate 3 has five legs 3A protruding downward from the four corners and the center of its underside. Each leg 3A is frustoconical, with its diameter decreasing downward. The bag opening machine 1 opens the opening of a bag F for packaging food or the like.

[0020] <Configuration of Cassette 10> The cassette 10 can hold a plurality of bags F folded flat with the opening facing upward. The bags F are made of a material such as resin film or paper that can be adsorbed by a pair of first suction pads 20 and one second suction pad 30, which will be described later. The cassette 10 is disposed on the base plate 3 at the left end of the front side. The cassette 10 has a cassette body 11, a pair of legs 13, a first adjustment dial 15, and a second adjustment dial 17.

[0021] The cassette body 11 includes a main plate 110, a pair of side plates 112, an upper plate 114, a lower plate (not shown), a pair of first guide portions 116, and a second guide portion 118. The cassette body 11 is formed into a substantially rectangular parallelepiped shape by the main plate 110, the pair of side plates 112, the upper plate 114, and the lower plate, with one side (the left side when the cassette 10 is placed on the base plate 3) open. The main plate 110 is flat. The main plate 110 is rectangular and long in one direction (the up-down direction when the cassette 10 is placed on the base plate 3). Each side plate 112 is flat. Each side plate 112 is continuous with the respective long sides of the main plate 110. Each side plate 112 is strip-shaped and long in one direction, extending from one end to the other end of the long sides of the main plate 110. The upper plate 114 is flat. The upper plate 114 is continuous with one end edge (the upper end edge when the cassette 10 is placed on the base plate 3) of the main plate 110 and the pair of side plates 112. The upper plate 114 is rectangular in shape and is long in the direction of the short side of the main plate 110. The upper plate 114 forms an eave portion 114A that protrudes and widens beyond the surface of the main plate 110. The lower plate is flat. The lower plate is continuous with the other end edges (the lower end edges when the cassette 10 is placed on the base plate 3) of the main plate 110 and the pair of side plates 112. The lower plate is rectangular in shape and is long in the direction of the short side of the main plate 110.

[0022] The main plate 110 has a pair of first openings 110A and one second opening 110B. The pair of first openings 110A are formed at one end side of the main plate 110 (the upper end side when the cassette 10 is placed on the base plate 3) and are spaced apart in the short-side direction of the main plate 110. The pair of first openings 110A are symmetrical with respect to a center line in the short-side direction of the main plate 110. Each of the first openings 110A has the same shape and is a rectangle that is long in the short-side direction of the main plate 110. The longitudinal direction of each first opening 110A is parallel to the direction in which the short side of the main plate 110 extends. The second opening 110B is located in the center of the short-side direction of the main plate 110 and extends from the other end of the main plate 110 toward one end (from the lower end toward the upper end when the cassette 10 is placed on the base plate 3). The second opening 110B has a rectangular shape that is long in the long-side direction of the main plate 110. The longitudinal direction of the second opening 110B is parallel to the direction in which the long sides of the main plate 110 extend. The cassette body 11 is fixed to the base plate 3 via legs 13 so that the surface of the main plate 110 is inclined slightly diagonally upward to the right from the horizontal. The cassette body 11 is also fixed to the base plate 3 so that the short sides of the main plate 110 are parallel to the short sides of the base plate 3. The surface of the main plate 110 faces directly opposite the suction surfaces of a pair of first suction pads 20, which will be described later.

[0023] Each first guide portion 116 has a clamping portion 116A, a first extending portion 116B, and a first pressing portion 116C. The clamping portion 116A of each first guide portion 116 is flat. Each clamping portion 116A protrudes from the front surface of the main plate 110 in a direction perpendicular to the front surface of the main plate 110. Each clamping portion 116A is rectangular and elongated in the long side direction of the main plate 110. The pair of clamping portions 116A are arranged parallel to the long side of the main plate 110 on the front surface side of the main plate 110. A bag F to be set in the cassette 10 is placed between the clamping portions 116A of the pair of first guide portions 116. Each clamping portion 116A has three through holes 116H formed therein, spaced at equal intervals along the long side.

[0024] The first extending portion 116B of each first guide portion 116 is flat. Each first extending portion 116B is continuous with the center of the long side of each clamping portion 116A extending toward the main plate 110. Each first extending portion 116B passes through each first opening 110A formed in the main plate 110 and extends toward the back surface side of the main plate 110. The width of each first extending portion 116B is slightly smaller than the width of the first opening 110A in the short direction. Each first extending portion 116B is connected to a first rotating shaft member (not shown) connected to the first adjustment dial 15 on the back surface side of the main plate 110. When an operator of the bag opening machine 1 (hereinafter referred to as "the operator") rotates the first adjustment dial 15, each first extension portion 116B moves symmetrically in the short side direction of the main plate 110 along the first opening 110A formed in the main plate 110, symmetrically about the center line in the short side direction of the main plate 110. In other words, in the bag opening machine 1, the operator rotates the first adjustment dial 15 in accordance with the width of the bag F to be set in the cassette 10, and adjusts the spacing between the clamping portions 116A continuous with each first extension portion 116B to the width of the bag F.

[0025] The first pressing portion 116C of each first guide portion 116 has a first piece 116M and a second piece 116N formed by bending the approximate center of the longitudinal direction of a rectangular flat plate at a right angle. Each first pressing portion 116C secures the first piece 116M to the clamping portion 116A using a bolt passing through one of three through holes 116H formed in the clamping portion 116A. The second piece 116N of each first pressing portion 116C extends inward from the long side of the clamping portion 116A that is farther from the surface of the main plate 110. The second piece 116N of each first pressing portion 116C is farther from the surface of the main plate 110 and is parallel to the surface of the main plate 110. The distance between the second piece 116N of each first pressing portion 116C and the surface of the main plate 110 is approximately equal to the protruding length of the eave portion 114A formed by the upper plate 114. The second pieces 116N of each first pressing portion 116C press down on both upper ends of the set bag F, preventing the upper end of the bag F from separating from the main plate 110. The through-hole 116H used to secure the first pieces 116M to the clamping portion 116A is selected according to the size of the bag F to be set in the cassette 10. In other words, each first pressing portion 116C selects a through-hole 116H according to the length of the bag F, and changes the position at which it is secured to the clamping portion 116A.

