JP2007210645A - Gripper pair used for bagging packaging machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide grippers 2 and 3 of a gusset bag having a small and relatively simple structure without requiring any strong spring for urging movable chucks 35 and 38 in the closing direction. <P>SOLUTION: A lock pin 58 is freely rotatably supported by fixed chucks 34 and 37, and a transmission mechanism for transmitting the driving force to the lock pin and turning the lock pin forwardly and backwardly by about 90° is installed on each gripper. The lock pin has a pressing unit protruded in the outside diameter direction in an eccentric manner. In the forward turn, the pressing unit abuts on the movable chuck to push, to close and to lock the movable chuck in a closed state. By the backward turn from the state, the movable chuck is unlocked. When two pairs of inner and outer chucks 4 and 5 are close to each other, the transmission mechanism is engaged with the lock pin to turn it. When the movable chucks are locked, the lock pin can be disengaged from the transmission mechanism, and the inner and outer chucks are movable to a separating positions. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a pair of grippers used in a bagging and packaging machine that grips both edges of a bag, conveys it along a predetermined path, and sequentially performs various packaging operations in the middle of the conveyance, and in particular, a bagging and packaging machine for a gusset bag It relates to a pair of grippers suitable when applied to.

  The gripper pair for gusset bags has two inner and outer chucks for gripping the side edges of the gusset bags that can be opened and closed at the tip of the gripper pair. Each gripper chuck consists of a fixed chuck and a movable chuck. The chuck and the outer chuck can move (contact / separate) each other between a proximity position and a separation position. In addition, the gripper pair is generally movable (contactable / separable) within the horizontal plane between the proximity position and the separation position in the packaging process (before and after bag supply), and the size (bag width) of the gusset bag is changed. Therefore, it is possible to adjust the distance between the grippers at the proximity position and the separation position.

As shown in the following Patent Documents 1 to 4, the four movable chucks are always urged in the closing direction by the coil springs installed therein, and the gripping state of the chucks is maintained only by the urging force of the springs. When opening the movable chuck, a cam installed at the bag feeding position is pressed against a roller attached to each movable chuck so as to open against the urging force of the spring.
The spring biases the movable chuck in the closing direction, and the biasing force of the spring is proportional to the amount of expansion and contraction. Therefore, in the conventional gripper, when the movable chuck is closed and the gusset bag is gripped (the gripping force) Force) is the smallest, and the biasing force of the spring when the movable chuck is opened is the largest. Therefore, it is necessary to use a strong spring to obtain a strong gripping force for stably gripping the gusset bag, and that spring is necessary for every four movable chucks, and is large to open the movable chuck. Since force is required, it is necessary to set the strength of each part high, and the gripper including the mechanism for opening the chuck is enlarged.

On the other hand, in the gripper disclosed in Patent Document 5, a biasing force (gripping force) in the closing direction is applied to the movable chuck only when the movable chuck is closed, instead of the above-described spring that biases the movable chuck in the closing direction. A leaf spring is used. On the other hand, the gripper disclosed in Patent Document 6 uses a coil spring that constantly biases the movable chuck in the opening direction, and the gripping force of the movable chuck is obtained by the elasticity of the elastic member constituting the movable chuck. Yes.
However, in these grippers, the mechanism for opening and closing the movable chuck is complicated, and there is a problem in applying to the grippers of gusset bags having four sets of chucks.

Japanese Utility Model Publication No. 55-90506 Japanese Utility Model Publication No. 7-18571 JP 2005-119727 A JP 2005-320012 A Japanese Patent Publication No. 6-55609 Japanese Patent Publication No. 7-37251

  The present invention has been made in view of the above-described problems of the prior art, and is packaged in a bag that grips both edges of the bag and conveys it along a predetermined path, and sequentially performs various packaging operations during the conveyance. An object of the present invention is to obtain a gripper pair having a small and simple structure without requiring a strong spring for biasing the chuck in the closing direction.

  The present invention (corresponding to a normal flat bag without gusset) grips both edges of the bag, conveys it along a predetermined path, and uses a gripper for a bagging and packaging machine that sequentially performs various packaging operations during the conveyance. A pair of chucks for gripping the side edges of the bags are installed at the front ends of the gripper pairs so that they can be opened and closed. Each gripper chuck is a gripper pair consisting of a fixed chuck and a movable chuck or a pair of movable chucks. A lock pin that locks the movable chuck in a closed and closed state is rotatably installed at a predetermined position of each gripper, and a transmission mechanism that transmits a driving force to the lock pin and rotates it forward and backward by a predetermined angle is installed in each gripper. When the lock pin rotates forward, the movable chuck is closed and locked in the closed state, and the lock pin rotates backward from this position to move forward. Wherein the locking of the movable chuck is to be released.

  A more specific configuration of the gripper pair is that the lock pin has a pressing portion protruding in an outer diameter direction, and the pressing portion abuts against the closing operation portion of the movable chuck when the locking pin rotates forward. The movable chuck is closed when the movable chuck is closed, rotated by a predetermined angle, and the movable chuck is closed. At this time, the reaction force applied from the closing operation portion to the pressing portion is set toward the axis of the lock pin. Thereby, the movable chuck is locked in the closed state, and the lock of the movable chuck is released by the lock pin rotating backward from this position.

