JPS5813404B2 - automatic packing machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tape tensioning device that can vary the tape tensioning force during packaging over a wide range in an automatic packaging machine.

Generally, the tape tightening force against the object to be packed is varied by adjusting the excitation current of an electromagnetic latch provided in the tape transport mechanism.

However, in the pullback process in an automatic packaging machine, a pullback force that is sufficient to pull the tape out of the guide is required, and it is difficult to obtain a tape tightening force that is greater than this pullback force, as disclosed in Japanese Patent Application Laid-Open No.
Although it is easy as disclosed in No. 92697, it is impossible to obtain a tape tightening force that is less than the pullback force.
The adjustable range of this tape tightening force has to be very narrow, so even if an electromagnetic clutch with a wide range of torque characteristics, such as a temporary electromagnetic powder clutch, is used, it cannot be used effectively. It is.

In addition, when using a friction plate type electromagnetic clutch, due to its characteristics, when operating at a torque less than 68 to 70% of the rated torque, the value varies, so the voltage was set so as to obtain the required pullback force. Even so, the required pullback force may not be obtained, so the voltage must be set high, which has the disadvantage that the variable range of torque is further narrowed.

The present invention applies a relatively high set voltage below the rated voltage to the electromagnetic clutch when the tape is pulled back, thereby increasing the transmission torque of the clutch, and applying the torque to the packed object before the subsequent tightening, regardless of the set voltage. It is an object of the present invention to provide a novel tape tightening device that can vary the tape tightening force over a wide range by applying a necessary tightening control voltage to obtain the tightening force without applying excessive tightening force to the object to be packaged.

Embodiments of the present invention will be described below with reference to the drawings.

In the figure, 1 is a housing, 2 is a mounting table for an object to be packed, and 3 is a tape guide frame, on which the object to be packed P is placed.

Reference numeral 5 denotes a tape transport mechanism having, for example, a feed roller 6 and a driven roller 7 that rolls into contact with the feed roller 6. A packing tape 9 made of synthetic resin pulled out from a tape reel 8 is clamped between the rollers 6 and 7. The tape 9 is sent out and pulled back by rotating it forward and backward.

Reference numeral 11 denotes an operating mechanism (sealer unit) for cutting and gluing the tape 9 wrapped around the object to be packed at the overlapping part, and includes three lifting rods 12, 13, 14 that move up and down, and an upper part of these lifting rods. A sliding table 15 that slides back and forth at the camshaft 1T has a heating plate 16 for welding the tape 9 at the overlapped portion thereof, and the upper rods 12, 13, 14 are moved in a predetermined order according to the rotation of the camshaft 1T. It moves up and down.

The rotational drive mechanism for the feed roller 6 and the camshaft 17 can be divided into a one-motor type and a two-motor type. In the former case, as shown in FIG.
, and connect the pulley 21 to the belt 23 and electromagnetic clutch 24.
and the pulley 2 to the camshaft 17 via the worm gear 25.
2 are connected to the feed roller 6 through a belt 27, for example, a friction plate type electromagnetic clutch 28, and a counter gear 29, and in the latter case, as shown in FIG. The camshaft 11 is connected to the camshaft 11 through the camshaft 11, and the externally powered motor M2 is connected to the feed roller 6 through the belt 34, electromagnetic clutch 35, and counter gear 36, respectively.

Note that these rotation transmitting grooves are not limited to the illustrated embodiment, and any transmission mechanism may be used, such as a gear instead of a belt.

S1 is a tape start end detection switch disposed near the sliding table 15, 82 is a switch that detects a tape pull-back operation, which will be described later, and S3, S4, and S5 are switches that detect the rotation angle of the camshaft 17.

Thus, the operation of the electromagnetic clutch 28 is controlled by the control circuit shown in FIG.

That is, for example, a relay A1, which will be described later, is connected between the power lines Ll and L2 to which a pull-back constant voltage that can generate the torque necessary for pulling back the tape at a value lower than the rated value of the electromagnetic clutch 28 is supplied.
A series circuit of a normally open contact a11 of the relay A2 and an electromagnetic clutch 28 is inserted, and a series circuit of a normally open contact a21 of the relay A2, a normally closed contact a31 of the J-ray A3, and a variable resistor VR, which will be described later, is inserted in parallel. The slider SL of the variable resistor VR is connected between the contact all and the electromagnetic clutch 28.

Also, relay A1 has one end connected to power line L2, the other end connected to normally closed contact a22 of relay A2, and self-holding contact al of relay A1.
2, a parallel circuit of the detection switch S4 and the break contact b of the detection switch S3, and the detection switch S1.
are connected in series to the power supply line L1.

Relay A2 has one end connected to power line L2, the other end connected to normally open contact k of timer T, and normally open contacts al4 and A of relay A1.
A parallel circuit of normally open contacts a41 of No. 4 and the detection switch S
It is connected to the power supply line L1 through the make contact m of No. 3 and the detection switch S1, respectively.