[0026] The second guide portion 118 has a placing portion 118A and a second extending portion (not shown). The placing portion 118A has a placing portion 118M and a second pressing portion 118N formed by bending approximately the center of the short side of a rectangular flat plate at a right angle. The placing portion 118M protrudes from the front surface of the main plate 110 in a direction perpendicular to the surface of the main plate 110. The placing portion 118M has a rectangular shape that is long in the short side direction of the main plate 110. The placing portion 118M extends parallel to the short side of the main plate 110. A bag F to be set in the cassette 10 is placed on the placing portion 118M and arranged between the placing portion 118M and the upper plate 114. The second pressing portion 118N is spaced apart from the surface of the main plate 110 and parallel to the surface of the main plate 110. The second pressing portion 118N has a rectangular shape that is long in the short side direction of the main plate 110. The distance between the second pressing portion 118N and the surface of the main plate 110 is approximately the same as the distance between the first pressing portion 116C and the surface of the main plate 110.

[0027] The second extension portion of the second guide member 118 is flat. The second extension portion is continuous with the center of the long side of the loading portion 118M that extends toward the main plate 110. The second extension portion passes through a second opening 110B formed in the main plate 110 and extends to the rear surface of the main plate 110. The width of the second extension portion is slightly smaller than the width of the second opening 110B in the short direction. The second extension portion is connected to a second rotating shaft member (not shown) that is connected to a second adjustment dial 17 on the rear surface of the main plate 110. When the operator rotates the second adjustment dial 17, the second extension portion moves along the long side of the main plate 110 along the second opening 110B formed in the main plate 110. In other words, the operator rotates the second adjustment dial 17 to adjust the height of the loading portion 118A that is continuous with the second extension portion in accordance with the length of the bags F to be set in the cassette 10. Regardless of the length of the bag F, the bag opening machine 1 ensures that the upper edge of the bag F set in the cassette 10 is in contact with the underside of the eave portion 114A or is positioned slightly below the underside of the eave portion 114A.

[0028] Each leg 13 has a first connecting portion 13A and a second connecting portion 13B formed by bending a flat plate at a right angle. Each first connecting portion 13A is flat. Each first connecting portion 13A is rectangular and long in one direction. Each first connecting portion 13A has a pair of elongated holes 13H formed at both ends of the long side direction and extending parallel to the long side direction. Each first connecting portion 13A is fixed to the base plate 3 by bolts (not shown) that pass through the elongated holes 13H.

[0029] Each second connecting portion 13B is continuous with the center of the long side of each first connecting portion 13A. When each first connecting portion 13A is fixed to the base plate 3, each second connecting portion 13B rises vertically from the base plate 3. Each second connecting portion 13B is connected to the other end of the side plate 112 of the cassette body 11 (the lower end when the cassette 10 is placed on the base plate 3). In other words, the bag opening device 1 fixes the cassette body 11 to the base plate 3 by each leg 13. More specifically, the cassette body 11 is fixed to the base plate 3 with the surface of the main plate 110 tilted slightly upward and to the right from the horizontal. This allows the bags F placed in the cassette 10 to be positioned so that they do not easily come off the surface of the main plate 110. The bag opening machine 1 can adjust the longitudinal fixing position of the base plate 3 of the cassette body 11 according to the size of the bag F to be set in the cassette 10 by using the long holes 13H formed in the first connecting portion 13A of each leg portion 13.

[0030] <Configuration of the first suction pad 20> Each first suction pad 20 includes a pad body P1, a first pipe P2, a second pipe P3, and a suction hose P4. The pad body P1 is made of silicone rubber. The suction surface of the pad body P1 is circular. The pad body P1 is connected to the tip of the first pipe P2. The rear end of the first pipe P2 is inserted into the tip of the second pipe P3 and connected. The pad body P1 and the first pipe P2 can move forward and backward along the central axis relative to the second pipe P3. The elastic force of a spring member (not shown) acts on the first pipe P2 in a direction that causes it to protrude from the tip of the second pipe P3. The pad body P1 can move forward and backward along the central axis relative to the second pipe P3, and because the elastic force of the spring member acts in the protruding direction, it can move forward and backward appropriately when suctioning a bag F, etc. The rear end of the second pipe P3 is connected to one end of the suction hose P4. The other end of the suction hose P4 is connected to a vacuum pump.

[0031] The pair of first suction pads 20 are held at the front end of the first bar member B1. The rear end of the first bar member B1 is connected to the front surface of a moving unit main body 51 of the moving unit 50 (described later). The first bar member B1 extends horizontally forward from the moving unit 50. The first bar member B1 holds the second tube portions P3 of the pair of first suction pads 20 at its front end, aligned in the front-rear direction. The circular suction surfaces of the pad main bodies P1 of each first suction pad 20 are aligned in the front-rear direction with almost no gaps between them. Each first suction pad 20 held by the first bar member B1 faces diagonally downward to the left. The center lines of each first suction pad 20 held by the first bar member B1 extend parallel to each other. An imaginary center line L, equidistant from the center lines of each first suction pad 20, extends in the left-right direction in a plan view, as shown in FIG. 4. The imaginary center line L passes through the center of the short side of the cassette main body 11 in a plan view. The suction surfaces of the pad bodies P1 of the first suction pads 20 held by the first bar member B1 are located on the same imaginary plane parallel to the surface of the main plate 110 of the cassette body 11 of the cassette 10 placed on the base plate 3. In other words, the suction surfaces of the pad bodies P1 of the first suction pads 20 and the surface of the main plate 110 of the cassette body 11 are located parallel to each other. The suction surfaces of the pad bodies P1 of the first suction pads 20 held by the first bar member B1 are at a height that allows each first suction pad 20 to suction the upper part of a bag F set in the cassette 10 when it moves to the first suction position. When suctioning the upper edge of a bag F set in the cassette 10, the pad bodies P1 of each first suction pad 20 move forward and backward in the central axial direction relative to the second pipe portion P3 depending on, for example, the number of bags F set. Therefore, the pair of first suction pads 20 can effectively suction one side of the upper edge of the bag F.

