JPS63232111A - Band stretcher in packaging machine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] [Industrial usage total]

The present invention involves the step of feeding the band to the outside of the wrapping machine main body using a pair of feed rollers that rotate while in sliding contact with each other, and pulling back the band that has passed around the object to be packed. a step of winding a band around the item to be packed;
The present invention relates to a band tightening device in a packing machine that performs a process of strongly tightening a band to an object to be packed.

[Technical background]

In the band tightening process in a packing machine, the band is fed out of the main body by a band supply mechanism within the main body of the packing machine, and the tip of the band is placed around the object to be packed by a band guide arch outside the main body or manually, and is gripped by a press member. The band is pulled back and tightened in the main body by a mechanism that wraps the band around the item to be packed (primary tightening), and then tightens it (secondary tightening). The strength of the band tightening force depends on the type of items to be packed.As for the means for sending the band out of the packing machine body, pulling it back, and tightening it, Japanese Patent Publication No. 58-39694 and Japanese Patent Application Laid-Open No. 61-2599
As described in Publication No. 12, a motor that always rotates at a constant speed and torque is connected to a drive shaft of a feed roller via a reduction mechanism, and the rotation shaft in the reduction mechanism and/or the feed roller is driven. By providing an electromagnetic clutch, a friction clutch, and a one-way clutch on the shaft and transmitting the rotation of the high-speed side or low-speed side output shaft of the reduction mechanism to the feed roller via a chain, pulley, or other motion transmission member, band supply and - There is one in which the secondary tightening is performed at high speed and low torque, and the secondary tightening is performed at low speed and high torque. In addition to the above-mentioned conventional methods, all packaging machines in the past have the versatility of being compatible with three-phase AC (200V) supplied to factories, etc. or single-phase AC (100V) for general household use. In order to achieve this, a three-phase AC/single-phase AC induction motor is used and rotated at a constant number of revolutions at the frequency of the region where it is used, and this rotational force is transmitted to the feed roller via a W4-speed mechanism and a friction clutch. It could be said to be a common method. In other words, all past packaging machines were
We focused on producing a low-cost packaging machine without using parts such as AC/DC converters and transformers, and we stuck to AC motors using the friction clutches, electromagnetic clutches, and various reverse motion transmission mechanisms mentioned above. This is what I was looking for. As a result, as mentioned above, in the conventional technology, friction clutches, one-way clutches, and various motion transmission mechanisms are essential, resulting in a large number of parts, a complicated assembly process, an increase in the size of the device, and an increase in cost. This had the following problem. In order to solve this problem, the applicant has already proposed a compact packaging machine in which a single-phase AC motor with a reduction gear is directly connected to the drive shaft of the feed roller, such as in Japanese Utility Model Application No. 61-48103. In this method, in order to obtain high torque during secondary tightening, the rotation of the motor is decelerated through a reducer, and the feed roller is simply rotated in forward and reverse directions at a low constant rotation speed, resulting in poor packaging efficiency and For example, the motor direct coupling mechanism is suitable for packing relatively small objects on a table, but it is somewhat difficult to use the motor direct coupling mechanism for general purposes.

【composition】

The present invention aims to solve the problems in the conventional means described above, and the inventors have discovered that a single-phase AC series-wound commutator motor or a DC series-wound or compound-wound motor can be used as a variable speed electric motor. They focused on the direct winding characteristic, in which the speed decreases as the load increases, and considered the use of this characteristic in the band supply and tightening processes in packaging machines.As a result of long-term experiments, they completed the present invention. This is what led me to do this.
The feed roller is characterized in that a motor with series winding characteristics is connected to the feed roller. Therefore, when the band is pulled back at high speed and low torque by a pair of feed rollers and wound around the packaged item (primary tightening) and tightened (secondary tightening),
The number of rotations IEm of the feed roller also decreases, and in accordance with this decrease in number of rotations, the torque of the series motor increases in inverse proportion to this, and the band is strongly tightened against the item to be packed at low speed and high torque.

