JPH07187118A - Packing machine - Google Patents

Abstract

PURPOSE:To make setting of stabilized force possible at all times for secondary fastening by a method wherein the secondary fastening is executed at the maximum torque with a stepping motor for feeding and back-feeding provided in a mechanism that winds and fastens a band around the outer circumference of an article to be packed. CONSTITUTION:As a stepping motor M2 for feeding and back-feeding is actuated, a band is supplied and wound round an article to be packed with a distance kept from the article, and setting is completed with the motor M2 stopped. Then, a cam motor M1 is actuated and the front end of the supplied band is clamped with a clamp cam operated by the cam motor, and at the same time the motor M1 stops. The motor M2 is then actuated to turn in the direction of back-feeding and primary fastening is started with high-speed, low-torque driving. Pulse generated on passing over a Hall element 108 on turning of an output shaft 82 is counted repeatedly with a CPU, and as tension above the required value works with the band brought into contact with the outer circumferential face of the article to be packed, the state is recognized as stepping-out, and the work is advanced automatically to the process of secondary fastening.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a packing machine, and in particular,
The present invention relates to a packing machine capable of automatically or semi-automatically performing a work of winding a tape-shaped band made of a thermoplastic resin such as polypropylene around a product to be packed and bonding the polymerized portion by welding.

[0002]

2. Description of the Related Art Generally, in order to improve the efficiency and labor saving of packing work, a tape-shaped band made of a thermoplastic resin is wound around an object to be packed, and the band is tightened. A packaging machine has been already put into practical use, which is capable of heating, melting, and pressure bonding, and automatically or semi-automatically performing the work up to cutting. That is, as is well known, this type of packaging machine rotationally drives a cam shaft and various cams fitted and fixed to the cam shaft by a driving force from an electric motor, and presses, a heater plate, Mechanisms such as a slide table are operated at different timings to perform binding work such as gripping, pressing, melting and cutting of bands.

In such a conventional packing machine, as the tightening operation of the band, there are two steps of tightening, that is, a primary tightening for tightening the band at high speed and low torque, and a secondary tightening for tightening the band at low speed and high torque. It is generally performed (see, for example, Japanese Patent Publication No. 4-13205). The transition from the primary tightening to the secondary tightening is performed by switching the operation mode with a switch or the like for detecting the tension (see, for example, Japanese Patent Laid-Open No. 61-21304).

Further, the applicant of the present invention has proposed the provision of a band according to the specification of Japanese Patent Application No. 5-226189 filed previously.
As a motor for tightening (feed / back feed) and a motor for driving a cam, a stepping motor that can control the rotation speed and movement amount quickly and accurately according to the number of pulses is used. The present invention proposes a packing machine in which a resonance prevention damper is provided on the output shaft of the device and a step-out sensor is arranged on the main body side of the damper and the motor so that the CPU counts the number of pulses by using a Hall element and a magnet. According to this proposal,
The CPU counts the number of motor drive pulses that are counted within one pulse interval that occurs when the magnet passes through the position where the Hall element is disposed, and the number exceeds a predetermined value (a load tension of a predetermined value or more If it is determined that step out has occurred, it is possible to automatically and smoothly switch from the primary tightening to the secondary tightening.
Generation of vibration and noise can be suppressed.

[0005]

In the conventional packing machine as described above, when the secondary tightening is performed, it is based on the experience of the operator according to the size, shape, property, etc. of the object to be packed. The secondary tightening was performed with the preset secondary tightening amount. That is, it is empirically determined that a futon that is easily deformed requires a relatively large amount of secondary tightening, whereas a small amount of secondary tightening that is difficult to deform such as wood is sufficient. Then, the secondary tightening was performed with the tightening amount set appropriately.

Therefore, the operator must adjust the secondary tightening amount by trial and error until the proper secondary tightening amount is obtained each time depending on the type of the object to be packaged, which requires a great deal of time and skill. There was a problem that skill was required and work efficiency decreased. The present invention has been made in view of such a problem, and an object thereof is to make it possible to easily set an optimum and stable secondary tightening force regardless of the type or property of the object to be packed. In addition, it is possible to prevent the band from being pulled out and damage to the items to be packed, etc.
Another object of the present invention is to provide a packaging machine that can reduce power consumption cost and can be configured easily and inexpensively.