  The present invention (corresponding to a gusset bag) is a gripper pair used in a bagging and packaging machine that grips two edges of each gusset bag and conveys it along a predetermined path, and sequentially performs various packaging operations during the conveyance. Two sets of inner and outer chucks that grip the side edges of the bag are installed at the tip of the gripper pair so that they can be opened and closed. Each gripper chuck is composed of a fixed chuck and a movable chuck, and an inner chuck and an outer chuck In a pair of grippers that are movable between a proximity position and a separation position, a lock pin that locks each movable chuck in a closed and closed state is rotatably supported at a predetermined position of each chuck, and is driven by the lock pin. A transmission mechanism that transmits force and rotates forward and backward by a predetermined angle is installed on each gripper, and the movable chuck is closed by rotating the lock pin forward. The movable chuck is unlocked by the reverse rotation of the lock pin from this position, and the transmission mechanism is configured so that the two inner and outer chucks are in the close position. When the movable chuck is locked by the lock pin by engaging with the lock pin and the movable chuck is locked by the lock pin, the lock pin can be detached from the transmission mechanism, and the two sets of inner and outer chucks are moved from the close position. It is possible.

  A more specific configuration of the gripper pair is that the lock pin has a pressing portion protruding in the outer diameter direction and a protrusion formed on the end surface, and the pressing portion closes the movable chuck when the lock pin rotates forward. The movable chuck is closed by abutting and pressing the operating portion, and the movable chuck is closed when the movable chuck is rotated by a predetermined angle and stopped. At this time, the reaction force applied from the closed operating portion to the pressing portion is applied to the axis of the lock pin. The movable chuck is locked in a closed state, and the lock pin is reversely rotated from this position so that the movable chuck is unlocked. As a part of the mechanism, a rotating member that rotates forward and backward by a predetermined angle is installed at a predetermined position of each gripper corresponding to each lock pin, and the protrusion is fitted along the length direction on the end surface of the rotating member. When the detachable groove is formed, and the two sets of inner and outer chucks are in the close position, the protrusion and the groove are oriented in the same direction, and the protrusion is inserted into the groove. The driving force can be transmitted, and when the movable chuck is locked by the lock pin, the direction of the ridge and the groove is parallel to the movement direction of the two sets of inner and outer chucks. It is possible to leave.

  As a means for opening the movable chuck when the lock by the lock pin is released, when the lock pin rotates in the reverse direction, the pressing portion abuts against the opening operation portion of the movable chuck, thereby pressing the movable chuck. A spring that applies an urging force for an always opening operation to each set of movable chucks is installed in each gripper, so that the movable chucks can be opened.

  According to the present invention, in a pair of grippers used in a bagging and packaging machine that grips both edges of a bag (including a gusset bag) and conveys it along a predetermined path, and sequentially performs various packaging operations during the conveyance, A pair of grippers having a small size and a simple structure can be obtained without requiring a strong spring for urging the chuck in the closing direction.

First, a pair of grippers (corresponding to gusset bags) according to the present invention will be specifically described with reference to FIGS.
(Overall structure of bag packing machine)
1 and 2 show a pair of grippers (left and right grippers 2, 3) installed around a table 1 that rotates intermittently of a rotary bag filling and packaging machine. Two sets of inner and outer chucks 4, 5 are openably and closably installed on the grippers 2, 3 in order to grip and suspend the two edges of the gusset bag G (see FIG. 7). .
Although not shown in FIGS. 1 to 3, at each process position around the table 1 (position where the grippers 2 and 3 stop), there are a bag supply and half-opening device (bag supply position), a printing device (printing position). ), An article supply device (filling position), a bag mouth sealing device (sealing position), a cooling sealing device (cooling position), etc. are arranged so that the packaging operation is sequentially performed each time the grippers 2 and 3 are stopped. It has become.

(Gripper pair structure)
The grippers 2 and 3 include gripper arms 7 and 8 (first arms 7a and 8a and second arms 7b and 8b fixed thereto, respectively) attached to a support shaft 6 fixed to the table 1 so as to be horizontally rotatable. ), And a chuck holder 12 mounted on the support shaft 11 fixed to the tip thereof so as to be horizontally rotatable. The chucks 4 and 5 and a main mechanism for opening and closing the chuck holder 12 are installed inside and outside the chuck holder 12. The gripper levers 7 and 8 are urged by the tension spring 13 in a direction approaching each other. The gripper arm 9 fixed to the gripper levers 7 and 8 and the chuck holder 12 attached to the tip of the gripper arm 9 have a substantially bilaterally symmetric structure.

(Gripper pair contact / separation mechanism)
A conventional technique (essentially the same as that described in Japanese Utility Model Publication No. 5-28169) is used as an approach / separation mechanism for causing the grippers 2 and 3 to approach or separate (open / close operation) within a horizontal plane. First, this mechanism will be briefly described.
In the vicinity of the support shaft 6 of the gripper arms 7 and 8, plate-like engagement portions 7c and 8c are formed inwardly of each other, and a long hole 14 is formed along the length direction of the engagement portion 7c. An engagement shaft 15 slidably fitted in the elongated hole 14 is fixed vertically to the joint portion 8 c, and a roller 16 is rotatably attached to the upper end of the engagement shaft 15. Further, an opening / closing operation part 8 d is formed in the vicinity of the support shaft 6 of the gripper arm 8.

A cylindrical cam 17 is installed at a lower position of the table 1 so as to be movable up and down (height can be adjusted), and an L-shaped lever (not shown) pivotally supported by a bracket (not shown) fixed to the lower surface of the table 1. A cam roller 18 that travels on the upper surface of the cylindrical cam 17 is attached to one end of the above-mentioned Japanese Utility Model Publication No. 5-28169, and an open / close roller (not shown) is attached to the other end of the L-shaped lever. The center of the cylindrical cam 17 coincides with the rotation center of the table 1, and the cylindrical cam 17 rotates at the same angle in synchronism with the intermittent rotation of the table 1, and when the table 1 stops, the same angle reversely rotates to the original position. Return.
The operating side 8e of the opening / closing operation part 8d of the gripper arm 8 is pressed against the opening / closing roller by the biasing force of the spring 13. When the cylindrical cam 17 rotates in the reverse direction, the cam roller 18 rolls along the upper surface of the cylindrical cam 17 and moves in the vertical direction, whereby the opening / closing roller swings via the L-shaped lever, and the gripper Since the operating side 8e of the opening / closing operation part 8d of the arm 8 is pressed against the opening / closing roller, the gripper arm 8 swings in a horizontal plane. On the other hand, since the engaging shaft 15 is fitted in the elongated hole 14, the gripper arm 7 also swings almost symmetrically at the same time, whereby the grippers 2 and 3 are brought into contact with and separated from each other (opening and closing operation in a horizontal plane).

