Bag supply device and packaging machine equipped with same

Abstract

To provide a packaging machine that is manufacturable at relatively low cost.SOLUTION: A bag-feeding device comprises a magazine 31 obtained by laminating and storing a plurality of bags in horizontal posture; a suction part 33 for sucking and holding a bag H from the magazine 31; and a cam mechanism for supplying the bag held by the suction part to the next step by appropriately converting a movement direction of the suction part 33, while transmitting driving of a drive source 37 to the suction part 33. It is so constituted that the cam mechanism converts to lifting / lowering movement for lifting / lowering the suction part 33 on the magazine 31, turning movement for turning the suction part 33 with a turning axis 32 as a center, and backward / forward movement for supplying the bag H to the next step by moving the suction part back and forth.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a bag supply device that supplies bags, and a packaging machine that places desired workpieces in bags supplied by the bag supply device. [Background technology]

[0002] Conventionally, a bag feeder for use in a packaging machine that supplies bags has been known, such as the bag feeder described in Patent Document 1. This bag feeder includes a magazine that can store a large number of predetermined bags stacked horizontally, a suction unit that stands by above the magazine, and a pad drive unit that moves the suction unit. The pad drive unit is composed of a cylinder that raises and lowers the suction unit and a swing cylinder that rotates the suction unit around a predetermined rotation axis. Therefore, the suction unit is configured to raise and lower in response to the drive of the cylinder to remove bags from the magazine, and to rotate in response to the drive of the swing cylinder to rotate the bag from a horizontal position to a vertical position with the opening facing upward. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5016275 Summary of the Invention [Problem to be solved by the invention]

[0004] However, as mentioned above, conventional packaging machines require both a lifting drive source and a turning drive source, which results in problems such as complicated control and high device costs. [Means for solving the problem]

[0005] The present invention was conceived in consideration of the above-mentioned problems, and aims to provide a bag supply device that can supply bags using a single drive source. To achieve this aim, the present invention provides a bag supply device that includes a magazine that stores a stack of horizontally oriented bags, a suction unit that sucks and holds bags from the magazine, and a cam mechanism that transmits drive from a drive source to the suction unit and appropriately converts the direction of movement of the suction unit to supply the bags held by the suction unit to a subsequent process, wherein the cam mechanism converts the movement of the suction unit into an up-and-down movement that raises and lowers the suction unit above the magazine, a pivoting movement that rotates the suction unit about a pivot axis, and a back-and-forth movement that moves the suction unit back and forth to supply the bags to the subsequent process. The cam mechanism preferably includes a cam follower provided on the suction portion, a fixed cam having a fixed cam groove formed therein, into which the cam follower fits and which defines the locus of the suction portion's vertical movement, pivotal movement, and back-and-forth movement, and a movable cam positioned opposite the fixed cam and capable of moving up and down in response to the drive source, the movable cam groove having a movable cam groove formed therein, into which the cam follower fits and which defines the locus of the suction portion's back-and-forth movement. The fixed cam groove of the fixed cam preferably has a horizontal portion that defines the locus of the back-and-forth movement, while the movable cam groove of the movable cam preferably has an inclined groove. When the movable cam is raised or lowered with the cam follower fitted in the horizontal and inclined grooves, the cam follower is guided by the grooves to move the suction portion back and forth. The drive source is preferably an electric actuator. The movable cam groove of the movable cam preferably has an open groove that opens upward, and the movable cam is preferably configured to be detachable from the cam follower.

[0006] A second object of the present invention is to provide a packaging machine equipped with the bag supply device described above. Preferably, the packaging machine further includes a gripping mechanism that receives and grips bags from the bag supply device, and a plurality of such gripping mechanisms are arranged on the rotary table. [Effects of the Invention]

[0007] The packaging machine of the present invention includes a cam mechanism that converts the lifting motion of the lifting drive source into lifting, pivoting, and forward motion of the suction unit, allowing bags to be fed to the next process by driving only a single lifting drive source. This eliminates the need to control multiple drive sources as in conventional packaging machines, providing advantages such as easier control. The cam mechanism, which consists of a cam follower that operates in conjunction with the suction unit and a fixed cam and movable cam that engage with the cam follower, also offers advantages such as relatively low manufacturing costs. Furthermore, the lifting drive source is an electric actuator, allowing the stopping position of the suction unit to be precisely adjusted, thereby enabling the bags and suction unit to wait in a position that does not interfere with the next process, thereby shortening cycle time. Furthermore, the movable cam has an opening groove, allowing the movable cam and cam member to be disengaged, preventing the suction unit from excessively pressing against bags in the magazine. This also offers advantages such as preventing damage to the suction unit and bags.