[0032] <Configuration of second suction pad 30> The second suction pad 30 has the same structure as the first suction pad 20 and includes a pad body P1, a first pipe P2, a second pipe P3, and a suction hose P4. The second suction pad 30 is held by the front end of the second bar member B2. The rear end of the second bar member B2 is connected to the front surface of the second arm intermediate portion 64C of the first interlocking portion 60 (described later). The second bar member B2 extends horizontally forward from the first interlocking portion 60. The center line of the second suction pad 30 held by the second bar member B2 extends along the imaginary center line L in a plan view, as shown in FIG. 4 . The pad body P1 of the second suction pad 30 moves forward and backward along the central axis relative to the second pipe P3 when the upper edge of the bag F is sandwiched between the pad bodies P1 of the pair of first suction pads 20 and adsorbed. This allows the second suction pad 30 to effectively adsorb the other side of the upper edge of the bag F.

[0033] The second suction pad 30 held by the second bar member B2 faces diagonally upward to the right in the second holding position. The suction surface of the pad body P1 of the second suction pad 30 in the second holding position is located on an imaginary plane parallel to the surface of the main plate 110 of the cassette body 11 of the cassette 10 placed on the base plate 3. The position of the suction surface of the pad body P1 of the second suction pad 30 in the second holding position is slightly lower than the position of the tip surface of the pad body P1 of each first suction pad 20 held by the first bar member B1. In a front view, the suction surface of the pad body P1 of the second suction pad 30 in the second holding position and the suction surface of the pad body P1 of each first suction pad 20 held by the first bar member B1 overlap in the height direction.

[0034] <Configuration of the Moving Mechanism of Each First Suction Pad 20> The movement mechanism for each first suction pad 20 is composed of a drive unit 40 and a movement unit 50. The drive unit 40 is a linear actuator. The drive unit 40 is fixed to the front surface of a flat crossbar 5 extending in the left-right direction above the rear end of the base plate 3. The crossbar 5 connects the upper ends of a pair of support members 7 rising from both the left and right ends of the rear end of the base plate 3. The crossbar 5 is flat. A plurality of holes 5H are formed at equal intervals within a predetermined area on the top surface of the crossbar 5 (see FIG. 4). The multiple holes 5H formed on the top surface of the crossbar 5 are used to secure the pivot support unit 61 of the first interlocking unit 60 (described later). The drive unit 40 has a fixed main body 41 extending horizontally in the left-right direction and a movable unit (not shown) that moves linearly in the left-right direction relative to the main body 41. The right end of the main body 41 of the drive unit 40 is located slightly to the right of the right end of the crossbar 5. 2, the left end of the main body 41 of the drive unit 40 is located to the right of the left end of the cross bar 5 in a front view and overlaps with the upper end of the cassette 10 placed on the base plate 3. The movable unit is driven by air pressure.

[0035] The moving unit 50 is flat. The moving unit 50 is connected to the movable part of the drive unit 40 on its rear side and is freely movable back and forth horizontally in front of the drive unit 40. In other words, the drive unit 40 moves the moving unit 50 back and forth horizontally. The moving unit 50 has a moving unit main body 51 and a protruding part 52. As shown in FIG. 2, the moving unit main body 51 is trapezoidal in shape with its left side inclined leftward from its top to its bottom when viewed from the front. When viewed from the front, the left side of the lower end of the outer periphery of the moving unit main body 51 is cut out in the shape of a horizontally elongated rectangle. The moving unit main body 51 has a rectangular opening 51A that is long in the left-right direction and penetrates in the front-to-back direction on its upper left side. The moving unit main body 51 has a rectangular opening 51B that is long in the up-down direction and penetrates in the front-to-back direction on its right side.

[0036] As shown in FIGS. 1 and 2 , the left side surface 53 of the moving unit main body 51 is an inclined surface S that slopes from the first holding position of the first suction pad 20 to the first suction position, i.e., leftward, from its upper end to its lower end. The upper side surface 54 of the moving unit main body 51 is a horizontal surface that continues from the upper end of the left side surface 53 and extends horizontally. The right side surface 55 of the moving unit main body 51 is a vertical surface that continues from the upper side surface 54 and extends vertically. The lower surface 56 of the moving unit main body 51 includes a right lower surface 56A and a left lower surface 56B, with the center in the left-right direction as the boundary. The right lower surface 56A of the moving unit main body 51 is one step lower than the left lower surface 56B. The left lower surface 56B of the moving unit main body 51 is a horizontal surface that continues from the lower end of the left side surface 53 and extends horizontally. The right lower surface 56A of the moving unit main body 51 is a horizontal surface extending horizontally, with its right end continuing to the lower end of the right side surface 55. The right end of the left lower surface 56B of the moving unit main body 51 and the left end of the right lower surface 56A are connected by a vertical surface extending vertically. The rear end of the first bar member B1 is connected to approximately the center of the front surface of the moving unit main body 51.

[0037] The protrusion 52 is continuous with the lower right surface of the moving unit main body 51 and protrudes downward. The protrusion 52 is provided continuous with the right side of the lower right surface of the moving unit main body 51. When viewed from the front, the protrusion 52 has a rectangular shape that is long in the left-right direction, as shown in FIG. 2. The thickness of the protrusion 52 is slightly thinner than the thickness of the moving unit main body 51. When viewed from the bottom, as shown in FIG. 4, the protrusion 52 is curved so that both front and rear ends on both the left and right sides bulge outward. The vertical length of the protrusion 52 is slightly smaller than the step between the left lower surface 56B and the right lower surface 56A of the moving unit main body 51. The horizontal length of the protrusion 52 is approximately half the horizontal length of the lower right surface 56A of the moving unit main body 51.

[0038] <Movement of the first suction pad 20> The pair of first suction pads 20 are held by the front end of a first bar member B1, the rear end of which is connected to the front surface of the moving unit main body 51. Therefore, the pair of first suction pads 20 move back and forth horizontally left and right as the moving unit 50 moves back and forth left and right. The first holding position is the state in which the pair of first suction pads 20 are located at the rightmost position during the left and right reciprocating movement of the moving unit 50. The suction position is the state in which each first suction pad 20 is located at the leftmost position during the left and right reciprocating movement of the moving unit 50. In other words, each first suction pad 20 moves back and forth horizontally between the first holding position and the suction position.