A star cam 19 is installed at a position above the table 1 so as to be rotatable (the position in the circumferential direction can be adjusted), and its center coincides with the center of rotation of the table 1. When the cam roller 18 rolls along the upper surface of the cylindrical cam 17 that rotates in reverse and moves downward, the opening and closing roller retracts, the gripper arm 8 (also the gripper arm 7) swings inward, and the gripper 2, 3 close to each other (closed operation), but the swing of the gripper arms 7 and 8 stops when the roller 16 comes into contact with the locking side 19a of the star cam 19, and at this time, the grippers 2 and 3 are in the proximity position. It becomes.
The proximity position of the grippers 2 and 3 is determined depending on where the circumferential position of the star cam 19 is set, and the separation position of the grippers 2 and 3 is determined depending on where the height position of the cylindrical cam 17 is set. Therefore, by adjusting the positions of both the star cam 19 and the cylindrical cam 17, the open / close ranges (proximity position and separation position) of the grippers 2 and 3 are adjusted.
The circumferential position of the star cam 19 and the height position of the cylindrical cam 17 are adjusted according to the bag width of the gusset bag.

(Chuck holder and first parallel link mechanism)
As shown in FIGS. 1 to 3, the chuck holder 12 includes an upper plate 20 and a lower plate 21, which are connected and fixed (five places) by connecting pins 22 in the vertical direction. One of the connection pins 22a (hereinafter referred to as a support shaft 22a) protrudes below the lower plate 21, and one end of a first connection rod 23 is rotatably connected to the protrusion in a horizontal plane. The other end of the rod 23 is rotatably connected to a support shaft 24 fixed to the table 1 in a horizontal plane. In addition, another one of the connecting pins 22 is shown as 22b (hereinafter referred to as a support shaft 22b).

  The support shaft 6, the support shaft 24, the support shaft 11, and the support shaft 22 a are set in a positional relationship so that a parallelogram is always formed when their axes are connected by a straight line in a horizontal plane. For this reason, in the grippers 2 and 3, a kind of parallel link mechanism (a first link mechanism) is provided between the support shafts 6, 11, 22 a and 24 (the gripper arm 7 (8), the chuck holder 12, the first connecting rod 23, the table 1). A parallel link mechanism is formed, and the chuck holder 12 always translates when the gripper arms 7 and 8 swing, and its posture (orientation) does not change. As a result, the gripper 2 is adjusted when the distance between the close position and the separate position of the grippers 2 and 3 is adjusted, or in the packaging process (before and after the bag supply process) in order to cope with the change in the size (bag width) of the gusset bag. , 3 can be brought close to each other between the proximity position and the separation position, the gripping surfaces of the inner and outer chucks 4, 5 can always be directed parallel to the bag width direction.

(Internal / external chuck contact / separation mechanism)
Long holes (guide holes) 25a to 27a are formed in the upper plate 20 in parallel in the inner and outer directions, and long holes (guide holes) 25b to 27b are formed in the lower plate 21 in the same manner. Since the length directions of the guide holes 25a to 27a and 25b to 27b are parallel to the line 28 passing through the center of the table 1 and the middle of the grippers 2 and 3, the chuck holder 12 is translated by the parallel link mechanism. This direction does not change as the grippers 2 and 3 move in and out (open / close). This is the same when the positions of the cylindrical cam 17 and the star cam 19 are adjusted as described above according to the bag width size.

  Racks 31 and 32 are arranged between the upper and lower plates 20 and 21 on both sides of the support shaft 11, and mesh with a pinion 33 that is rotatably supported by the support shaft 11. The outer chuck 5 is installed at the tip of the rack 31, and the inner chuck 4 is installed at the tip of the rack 32. The outer chuck 5 includes a fixed chuck 34 and a movable chuck 35. The end of the fixed chuck 34 is fixed to the tip of the rack 31, and the movable chuck 35 is freely rotatable in a horizontal plane on a fulcrum shaft 36 fixed to the fixed chuck 34 ( It is supported so as to be openable and closable with respect to the fixed chuck 34. The inner chuck 4 includes a fixed chuck 37 and a movable chuck 38, and the bent end of the fixed chuck 37 is fixed to the tip of the rack 32. The movable chuck 38 rotates in a horizontal plane around a fulcrum shaft 39 fixed to the fixed chuck 37. It is supported freely (openable and closable with respect to the fixed chuck 37).

Cylindrical shafts 41 are fixed to the upper and lower surfaces of the rack 31, and only upper and lower end portions thereof are cut out on both side surfaces to be formed into a bowl shape, and are slidably fitted into the guide holes 25a and 25b of the upper and lower plates 20 and 21. is doing. Similarly, cylindrical shafts 42 are fixed to the upper and lower surfaces of the rack 32 and the fixed chuck 37, and only the upper and lower ends thereof are formed into a bowl shape like the shaft 41, and are slidable in the guide holes 26a, 26b and 27a, 27b. Is inserted.
A tension spring 40 is disposed between the fixed chuck 34 of the outer chuck 5 and one of the connecting pins 22 to urge the rack 31 inward (table 1 side), and simultaneously reverse the rack 32 via the pinion 33. As a result, in the state where no other force is applied, the inner and outer chucks 4 and 5 are in the proximity positions (the respective fixed chucks 34 and 37 are in contact with each other as shown in FIGS. ).