[0008] Furthermore, a packaging machine equipped with the above-described bag feeding device has the advantage that the bag feeding device can be controlled by a single drive source, making control simple, and therefore can be manufactured inexpensively. Furthermore, because the suction unit is designed to move forward, even in a packaging machine in which the gripping mechanism rotates in accordance with the rotation of the turntable, there is the advantage that the suction unit and bags can be prevented from interfering with the gripping mechanism, allowing bags to be handed over reliably. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a schematic plan view showing the structure of a packaging machine according to the present invention. [Figure 2] 2 is a schematic plan view showing the operation of transitioning from the state in FIG. 1 to the next state. [Figure 3] 2 is an enlarged, partially cross-sectional side view of a main portion showing the structure of the bag supply device according to the present invention. FIG. [Figure 4] 4 is an enlarged, partially cross-sectional side view of a main part showing an operation of transitioning from the state of FIG. 3 to the next state. [Figure 5] 5 is an enlarged, partially cross-sectional side view of a main part showing an operation of transitioning from the state of FIG. 4 to the next state. [Figure 6]2 is an enlarged plan view of a main part showing the structure of the bag feeding device according to the present invention. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0010] An embodiment of the present invention will now be described with reference to the drawings. In FIGS. 1 and 2, reference numeral 10 denotes a packaging machine 10 that places predetermined workpieces in rectangular bags H. As shown in FIG. 1, the packaging machine 10 includes a drive motor 12 fixed to a base 11 and a rotary table 13 that is driven by the drive motor 12 and can rotate intermittently. The rotary table 13 is also provided with a plurality of gripping mechanisms 20 that grip the bags H at predetermined intervals along the circumference. Also provided on the base 11, as shown in FIG. 1, are a bag feeder 30 that supplies bags H to a position where the gripping mechanisms 20 are stopped by the rotary table 13 for intermittent rotation, an opening mechanism 40 that opens the bags H, a loading mechanism 50 that places works in the opened bags H, a sealing mechanism 60 that closes the openings of the bags H containing the works, and a discharge chute 70 that discharges the bags H with their openings closed. The packaging machine 10 also includes a control unit (not shown) that controls the operation of each mechanism.

[0011] The bag H is a rectangular flat bag with one side that can be opened, and is set to a capacity that allows the workpiece to be stored inside. The bag H has a two-layer structure consisting of an outer layer made of aluminum and an inner layer made of polypropylene, which is an example of a thermoplastic resin, and is configured so that the polypropylene inner layer is welded when heated, making it possible to seal the heated area.

[0012] The gripping mechanism 20 has a pair of gripping claws 21, 21 that grip the side edges of the bag H, and these gripping claws 21, 21 are configured to be able to open and close when driven by a predetermined gripping claw opening and closing mechanism.

[0013] As shown in FIG. 3, the bag supply device 30 includes a magazine 31 capable of storing the bags H. The magazine 31 is configured in a box shape that opens upward, and stores a plurality of horizontally oriented bags H stacked inside. A horizontally extending pivot shaft 32 is provided above the magazine 31, and a suction unit 33 is supported by the pivot shaft 32 so as to be rotatable and suspended. The suction unit 33 has a slide table 331 supported by the pivot shaft 32, and the slide table 331 is positioned so that its sliding portion 332 slides toward and away from the pivot shaft 32. A suction pad 34 capable of suction-holding the bags H is attached to the sliding portion 332, and a supply suction means (not shown) is connected to the suction pad 34. Therefore, when the supply suction means is activated, the bags H can be suction-held by the suction pad 34. The bags H are aligned in magazine 31 so that the openings face forward, and so that the openings face upward when bag supply device 30, which will be described later, is turned.