[0007]

In order to achieve the above object, a packing machine according to the present invention is a drive source of a mechanism for carrying out work such as sending out and tightening of a band wound around the outer periphery of an article to be packed. A packing machine including a certain feed / back feed stepping motor, and performing secondary tightening with a maximum torque based on a speed-torque characteristic of the feed / back feed stepping motor,
The present invention is characterized by comprising current supply means for supplying a current to the feed / back feed stepping motor, and operation means for varying the maximum torque by changing the output current from the current supply means.

[0008]

[Operation] In the packing machine according to the present invention configured as described above, by changing the supply current to the feed / back feed motor by operating the operation means,
By changing the maximum torque used for secondary tightening, the optimum and stable secondary tightening force can always be obtained.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1 is a schematic plan view with a top plate removed to show the entire interior of a packaging machine according to an embodiment of the present invention, FIG. 2 is a schematic front view, and FIG. 3 is a schematic side view taken along the line III-III of FIG. is there.

1 to 3, the packing machine 1 of this illustrated example
Is a column 3 equipped with casters 2, 2, ... at its lower end,
, ..., a top plate 4 horizontally mounted and attached to the upper ends of the columns 3, 3, ..., Side plates 5 that are attached to surround the four side surfaces, and side plates 5 of the side plates 5. A substantially box-shaped packing machine main body 10 including an inspection port and the like (not shown) that are openably provided at appropriate places is provided as a frame member. Further, a band guide arch (not shown), which is formed on the upper part of the packing machine body 10 and is made of a tubular body formed in a substantially U-shape downward, for automatically arranging the band B around the object to be packed. Can be installed if necessary. In addition, the columns 3, 3,
The top plate 4 is integrally formed of, for example, an extruded aluminum material.

A band reel 6 into which a band coil can be loaded is installed inside the main body 10 of the packing machine with its central axis 6a facing sideways. In addition, a plate-like support plate 11 extending horizontally in the horizontal direction is fixed to the upper part of the inside of the packing machine body 10 opposite to the side where the band reel 6 is installed (right side in FIGS. 1 and 2). And the support plate 11
A frame 12 having a substantially U-shaped horizontal cross section is mounted and fixed on the upper surface of the. Between the left and right side plates 12a and 12b of the frame 12, a band supply end processing means K (details will be described later), which is composed of various cams and arms for gripping, pressing, melting, and cutting the band B. Is provided. Also, the left side plate 12a of the frame 12
The cam driving stepping motor M ₁ with a speed reducer 7 for driving the band supply end processing means K is provided on the outer surface of the
Are arranged in rows, and on the outer side of the right side plate 12b,
Band feeding / tightening (feed / backfeed) means F including a feed / backfeed stepping motor M ₂ , which can be rotated in the forward and reverse directions, a feed / backfeed roller 8, a rocker roller 9, and the like is provided in parallel and fixed.

Next, details of the packing machine 1 of the illustrated example will be described. 4 is an enlarged view of a main part of FIG. 2, and FIG. 5 is an enlarged view of a main part of FIG. First, the band supply end processing means K will be described. The cam driving stepping motor M ₁
The driving force from is reduced by the speed reducer 7 and transmitted to the cam shaft 14 which is axially supported by the rolling bearing 13. The camshaft 14 is laid across both side plates 12a and 12b of the frame 12,
A roller bearing 15 is pivotally supported on the right side plate 12b.

As shown in FIG. 4, the heater cam 21, the front clamp cam 22, the press cam 23, the slide cam 24,
The rear clamp cam 25 and the middle slide cam 26 are fitted in the cam shaft 14 and fixed by the key 16. Each of the cams 21 to 26 is
It is formed by stacking two plate members of the same shape punched into a predetermined cam shape by a press. Then, in the gap formed between the cams 21 to 26 adjacent to each other, a circular shape made of plastic or the like that is inserted into the cam shaft 14 concentrically with the cams 21 to 26. The plate material spacers 17, 17, ... Are interposed, and the spacers 17, 17, ..
1 to 26 are fixed together by bolts 18, 18.