[0039] <Configuration of the Moving Mechanism of the Second Suction Pad 30> The movement mechanism of the second suction pad 30 is composed of a drive unit 40, a movement unit 50, and a first interlocking unit 60. The first interlocking unit 60 has a pivotal support unit 61 and an arm unit 63. The first interlocking unit 60 corresponds to the interlocking unit. As shown in Figures 1, 3, and 4, the pivotal support unit 61 includes a pivotal support unit main body 61A, a first fixed plate 61B, and a first rotating shaft unit 61C. The pivotal support unit main body 61A has a rectangular parallelepiped shape that is long in the front-rear direction. The pivotal support unit main body 61A is attached to the upper surface of the central part of the left and right of the first fixed plate 61B. The first fixed plate 61B has a flat plate shape. The left and right width of the first fixed plate 61B is wider than the left and right width of the pivotal support unit main body 61A. The first fixed plate 61B has through holes 61H that penetrate vertically on both the left and right sides of the pivotal support unit main body 61A (see Figure 4). The first fixing plate 61B is fixed to the upper surface of the cross bar 5 by threading bolts that pass through a pair of through-holes 61H in the first fixing plate 61B into two selected holes from a plurality of holes 5H formed in the upper surface of the cross bar 5. In this way, the attachment position of the first fixing plate 61B can be adjusted in the left-right direction depending on the size of the bags F to be set in the cassette 10. The front surface of the pivot support body 61A protrudes forward beyond the front side surface of the first fixing plate 61B. The first rotating shaft 61C extends horizontally forward from the front surface of the pivot support body 61A. In other words, the first rotating shaft 61C is perpendicular to the left-right horizontal direction, which is the movement path of each first suction pad 20.

[0040] As shown in FIG. 3, the arm portion 63 includes an arm body 64, a first roller R1, and a second roller R2. The arm body 64 is flat. From top to bottom, the arm body 64 includes an upper arm portion 64A, a first intermediate arm portion 64B, a second intermediate arm portion 64C, and a lower arm portion 64D. The upper end of the upper arm portion 64A is connected to the first rotating shaft portion 61C. When the arm portion 63 hangs down from the first rotating shaft portion 61C, the upper arm portion 64A extends vertically from the first rotating shaft portion 61C. When the arm portion 63 hangs down from the first rotating shaft portion 61C, the first intermediate arm portion 64B extends diagonally downward and leftward from the lower end of the upper arm portion 64A. The second arm intermediate portion 64C extends vertically from the lower end of the first arm intermediate portion 64B when the arm portion 63 hangs down from the first rotating shaft portion 61C. The arm lower portion 64D extends rightward from the lower end of the second arm intermediate portion 64C when the arm portion 63 hangs down from the first rotating shaft portion 61C. The front surface of the second arm intermediate portion 64C is connected to the rear end of the second bar member B2. The first roller R1 is rotatably attached to a horizontal shaft extending rearward from the boundary between the arm upper portion 64A and the first arm intermediate portion 64B. The first roller R1 extends rightward beyond the right side of the arm upper portion 64A. The second roller R2 is rotatably attached to a horizontal shaft extending rearward from the outer periphery of the arm lower portion 64D.

[0041] <Movement of the second suction pad 30> When the moving unit 50 moves leftward from its rightmost position (see FIG. 2 ) to a predetermined position during its left-right reciprocating movement, the first roller R1 of the arm 63 comes into contact with the inclined surface S, which is the left side of the moving unit main body 51, as shown in FIG. 7. At this time, the suction surfaces of the pair of first suction pads 20 and one suction pad come into contact with each other, as shown in FIGS. 7 and 8. As the moving unit 50 moves further leftward, the first roller R1 rotates while contacting the inclined surface S of the moving unit main body 51 and moves upward along the inclined surface S. At this time, the arm 63 rotates clockwise around the first rotation shaft 61C and rises to the raised position. In other words, the moving unit 50 pushes up the arm 63, which constitutes the first interlocking unit 60. As a result, the second suction pad 30, held by the front end of the second bar member B2 connected to the arm intermediate portion, rises clockwise along an arc centered on the first rotation shaft 61C. The lower end position of the second suction pad 30 on the arc is the second holding position, and the upper end position is the retracted position. In other words, while the moving unit 50 moves from the rightmost position to the leftmost position in the left-right reciprocating movement, it pushes up and supports the first interlocking unit 60, thereby moving the second suction pad 30 from the second holding position to the retracted position.

[0042] As the moving unit 50 moves further leftward, the first roller R1 rotates while contacting the upper surface of the moving unit main body 51. The first roller R1 corresponds to the contact portion. The second roller R2 of the arm unit 63 contacts the left end of the upper surface of the moving unit main body 51 before the first roller R1 disengages from the right end of the upper surface of the moving unit main body 51. The second roller R2 of the arm unit 63 remains in contact with the upper surface of the moving unit main body 51 even when the moving unit 50 stops moving leftward after the first roller R1 disengages from the right end of the upper surface of the moving unit main body 51 (see FIG. 11). The arm unit 63 remains in the raised position while at least one of the first roller R1 and the second roller R2 is in contact with the upper surface of the moving unit main body 51. In other words, the moving unit 50 supports the arm unit 63, which constitutes the first interlocking unit 60, in the raised position and maintains the second suction pad 30 in the retracted position.

[0043] During the reciprocating movement of the moving unit 50 in the left-right direction, when the moving unit 50 moves rightward from its leftmost position, the second roller R2 of the arm 63 rotates while contacting the upper surface of the moving unit main body 51. As the moving unit 50 further moves rightward, the first roller R1 of the arm 63 contacts the right end of the upper surface of the moving unit main body 51 before the second roller R2 disengages from the left end of the upper surface of the moving unit main body 51, and rotates while contacting the upper surface of the moving unit main body 51. As the moving unit main body 51 moves further rightward, the first roller R1 rotates from the upper end of the inclined surface S while contacting the inclined surface S, and moves downward along the inclined surface S. At this time, the arm 63 rotates counterclockwise around the first rotating shaft 61C and descends to the lowered position. As a result, the second suction pad 30 held by the front end of the second bar member B2 connected to the arm intermediate portion descends counterclockwise along an arc centered on the first rotating shaft 61C. As the moving unit 50 moves further to the right, it no longer supports the arm unit 63, which has lowered to the lowered position. In other words, as the moving unit 50 moves from the leftmost position to the rightmost position in its reciprocating movement in the left-right direction, it no longer supports the first interlocking unit 60, and the second suction pad 30 moves from the retracted position to the second holding position. In this way, the second suction pad 30 reciprocates on an arc centered on the first rotation shaft 61C between the second holding position and the retracted position.

