JPH0872810A - Packaging machine - Google Patents

Abstract

PURPOSE: To simplify an electric power drive system of two stepping motors by connecting the two stepping motors to a driver and a constant-voltage output device through a current switching device, respectively. CONSTITUTION: Drive current, which being constant current, is outputted to a driver D based on a pulse signal from a pulse generator P, as a means for driving two stepping motors M1 , M2 to output auxiliary current of constant- voltage to a constant-voltage output device C. And a current switching device S is provided to switch two output currents so that each of the stepping motors M1 , M2 can be connected to any one of the driver D and the device C. Thus a power drive system of the stepping motors M1 , M2 can be simplified so that cost can be reduced.

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, While a mechanism such as a slide table is operated at a different timing to perform work such as gripping, pressing, melting, and cutting of the band, the tightening operation of the band is performed by an electric motor at high speed and low torque. Tightening is performed in two stages: primary tightening for tightening and secondary tightening at low speed and high torque (see, for example, Japanese Patent Publication No. 4-13205).

Further, the applicant of the present invention has disclosed in Japanese Patent Application No. Hei 5-226189 filed earlier that the number of pulses as a motor for supplying / tightening (feed / back feed) a band and a motor for driving a cam. In addition to using a stepping motor that can control the rotation speed and movement amount as quickly and accurately as possible, a resonance prevention damper is provided on the output shaft of the feed / back feed motor, and a hall element is provided on the damper and motor body side. We proposed a packing machine with a step-out sensor that uses a magnet and a magnet to count the number of pulses in the CPU.

[0004]

The electric power drive system of the two stepping motors of the conventional packing machine as described above is shown in FIG.
As shown in, the cam driving stepping motor M ₁
And stepping motor M ₂ for feed and back feed
Each with, by arranging the driver D _1, D ₂ of the pulse generator P _1, P ₂ and both said pulse generator P _1, the pulse signal from the P ₂ drive current respectively output therebetween Is connected. Then, in response to a signal from the operating means T, a control signal is issued from the computer CPU to the both pulse oscillators P ₁ and P _2, and the both pulse oscillators P ₁ and P ₂ are transmitted.
₁ and P ₂ output pulse signals to both drivers D ₁ and D ₂ which are current supply means. Each of the cam driving stepping motor M ₁ and the feed / backfeed stepping motor M ₂ has a speed proportional to the input pulse speed (that is, the current flowing through the motor winding) from each of the drivers D ₁ and D _2. It rotates with.

In the conventional electric power drive system for two motors of a packing machine, a pulse oscillator P ₁ and a driver D ₁ and a pulse oscillator P ₂ and a driver D ₂ are provided for the respective motors M ₁ and M _2. It is necessary for the set, the device becomes complicated and expensive, and there is a problem that the power consumption increases because each motor is in a state where current is constantly applied during one process of the packing work. .

The present invention has been made in view of the above problems, and an object thereof is to simplify the electric power drive system of the two stepping motors M ₁ and M ₂ . The present invention is to provide a packaging machine that can be configured at a low cost by reducing the number of control devices used and also used, and powering off unused stepping motors as needed to reduce power consumption costs. .

[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. In a packaging machine equipped with a certain feed / back feed stepping motor and a cam driving stepping motor that drives band feeding end processing means for gripping, pressing, melting, cutting, etc. of the band, the two stepping motors are driven. As a means to do so, a driver for outputting a drive current of a constant current by a pulse signal from a pulse oscillator, a constant voltage output device for outputting an auxiliary current of a constant voltage, and a current switching device are provided, and the two stepping motors are respectively It is characterized in that it is connected to the driver and the constant voltage output device through the current switching device.

[0008]

[Operation] In the packing machine 1 according to the present invention configured as described above, the computer C is operated by operating the operation means T.
A signal is issued from PU, a drive current is output from the driver D by a pulse signal from the pulse oscillator P, and the current switching device S is operated to operate the cam driving stepping motor M.
₁ and stepping motor M for feed / back feed
_To each of the ₂ and ₂ , the current is separately supplied from the driver D and the constant voltage output device C to rotate and drive one motor, and the other motor is held or powered off, and the band B is fed out and tightened. The work and the work of gripping, pressing, melting, and cutting the band B are separately performed at different times.

[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 including various cams and arms for gripping, pressing, melting and cutting the band B is arranged. . Further, on the outer surface of the left side plate 12a of the frame 12, together with the stepping motor M ₁ is arrayed cam drive with reduction gears 7 which allowed to drive the band feed end processing unit K, out of the right side plate 12b Band feed / tightening (feed / back feed) means F including a feed / back feed stepping motor M ₂ , a feed / back feed roller 8, a rocker roller 9, and the like, which can rotate in the forward and reverse directions, is provided in parallel on one side and fixed. ing.