(Internal / external chuck contact / separation drive mechanism)
As shown in FIGS. 2 and 3, swinging levers 43 and 44 are attached to the support shafts 6 and 6 below the gripper levers 7 and 8 so as to be horizontally rotatable and connected to the lower ends of the support shafts 6 and 6, respectively. The plate 45 is fixed.
A support shaft 46 is fixed horizontally below the connection plate 45, and an L-shaped lever 47 is rotatably attached to the support shaft 46. A support shaft 48 is fixed horizontally to the lower end of the L-shaped lever 47, and a cam roller 49 is rotatably attached to the support shaft 48, and the upper surface of the cylindrical cam 51 installed below the table 1 is covered with the support shaft 48. Run. The center of the cylindrical cam 51 coincides with the center of rotation of the table 1 and can be moved up and down (height can be adjusted). A pressing roller 52 is rotatably attached to an upper end portion of the L-shaped lever 47, and comes into contact with a contact plate 53 fixed to the base portion of the swing lever 44.

  The swing levers 43 and 44 have plate-like operating portions 43a and 44a extending inwardly from each other, and an elongated hole 43b is formed in the vicinity of the distal end of the operating portion 43a along the length direction thereof. An engagement shaft 44b that is slidably fitted in the elongated hole 43b is fixed vertically in the vicinity of the distal end of the shaft. Support shafts 43c and 44c are fixed to the tips of the operating portions 43a and 44a, respectively, and one end of a second connecting rod 54 is rotatably connected to the support shafts 43c and 44c in a horizontal plane. On the other hand, as a part of the chuck contact / separation mechanism, a connecting portion 55 is fixed to the rack 32, a support shaft 56 is fixed to the connecting portion 55, and the other end of the second connecting rod 54 is horizontally rotatable with respect to the support shaft 56. It is connected to.

  As shown in FIGS. 2 and 3, when the inner and outer chucks 4 and 5 are in the close position (the fixed chucks 34 and 37 are in contact with each other), the cam roller 49 runs along the upper surface of the cylindrical cam 51 and moves upward. When the lever moves to a predetermined height, the L-shaped lever 47 swings around the support shaft 46 and the pressing roller 52 comes into contact with the contact plate 53. By pushing this, the swing lever 44 moves toward the center of the table 1. On the other hand, since the engagement shaft 44b is fitted in the elongated hole 43b, the swing lever 43 also swings almost symmetrically at the same time, pulling the second connecting rod 54 toward the center of the table 1, and In the chuck holders 12 and 12, the rack 32 (and the inner chuck 4) is moved in the same direction, the rack 31 (and the outer chuck 5) is moved in the opposite direction by the same distance, and the inner and outer chucks 4 and 5 are moved toward the separated position. You . The state when the inner and outer chucks 4, 5 reach the separated position is shown in FIGS. On the contrary, when the cam roller 49 moves downward from the state, the inner and outer chucks 4 and 5 move toward the close position by the biasing force of the spring 40, and the pressing roller 52 contacts when the cam roller 49 becomes a predetermined height or less. At this time, the inner and outer chucks 4 and 5 reach the close positions. In addition, by adjusting the height of the cylindrical cam 51, the moving distance of the racks 31 and 32, that is, the separation distance between the inner and outer chucks can be adjusted.

(Inner / outer chuck and second parallel link mechanism)
As shown in FIGS. 1 to 3, when the inner and outer chucks 4 and 5 are in the close position, the support shaft 6, the support shaft 11, the support shaft 56, and the support shaft 44 c connect these axes in a straight line in the horizontal plane. The positional relationship is set so that a parallelogram is sometimes formed. Therefore, in the gripper 3 (the same applies to the gripper 2), when the inner and outer chucks 4 and 5 are in the close position, a kind of parallel link mechanism (second parallel link mechanism) is provided between the table support shafts 6, 11, 56, and 44c. Is configured.
Since the first and second parallel link mechanisms are formed in the gripper 3, when the inner and outer chucks 4 and 5 are close to each other, the chuck holder 12 can be moved even if the gripper arms 7 and 8 are swung. The positional relationship between the support shaft 11 that supports the shaft and the support shaft 56 that supports the second connecting rod 54 does not change (only translates), and as a result, the inner and outer chucks 4 and 5 do not move from the close position (position). The rocking levers 43 and 44 do not rock. Thus, when the inner and outer chucks 4 and 5 are in the close position, the contact / separation (opening / closing operation) of the grippers 2 and 3 does not affect the contact and separation of the inner and outer chucks 4 and 5. Therefore, even if the grippers 2 and 3 are brought into and out of proximity between the proximity position and the separation position in the packaging process (before and after the bag supply process), the inner and outer chucks 4 and 5 are not thereby opened, and the size of the gusset bag Even if the distance between the grippers 2 and 3 at the proximity position and the separation position is adjusted corresponding to the change in the (bag width), the separation distance between the inner and outer chucks 4 and 5 does not fluctuate alone.

The outer chuck 5 includes a fixed chuck 34 and a movable chuck 35, and a lock pin 58 that is rotatably supported by the fixed chuck 34 at a predetermined position between the fixed chuck 34 and the movable chuck 35.
As clearly shown in FIG. 6, the movable chuck 35 includes a base portion 59 and a clamping portion 61 fixed to the tip end portion 59 a, and is rotatably supported by a fulcrum shaft 39 fixed to the fixed chuck 34 at the base portion 59. ing. The base 59 is made of a plate having a uniform thickness except for the front end 59a, and has a recess 63 comprising a notch-like opening 63a communicating with the outside at the center and a substantially racetrack-shaped hole 63b integrated therewith. It is formed to penetrate in the direction.
The fixed chuck 34 includes a base portion 64 and a sandwiching portion 65. The base portion 64 has a groove 66 formed at a central portion in the thickness direction with a width that can accommodate the base portion 59 (portion excluding the tip portion 59a) of the movable chuck 35, and is movable. The chuck 35 has a base 59 supported by a fulcrum shaft 39 in a groove 66 and is openable and closable with respect to the fixed chuck 34. In addition, a notch-shaped opening 64a having a width slightly narrower than that of the racetrack-shaped hole 63b is formed in the thickness direction so as to support the shaft of the lock pin 58 on one side of the bottom of the opening 64a. An arc-shaped depression (supporting part 64b) is formed.