[0044] <Configuration of the insertion unit 70> The input section 70 includes a funnel section 71 and a cylindrical section 72. The funnel section 71 has a truncated cone shape whose diameter decreases from the top to the bottom. The funnel section 71 includes a connecting plate 73 extending rearward from the rear surface of its upper portion. The vertical central axis of the funnel section 71 and the vertical central axis of the cylindrical section 72 are aligned on the same line. As shown in FIG. 4, the vertical central axes of the funnel section 71 and the cylindrical section 72 intersect with an imaginary center line L. The connecting plate 73 has a pair of elongated holes 73H formed at its rear end, aligned laterally. The connecting plate 73 is connected to the front end of a lifting plate 74 (described later) by bolts passing through the elongated holes 73H. The mounting position of the connecting plate 73 relative to the lifting plate 74 can be adjusted laterally using the elongated holes 73H formed at its rear end. The cylindrical section 72 is cylindrical and is continuous with the lower end of the funnel section 71. The cylindrical portion 72 has a lower end opening which is an insertion port 72A.

[0045] <Configuration of lifting mechanism of insertion unit 70> As shown in FIGS. 1 and 3 to 6, the lifting mechanism of the feeding section 70 is made up of a lifting plate 74, a pair of guide rods 75, a second fixed plate 76, a second interlocking section 77, and a support section 80. The lifting plate 74 is flat. The front end edge of the lifting plate 74 extends forward beyond the drive section 40. The rear end edge of the lifting plate 74 extends rearward beyond the cross bar 5. A pair of through holes 74H are formed at the front end of the lifting plate 74, through which bolts passing through the elongated holes 73H of the connecting plate 73 are inserted. The lifting plate 74 connects to the feeding section 70 by bolts passing through the through holes 74H and the elongated holes 73H of the connecting plate 73.

[0046] As shown in Figures 3, 5, and 6, the pair of guide rods 75 extend downward from the rear end of the lifting plate 74, at the bottom surface, separated in the left-right direction. Each guide rod 75 is cylindrical. Each guide rod 75 passes through a pair of through holes 76H formed in a second fixed plate 76 fixed to the upper surface of the cross bar 5, penetrating the lifting plate 74 in the vertical direction. The second fixed plate 76 is fixed to the upper surface of the cross bar 5, to the right of the support portion 61. A retaining ring 75A is attached to the lower end of each guide rod 75. The outer diameter of the retaining ring 75A is larger than the inner diameter of the through hole 76H. Therefore, the retaining ring 75A prevents each guide rod 75 from slipping out of the through hole 76H. When the insertion unit 70 is in the insertion position, the pair of guide rods 75 extend downward below the support plate 81, which will be described later.

[0047] As shown in Figures 1 and 3, the second interlocking part 77 includes an interlocking part main body 77A and a third roller R3. The interlocking part main body 77A is flat. The interlocking part main body 77A is continuous with the lower surface of the lifting plate 74. The interlocking part main body 77A is forward of the drive part 40 and extends vertically to the right of the arm part 63. The interlocking part main body 77A extends downward below the lower end of the drive part 40. The third roller R3 is rotatably attached to a horizontal shaft extending toward the rear side of the lower end of the interlocking part main body 77A. The third roller R3 protrudes from the outer peripheral edge of the lower end of the interlocking part main body 77A.

[0048] As shown in Figures 2, 3, 5, and 6, the support unit 80 has a support plate 81 and a second rotating shaft 82. The support plate 81 is flat. The support plate 81 is horizontally disposed below the lower edge of the cross bar 5 and above the lower surface of the convex portion 52 of the moving unit 50. The support plate 81 rotates around the second rotating shaft 82 extending vertically. The right front corner of the support plate 81 is in contact with the rear surface of the convex portion 52 of the moving unit 50 that is located at the rightmost position during reciprocal movement in the left-right direction. In this state, the support plate 81 is in an unsupported state in which it does not support the guide rods 75. In other words, the pair of guide rods 75 extend downward below the support plate 81.

[0049] In a bottom view in the unsupported state, the right end surface 81M of the support plate 81 extends substantially linearly in the front-to-rear direction, as shown in FIG. 5. In a bottom view in the unsupported state, the rear end surface 81B of the support plate 81 has a substantially semicircular protrusion rearward at the portion through which the second rotating shaft 82 passes, and the remaining portion extends linearly in the left-to-right direction. In a bottom view in the unsupported state, the rear end surface 81B to the left of the second rotating shaft 82 extends leftward and forward of the left guide rod 75. In a bottom view in the unsupported state, the portion extending to the left of the second rotating shaft 82 is a support region 81R that contacts the lower end surface of the left guide rod 75, preventing the guide rod 75 from descending and supporting it in an elevated position. In a bottom view in the unsupported state, the right front surface 81F, which extends from the right front corner of the support plate 81 to a position forward of the second rotating shaft 82, extends at a slight angle rearward and leftward. When viewed from the bottom in the unsupported state, the support plate 81 has a protrusion 81T that is provided so that a portion to the left of the left end of the right front surface 81F protrudes further forward than the front surface of the moving unit main body 51. When viewed from the bottom in the unsupported state, the front corner of the protrusion 81T and the left end of the right front surface are continuous with both ends of the middle side surface 81C that extends in a straight line in the front-to-rear direction. When viewed from the bottom in the unsupported state, the front corner of the protrusion 81T and the left end of the rear end surface 81B are continuous with both ends of the left side surface, which is an inclined surface that bulges slightly diagonally forward and left.

[0050] <Lifting of the insertion section 70> 2 and 3, when the third roller R3 of the interlocking unit main body 77A is positioned at the rightmost position during the left-right reciprocating movement of the moving unit 50, the third roller R3 is in contact with the inclined surface S, which is the left side surface of the moving unit main body 51. In this state, the insertion unit 70 is positioned at the insertion position. In a front view, the cylindrical portion 72 positioned at the insertion position is positioned between the pair of first suction pads 20 positioned at the first holding position and the pair of second suction pads 30 positioned at the second holding position.