【Example】

The details of the present invention will be explained below based on an example illustrated in the drawings. The pair of feed rollers includes a feed roller 23 connected to a drive source attached to the substrate 41, and a driven roller 24 that rotates in sliding contact with the feed roller 23. 21 is a motor connected to an AC power source via a rectifier, for example, with a rated voltage of 140V and an operating voltage of 140V to 8
It is a DC series motor that can change the number of rotations between 0V and adjust the tightening strength, is integrally equipped with a deceleration mechanism 39, and is fixed to the substrate 41. The output shaft 37 of the speed reduction mechanism passes through the substrate 41, and the feed roller 23 is directly connected to the shaft end. The feed roller 23 is rotatably fitted into a circular cutout of a stepped portion 57 formed on the substrate 41 and consisting of a straight portion and a curved portion, and is provided so as to be able to come into pressure contact with a driven roller 24, which will be described later. Further, in the substrate 41, a band passage groove 5 is formed in the shape of a narrow groove slightly wider than the band thickness, continuous with the step portion 57.
A cutout step 53 is cut through the groove 9 to avoid the lower outer circumferential surface of the driven roller 24. The widths of the step portions 57, 63 and the band passage groove 59 are formed to be slightly larger than the width of the band used. 1 and 3, reference numeral 31 denotes a support plate, which is attached to the base plate 41 so as to cover the step portions 57, 53, the band passage groove 59, and the band shooter 35, which will be described later.
The rollers are rotatably sandwiched between the rollers and the substrate 41, and the band is prevented from coming off from both rollers and each band path when the band is supplied and pulled back. The driven roller 24 consists of a bearing inserted into a shaft 25 as shown in FIG.
It is rotatably supported by a bearing plate 51 fixed to the support plate 31, and is connected to a rod 27 having a spring 2B of the solenoid 20 mounted around the head of the shaft 26 exposed from the bearing plate 51. The eccentric shaft 26 is biased by a spring 28 in a direction in which the shaft 25 of the driven U-roller 24 is moved away from the outer periphery of the feed roller 23 about the shaft 26 during normal times. The drive shaft 32 of the motor 21 faces inside the deceleration mechanism 39,
The shaft 32 has a pinion carved into its tip, and a stop ring 33 is provided at the t&end of the shaft, and a magnet 36 is embedded in the stop ring 33. Further, 38 is a rotation detecting section, and the magnet 3
6 detects the rotation speed of the drive shaft 32, and when the rotation speed falls below the set rotation speed, an output signal is obtained. 22 is a guide roller that is attached to the band insertion opening 34 of the band passage groove 59, and 55 is a band tip insertion portion that is attached to the base plate 41 on the upper surface of the band shooter 35. 58 is a shooter guide, and this guide 58 is
In normal times, the tip is biased by a spring such as a torsion spring, and the tip is locked on a step cut into the substrate 41, and a gap is provided between the arched curved portion of the lower surface and the upper surface of the outer periphery of the feed roller 23 to allow the band to pass through. A band passage 47 is formed on the feed roller 23, and a band passage 47 is formed on the bottle 52 as shown by the two-dot chain line in FIG.
The feed roller 23 is rotatably attached so as to open the upper surface of its outer periphery. Further, in FIG. 2, reference numeral 42 denotes an electromagnetic brake, which is provided on the output shaft 32 of the DC motor 21. In addition, each press member, etc., which is rotatably driven by a camshaft motor and grips the band tip and supply end, presses and cuts the overlapping surface of the band, and the like is provided.
54 is the right press, and 56 is the slide table. Then, a band passing groove 59 is inserted from the band reel (not shown).
The band is inserted through the band insertion opening 34 via the guide roller 22, and the return shaft 26 of the driven roller 24 is connected to the spring 28.
The DC motor 2 pushes the band through the gap formed between the feed roller 23 and the driven roller 24.
1 is incorrectly rotated in the forward direction, the timer is activated at the same time, and the solenoid 20 is applied and energized for a predetermined period of time, the rod 27 rotates, and the eccentric shaft 26 rotates with respect to the feed roller 23. The feed roller 23 rotates for the time set, and the driven roller 2 rotates with respect to the feed roller 23.
4 are in pressure contact, the band is held between both rollers, and the guide 58
A predetermined amount of the band passes through the band shooter 35 through the band passage 47 between the lower surfaces and is supplied to the outside of the main body, and the band is arranged or wound in a loop around the object to be packed. In response to a time-up signal from the timer or a signal detecting that the band tip is pushed into the lower surface of the slide table 56 of the seal unit through the band tip insertion portion 55, the solenoid is turned OFF, and the feed by the solenoid 20 is turned off. The pressure of the driven roller 24 against the roller 23 is released, and at the same time, a voltage is applied to a camshaft motor (not shown), the camshaft starts rotating, and the right press 54 reaches a state where the band tip is held between it and the slide table 56. The camshaft is stopped by a signal from a switch means that detects the grasping of the band tip from the rotation angle of the camshaft. The stop signal of the camshaft motor applies and energizes the solenoid 2.0 again, causing the driven roller 24 to come into pressure contact with the feed roller 23, and also becomes a signal that starts the reverse drive of the DC motor 21, causing the band to move to the feed roller. 23 and the driven roller 24, it is pulled back at high speed and with low torque to wrap around and tighten the packaged object)
When tightening (secondary tightening), the rotation speed of the feed roller 23 also decreases, and the torque increases in accordance with this decrease in rotation speed, and this torque is transmitted to the DC motor 21 via the output shaft 37 of the reduction mechanism. Due to the direct winding characteristic of the DC motor 21, the feed roller 23 rotates at low speed and high torque, and the band is strongly tightened around the item to be packed. At this time, the rotation speed of the magnet 36 in the stop ring 33 provided at the end of the output shaft 32 of the DC motor 21 also decreases, and finally comes to a stop. Therefore, the rotation detection unit 3B provided near the rotation locus of the magnet 36 emits a detection signal that detects a decrease in the rotation speed of the output shaft 37 of the deceleration mechanism, that is, the feed roller 23 (reduction including stoppage), The electromagnetic brake 42 on the output shaft 32 of the DC motor 21 is actuated to stop the reverse drive, and the front camshaft motor rotates again.The band supply end is gripped by the left press 58 to maintain the tightened state, and the solenoid is turned OFF, the pressure of the driven roller 24 against the feed roller 23 by the solenoid 20 is released, and then the middle press is raised and the band overlapped portion is welded by the heater pushed between the band overlapped portions, and the band supply end is welded. Side cutting is performed, the band bonding process is completed, the camshaft motor is stopped, the solenoid is activated as described above, and the DC motor 21 is activated.
The electromagnetic brake 42 on the output shaft 32 is released, and the DC motor 21 rotates forward for a set time to supply a predetermined amount of the band to the outside of the main body, thereby completing one packing process. In the above embodiment, the purpose is achieved by turning on the DC motor 21, so the electromagnetic brake 42 is not essential.