[0014] 6, suction portion 33 is provided with cam follower 35 arranged parallel to pivot shaft 32. Cam follower 35 is connected to sliding portion 332 of slide table 331 and configured to maintain a fixed distance from suction pad 34. Bag feeder device 30 also has fixed cam 36 that engages with cam follower 35 and lifting drive source 37 that raises and lowers cam follower 35. Fixed cam 36 is a plate-like member that is thinner than cam follower 35 in the longitudinal direction, and has fixed cam groove 361 formed therethrough that engages with cam follower 35. The fixed cam groove 361 is composed of a vertical groove 362 extending in the up-down direction, a curved groove 363 that continues from the upper end of the vertical groove 362 and gradually curves forward (toward the radial inside of the rotary table 13) as it extends upward, and a horizontal groove 364 that continues from the upper end of the curved groove 363 and extends forward. Furthermore, a movable cam 38 is connected to the movable part of the lifting drive source 37. The movable cam 38 is a plate-like member that is disposed opposite the fixed cam 36, and a movable cam groove 381 that engages with the cam follower 35 is also formed in the movable cam 38. The movable cam groove 381 is formed at a position overlapping the vertical groove 362 of the fixed cam groove 361 and is composed of an open groove 382 that opens upward, and an inclined groove 383 that continues from the front of the open groove 382 and gradually inclines downward as it extends forward.

[0015] Due to the above structure, when the lifting drive source 37 has lowered the movable part, the cam follower 35 descends along the fixed cam groove 361 due to the weight of the slide table 331, etc., and the suction pad 34 comes into contact with the uppermost bag H in the magazine 31. On the other hand, when the lifting drive source 37 raises the movable cam 38, the open groove 382 of the movable cam 38 abuts against the cam follower 35, pushing it upward. As a result, the cam follower 35 rises along the fixed cam groove 361, and the sliding part 332 and the suction pad 34 of the slide table 331 rise as shown by the two-dot chain line in Figure 3, and the slide table 331 rotates until it faces horizontally as shown in Figure 4. 5, the cam follower 35 advances along the inclined groove 383 of the movable cam groove 381 and the horizontal groove 364 of the fixed cam groove 361, thereby advancing the sliding portion 332 of the slide table 331 and the suction pad 34 connected thereto. In this way, the fixed cam 36 has the fixed cam groove 361 formed therein, which fits into the cam follower 35 and forms the locus of the up-and-down movement, pivoting movement, and back-and-forth movement of the suction part 33, and the movable cam 38 has the movable cam groove 381 formed therein, which fits into the cam follower 35 and forms the locus of the back-and-forth movement of the suction part 33, thereby enabling the suction part 33 to be moved up and down, pivoting, and back-and-forth by driving a single lifting drive source 37. The lifting drive source 37 is an electric actuator configured to be able to adjust the lift stop position of the movable part, and is configured to be able to adjust the amount by which the movable part and movable cam 38 push the cam follower 35 forward in accordance with a signal from the control unit.

[0016] The opening mechanism 40 is provided at approximately the same height as the gripping mechanism 20, and includes a pair of opening suction pads 41, 41 that abut against the front and back surfaces of the bag H gripped by the gripping claws 21, 21, respectively, and a pad opening drive unit (not shown) that drives the opening suction pads 41, 41 back and forth in a direction perpendicular to the bag H. An opening suction means (not shown) is continuous with the opening suction pad 41, and when the opening suction means is activated, the opening suction pad 41 can suck the bag H.

[0017] The feeding mechanism 50 is composed of a feeding chute 51 provided above the gripping mechanism 20, and a feeding drive unit (not shown) that raises and lowers the feeding chute 51. An external component supply device (not shown) is connected to the upper side of the feeding chute 51, and is configured so that any number of components supplied from the component supply device can be fed into the bag H.

[0018] The sealing mechanism 60 is composed of a pair of heater members 61, 61 arranged to clamp the area near the opening of the bag H, and a sealing drive unit (not shown) that drives the heater members 61, 61 back and forth in a direction perpendicular to the bag H, and the heater members 61, 61 are configured to heat the bag H to a temperature at which it can be welded when electricity is applied.

[0019] The discharge chute 70 is made of a hollow tubular member that is wide enough for the bag H, and is arranged so that its upper open end is positioned below the bag H held by the holding mechanism 20.