[0051] As the moving unit 50 moves further leftward, the third roller R3 rotates while contacting the inclined surface S of the moving unit main body 51, and moves upward along the inclined surface S. At this time, the interlocking unit main body 77A rises to the raised position. In other words, the moving unit 50 pushes up the second interlocking unit 77. As a result, the lifting plate 74 connected to the second interlocking unit 77, the feeding unit 70 connected to the lifting plate 74, and the pair of guide rods 75 extending downward from the lifting plate 74 rise vertically upward. The lower end position of the feeding unit 70 is the feeding position, and the upper end position is the raised position. In other words, the feeding unit 70 moves from the feeding position to the raised position.

[0052] As the moving unit 50 moves further leftward, the third roller R3 rotates while contacting the upper surface of the moving unit main body 51, as shown in Figures 7 and 8. In this state, the input unit 70 is held in the raised position. When the input unit 70 is in the raised position, the lower ends of the pair of guide rods 75 are positioned slightly above the support plate 81, as shown in Figure 9.

[0053] As shown in FIGS. 7 and 8 , when the moving unit 50 moves leftward and the first roller R1 of the arm 63 contacts the inclined surface S, which is the left side surface of the moving unit main body 51, the left end surface of the convex portion 52 of the moving unit 50 contacts the middle side surface of the support plate 81, and the support plate 81 begins to rotate counterclockwise around the second rotating shaft 82 in bottom view. As the moving unit 50 moves further leftward, the support plate 81 further rotates counterclockwise around the second rotating shaft 82 in bottom view, as shown in FIG. 10 , and the convex portion 52 of the moving unit 50 passes in front of the front end corner of the protruding portion 81T of the support plate 81 from right to left. By this time, the support plate 81 has rotated counterclockwise around the rotation shaft, so that the support region 81R is positioned below the left guide rod 75. 11 to 13, even if the third roller R3 comes off the right end of the upper surface of the moving unit main body 51, the lower end surface of the left guide rod 75 comes into contact with the support region 81R of the support plate 81, preventing the guide rod 75 from descending and supporting the guide rod 75 in the raised position. Therefore, the lifting plate 74 and the feeding unit 70 connected to the lifting plate 74 are supported by the support plate 81 in the raised position.

[0054] As the moving unit 50 moves back and forth in the left-right direction, it moves rightward from its leftmost position, and the protrusion 52 of the moving unit 50 passes in front of the front corner of the protrusion of the support plate 81 from left to right (see FIG. 10 ), and the right end surface of the protrusion 52 of the moving unit 50 comes into contact with the right front surface of the support plate 81. As the moving unit 50 moves further rightward, the support plate 81 rotates clockwise around the second rotation shaft 82 in a bottom view, and the support region 81R of the support plate 81 is no longer positioned below the left guide rod 75 (see FIG. 15 ). In this state, the third roller R3 rotates while contacting the upper surface of the moving unit main body 51. As the moving unit 50 moves further rightward, the third roller R3 rotates while contacting the upper end of the inclined surface S and moves downward along the inclined surface S. At this time, the interlocking unit main body 77A descends to its lowered position. As a result, the lifting plate 74 connected to the second interlocking portion 77, the feeding portion 70 connected to the lifting plate 74, and the pair of guide rods 75 extending downward from the lifting plate 74 descend vertically downward. In other words, the feeding portion 70 moves from the raised position to the feeding position. In this way, the feeding portion 70 moves back and forth between the feeding position and the raised position.

[0055] <Opening of bag F by bag opening machine 1 and insertion of packaged items> This bag opening machine 1 opens the openings of bags F as will be explained below. First, as shown in Figure 1, the operator places multiple bags F that have been folded flat and stacked with the openings facing up into cassette 10. At this time, the operator rotates first adjustment dial 15 to match the size of the bags F, adjusting the spacing between clamping portions 116A of the pair of first guide portions 116 to the width of the bags F, and then rotates second adjustment dial 17 to adjust the height of placement portion 118A of second guide portion 118.

[0056] Next, when the operator drives the bag opening machine 1, the movable part of the drive unit 40 moves from the right end to the left end of the horizontally extending main body. When the moving unit 50 connected to the movable part begins to move leftward, as shown in FIG. 2, the pair of first suction pads 20 located in the first holding position begin to move leftward, i.e., from the first holding position to the first suction position. Then, as shown in FIG. 7, the input unit 70 moves from the input position to the raised position, during which time the pair of first suction pads 20 move leftward below the input unit 70. In this way, the input unit 70 does not interfere with the movement of the pair of first suction pads 20. Furthermore, as the moving unit 50 moves leftward, the support region 81R of the support plate 81 is positioned below the left guide rod 75, preventing the guide rod 75 from descending and supporting the guide rod 75 in the raised position. This causes the input unit 70 to move to the raised position.

[0057] After the insertion unit 70 moves to the raised position, as the moving unit 50 moves leftward, the second suction pad 30 moves upward in the clockwise direction on an arc centered on the first rotation shaft 61C, moving from the second holding position to the retracted position. At this time, the pair of first suction pads 20 move leftward below the second suction pad 30 that has moved to the retracted position. In this way, the second suction pad 30 does not interfere with the movement of the pair of first suction pads 20.

[0058] After the second suction pad 30 moves to the retracted position, the movable part of the drive unit 40 arrives at the left end of the main body. Then, as shown in FIG. 11 , the movement of the movable unit 50 to the left stops, and the pair of first suction pads 20 suction onto one side of the upper edge of the bag F set in the cassette 10. At this time, because the surface of the main plate 110 of the cassette main body 11 and the suction surface of the pad body P1 of each first suction pad 20 are parallel, the one side of the upper edge of the bag F can be properly suctioned. Furthermore, each suction pad is elastically acted upon in a direction in which the pad body P1 protrudes relative to the second pipe portion P3 held by the first bar member B1, and is freely movable in the central axis direction. Therefore, the one side of the upper edge of the bag F can be properly suctioned even if the number (thickness) of stacked bags F changes.

[0059] Next, the movable part of the drive unit 40 moves from the left end to the right end of the main body. When the moving part 50 connected to the movable part starts to move to the right, the pair of first suction pads 20 start to move rightward, that is, from the first suction position to the first holding position, while adhering to the upper edge of one side of one bag F. When the pair of first suction pads 20 adhering to one bag F move rightward below the second suction pad 30 positioned in the retracted position, the second suction pad 30 descends counterclockwise on an arc centered on the first rotation shaft 61C, moving from the retracted position to the second holding position, as shown in Figures 14 and 15 .