The lock pin 58 includes two disk-shaped flanges 67 and 68, cylindrical shaft portions 69 and 69, a pressing portion 71 between the shaft portions 69 and 69, and a protrusion formed on the lower end surface. 72. The pressing portion 71 has a flat racetrack-shaped cross section when viewed in a cross section perpendicular to the axial direction of the lock pin 58, and protrudes eccentrically in the outer diameter direction when viewed from the shaft center (shaft portion 69). Has a flat racetrack-shaped cross section, and is formed so that the long axis is parallel to the pressing portion 71 (flat in the same direction).
Although the details of the inner chuck 4 are omitted, the inner chuck 4 has a substantially symmetric structure with respect to the outer chuck 5.

The flanges 67 and 68 of the lock pin 58 are located on both side surfaces of the fixed chuck 34, the shaft portions 69 and 69 can be supported by the support portion 64 b of the fixed chuck 34, and the pressing portion 71 can be rotated by the concave portion 63 of the movable chuck 35. It can rotate in the gap.
When the lock pin 58 is rotated from the state of FIG. 6A so that the long axis of the pressing portion 71 is directed in the vertical direction (the length direction of the racks 31 and 32), the pressing that protrudes eccentrically in the outer diameter direction. The tip of the portion 71 abuts against and presses the inner surface (the closing operation portion 73) of the concave portion 63 of the movable chuck 35, thereby closing the movable chuck 35. Further, as shown in FIG. 5A, the rotation is stopped when the long axis of the pressing portion 71 is directed in the vertical direction (the length direction of the racks 31 and 32). At this time, the clamping part 61 of the movable chuck 35 is pressed against the clamping part 65 of the fixed chuck 34, and a reaction force corresponding to the pressing force is applied from the closing operation part 73 to the pressing part 71. This reaction force moves along the major axis direction of the pressing portion 71 toward the axis of the lock pin 58 and does not rotate the lock pin 58. The movable chuck 35 is fixed (locked) at this position. This locked state is maintained unless an external force is applied.

Next, when the lock pin 58 is rotated in the reverse direction from the state of FIG. 5A, the lock state of the movable chuck 35 is released, and the tip of the pressing portion 71 is further moved to the inner surface (opening operation portion) of the concave portion 63 of the movable chuck 35. 74; an inner surface on the opposite side of the closing operation portion 73) and pressing, and the movable chuck 35 is opened as shown in FIG.
In addition, since the support part 64b which supports the axial part 69 of the lock pin 58 is only an arc-shaped seat, the axial center of the lock pin 58 is not fixed. However, since the pressing portion 71 is disposed in the narrow gap of the concave portion 63, the shaft center of the lock pin 58 is not greatly shaken with the rotation. In particular, while the pressing portion 71 is in contact with the closing operation portion 73, the shaft portion 69 is pressed against the support portion 64b by the reaction force received from the closing operation portion 73, and the shaft center can rotate without being shaken.

(Driving force transmission mechanism that rotates the lock pin)
As shown in FIGS. 4 and 5, rotating members 75 and 76 are rotatably attached to the lower plate 21. The rotating members 75 and 76 have a shaft portion 77 protruding above the lower plate 21 and gears 78 and 79 disposed on the back surface side of the lower plate 21, and grooves 81 are formed on the end surfaces of the shaft portions 77. The gears 78 and 79 mesh with each other. The shaft portions 77 of the rotating members 75 and 76 are respectively installed directly below the lock pin 58 when the inner and outer chucks 4 and 5 are in the close position (see FIG. 2), and the protrusions 72 of the lock pin 58 are formed in the groove 81. Can be inserted or removed along the length direction.

As shown in FIGS. 2 and 4, on the back side of the lower plate 21, a sector gear 83 is rotatably attached to a support shaft 82 fixed to the lower plate 21, and meshes with the gear 78. Similarly, on the back side of the lower plate 21, a support shaft 22 b (one of the connecting pins 22) fixed to the upper and lower plates 20, 21 protrudes under the lower plate 21, and one end of the action lever 84 is rotatable on the protruding shaft. It is supported by. A connecting shaft 85 is fixed to the other end of the operating lever 84, and one end of the operating roller 86 and the connecting plate 87 is rotatably attached to the connecting shaft 85, and the other end of the connecting plate 87 is fixed to the sector gear 83. The shaft 88 is rotatably attached.
As shown in FIG. 2, two action rollers 86 (one on each of the left and right grippers 2, 3) are installed in the radial direction of the table 1 at the product bag discharge position and the empty bag supply position. Chuck opening / closing bars 89 that are moved inwardly or outwardly (indicated by arrows) are provided. When the action roller 86 is pressed by the chuck opening / closing bar 89, the driving force is transmitted to the lock pin 58 via the connecting plate 87, the fan-shaped gear 83, and the rotating members 75 and 76 (the gears 78 and 79 and the groove 81 of the shaft portion 77). Is done.