A front clamp 40 is arranged between the left and right side plates 12a and 12b to move up and down by following the rotation of the front clamp cam 22. The front clamp 40 is integrally formed with the spring fitting insertion portion 41 having a gate-shaped cross section, and can be rotatably locked to a pivot shaft 42 at the base end portion. Notch ring portion 43a
And a head portion 45 fixed to the upper part of the spring fitting insertion portion 41 with a bolt or the like. This front clamp 40
Is molded from a press-molded shape member such as aluminum, and a guide hole 44 for guiding when supplying the band is formed in the head portion 45.

On the inner side surfaces of the left and right leg portions of the gate-shaped cross section of the spring fitting insertion portion 41, the spring fitting insertion portion 41 extends laterally (rightward in FIG. 5) in parallel with the arm portion 43. A pressed steel cam roller support member 51,
51 is attached. The cam roller support member 51,
A spring member 46 having a cushioning function is fitted and inserted in the upper portion of 51, and a cam roller 52 that swings following the front clamp cam 22 is sandwiched in the lower portion thereof. Then, the base end portion 5 of the cam roller support member 51 pivotally fixed to the arm portion 43 of the front clamp 40.
1a includes the cam roller 52 and the front clamp cam 2
A spring member 53, which urges the plate 2 to press, is interposed between the support plate 11 and the spring member 53.

Similarly, the press 55 and the rear clamp 56 have substantially the same structure as that of the front clamp 40, and cam rollers 57 and 58 swinging following the press cam 23 and the rear clamp cam 25, respectively. A cutter member 59 for cutting a band is integrally fixed to the upper end portion of the press 55.

Further, as shown in FIG.
A heater member 61, a slide member 62, and a middle slide member 63 are swingably arranged near the upper end between a and 12b. The heater member 61 has a plate-shaped heater plate 64 positioned at the upper end portion, and a heater arm 65 fixed to the lower surface of the heater plate 64 and extending downward.
And the heater arm 65 includes the side plates 12a, 1
It is pivotally supported by a pivot shaft 30 spanning between 2b. The heater arm 65 is connected to the cam roller 7
It is attached so as to be capable of swinging in conjunction with the heater cam 21 via 1.

Similarly, the slide member 62 has a plate-like slide table 67 fixed to the upper end of a slide arm 66 pivotally supported by the pivot shaft 30. The slide arm 66 is swingably attached to the slide cam 24 via a cam roller 72. Further, the middle slide member 63 is arranged on the side opposite to the arrangement of the heater member 61 and the slide member 62 with respect to the pivot stop shaft 30. That is, the middle slide member 63 is configured by fixing the middle slide 74 to which the limit switch L is fixed to the upper end portion of the middle slide arm 73 pivotally supported by the pivot shaft 30. The middle slide arm 73 is swingably attached to the middle slide cam 26 via a cam roller 75. The heater member 6
1, the cam rollers 71, 72 and 75 are respectively attached to the heater cam 21, the slide cam 24 and the middle slide cam 26 at the lower end portions of the arms 65, 66 and 73 of the slide member 62 and the middle slide member 63. Spring members 76, 76, 76 for urging to press are interposed between the support plate 11 and the spring members.

Next, the band supply / tightening means F will be described. 6 is a vertical cross-sectional view in which a main part of the feed / back feed stepping motor M ₂ is cut away, and FIG. 7 is a view taken along the line VII-VII in FIG. A known stepping motor with a speed reduction mechanism is used as the feed / back feed stepping motor M _{2 in the} illustrated example. That is, in the motor body 81, a stator having a multi-phase winding, a rotor integrally provided with an output shaft 82 at its core, and a reduction mechanism for transmitting the driving force from the output shaft 82. (Neither shown).

On the output side (left side in FIG. 6) of the motor body 81, there is a feed unit connected to the speed reducing mechanism.
A back feed roller shaft 86 is provided so as to project from the motor main body 81, and the feed / back feed roller 8 is fixed to the outer end portion of the feed / back feed roller shaft 86. An attachment shaft 89 for fixing the band guide cover 98 attached to the outside of the front end portion of the feed / back feed roller 8 projects forward and is fitted in the vicinity of the output side peripheral portion of the motor body 81. Has been.