[0060] The second suction pad 30, which has moved to the second holding position, sandwiches the upper edge of a single bag F between the pair of first suction pads 20 and suctions the other side of the upper edge of the bag F. At this time, the second suction pad 30 rotates counterclockwise downward along an arc centered on the first rotation shaft 61C, so that it faces the pair of first suction pads 20 facing diagonally downward left along a trajectory that extends from diagonally downward left to diagonally upward right toward the second holding position. Furthermore, the pad main body P1 of the first suction pad 20 and the pad main body P1 of the second suction pad 30 are subjected to the elastic force of the spring member in the protruding direction, allowing them to move forward and backward relative to the second pipe portion P3. Therefore, the first suction pad 20 and the second suction pad 30 can securely sandwich the upper edge of a single bag F. Furthermore, the second suction pad 30 can securely suction the other side of the upper edge of a single bag F.

[0061] Furthermore, when the moving section 50 moves to the right, as shown in Figures 16 and 17, the pair of first suction pads 20 move from a state in which they sandwich the upper edge of one bag F between them and the second suction pad 30 toward the first holding position. In other words, the pair of first suction pads 20 move away from the second suction pad 30. As this movement occurs, the opening of one bag F gradually opens. As the opening of one bag F gradually opens, the support plate 81 no longer supports the guide rod 75, and the insertion section 70 descends from the raised position toward the insertion position.

[0062] When the pair of first suction pads 20 is positioned at the first holding position, each first suction pad 20 adheres to one side of the upper edge of one bag F, and the second suction pad 30, positioned at the second holding position, adheres to the other side of the upper edge of one bag F, completing the opening of the bag F by the bag opener. In this state, the input unit 70 is positioned at the input position, and the tubular portion 72 of the input unit 70 is inserted into the bag F through the open opening of the bag F. After inserting the packaged item, such as food, into the bag F from the input unit 70, the operator removes the bag F from the pair of first suction pads 20 and one second suction pad 30. Thereafter, the movable portion of the drive unit 40 again begins to move toward the left end of the main body, and the bag opener repeats the above operation of opening the opening of each bag F from the plurality of bags F set in the cassette 10.

[0063] As described above, the bag opening machine 1 of the first embodiment includes a cassette 10 for setting a plurality of bags F folded flat with the opening facing up, a pair of first suction pads 20 that reciprocate horizontally between a first suction position and a first holding position, and one second suction pad 30 that reciprocates between a retracted position and a second holding position in accordance with the movement of each first suction pad 20 so as not to interfere with the movement of each first suction pad 20. The first suction positions of the pair of first suction pads 20 are positions where they suction one side of the upper edge of a bag F that has been folded flat and set in the cassette 10, and the first holding position is a position where they hold the bag F in an open state with the one side of the upper edge suctioned. The retracted position of the second suction pad 30 is a position off the movement path of each first suction pad 20, and the second holding position is a position where the second suction pad 30 faces each first suction pad 20 and holds the other side of the upper edge of the bag F in a suction state. While each first suction pad 20 suctions one side of the upper edge of the bag F and moves from the first suction position to the first holding position, the second suction pad 30, which moves from the retracted position to the second holding position, sandwiches the upper edge of the bag F between itself and each first suction pad 20 and suctions the other side of the upper edge of the bag F, and the opening of the bag F is opened as each first suction pad 20 moves away from the second suction pad 30.

[0064] Because each first suction pad 20 of this bag opening device 1 only moves back and forth horizontally between the first suction position and the first holding position, the orientation and angle of each first suction pad 20 are always constant. Therefore, each first suction pad 20 can reliably suction one side of the upper edge of a bag F folded flat at the first suction position. Furthermore, this bag opening device 1 can properly sandwich the upper edge of the bag F between each first suction pad 20 and one second suction pad 30, and the second suction pad 30 can reliably suction the other side of the upper edge of the bag F. Thus, when each first suction pad 20 suctions one side of the upper edge of the bag F and when each first suction pad 20 suctions one side of the upper edge of the bag F and when each first suction pad 20 suctions the upper edge of the bag F and sandwiches the upper edge of the bag F between each second suction pad 30, the orientation and angle of each first suction pad 20 do not deviate, and each first suction pad 20 and second suction pad 30 can reliably suction the upper edge of the bag F to open the opening of the bag F.

[0065] Therefore, the bag opening machine 1 of the first embodiment can open the opening of the bag F well.

[0066] The second suction pad 30 of the bag opening machine 1 of Example 1 moves back and forth on an arc centered on a horizontal axis that is perpendicular to the movement path of each first suction pad 20. Therefore, by using the space above the movement path of each first suction pad 20 as the movement path of the second suction pad 30, the bag opening machine 1 can be made more compact.

[0067] The bag opening machine 1 of Example 1 is equipped with a moving unit 50 that moves together with each first suction pad 20, a drive unit 40 that moves the moving unit 50, and an interlocking unit that moves the second suction pad 30 in conjunction with the movement of the moving unit 50. Therefore, this bag opening machine 1 can reciprocate each of the first suction pads 20 and the second suction pad 30 using a single drive unit 40.

[0068] The moving unit 50 of the bag opening machine 1 of Example 1 supports and pushes up the interlocking unit while moving each first suction pad 20 from the first holding position to the first suction position, thereby positioning the second suction pad 30 at the retracted position, and then stops supporting the interlocking unit while moving each first suction pad 20 from the first suction position to the first holding position, causing the second suction pad 30 to be positioned at the second holding position. Therefore, when moving the second suction pad 30 from the second holding position to the retracted position, the bag opening machine 1 pushes up the second suction pad 30 together with the interlocking unit by the driving force of the drive unit 40. In other words, in this bag opening machine 1, the second suction pad 30 moves from the second holding position to the retracted position by the driving force of the drive unit 40. Meanwhile, when moving the second suction pad 30 from the retracted position to the suction position, if the moving unit 50 is moved to a position where it does not support the interlocking unit by the driving force of the drive unit 40, the interlocking unit and the second suction pad 30 descend by gravity and move to the suction position. Therefore, this bag opening machine 1 can reduce the power required for the drive unit 40.