Relay A4 and timer T are connected in parallel with relay A2 and timer contact k, respectively.

In this case, the timer T is set so that the contact k is turned on before the packaging tape 9 is pulled back and the detection switch S2 is turned on, as will be described later. A tightening control voltage corresponding to the object to be packed is applied to the electromagnetic clutch 28 from when it comes out to when it wraps around the object to be packed.

That is, firstly, since the electromagnetic clutch has a time delay in changing the excitation current with respect to the change in the applied voltage, even if the applied voltage is changed from the rated voltage to the tightening control voltage, the transmission torque of the electromagnetic clutch does not change immediately. Changing to the tightening control voltage at the time of completion of pulling back is good when obtaining a tightening force greater than the rated tightening force, but when obtaining a tightening force less than the rated tightening force, it is necessary to change the tightening control voltage to the desired tightening force in the first half of the tape tightening section. Since a tightening force is applied and there is a risk of damaging the packaged items, the voltage applied to the electromagnetic clutch 28 is changed to the desired tightening control voltage before the tape tightening section, and the desired tape tightening force is applied from the beginning of the tape tightening section. I'm trying to get it.

One end of the relay A3 is connected to the power supply line L2, and the other end is connected to the power supply line L1 through a parallel circuit of a resilient holding contact a32, the switch S5, a break contact m, and a detection switch S1.

Next, the operation of the above configuration of the present invention will be explained.

Now, as shown in FIG. 1, the packing tape 9 is pulled out from the reel 8, passes between the feed roller 6 and the driven roller 1, passes through the guide frame 3, and is introduced under the table 15, and the detection switch S1 is turned on. It is also assumed that the transmission mechanism is of the one-motor type shown in FIG.

If you turn on the start switch (not shown) in this state,
The motor MO is driven to rotate in the opposite direction, and the electromagnetic clutch 24 is actuated to rotate the camshaft 11. In response, the lifting rod 14 rises and clamps the starting end of the tape between it and the table 15.

Next, the detection switch S4 related to the camshaft is turned on,
As a result, relay A1 is energized and self-held, and its contact att is closed, thereby applying a rated voltage to electromagnetic clutch 28, and this clutch is operated to generate rated dynamic friction torque.

Based on this, the feed roller 6 is reversely rotated (clockwise in FIG. 1) to pull back the tape 9, and at the same time, the clutch 24 is deactivated and the camshaft 11 is stopped.

On the other hand, energization of relay A1 also closes its contacts all, so relay A4 is energized and its self-holding contact a41
is closed, the timer T is activated, and the packing tape 9
The timer contact k is turned on and the relay A2 is energized before it wraps around the object to be packed, that is, before the detection switch S2 is turned on.

Therefore, normally closed contact a22 of relay A2 opens, and relay A
Since the self-holding of the relay A1 is released, the normally open contact att of the relay A1 is opened, and the application of the rated voltage to the electromagnetic clutch 28 is released.

At the same time, the normally open contact a21 of relay A2 closes, thereby applying a control voltage to the electromagnetic clutch 28, which is lowered by the variable resistor VB depending on the object to be packed.
Thereafter, when the packing tape 9 wraps around the object to be packed, the transmission torque of the clutch is changed to a value according to the object to be packed, and the tape 9 is tightened, and the clutch 24 is operated again, and the camshaft 17 is activated again. As it is rotated, the lifting rod 12 is raised and the tightening side end of the tape 9 is clamped between it and the table 15.

Next, the detection switch S5 related to the camshaft 17 is turned on, and the relay A3 is energized, which is self-retained and its contact a31 is opened, so that the electromagnetic clutch 28
Power is cut off and it becomes inactive.

During this time, the camshaft 17 continues to rotate, so the heating plate 16 is inserted between the tapes, and the lifting rod 13 is raised to cut and bond the tape 9.

When the camshaft 17 returns to its original position, the associated detection switch S3 is turned on, and the camshaft 17 is stopped, its break contact m is turned off, and its make contact b is turned on, thereby causing relays A2A3, A4, and Timer T
is deenergized, relay A1 is energized, and electromagnetic clutch 2
The rated voltage is applied again to 8, and at the same time the motor MO
is rotated forward.

Therefore, the feed roller 6 rotates normally (counterclockwise in FIG. 1) to guide the tape 9 through the guide frame 3 and below the table 15.

When the leading edge of the tape reaches the detection switch S1, it is instantaneously turned off and the relay A1 is deenergized, thereby cutting off the energization of the electromagnetic clutch 28 and stopping the motor MO, returning to the initial state.