On the other hand, a plate-shaped Hall element mounting member 1 having a Hall element 103 fixed to the outer surface of the rear cover 81a on the opposite output side (right side in FIG. 6) of the motor body 81.
05 is attached, and screwing pins 96, 96, ... For preventing the brake band 31 from coming off, which will be described later, are arranged and screwed so as to project on the circumference thereof. At the lower end of the Hall element mounting member 105, a magnet 1 described later is provided.
Hall sensors leads 106 for transmitting a pulse generated when 02, ... Pass above the Hall element 103 to a CPU (not shown) (see FIG. 7). Thus, the Hall element 103 and the magnet 1
02, ..., CPU and the like constitute a step-out sensor.

The output shaft 82 is a stepped shaft extending on the opposite side to the output side and having a small diameter portion 82a formed at the tip thereof. A cylindrical sleeve 83 having a plurality of steps is integrally fitted and fixed to the periphery of the output shaft 82 and the small diameter portion 82a by a key or the like. That is, the sleeve 8
3 is a large-diameter portion 83a that is externally fitted and fixed to the output shaft 82.
And a small-diameter portion 83c and a small-diameter portion 83b that extend rearward from the large-diameter portion 83a and are successively reduced in diameter. The middle-diameter portion 83b is fitted onto the small-diameter portion 82a of the output shaft 82. It is fixed. Further, a collar portion 83d having a circular outer shape is integrally formed around the large diameter portion 83a, and the four flange portions 83d are formed on the outer surface of the collar portion 83d at a position facing the Hall element 103. The magnets 102, ... Are embedded with part of the surface exposed. The sleeve 83 configured as described above can rotate integrally with the output shaft 82.

Around the part of the large diameter portion 83a of the sleeve 83 and the middle diameter portion 83b, as a member of a reverse rotation preventing means, through the rolling bearings 84 and 85 and the one-way clutch 87, a cylindrical shape is formed. Large diameter part 88a and small diameter part 88
A stepped cylindrical brake actuating member 88 of b is attached. Further, the small diameter portion 8 of the sleeve 83
A hub portion 101a, which is fixed to the small diameter portion 83c by spline fitting or the like, and a hub portion 10 around the circumference 3c.
A donut-shaped outer insertion portion 1 which is integrally fitted around the periphery of 1a.
01b, and a resonance preventing damper 101 that is rotatable integrally with the output shaft 82 is fixed.

Further, as shown in FIG. 7, around the large-diameter portion 88a of the brake operating member 88, the feed direction D _F (of the brake operating member 88 in cooperation with the one-way clutch 87 during operation). Rotation in the clockwise direction in FIG. 7, that is, the feed / back feed roller 8
Of the brake band 31 for freely rotating the rotation of the vehicle
The trailing end 31a of the brake band 31 is locked to a screwing pin 97 provided rearwardly from the rear cover 81a, and the leading end 31b is attached to the packing machine body 10. Plunger-type drive solenoid 1 attached to appropriate location
It is locked to the tip of the movable iron core 111 of 10. A fixed iron core (not shown) around which a coil is wound is installed inside the drive solenoid 110, and the movable iron core 111 is generated by a magnetic attraction force obtained by energizing the coil.
Are linearly moved downward, and the brake band 31
Is operated to lock the rotation of the feed / back feed roller 8 in the feed direction D _F as required. A feed / brake mechanism S is composed of the brake operating member 88, the brake band 31, and the drive solenoid 110.

Further, the rocker roller 9 is attached so as to be constantly in pressure contact with the feed / back feed roller 8 by pressing means (not shown) (see FIG. 4).
And as can be seen from FIG. 4, the band reel 6
The band B wound around the tape passes through the pressure contact portions of the feed / back feed roller 8 and the rocker roller 9 via the twist roller 92 and the idle roller 93, and the inside of the tubular band guide member 94, the front portion. It passes through the guide hole 44 of the clamp 40, the gap between the press 55 and the middle slide 74, the gap between the rear clamp 56 and the slide table 67, and the like, and exits from the top plate 4 to the upper outside. Next, the tip end portion of the band B, which is wound around the object to be packed in a loop shape (if a band arch is installed, passes through the inside to form a loop), the slide table 67 is attached. Is again introduced into the inside of the packing machine 1 from the band introduction port 95 formed on the side of
It is configured to pass through a gap between the slide table 67 and the middle slide 74 and come into contact with the limit switch L to complete the setting.

