JPH0317701B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a band tightening method and device in a packaging machine.

[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 inside the main body of the packing machine, and the band is placed around the object to be packed by a band guide arch outside the main body or by hand. It is gripped, wrapped around the item to be packaged by the band tightening mechanism inside the main body (primary tightening), and then tightened (secondary tightening).
The method is divided into two steps, and the strength of the band tightening force on the items to be packed can be adjusted depending on the type of items to be packed. for example,
Flexible items such as futons require a tightening width that is considerably larger than the external dimensions of the item to be packed.
For hard items such as cardboard or wooden boxes, the band should be tightened to the extent that it does not sag around the item to provide sufficient strength. The tightening strength is adjusted by means of adjusting or detecting the start or end of the set tightening process.

[Conventional technology and problems]

As a means of such a tightening process, as a means of tightening the band with an arm, firstly, as shown in Utility Model Publication No. 24233 of 1972, the band is rotated by a signal surrounded by the object to be packed. a main lever that slides a certain stroke by a cam, has a band guide groove at the top, and automatically returns to its original position by springing;
A band clamping pawl that is rotated in one direction by a spring and urged away from the band guide groove surface is pivotally supported on the upper part of the main lever, and the amount of sliding movement of the lever that operates this band clamping pawl is limited. The second method is to use a packing band as disclosed in Publication of Utility Model Publication No. 20486 of 1981, which uses a stopper member that can be moved and adjusted to set the tightening start time. A rotary ring that rotates in synchronization with the shaft is provided on a shaft that tightens and drives the shaft, and one end of a swinging arm is loosely fitted onto the shaft, and an idler roller is rotatably supported on the other end of the swinging arm. At the same time, the idler roller is brought into sliding contact with the rotary wheel so as to be able to freely roll, and the band is wound around the object to be packed and tightened, and when the band is pulled back and the tightening is completed, the inertia of the idler roller when the rotary wheel is stopped causes the swinging. A limit switch is constructed so that the arm can be swung to open and close the limit switch, and the limit switch brakes the drive shaft and then stops the motor. A pair of rollers rotating in opposite directions are arranged side by side at appropriate intervals, and a packing band is wound around the pair of rollers in an S-shape. A pinch roller is provided on the side, and the pinch roller is in sliding contact with the tightening drive roller, and another roller is rotated around the axis of the roller to press and urge the band feeding side of the packing band in the direction of the pair of rollers. A limit switch is provided which is freely supported on the shaft and is actuated by the movement of the other roller, and a timer which is actuated by a signal from the limit switch,
There is a means characterized in that the rotation of the roller that performs the tightening drive is freely controllable according to the set time of the timer, and fourthly, as in JP-A No. 199408 of 1981, a drive shaft of the tightening roller is provided. A rotation detection unit is provided to detect the rotation speed of the magnet that rotates synchronously with the
It has been proposed to detect that the number of rotations of the roller has decreased to a set value and/or has stopped upon completion of tightening the band, and then cut off the power to an electromagnetic clutch interposed between the drive source and the drive source. .

These conventional tightening strength control means are arm-type ones that limit the first constant stroke.
The control range in the final tightening process is narrow, making it impossible to obtain fine adjustment or weak tightening force, and making it impossible to make the packaging machine as a whole, especially the feed unit, more compact.Furthermore, the control means for the tightening method using rollers is In the third method, the control range is narrow because it is based on the tension of the spring, and, like the fourth method, it is not possible to perform tightening with an extremely weak force. Since it has a complicated structure, it is difficult to make it compact, and it is difficult to obtain the desired tightening strength when packing various miscellaneous items. That is, since it assumes slippage due to unstable spring tension and friction of an electromagnetic clutch, etc., there is a problem in that each set value does not correspond to the actual tightening state, and so-called variations increase.

〔the purpose〕

An object of the present invention is to solve the above-mentioned problems of the prior art, and to easily adjust the tightening strength by using the actual tensile force applied to the band in the tightening process as a standard, and to make it possible to make the entire packaging machine more compact. The object of the present invention is to provide a tightening method and device that requires less tightening.

〔composition〕

In the present invention, in order to achieve the above object,
First, by tightening the band, an electromagnet holds a member that swings in a predetermined position due to the tensile force applied to the band, and the tension force applied to the band that is being tightened causes the member to swing against the magnetic force of the electromagnet. Second, the method is characterized in that tightening is completed by a signal from a detection means that detects the movement of the band. This device is provided with a member that can be freely swung by a force, this member can be held in a predetermined position by an electromagnet, and a switch means that detects the swiveling of the member is provided, and the device is equipped with a switch means for detecting the swinging of the member, and is capable of performing primary tightening and/or A member that swings due to the tensile force applied to the band in the secondary tightening is held in a predetermined position by an electromagnet, and the member swings against the magnetic force of the electromagnet using the tensile force applied to the band in the tightening process. The tightening process is completed by a signal from a switch means that detects the swinging.