  More specifically, the chuck opening / closing bar 89 is moved radially inward at the product bag discharge position. Then, the rotating members 75 and 76 and the lock pins 58 rotate about 90 degrees, and the pressing portion 71 (and the ridge 72) that has been oriented in the vertical direction until then is lateral (as shown in FIG. 6A). (The direction substantially perpendicular to the length direction of the racks 31, 32), and accordingly, the movable chucks 35, 38 are unlocked, and the opening operation part 74 is pressed by the pressing part 71, thereby moving the movable chucks 35, 38. open. On the other hand, at the bag supply position, the chuck opening / closing bar 89 is moved outward in the radial direction. Then, the rotating members 75 and 76 and the lock pins 58 are rotated in the opposite direction by about 90 degrees, and the pressing portion 71 (and the ridge 72) which has been oriented in the horizontal direction until then is vertically moved as shown in FIGS. With the direction turned, the closing operation portion 73 is pressed by the pressing portion 71, and the movable chucks 35 and 38 are closed and locked.

When the inner and outer chucks 4 and 5 are in the close position, the protrusion 72 of the lock pin 58 is always fitted in the groove 81 of the rotating members 75 and 76. Accordingly, the driving force of the chuck opening / closing bar 89 is transmitted to the lock pin 58, and the movable chucks 35 and 38 can be opened and closed. When the inner and outer chucks 4 and 5 are close to each other and the movable chucks 35 and 38 are closed (locked by the lock pin 58), the protrusion 72 and the groove 81 are in the vertical direction, that is, the length of the racks 31 and 32. It is facing the direction. Accordingly, the protrusion 72 can be detached from the groove 81 along the length direction of the groove 81, and as shown in FIGS. 4 and 5, the racks 31 and 32 are moved in the reverse direction to move the inner and outer chucks 4 and 5 to each other. Can be separated. Even if the inner and outer chucks 4 and 5 are close to each other, if the movable chucks 35 and 38 are open (not locked by the lock pin 58), the direction of the protrusion 72 and the groove 81 is the length of the racks 31 and 32. Since the direction is not directed (the direction of the protrusion 72 and the groove 81 is different from the moving direction of the racks 31 and 32), the protrusion 72 cannot be detached from the groove 81. Therefore, the inner and outer chucks 4 and 5 cannot be separated.
In the state where the inner and outer chucks 4 and 5 are separated from each other, the protrusion 72 is detached from the groove 81, so that the driving force cannot be transmitted to the lock pin 58, and the movable chucks 35 and 38 are maintained in the locked state. However, when the inner and outer chucks 4 and 5 come close to each other and the protrusion 72 is reinserted into the groove 81, the driving force of the chuck opening / closing bar 89 can be transmitted to the lock pin 58, and the lock is released to move the movable chuck 35, 38 can be opened and closed.

Subsequently, a part of the operation of the gripper pair in the bag filling and packaging machine will be described with reference to FIGS.
(1) When the pair of grippers is stopped at the product bag discharge position due to the intermittent rotation of the table 1, the grippers 2 and 3 are in the close position, and the inner and outer chucks 4 and 5 are also in the close position. Operates to open the movable chucks 35 and 38 and drop the product bag. Subsequently, the grippers 2 and 3 are opened by the action of the cam roller 18 that rolls on the upper surface of the reversely rotating cylindrical cam 17 and stops at the separated position.
(2) When the table 1 rotates intermittently and the gripper pair stops at the bag supply position, the transfer suction cup 92 of the bag supply device 91 is moved to the outer surface of the gusset bag G (the radius of the table 1) as shown in FIG. The gusset bag G is horizontally moved from the front of the grippers 2 and 3 and supplied to the grippers 2 and 3.

(3) As shown in FIG. 7B, the transfer suction cup 92 of the bag supply device 91 stops and positions the gusset bag G at a predetermined position, and at the same time, the auxiliary suction cup 93 of the half opening device (only the auxiliary suction cup 93 is shown). Advances in the direction of the arrow and sucks the inner surface of the gusset bag G (the surface facing the inner side in the radial direction of the table 1), and then the auxiliary suction cup 93 moves backward in the direction of the arrow as shown in FIG. Half-open the gusset bag G. At this time, the inner and outer two side edges G1 and G2 of the gusset bag G are positioned between the fixed chuck 34 and the movable chuck 35 of the outer chuck 5 and between the fixed chuck 37 and the movable chuck 38 of the inner chuck 4, respectively. Is done.
(4) Subsequently, as shown in FIG. 8 (d), the grippers 2 and 3 are closed by the action of the cam roller 18 rolling on the upper surface of the reversely rotating cylindrical cam 17, and stopped at the close position. At this time, the side edge G1 of the gusset bag G enters the openings of the fixed chuck 34 and the movable chuck 35 of the outer chuck 5, and the side edge G2 enters between the openings of the fixed chuck 37 and the movable chuck 38 of the inner chuck 4.
Further, the chuck opening / closing bar 89 is actuated to rotate the lock pin 58, whereby the movable chucks 35 and 38 are closed and locked as shown in FIG. G1 and G2 are gripped. Subsequently, the transfer suction cup 92 moves backward, and the auxiliary suction cup 93 also moves to a retracted position where it does not interfere with the grippers 2 and 3.

(5) Next, in the process in which the table 1 rotates intermittently and the gripper pair moves from the bag supply position to the next stop position, the cam roller 49 travels along the upper surface of the cylindrical cam 51 and rises to a predetermined height. Accordingly, the inner chuck 4 is moved inward and the outer chuck 5 is moved outward by a predetermined distance via the contact / separation mechanism and the contact / separation drive mechanism described above. Thereby, as shown in FIG. 9, the gusset bag G is opened. During this time, the movable chucks 35 and 38 are kept locked by the lock pin 58.
If the bag width changes, the folding depth of the gusset also changes. Therefore, it is necessary to change the separation interval between the inner and outer chucks 4 and 5. This separation interval can be changed by changing the height of the cylindrical cam 51. Can be adjusted.