When the transmission mechanism is shown in FIG. 3, the motor M1 is driven to rotate only in the region in which the camshaft 17 shown in FIG.
The motor M2 starts its reverse rotation drive by the detection switch S4, stops by the detection switch S6, starts its forward rotation drive by the detection switch S3, and stops it by the detection switch S1.
The operation of the electromagnetic clutch 36 is controlled by the circuit shown in FIG. 4, or the detection switch S3 in FIG.
Omit relay AI, normally open contacts al4, a41 of A4
, normally open contact a32 of relay A3 and detection switch S5 are directly connected to detection switch S1, and detection switch S3
normally open contact a33 of relay A3 instead of break contact b
is inserted, and the normally closed contact a34 of relay A3J is inserted before relay A4 and timer T,
A rated voltage is applied to the electromagnetic clutch 36 by a detection switch S4, a control voltage dropped by a variable resistor VB is applied by a timer T, and a control voltage is applied to the electromagnetic clutch 36 by a detection switch S4.
5, the rated voltage is applied again and the current is cut off by turning off the detection switch S1, or furthermore, the rated voltage is constantly applied to the electromagnetic clutch 36 by the operating circuit shown in FIG. Only start switch SO
The contact of the timer T operated by k is turned on before the detection switch S2 is turned on, and then the switch S is turned on.
By applying a control voltage depending on the object to be packed until the switch 5 is turned on, the same packing function as in the case of FIG. 2 can be obtained.

In the case of FIG. 6, when the start switch SO is turned on, the required power is applied between the power lines L1 and L2, and when the detection switch S1 is activated, the power is cut off. It is economical because it can suppress the voltage applied to.

As described above, according to the present invention, a required voltage lower than the rated voltage is applied to the tape pullback point of the electromagnetic clutch, and a control voltage to obtain a tightening force according to the object to be packed is applied before the subsequent tightening. Therefore, the control voltage is not limited to the voltage corresponding to the pullback force required for the tape to separate from the tape guide frame, but may simply be the voltage required to tighten the object to be packed. Therefore, even if a friction plate type electromagnetic clutch is applied, the variable range of the control voltage and thus the transmission torque can be widened, and if a clutch with good characteristics such as an electromagnetic powder clutch is used, the variable range can be widened, and the pullback force can be lower than Because it can obtain a weak tightening force, it has the feature that it can reliably pack even fragile or deformable items. In Father's example, we have explained the case where the voltage applied to the electromagnetic clutch is changed using the timer T, but this is not limited to this, but it is possible to use a switch that detects the time from when the tape comes out of the tape guide until it wraps around the packaged item. Detected in S6 and made to correspond to FIG. 4, as shown in FIG. 7, timer T and relay A4 in FIG. 4 are omitted, and contact al4 is replaced by relay A2.
The self-holding contact 223 of the detection switch S
6 may be used instead of the control circuit shown in FIG. 6, and the timer T in FIGS. 5 and 6 may be replaced with a detection switch S6.

Furthermore, in each of the above-mentioned embodiments, a case has been described in which one electromagnetic clutch is used and the applied voltage is changed, but as shown in FIG. A pulley 41 forming an armature is rotatably disposed around a shaft 42, and rotors R1 and R2 having excitation coils fixed to the shaft 42 are disposed opposite to the armature. If the configuration uses a clutch, one clutch R
1 and the other clutch R2 are applied with a tightening control voltage, respectively, and the clutch CL1 is operated in the pull-back and delivery sections, and the clutch OL2 is operated in the tightening section. The same effects can be obtained.

Furthermore, as shown in FIG. 9, the present invention can of course be applied to a packaging machine having a feed roller 46 for pulling back and feeding out the tape, and a tension roller 4T for tightening the tape.

[Brief explanation of drawings]

Fig. 1 is a schematic front view of an automatic packaging machine to which the present invention can be applied, Figs. 2 and 3 are plan views showing an example of its power transmission mechanism, and Figs. 4 to 7 are diagrams of an operating circuit. FIG. 8 is a plan view showing another example of the power transmission mechanism, and FIG. 9 is a front view showing another example of the automatic packaging machine. 3 is a tape guide frame, 5 is a tape transport mechanism, 9 is a packing tape, MO, M1, M2 are motors, 28, 36, OLI
, OL2 is an electromagnetic clutch, 81 to S6n detection switch,
T is for timer.

Claims (1)

[Claims] 1. In an automatic packaging machine in which the tip of the packaging tape guided by a tape guide arch is held in a sealer unit and then the tape is pulled back and tightened by a tape transfer mechanism equipped with an electromagnetic clutch, the electromagnetic clutch is operated at a voltage lower than the rated voltage. A voltage lower than or equal to the set voltage that is inserted in the set voltage line and provides a weak tightening force to the electromagnetic clutch according to the object to be packed from the time when the tape leaves the tape guide until the tape wraps around the object to be packed. An automatic packing machine characterized by applying a tightening control voltage of