〔Example〕

The details of the present invention will be explained below based on an example illustrated in the drawings.

In FIG. 1, the feed unit 70 consists of a feed roller 23 connected to a drive source, and a substrate 41 bearing a driven roller 24 that rotates in sliding contact with the feed roller 23.

In FIG. 3, a feed motor 21 is, for example, a reversible geared motor with an operating voltage of 100 V, is integrally equipped with a speed reducer, and is fixed to the substrate 41. The output shaft of the reducer passes through the substrate 41 and is connected to the drive shaft 37 of the feed roller 23. That is, as shown in FIG. 1, the feed roller 23 is provided so as to be in pressure contact with a driven roller 24, which will be described later, which is rotatably fitted into a circular cutout of a stepped portion 66 made of a straight portion and a curved portion cut into the substrate 41. It is being Furthermore, the step portion 66 is provided on the substrate 41.
The driven roller 2 is passed through a band passage groove 69 formed in a narrow groove shape that is slightly wider than the band thickness.
A circular notch step portion 67 that avoids the lower surface of the outer periphery of 4 is cut. The widths of the step portions 66, 67 and the band passage groove 69 are formed to be slightly larger than the width of the band used.

In Figures 2 to 4, 31 is a support plate;
The step portions 66 and 67, the band passing groove 69, and a band shutter 35 to be described later are attached to the substrate 41 so as to be covered, and each roller is rotatably held between the substrate 41 and the band when the band is supplied and pulled back. Prevents it from coming off both rollers and each band path.

The driven roller 24 is made up of a shaft 25 with a bearing inserted therein, as shown in FIG. The crank 27 is rotatably supported by a bearing plate 61 fixed to the plate 31, and as shown in FIG. One end of the spring 28 is connected to the other end of the spring 28, which has one end fixed to the base plate 41. The crank 27 is urged by the spring 28 toward the back of the paper in FIG. The outer periphery of the driven roller 24 is the feed roller 2.
3. Constantly pressed against the outer periphery.

In addition, as shown in the same figure, the feed roller 23 has annular grooves and depressions 36 formed around the entire circumference.
A stepped portion 66 cut into the substrate 41 by the band shooter 35 having a tip shape that fits loosely into the unevenness 36
It is provided on the straight part of.

The feed unit 70, which consists of the pair of rollers 23, 24, a drive mechanism, the substrate 41, and the support plate 31, moves together in the band supply direction due to the tensile force applied to the band when tightening the band. It constitutes a member that is swingably supported so that it can move toward and away from the shaft. That is, as shown in FIG. 3, a bearing 4 is installed on the surface facing the feed motor 21 below one machine frame 13 that supports mechanisms such as band adhesion and cutting.
4, 44 are attached, and a shaft 43 is rotatably attached to these bearings 44, 44, one end of the shaft 43 is attached to the base plate 41, and the other end is attached to the plate piece 42 that supports the end of the feed motor 21 on the side opposite to the base plate 41. Insert. Further, as shown in FIG. 1, the shaft mounting position of the feed unit is such that the center of gravity of the entire feed unit 70 is taken into account, and the upper part of the side surface of the board 41 on the machine frame 13 side is located on the machine frame 13.
It is attached so that a slight gap 48 is created between it and the upper edge.

Furthermore, an electromagnet 80 using a dry single-plate electromagnetic brake is installed at a portion of the support plate 31 that is bent parallel to the machine frame 13. That is, as shown in FIG. 2, the support plate 31 has a planar L-shape with the edge on the machine frame 13 side bent at a substantially right angle, and the electromagnet 80 has a field core 81 containing a coil attached to the support plate 3.
1, a shaft 82 having a spherical tip is fitted into the collar, and the shaft center 8 of the shaft 82 is fixed to the bent surface of
The rear end of 4 is fixed to the side surface of the machine frame 13 via a holding member 83. Furthermore, an armature 85 having a central insertion hole with a recess corresponding to the spherical surface of the tip of the shaft 82 is fitted into the shaft core 84, and a spring 86 that biases the armature 85 toward the field core 81 is attached to the shaft core 84. It is surrounded by a ring. 87
A nut locks one end of the spring 86 and adjusts the resistance of the spring 86 by rotating it. Therefore, the shaft 82 and the armature 85 provided on the shaft head are fixed in position, and the field core 81 swings together with the substrate 41 and the support plate 31.