[0020] Next, the operation of the packaging machine 10 configured as above will be described. As shown in Fig. 3, when a drive signal is input while the suction pad 34 is in contact with the top bag H in the magazine 31, the control unit activates the gripping jaw opening / closing mechanism to open the gripping jaws 21 and drives the air intake means to suction and hold the bag H on the suction pad 34. When the suction pad 34 adsorbs the bag H, the lifting drive source 37 is driven to lift the movable cam 38. As a result, the cam follower 35, which is pushed up by the movable cam 38, rises along the fixed cam groove 361, and the suction pad 34 and the bag H are driven to rise and rotate in conjunction with the cam follower 35, as indicated by the two-dot chain line in Fig. 3. At this time, the cam follower 35 moves diagonally upward and forward along the curved groove 363 of the fixed cam groove 361, so that the point of contact with the movable cam 38 moves from the open groove 382 toward the inclined groove 383. As a result, as shown in FIG. 4, when the cam follower 35 reaches the curved groove 363 of the fixed cam groove 361, the cam follower 35 abuts against the inclined groove 383 of the movable cam 38. Therefore, the lifting drive source 37 further raises the movable cam 38, allowing it to advance along the horizontal groove 364 and the inclined groove 383. As shown in FIGS. 5 and 6, the suction pad 34 and the bag H advance, allowing the bag H to be supplied to the gripping mechanism 20 waiting in front. Since the device is equipped with both the fixed cam 36 and the movable cam 38 and can raise, lower, rotate, and advance the suction pad 34 with a single lifting drive source 37, control is simplified and manufacturing costs are relatively low. At the same time, a linear drive source for advancing the suction pad 34 is not required, and the area around the suction pad 34 is smaller than in conventional supply devices, allowing for a more compact device. Furthermore, the lifting drive source 37 is an electric actuator that can adjust the lift stop position of the movable cam 38, and the amount of forward pushing of the cam follower 35 can be precisely controlled, which makes it easy to adjust the position when changing levels, etc., and also reduces the burden on the worker.

[0021] When a bag H is supplied as described above, the control unit operates the gripper opening / closing mechanism in the reverse direction to close the gripper claws 21. When the gripper claws 21 close and grip both side edges of the bag H, the control unit stops driving the supply suction means and reversely drives the lifting drive source 37 to lower the movable cam 38. As a result, the suction pad 34 descends until it abuts against the uppermost bag H in the magazine 31 and stops. At this time, because the open groove 382 is formed in the movable cam groove 381, when the suction pad 34 abuts against the bag H and stops, the movable cam 38 can separate from the cam follower 35. Therefore, no force other than the weight of the sliding portion 332 of the slide table 331, such as a downward thrust from the lifting drive source 37, is applied to the suction pad 34 and the bag H. In this way, excessive downward thrust is not applied to the bags H or suction pads 34, preventing damage to the suction pads 34 and wrinkling of the bags H. At the same time, there is no need to adjust the lowering stop position of the lifting drive source 37 according to the number of bags H remaining in the magazine 31, and there is no need to provide a mechanism for adjusting the height of the uppermost bag H to a constant value regardless of the number of bags H remaining in the magazine 31, simplifying the control of the bag supply device 30. Furthermore, because the lifting drive source 37 is an electric actuator that can adjust the lifting stop position of the movable cam 38 and can precisely control the amount that the cam follower 35 is pushed forward, position adjustments during tasks such as changing shelves are easier, reducing the burden on the worker.

[0022] After the suction pads 34 have separated from the bag as described above, the control unit rotates the turntable 13 to move the gripping mechanism 20 and bag H toward the opening mechanism 40. When the gripping jaws 21 reach a position opposite the opening mechanism 40, the control unit stops the turntable 13 and drives the opening drive unit to move the opening suction pads 41, 41 closer to each other. When the approaching opening suction pads 41, 41 come into contact with the front and back surfaces of the bag H, respectively, the control unit drives the opening suction means and again drives the pad opening drive unit to move the opening suction pads 41, 41 away from each other. As a result, the front and back surfaces of the bag H are pulled in different directions, opening the bag H. When the bag H is opened, the control unit stops the opening suction means and removes the opening suction pads 41, 41 from the bag H. When the opening suction pads 41, 41 are released from the bag H, the control unit rotates the turntable 13 again, and moves the gripping mechanism 20 and the bag H toward the insertion mechanism 50.

[0023] When the gripping claws 21 reach below the feeding mechanism 50, the control unit stops the turntable 13 and drives the feeding drive unit to insert the feeding chute 51 into the opening of the bag H. When the feeding chute 51 is inserted into the bag H, the component supply device is driven to feed the components into the bag H. When a predetermined amount of components has been fed, the control unit double-acts the feeding drive source to remove the feeding chute 51 from the bag H and rotates the turntable 13 again to move the gripping mechanism 20 and the bag H toward the sealing mechanism 60. Thereafter, when the moving gripping claws 21 reach below the sealing mechanism 60, the control unit stops the turntable 13 and drives the sealing drive unit to bring the heater members 61, 61 closer to each other. The heater members 61, 61, which have come close to each other in this manner, come into contact with the front and back surfaces of the bag H, respectively, and the vicinity of the opening of the bag H is welded by the heat of the heater members 61, 61. The control unit then double-acts the sealing drive unit to move the heater members 61, 61 away from the front and back surfaces of the bag H, and rotates the turntable 13 again to move the gripping mechanism 20 and the bag H toward the discharge chute 70. When the gripping claws 21 reach the top of the discharge chute 70, the control unit stops the turntable 13 and drives the gripping claw opening and closing mechanism, which opens the gripping claws 21 and drops the bag H into the discharge chute 70. The control unit then rotates the turntable 13 again, and moves the gripping mechanism 20 toward the bag supply device 30 to receive the next batch of bags H.