Next, another gripper pair (corresponding to a normal flat bag) according to the present invention will be specifically described with reference to FIGS. Although not shown, this pair of grippers is installed in the same type of rotary bagging and packaging machine as described above. In the rotary bag filling and packaging machine, each gripper constituting the gripper pair is similar to the grippers 2 and 3 described above, and has a gripper arm attached to a support shaft fixed to the table so as to be horizontally rotatable, and a tip thereof. A chuck holder is mounted on a fixed support shaft so as to be horizontally rotatable.
10 and 11 show only the tip of the chuck holder 94 on one side. Unlike the chuck holder 12 described above, the chuck holder 94 is a simple plate, but the gripper arm is swung by a parallel link mechanism (not shown) similar to the first parallel link mechanism of the chuck holder 12. When you do, always do translational movement, the direction does not change.

Since this gripper normally grips the side edge of the bag, the chuck holder 94 is provided with only one chuck 95.
The chuck 95 includes two movable chucks 96 and 97. The movable chuck 96 includes a base portion 98 and a clamping portion 99, and is rotatably supported on a fulcrum shaft 101 fixed to the chuck holder 94 at the base portion 98. The movable chuck 97 includes a base portion 102 and a clamping portion 103, and is rotatably supported by a fulcrum shaft 104 fixed to the chuck holder 94 at the base portion 102. The distal end portion 102a of the base portion 102 of the movable chuck 97 is formed on a plate having a uniform thickness that is thinner than other portions of the base portion 102, and the distal end portion 98a of the base portion 98 of the movable chuck 96 is fixed to the fixed chuck described above. As in the case of 34, a groove having a width in which the distal end portion 102a can be fitted and slid is formed in the central portion in the thickness direction.
Chuck opening / closing gears 105 and 106 are fixed to the movable chucks 96 and 97, respectively, and are rotatably supported by the fulcrum shafts 101 and 104. The chuck opening / closing gears 105 and 106 mesh with each other, so that the movable chucks 96 and 97 can rotate symmetrically with respect to each other in the horizontal plane around the support shafts 101 and 104 to open and close.

A compression spring 107 is installed between the base portions 98 and 102 of the movable chucks 96 and 97 on the side opposite to the sandwiching portions 99 and 103 with the fulcrum shafts 101 and 104 interposed therebetween, so that the movable chucks 96 and 97 are always opened. Energized.
Between the bases 98 and 102 of the movable chucks 96 and 97, a lock pin 108 is vertically installed on the opposite side of the compression spring 107 with the fulcrum shafts 101 and 104 interposed therebetween. The lock pin 108 is formed to protrude from a cylindrical base portion 109, a pressing portion 111 that protrudes from the upper end surface of the base portion 109, and a lower end surface of the base portion 109, and is rotatably supported by the chuck holder 94. The shaft portion 112 is formed. The pressing portion 111 has a flat racetrack-like cross section when viewed in a cross section perpendicular to the axial direction of the lock pin 108, and both ends protrude eccentrically in the outer diameter direction when viewed from the axial center (shaft portion 112). Yes.

  On the back side of the chuck holder 94, a gear 113 is fixed to the shaft portion 112, and a sector gear 115 is rotatably attached to a support shaft 114 fixed to the chuck holder 94. The gear 113 is connected to the gear 78 described above. Similarly, it engages with the sector gear 115. In FIG. 10B, a connecting plate 117 is rotatably attached to a connecting shaft 116 fixed to the sector gear 115. This connecting plate 117 advances and retreats in the substantially length direction similarly to the connecting plate 87 shown above, and the driving force of the chuck opening / closing bar (see chuck opening / closing bar 89) is locked via the sector gear 115 and the gear 113. This is transmitted to the pin 108 and rotated approximately 90 degrees forward and backward.

When the lock pin 108 is rotated from the state of FIG. 11 so that the long axis of the pressing portion 111 is directed in the vertical direction, both ends of the pressing portion 111 protruding in the outer diameter direction are the base portions 98 of the movable chucks 96 and 97. , 102 abuts against and presses the inner surfaces (the closing operation portions 118, 119), and the movable chucks 96, 97 are closed. As shown in FIG. 10A, the rotation is stopped when the long axis of the pressing portion 111 is oriented in the vertical direction. At this time, the sandwiching portions 99 and 103 of the movable chucks 96 and 97 are pressed against each other, A reaction force corresponding to the pressing force is applied from the closing operation portions 118 and 119 to the pressing portion 111. This reaction force is directed to the axial center of the lock pin 108 along the long axis direction of the pressing portion 111 and does not turn the lock pin 108, and the movable chucks 96 and 97 are fixed (locked) at this position. This locked state is maintained unless other external force is applied.
Next, when the lock pin 108 is rotated in the reverse direction from the state shown in FIG. 10A, the locked state of the movable chucks 96 and 97 is released, and the movable chucks 96 and 97 are opened by the action of the spring 107. As shown in FIG.

It is a top view of the gripper pair (corresponding to a gusset bag) according to the present invention. It is AA sectional drawing of FIG. It is BB sectional drawing of FIG. It is the bottom view (a) and right side view (b) of the chuck holder part of the gripper pair. It is the plane sectional view (a), the right view (b), and the front view (c) of the chuck holder portion of the gripper pair. FIG. 4 is a plan sectional view (a) of an outer chuck of the gripper pair, a plan view (b) of a movable chuck, a plan view (c) of a fixed chuck, and a perspective view (d) of a lock pin. It is a figure explaining operation | movement of the said gripper pair in a bag supply position. It is a figure explaining operation | movement of the said gripper pair similarly. It is a figure explaining operation | movement of a gripper pair similarly. It is a top view of the chuck | zipper part of another gripper pair (normal flat bag corresponding | compatible) which concerns on this invention. It is a top view when the chuck | zipper will be in an open state.