Further, a limit switch 45 is fixed to the machine frame 13, and the tip of a touch pin 46 protruding from the limit switch 45 is attached so as to face above the side surface of the body of the feed motor 21 through a slight gap. Therefore, the touch pin 46 is pushed by the sliding movement of the substrate 41, that is, the feed motor 21, and the limit switch 45 generates a signal.

In FIG. 1, a limit switch 64 is provided at the edge of the band guide 57 below the seal unit 50, and is operated by the tip of the inserted band. In addition, 22 is a guide roller and a band passing groove 69.
65 is a band tip insertion part and is attached to a guide 68,
During normal times, this guide 68 is biased by a spring and its tip is locked onto the machine frame 13, and a band passage is provided above the feed roller 23 by providing a band passage permitting gap between the lower arcuate curved portion and the upper surface of the feed roller 23. 47, and is rotatably mounted as shown by the two-dot chain line in FIG. 1 as required.

The seal unit 50 includes press members, etc., which grip the band tip and supply end, press and cut the overlapping surface of the band by a camshaft rotationally driven by a camshaft motor (not shown), and 54 is a right press. , 58 is left press, 55 is middle press, 5
6 is a slide table, and 57 is a band guide.

Then, a band is inserted from a band reel (not shown) through the band insertion opening 34 of the band passing groove 69, and the eccentric shaft 26 of the driven roller 24 is rotated upward in the plane of the paper against the spring 28 by the crank 27, and the feed roller 23 and the driven roller are rotated. When the band is inserted with a slight gap formed between 24 and the feed motor 21 is driven forward, the feed roller 23 rotates for the time set by the timer and the band shutter 35
A predetermined amount of the band is supplied outside the main body through the band passage 47 between the upper surface and the lower surface of the guide 68. Next, the tip of the band, which is arranged or wound in a loop around the object to be packed, is inserted into the slide table 56 of the sealing unit 50 via a band guide arch (not shown) or manually, through the band tip insertion section 65.
When the limit switch 64 near the slide table 56 is pressed, the camshaft starts rotating, and the right press 54 moves the tip of the band between it and the slide table 56. When the gripping state is reached, this is stopped by a signal from a switch means that detects this from the rotation angle of the camshaft. A rated voltage of, for example, 30 V has already been applied to the coil of the electromagnet 80 by the main switch, the field core 81 has attracted the armature 85, and a gap 48 is formed between the board 41 and the machine frame 13. When the limit switch 64 is pushed in, a set tightening voltage, for example 10V, is simultaneously applied to the coil of the electromagnet 80. The camshaft motor is stopped by feed motor 2.
1, the band is pulled back between the feed roller 23 and the driven roller 24, and wound around the object to be packed (primary tightening) and tightened (secondary tightening). When the band is tightly tightened around the item to be packed, the band is held between the feed roller 23 and the driven roller 24 due to the tensile force applied to the band, and the substrate 41 is moved to the machine frame 13 while rotating.
A force is applied to pull back the field core 81 of the electromagnet 80 attached to the support plate 31 fixed to the base plate 41 in the same direction. The armature 85 tries to separate from the spherical head surface, but the armature 85 is attracted to the field core 81 due to the tightening setting voltage, and the field core 81 will not hold until the tightening torque corresponding to this setting voltage is exceeded. It is adsorbed, and the band tightening process continues. When the tightening torque is exceeded, the field core 81 separates from the armature 85 against the magnetic force of the electromagnet, and the swingable member consisting of the entire base plate 41 slides toward the machine frame 13. This sliding movement causes the outer box of the feed motor 21 to push the touch pin 46 of the limit switch 45 installed near the feed motor 21, and the limit switch 45 generates a signal, causing the front camshaft motor to rotate again and the band supply end to the left press. 58
This grip is detected by a limit switch provided on the camshaft, and the reverse rotation of the feed motor 21 is stopped in response to this signal. Then, by rotating the camshaft, the middle press 55
rises, the heater welds the overlapping part of the band and cuts the band supply end side, the band adhesion process is completed, the camshaft motor stops, and the feed motor 21
rotates forward for a set time to supply a predetermined amount of the band to the outside of the main body, and at the same time, a rated voltage is applied to the coil in the field core 81 of the electromagnet 80, and the member consisting of the entire board 41, which is swung by the band tensile force, Dead weight, armature 85 and field core 81
It returns to its previous position due to magnetic attraction. At this time, the abutting surfaces of the armature 85 and the shaft 82 are both formed into spherical surfaces that can be freely abutted, and the entire surfaces of both are tightly attracted.