Next, the operation of the packing machine of one embodiment of the present invention thus constructed will be described. FIG. 8 is a time chart used for explaining the operation of the packing machine, and particularly shows the operation of the front clamp 40 and the rear clamp 56. First, when a start switch of a control device (not shown) is operated to operate the feed / back feed stepping motor M ₂ , the feed / back feed roller 8 starts to rotate and feeds the band B to feed (supply). As described above, the band B is rotated around the object to be packed with a distance and brought into contact with the limit switch L to stop the feed / back feed stepping motor M ₂ and Band B set is complete. During this band feed period, the reverse rotation preventing means for preventing rotation in the feed direction is deactivated, and the output shaft 82 rotates in the feed direction D _F at a predetermined rotation speed (see FIGS. 6 and 7). .

Next, the cam driving stepping motor (cam motor) M ₁ is activated to drive the front clamp cam 2
2 rotates, and the arm portion 43 swings upward about the pivot shaft 42 by the operation of the cam roller 52 that is a follower thereof, and the front clamp 40 rises, and the upper end surface of the front clamp 40. And the lower end of the slide table 67 clamps the supply tip of the band B. At the same time, the cam driving stepping motor M ₁ is stopped, and the feed / backfeed stepping motor M ₂ is activated to rotate in the tightening (backfeed) direction D _B opposite to the supply (feed) direction. Initially, primary tightening is performed by high-speed, low-torque driving. The brake band 31 is operated to lock the brake operating member 88 from an appropriate time after the start of the primary tightening until the end of the secondary tightening and the clamp by the rear clamp 56. Therefore, the one-way clutch 87 prevents the output shaft 82 from rotating in the reverse direction.
Is also locked (see FIGS. 6 and 7).

When the primary tightening is started, the flange portion 83 of the sleeve 83 is rotated along with the rotation of the output shaft 82.
d, and the magnet 102 fixed to the collar portion 83d, ...
Also rotates together. Since the magnets 102, ... Are arranged with a phase difference of 90 °, the output shaft 82 is
Every four rotations, the magnets 102, ...
03, and pulses are generated at intervals corresponding to the actual rotation speed of the output shaft 82. Therefore, assuming that the output shaft 82 rotates at, for example, 200 pulses / revolution that is regarded as being out of step, motor drive pulse power generation means (Fig. The pulse number corresponding to the predetermined output shaft rotation number (not shown) is 50 pulses / 4 half rotations (the unit is omitted hereinafter).

FIG. 9 is a flow chart for explaining the operation of the step-out sensor. First, when a pulse is input from the Hall element 103 by the rotation of the magnets 102, ..., The CPU resets the count number of the drive pulse of the pulse motor and restarts the count. At this time, since the magnets 102, ... Have a certain width, a pulse is always input at 50 or less when the magnets 102 ,. Become. In this state, the band B comes into contact with the outer peripheral surface of the article to be packed and a tension of a predetermined value acts on the band B, and when a torque of a predetermined value or more is applied to the output shaft 82, the pulse count exceeds 50, Therefore, it is considered that the step has been lost, and the next operation (secondary tightening) is automatically performed. That is, the operation mode of the feed / back feed stepping motor M ₂ is automatically switched, and the drive tightening is performed by the low speed and high torque to perform the secondary tightening. On the other hand, the pulse count is 50
If it does not exceed, the step has not been performed yet, so the operation returns to the above and the above operation is repeated (primary tightening is performed).

As described above, as shown in FIG. 8, the solenoid 110 is activated before the secondary tightening is started, and the movable iron core 111 is lowered to cause the brake band 31 to move to the large diameter portion 88a of the brake operating member 88. Is pressed against the periphery of the brake actuating member and the brake actuating member 88 is locked. The brake operating member 88 and the output shaft 82
The one-way clutch 87 is interposed between the output shaft 82 and the brake operating member 88 before the rear clamp 56 is operated before the secondary tightening is completed. The band B wound around the object to be packed by rotating in the direction D _F in the reverse direction.
It is possible to prevent mechanically from loosening mechanically.