【effect】

As described above, the present invention has an extremely simple structure in which a motor with a series winding characteristic connected to an AC power supply circuit is connected to the feed roller via a reducer. By using this machine, secondary tightening can be performed at high speed and low torque, and secondary tightening can be performed at low speed and high torque, which provides the necessary and sufficient tightening as a general-purpose packaging machine, and can also be used to make the entire packaging machine more compact. This provides an extremely effective means of achieving this goal.

[Brief explanation of drawings]

The figure shows an embodiment of the invention. 1 and 2 are sectional views of essential parts, and FIG. 3 is a side view. 20... Solenoid 21... DC motor 23... Feed roller 24... Followed roller 26... Eccentric shaft 32... Output shaft (motor) 36... Magnet
37... Output shaft (reducer, shaft of feed roller 23) 38... Rotation detection section 41... Substrate 47... Band passage patent applicant Strabak Co., Ltd. agent Kakashi Masaaki Kokura 1st Figure 2 Figure 3

Claims (3)

[Claims] (1) In a packing machine, the main body includes a feed roller that feeds, pulls back, and tightens the packing band, a gripping mechanism for the band tip and the feeding end, and a camshaft that operates the bonding and cutting mechanism for the overlapping part of the band. A band tightening device characterized in that a motor with a series winding characteristic connected to an AC power source is connected to the feed roller via a speed reducer. (2) The band tightening device according to claim 1, wherein a series- or compound-wound DC motor connected to an AC power supply via a rectifier is directly connected to the feed roller via a speed reducer. (3) The band tightening device according to claim 1, wherein a single-phase AC series-wound commutator motor is directly connected to the feed roller via a speed reducer.