Therefore, by adjusting the voltage applied to the coil of the electromagnet 80, the force that causes the field core 81 to separate from the armature 85 against the magnetic force due to the applied voltage due to the tensile force of the band applied when the band is tightened, that is, the substrate By the sliding movement of 41, it is possible to control the tightening strength obtained as the actuation timing of the limit switch 45.

In the prototype experiment according to the present invention, the applied voltage ranged from 24V to
Stepless control results were obtained in the range from 31.6Kg to 8.1Kg in the range up to 0V (when applying the set voltage, the substrate 41 was pulled with a 50Kg spring scale).

Although not shown in the drawings, by interposing a flat ring made of an extremely thin and uniform thickness on the field core 81 side surface of the armature 85, a gap is formed between both members when the armature is attracted, so that the field By reducing the magnetic force of the core,
It is possible to control the weaker so-called "ultra-weak tightening", and it is possible to wrap cake boxes, etc. with bands without crushing them (0.6 kg as measured above).

In addition, by attaching another electromagnet to the armature side and making the parts of the second electromagnet with the same polarity face each other, a gap is formed between the feed unit 70 and the machine frame 13 by the repulsive force of both electromagnets.
0 may be held at a predetermined position, and the feed unit 70 may be swung against the magnetic force of the electromagnet by the tension of the band due to tightening. In this case, it is theoretically possible to use a method in which one of the electromagnets is a permanent magnet and its magnetic poles are opposed to each magnetic pole of the other electromagnet. Furthermore, in the case of a tightening device as in the above-mentioned Utility Model Publication No. 57-27682, which is equipped with a roller that swings due to the tensile force applied to the band when tightening the band, the shaft supporting the roller is moved to a predetermined position by an electromagnet. It is possible to configure it so that it is held at

[Effects] As described above, the present invention has an extremely simple configuration that enables accurate control of the tightening strength without variation based on the tension when tightening the band, and is effective not only for the feed unit but also for the feed unit. This provides an extremely effective tightening means that can also be used to make the entire packaging machine more compact.

In the above embodiment, the tightening in the secondary tightening was explained, but the present invention also replaces the timer that sets a uniform length for the band pulling back by the roller in the arm type tightening, that is, the control of the primary tightening. can be applied similarly. In other words, with primary tightening using a timer, the band is pulled back with the same length regardless of the size of the item to be packed, and tightening is performed at a constant stroke, resulting in insufficient tightening. In the case of two, according to the present invention, it is possible to automatically control the amount of band pulling back, that is, the amount of primary tightening, and it is possible to perform sufficient tightening for objects of any size.

[Brief explanation of the drawing]

The figure shows an embodiment of the invention. Figure 1 is a front view with the electromagnet and support plate omitted, Figures 2 and 3 are partially sectional plan views,
FIG. 4 is a schematic cross-sectional view of the feed roller and the driven roller. 13...Machine frame, 23...Feed roller, 24
... Driven roller, 31 ... Support plate, 34 ... Band insertion slot, 35 ... Band shooter, 37 ... Drive shaft, 41 ... Board, 43 ... Shaft, 45 ... Limit switch, 46 ... Touch pin, 47 ... band passage, 48 ... gap, 69 ... band passage groove, 70 ... feed unit, 80 ... electromagnet, 81 ... field core, 85 ... armature.

Claims (1)

[Scope of Claims] 1. Grip the tip of the band supplied outside the main body, tighten the band to tighten it to the object to be packed, and then grasp the supplied end of the tightened band and remove the band overlapping portion in the tightened state. In a packaging machine for gluing, when the band is tightened, an electromagnet holds the member that swings in a predetermined position due to the tensile force applied to the band, and the tensile force applied to the tightened band resists the magnetic force of the electromagnet and causes the member to swing in place. A band tightening method characterized in that tightening is completed by a signal from a detection means that detects swinging of a member. 2. A packing machine that is equipped with a mechanism for supplying and tightening the packing band in the main body, a mechanism for gripping the band tip and the supply end, and various mechanisms necessary for packing such as gluing the overlapping parts of the bands, and a mechanism for tightening the band. A feed unit is provided with a member that can swing freely by the tensile force applied to the band when the band is tightened, together with or alone with this feed unit. A band tightening device characterized by being provided with a switch means for detecting.