Next, the band B is subjected to negative tension by secondary tightening.
The load tension is the set upper limit value.
When the maximum torque reaches the
In addition to the shaft 82, the feed / back feed system
Pping motor M₂ Lost sync with the input pulse, yes
Stops automatically due to a step out. And this automatic stop
Occasionally, the reverse rotation prevention means 87 and S act to stop the operation.
The stopped state is automatically held. On the other hand, secondary
After the tightening is completed, the cam driving stepping motor M₁ 
Will restart. As a result, the rear clamp cam 25 is
It operates and the rear clamp 56 rises. And said
The rear portion of the overlapping portion of the band B is the rear clamp 56
The upper surface and the lower surface of the slide table 67 clamp the clan.
Be pushed. During this time, the brake band 31
Before the rear clamp 56 acts.
In addition, the feed / back feed stepping mode
Ta M ₂ Since the stopped state of is also held mechanically,
Prevent loosening of the band B wound around the package.
You can

FIG. 10 is an example of a schematic diagram of a drive system of the feed / back feed stepping motor M ₂ . FIG. 11 is an example of a speed-torque characteristic diagram of the feed / back feed stepping motor M ₂ , in which a solid line indicates a case where an output current from a driver D described later is 4 A and a broken line indicates a case where the output current is ₂ A. In FIG. 10, C
PU outputs a signal to the pulse oscillator P by the signal from the operating means T, and the pulse oscillator P outputs a pulse signal to the driver D which is a current supply means. The feed / back feed stepping motor M ₂ rotates at a speed proportional to the input pulse speed from the driver D (that is, the current flowing through the motor winding). In this way, the output current from the driver D can be changed by operating the operating means T, and further, the maximum torque used for secondary tightening can be changed, as will be described later.

In FIG. 11, the maximum tightening torque (low speed / high torque) at the rotational speed (pulse speed) N ₁ is used for the secondary tightening, and the torque at N ₂ (high speed / low torque) is used for the primary tightening. There is. In addition, FIG.
As can be seen from the above, the magnitude of the torque is
Changes almost proportionally to the output current of, for example, the maximum tightening torque at an output current of 4 A at N ₁ is 130 kgf
If it is cm, the maximum tightening torque at 2 A for N ₁ is 65 kgf · cm. The output current of the driver D can be freely changed by a simple operation of the operating means T including an analog or digital operating dial or the like. Therefore, even when the type of the object to be packed is changed, for example, the current is 4 A in the case of the object that is difficult to deform, and the current is 2 A in the case of the object that is easily deformed. The optimum secondary tightening force can always be obtained by a simple operation of simply switching the setting of the means T. It is necessary to change the output current of the driver D not only according to the type of the object to be packed but also depending on the type of the band B such as thickness, strength and sectional shape. The packing machine of the present invention that enables is of great advantage.

Next, in the width direction of the band B,
The heater plate 64 and the front attached to the
The heater arm for supporting and fixing the slide 74 in the description
65 and the middle slide arm 73 are the heater cams.
21 and following the rotational movement of the middle slide cam 26
Via the cam rollers 71 and 75 that are operated,
Moves back and forth interlocking with each other with the pivot shaft 30 as the center of rotation.
Rotate accordingly. That is, the middle slide 74 is
Direction to exit from the overlapping part of band B (right direction in Fig. 5)
When it is slid onto the
The heater plate 64 is also guided by the guide 74.
It is slid in the direction (rightward in FIG. 5). This
In this way, the heater plate 64 is attached to the inner slide 7
Instead of position 4 (see Figure 4), keep a distance from each other
Of the overlapped portion of the band B, which is arranged in a tension state up and down.
It is inserted into the gap and immediately after that
Raise by actuation of the scum 23 and the cam roller 57.
Simultaneous pinching with the press 55, which is tightened,
The opposite surface of the overlapping portion of the band B is melt-pressed. here
Then, the press 55 is first applied to the overlapping portion of the band B.
Is lightly pressed and then lowered once. That
At the same time, whether the heater plate 64 is a band overlapping portion
(Left side as seen in Fig. 5)
The press 55 moves up again, and the cutter member 59
The front clamp 40 side of the band B is cut. So
Then, the press 55 strongly adheres to the overlapping portion of the band B.
It is pressed, and in that state the band overlapped part is
For a while (for example, 1 to 1.7 seconds), the press 55 is
It is lowered. The press 55 was raised.
During the first pressing operation and during the cooling period, the cam drive
Dynamic stepping motor M ₁ Is held in the stop position
It