Explanation of symbols

2, 3 Gripper 4 Inner chuck 5 Outer chuck 7, 8 Gripper arm 12 Chuck holder 20, 21 Upper and lower plates 25a-27a, 25b-27b Guide holes 31, 32 Rack 34, 37 Fixed chuck 35, 38 Movable chuck 58 Lock pin 71 Pressing portion 72 Projection 73 Moving chuck closing operation portion 74 Moving chuck opening operating portion

Claims (6)

A pair of chucks for gripping the side edges of a bag, which is a pair of grippers used in a bag-packing and packaging machine that grips both edges of a bag and conveys it along a predetermined path and sequentially performs various packaging operations during the conveyance. Is installed at the front end of the gripper pair so that the chuck of each gripper is a gripper pair consisting of a fixed chuck and a movable chuck or a pair of movable chucks. A transmission mechanism that is rotatably installed at a predetermined position of the gripper and that transmits a driving force to the lock pin and rotates forward and reverse by a predetermined angle is installed at each gripper, and the movable chuck is closed by rotating the lock pin forward and backward. The lock is locked in the closed state, and the lock of the movable chuck is released when the lock pin rotates backward from this position. Grippers for use in a bag-filling packaging machine, characterized in that there. A pair of chucks for gripping the side edges of a bag, which is a pair of grippers used in a bagging and packaging machine that grips and conveys both edges of a bag along a predetermined path and sequentially performs various packaging operations during the conveyance. Is installed at the front end of the gripper pair so that the chuck of each gripper is a gripper pair consisting of a fixed chuck and a movable chuck or a pair of movable chucks. A transmission mechanism that is rotatably installed at a predetermined position of the gripper, transmits a driving force to the lock pin, and rotates forward and reverse by a predetermined angle is installed in each gripper, and the lock pin has a pressing portion that protrudes in the outer diameter direction. When the lock pin rotates in the forward direction, the pressing portion comes into contact with the closing operation portion of the movable chuck and presses to close the movable chuck, and rotates and stops at a predetermined angle. The movable chuck is closed, and at this time, the reaction force applied from the closing operation portion to the pressing portion is set to face the axis of the lock pin, whereby the movable chuck is locked in the closed state, and A pair of grippers used in a bagging and packaging machine, wherein the lock of the movable chuck is released by reversely rotating the lock pin from this position. A pair of grippers used in a bag-packing and packaging machine that grips both edges of a gusset bag and transports it along a predetermined path in the middle of the transport, and grips the side edges of the bag. Two sets of inner and outer chucks are installed at the tip of the gripper pair so that they can be opened and closed. Each chuck of each gripper consists of a fixed chuck and a movable chuck, and the inner chuck and the outer chuck move between a proximity position and a separation position. In the gripper pair that is made possible, a lock pin that locks each movable chuck in a closed and closed state is rotatably supported at a predetermined position of each chuck, and a driving force is transmitted to the lock pin to rotate forward and reverse by a predetermined angle. A transmission mechanism is installed in each gripper, and when the lock pin rotates forward, the movable chuck is closed and locked in a closed state, and the lock pin is locked. The movable chuck is unlocked by reversely rotating the pin from this position, and the transmission mechanism is engaged with the lock pin when the two inner and outer chucks are in the close position to drive the driving force. And when the movable chuck is locked by the lock pin, the lock pin can be detached from the transmission mechanism, and the two sets of inner and outer chucks can be moved from close positions. A pair of grippers used in stuffing and packaging machines. A pair of grippers used in a bagging and packaging machine that grips both edges of a gusset bag and transports it along a predetermined path, and sequentially performs various packaging operations during the transportation, and grips the side edges of the bag. Two sets of inner and outer chucks are installed at the tip of the gripper pair so that they can be opened and closed. Each chuck of each gripper consists of a fixed chuck and a movable chuck, and the inner chuck and the outer chuck move between a proximity position and a separation position. In the gripper pair that is made possible, a lock pin that locks each movable chuck in a closed and closed state is rotatably supported at a predetermined position of each chuck, and a driving force is transmitted to the lock pin to rotate forward and reverse by a predetermined angle. A transmission mechanism is installed in each gripper, and the lock pin has a pressing portion protruding in the outer diameter direction and a protrusion formed on the end surface, and the lock pin rotates in the forward direction. When the pressing portion comes into contact with and presses the closing operation portion of the movable chuck to close the movable chuck, and when the movable chuck is rotated by a predetermined angle and stopped, the movable chuck is closed, and at this time, the closing operation portion is applied to the pressing portion. The reaction force is set so as to be directed toward the axis of the lock pin, whereby the movable chuck is locked in a closed state, and the lock pin is reversely rotated from this position to unlock the movable chuck. As a part of the transmission mechanism, a rotating member that rotates forward and backward by a predetermined angle is installed at a predetermined position of each gripper corresponding to each lock pin, and the protrusion is long on the end surface of the rotating member. A groove that can be inserted or removed along the vertical direction is formed, and when the two sets of inner and outer chucks are in the close position, the protrusion and the groove are directed in the same direction, and the protrusion is inserted into the groove. The driving force can be transmitted from the transmission mechanism to the lock pin, and when the movable chuck is locked by the lock pin, the direction of the ridge and the groove is parallel to the movement direction of the two sets of inner and outer chucks, Accordingly, the pair of grippers used in the bagging and packaging machine, wherein the protrusions can be detached from the groove. 5. The device according to claim 1, wherein when the lock pin rotates in the reverse direction, the pressing portion contacts and presses the opening operation portion of the movable chuck to open the movable chuck. A pair of grippers used in the bag-packing and packaging machine described above. The pair of grippers used in the bagging and packaging machine according to any one of claims 1 to 4, wherein each gripper is provided with a spring that applies an urging force for normally opening operation to the movable chuck.

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