[0069] The moving section 50 of the bag opening machine 1 of Example 1 has an inclined surface S that slopes leftward from the top to the bottom (from the first holding position side of each first suction pad 20 to the first suction position side), and the interlocking section has a contacting section that moves while making contact along the inclined surface S. Therefore, in this bag opening machine 1, the contacting section of the interlocking section moves while making contact along the inclined surface S of the moving section 50, so that the second suction pad 30 can be smoothly raised and lowered in conjunction with the moving section 50. Furthermore, by changing the inclination angle of the inclined surface S, this bag opening machine 1 can adjust the movement speed of the second suction pad 30 relative to each first suction pad 20, and the second suction pad 30 can sandwich the upper edge of the bag F between itself and each first suction pad 20 and effectively suck the other side of the upper edge of the bag F.

[0070] The bag opening machine 1 of Example 1 is equipped with an insertion unit 70 that has a tubular portion 72 that forms an insertion opening 72A, and that moves up and down between an insertion position and a raised position to insert the packaged item into a bag F. The insertion position is a position where the tubular portion 72 is inserted into the bag F from the upper end of the bag F whose opening has been opened, and the raised position is a position where it does not interfere with the movement of each first suction pad 20. Therefore, in this bag opening machine 1, the insertion unit 70 moves so as not to interfere with the movement of each first suction pad 20, and the tubular portion 72 of the insertion unit 70 can be smoothly inserted into the bag F from the opening of the open bag F.

[0071] The feeding section 70 of the bag opening machine 1 of Example 1 starts to rise from the feeding position to the raised position when each first suction pad 20 starts to move from the first holding position to the first suction position, and after the second suction pad 30 moves from the retracted position to the second holding position, the feeding section 70 descends from the raised position to the feeding position while each first suction pad 20 moves to the first holding position. Therefore, this bag opening machine 1 can insert the tubular section 72 of the feeding section 70 into the bag F while opening the opening of the bag F, thereby shortening the cycle time.

[0072] The bag opening machine 1 of Example 1 is equipped with a moving unit 50 that moves together with each first suction pad 20, and a support unit 80 that moves in conjunction with the movement of the moving unit 50 and supports the insertion unit 70 located in the raised position. Therefore, in this bag opening machine 1, the support unit 80 can support the insertion unit 70 in the raised position or not in response to the movement of each first suction pad 20 moved by the drive unit 40. In other words, the support unit 80 also moves back and forth between a position where it supports the insertion unit 70 and a position where it does not support it, by the drive force of the drive unit 40.

[0073] The present invention is not limited to the first embodiment described above with reference to the drawings, and the following embodiments are also included within the technical scope of the present invention. (1) The first suction portion may be one suction pad or three or more suction pads. (2) The second suction portion may be two or more suction pads. (3) The shape and size of the first suction pad and the second suction pad may be changed as appropriate. (4) The inclination angles of the first and second suction pads may be changed as needed. In this case, it is advisable to change the angle of the surface of the main plate of the cassette to match the suction surface of the first suction pad. (5) The shape of the insertion part may be changed as appropriate. (6) The bag does not need to have an insertion section. In this case, an operator can insert the packaged material directly into the opened bag. [Explanation of symbols]

[0074] 1...Bag opening machine 10...Cassette 20...First suction pad (first suction portion) 30...Second suction pad (second suction portion) 40...Drive unit (linear actuator) 50...Moving section 60...First interlocking part (interlocking part) 70...Input section 72...Cylinder part 72A…Inlet 80...Support part F…Bag R1...First roller (contact part) S…Slanted surface

Claims

1. a cassette into which a plurality of flattened bags are set with their openings facing upward; a first suction unit that reciprocates horizontally between a first suction position and a first holding position; a second suction unit that reciprocates between a retracted position and a second holding position in association with the movement of the first suction unit so as not to interfere with the movement of the first suction unit; It is equipped with the first suction position is a position where one side of an upper edge of the bag that has been folded flat and set in the cassette is suctioned; the first holding position is a position where the bag is held in an open state by suction on one side of the upper edge portion, the retracted position is a position that is out of a movement path of the first suction unit, the second holding position is a position facing the first suction portion and holding the other surface side of the upper edge of the bag in a suction state, A bag opening machine in which, while the first suction portion suctions one side of the upper edge of the bag and moves from the first suction position to the first holding position, the second suction portion, moving from the retracted position to the second holding position, suctions the other side of the upper edge of the bag, sandwiching the upper edge of the bag between itself and the first suction portion, and the first suction portion moves away from the second suction portion to open the opening of the bag.

2. The bag opening machine according to claim 1 , wherein the second suction unit moves back and forth on an arc centered on a horizontal axis perpendicular to the movement path of the first suction unit.

3. a moving unit that moves together with the first suction unit; a drive unit that moves the moving unit; a linking unit that moves the second suction unit in conjunction with movement of the moving unit; 3. The bag opening machine according to claim 1, further comprising:

4. The moving unit is the interlocking portion is pushed up and supported while the first suction portion is being moved from the first holding position to the first suction position, thereby positioning the second suction portion at the retracted position; The first suction portion is moved from the first suction position to the first holding position, and the interlocking portion is no longer supported, and the second suction portion is moved to the second holding position. The bag opening machine according to claim 3.

5. the moving part has an inclined surface that is inclined from an upper end to a lower end from the first holding position side of the first suction part to the first suction position side, The interlocking portion has a contact portion that moves while contacting the inclined surface. The bag opening machine according to claim 3.

6. The bag has a cylindrical portion that forms an insertion port, and is provided with an insertion section that moves up and down between an insertion position and a raised position and inserts the packaged item into the bag, the insertion position is a position where the tubular portion is inserted into the bag from the upper end of the bag with the opening open, The raised position is a position that does not interfere with the movement of the first suction part.

3. A bag opening machine according to claim 1 or 2.

7. The input unit is When the first suction unit starts moving from the first holding position to the first suction position, it starts rising from the loading position to the raised position, After the second suction unit moves from the retracted position to the second holding position, the first suction unit moves from the raised position to the loading position while the first suction unit moves to the first holding position.

3. A bag opening machine according to claim 1 or 2.

8. a moving unit that moves together with the first suction unit; a support part that moves in conjunction with the movement of the moving part and supports the insertion part positioned at the raised position; 7. The bag opening machine according to claim 6, further comprising:

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