Finally, during the entire process, the slide table 67, which is held on the same horizontal surface as the upper surface of the top plate 4, has the cam roller 72, which is a follower of the slide cam 24, and the slide table 67. Slide arm 66
And the like, and is rotated in the retreating direction (leftward in FIG. 5) about the pivot shaft 30 as the center of rotation. As described above, the packing machine according to the present invention performs the secondary tightening with the preset torque according to the type of the object to be packed or the band B, and at the time of the secondary tightening, the stepping motor M ₂ for feed / back feed. Is mechanically held by using the feed / brake mechanism S and the reverse rotation preventing means, an optimum and stable secondary tightening force can always be obtained regardless of the type of the article to be packed, and the band B It is possible to prevent the product from being pulled out or the packaged object from being damaged. Further, it is possible to reduce the power consumption as compared with the case where the stopped state is maintained by the motor.

Although one embodiment of the present invention has been described in detail above, the present invention is not limited to the above embodiment, and various designs can be made without departing from the present invention described in the claims. You can make changes. For example, in the illustrated example, the stepping motor M ₁ is used as the cam driving motor, but it goes without saying that another motor such as an induction motor may be used.

In the illustrated example, a band-type brake is used as the feed / brake mechanism S. However, for example, the brake is provided by a rod-shaped stopper member or the like that can advance and retreat in a direction parallel to the output shaft 82. Actuating member 8
It is also possible to prevent the rotation of 8.

The operation mode may be switched from the primary tightening to the secondary tightening by using the tension sensor without using the step-out sensor. Further, the magnets 102 arranged on the same radius centered on the output shaft 82,
It goes without saying that the uniform phase difference of 102, ... Is not limited to 90 °.

[0039]

As can be understood from the above description, according to the present invention, an optimum and stable secondary tightening force can always be obtained regardless of the type of the object to be packed, and the band It is possible to prevent the product from being pulled out and damaged and to reduce the power consumption cost, and also the structure can be made simple and inexpensive.

[Brief description of drawings]

FIG. 1 is a schematic plan view with a top plate removed to show the entire interior of a packing machine according to an embodiment of the present invention.

FIG. 2 is a schematic front view of the packing machine shown in FIG.

FIG. 3 is a schematic side view taken along the line III-III in FIG.

FIG. 4 is an enlarged view of a main part of FIG.

5 is an enlarged view of a main part of FIG.

FIG. 6 is a view showing a feed provided to the packing machine according to the embodiment of the present invention.
FIG. _{3 is} a vertical cross-sectional view of a backfeed stepping motor M ₂ .

FIG. 7 is a view taken along the line VII-VII in FIG.

FIG. 8 is an example of a time chart provided for explaining the operation of the packing machine according to the embodiment of the present invention.

FIG. 9 is an example of a flowchart illustrating the operation of a step-out sensor provided in the packing machine according to the embodiment of the present invention.

FIG. 10 is a schematic diagram of a drive system of a feed / back feed stepping motor M ₂ provided in a packing machine according to an embodiment of the present invention.

FIG. 11 is a speed-torque characteristic diagram of the feed / back feed stepping motor M ₂ provided in the packing machine according to the embodiment of the present invention.

[Explanation of symbols]

B Band D Current supply means (driver) F Feeding and tightening work mechanism M ₂ Feed / back feed stepping motor T Operating means

Claims (1)

[Claims] 1. A feed / backfeed stepping motor M ₂ which is a drive source of a mechanism F for feeding and tightening a band B wound around the outer periphery of an article to be packed, and the feed / backfeed A stepping motor M ₂ for feed / back feed, which is a packing machine configured to perform secondary tightening with a maximum torque based on a speed-torque characteristic of the stepping motor M _{2 for}
Current supply means D for supplying a current to the current supply means D
A packing machine comprising an operating means T for varying the maximum torque by changing the output current from the packing machine.