[0024] The bag supply device 30 according to the present invention is not limited to the above-described configuration, and various modifications are possible without departing from the spirit of the invention. For example, the bag supply device 30 is not limited to the packaging machine 10 configured to transfer bags H as the rotary table 13 rotates. It may also be applied to other packaging machines, such as a packaging machine (not shown) that opens bags H and accommodates workpieces at the position where the bag supply device 30 supplies the bags H, as shown in Patent Document 1. In the case of a packaging machine such as that shown in Patent Document 1, a separate suction pad for opening the bags may be provided opposite the suction pad 34, and the lifting drive source 37 may be configured to lower the movable cam 38 after the opening suction pad adsorbs the bag. This causes the suction pad 34 to retreat, allowing the bag to be opened.

[0025] Furthermore, it is preferable that the cam mechanism consisting of cam follower 35 and the fixed cam 36 and movable cam 38 be changed according to the size of the packaging machine and the bags, etc. Furthermore, after suction pad 34 contacts the next-stage bag H, bag feeder 30 may again drive suction means and lift drive source 37 to transport the next-stage bag H to the vicinity of gripping mechanism 20. At this time, it is preferable that lift drive source 37 stop at a predetermined position so that suction pad 34 and bag H, etc. do not get caught in the next-stage gripping mechanism 20. By having bags H wait before the next-stage gripping mechanism 20 arrives in this way, it is possible to shorten the supply time of bags H and improve the cycle time. [Explanation of symbols]

[0026] 10 … Packaging machine 13... Rotating table 20 … Gripping mechanism 30 … Bag feeding device 31 … Magazine 32 ... Swivel axis 33 … Adsorption part 34...suction pad 35... Cam follower 36... Fixed cam 361... Fixed cam groove 37 ... Supply lift drive source 38... Movable cam 381... Movable cam groove

Claims

1. a magazine for storing a plurality of horizontally oriented bags in a stack; a suction unit that suctions and holds the bag from the magazine; a cam mechanism that transmits drive from a drive source to the suction unit, appropriately changes the direction of movement of the suction unit, and supplies the bag held by the suction unit to a next process, In the bag feeding device, the cam mechanism is configured to convert the movement into an up-and-down movement that raises and lowers the suction unit on the magazine, a rotational movement that rotates the suction unit around a rotational axis, and a back-and-forth movement that moves the suction unit back and forth to supply bags to the next process, The cam mechanism a cam follower provided on the attraction portion; a fixed cam having a fixed cam groove formed therein, into which the cam follower is fitted and which defines the locus of the lifting and lowering movement, the turning movement, and the back and forth movement of the suction part; a movable cam provided at a position opposite to the fixed cam so as to be able to move up and down in accordance with the driving of the drive source, the cam follower being fitted therein, and having a movable cam groove formed therein that forms a forward and backward movement locus of the suction portion, a bag feeder configured such that, in the fixed cam groove of the fixed cam, the portion that forms the back-and-forth movement locus is formed as a horizontal groove, while the movable cam groove of the movable cam is formed as an inclined groove, and when the movable cam is raised and lowered with the cam follower fitted in the horizontal groove and the inclined groove, the cam follower is guided by these grooves, causing the suction portion to move back and forth.

2. 2. The bag supply device according to claim 1, wherein the drive source is an electric actuator.

3. 3. The bag feeding device according to claim 1, wherein the movable cam groove of the movable cam has an open groove that opens upward, and the movable cam is configured to be detachable from the cam follower.

4. A packaging machine equipped with the bag supply device according to any one of claims 1 to 3.

5. 5. The packaging machine according to claim 4, further comprising a gripping mechanism for receiving and gripping bags from the bag supply device, a plurality of such gripping mechanisms being arranged on the rotary table.

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