Next, the drive systems of the two stepping motors of one embodiment of the present invention will be described in detail. FIG. 5 shows a feed / back feed stepping motor M ₂ that is a drive source of a mechanism F that performs operations such as sending out and tightening of the band B used in the packing machine of the present embodiment, and gripping, pressing, melting of the band B. FIG. 7 is a schematic diagram of a drive system including a cam driving stepping motor M ₁ that drives a band supply end processing unit K that performs work such as cutting.

As the two driving stepping motors M ₁ and M ₂ , known stepping motors with a reduction mechanism are used. That is, in the motor body, a stator having a multi-phase winding, a rotor integrally provided with an output shaft at its core, and a reduction mechanism for transmitting a driving force from the output shaft (both are (Not shown). The publicly known stepping motor is a control motor that moves by a pulse signal, and by controlling the pulse signal, start, stop, forward / reverse rotation, speed change, etc. can be freely controlled. A direct current is applied to the stator winding, the rotor is attracted by the electromagnetic force generated there to generate a rotating force, and the current in the stator winding is sequentially switched to rotate by a predetermined angle. .

The known stepping motor is
It rotates by a predetermined angle for one input pulse given to the drive circuit, holds its stop position when there is no more input, and has a large holding force at the time of stop. It has a feature that it can be started and stopped rapidly and complicatedly depending on how to apply a pulse, in proportion to the frequency, and the present invention is also utilized by making use of this feature.

The two feed / back feed stepping motors M ₂ and cam driving stepping motors M ₁ supply a driver D for outputting a constant driving current through a current switching device S or a constant voltage auxiliary current. It is connected to a constant voltage output device C for outputting. The constant voltage output device C outputs a constant voltage current based on the output signal of the computer CPU, and the driver D generates a drive pulse of a constant current according to the pulse signal from the pulse oscillator P based on the output signal of the computer CPU. Output. The operation means T outputs various operation signals for performing work such as sending out and tightening of the band B of the packing machine 1 and work such as gripping, pressing, melting and cutting of the band B. The computer CPU inputs and analyzes these various operation signals, and outputs necessary control signals to the pulse oscillator P, the constant voltage output device C, and the current switching device S according to its work. The current switching device S is the computer C.
Based on the output signal of PU, the two stepping motors M ₁ and M ₂ are driven by the driver D and the constant voltage output device C.
, And the two stepping motors M ₁ and M ₂ are not connected to the same device of the drive D or the constant voltage output device C at the same time.

Next, the operation of the packing machine according to the embodiment of the present invention thus constructed will be described. FIG. 4 is a time chart used for explaining the operation of the packaging machine of the embodiment, and particularly shows the operating states of the stepping motors M ₁ and M ₂ . In the figure, the upper stage shows the operation state of the feed / back feed stepping motor M ₂ and the lower stage shows the operating state of the cam driving stepping motor M ₁ , and the upper stage of each of the slipping motors M ₁ and M ₂ is the driver D and the lower stage. Indicates the output state of the constant voltage output device C.
The work proceeds from left to right in the figure.

First, in the packing operation state at the left end of FIG. 4, when the current switching device S of the drive system is in the switching state of the solid line as shown in FIG. 5, the start switch (operating means T) of the control device (not shown) is pressed. When the feed / back feed stepping motor M ₂ is operated by operating the CPU to output a signal to the CPU to output the driver D via the pulse generator P, the feed / back feed roller 8 starts to rotate. Then, the band B is sent out and fed. As described above, the band B is rotated around the object to be packed with a distance, and is brought into contact with a limit switch (not shown) to stop the output of the driver D to stop the output of the feed / back feed stepping motor M ₂ And the setting of the band B is completed. During this band feed period, the cam driving stepping motor M ₁ is connected to the constant voltage output device C as shown in FIG. 5, and the constant voltage output device C supplies a constant voltage auxiliary current. The rotor of the cam driving stepping motor M ₁ is held at its stop position (hereinafter referred to as “hold”).

Next, by a signal from the operating means T of the control device,
A signal is issued from the CPU to turn off the current switching device S.
Instead, the state of the dotted line in FIG.
Output from the stepping motor for driving the cam
(Cam motor) M₁Is activated to operate the cam / arm, etc.
Let the feed tip of the band B be on the lower surface of the slide table.
The part is gripped (detained). Switching of the current switching device S
At the same time, the feed / back feed stepping pin
Gmotor M₂Is connected to the constant voltage output device C,
The constant-voltage output device receives an auxiliary power by the signal from the CPU.
Since the current is not output, the feed
Backfeed stepping motor M ₂Power off
State.

Subsequently, the current switching device S is switched again by the signal from the CPU based on the signal from the operating means T to bring the state of the solid line in FIG.
When the signal is output from the driver D, the feed / back feed stepping motor M ₂ is started,
The rotation starts in the tightening (backfeed) direction opposite to the supply (feed) direction, and the primary tightening is performed by high-speed, low-torque driving. The secondary tightening is performed at an appropriate time after the primary tightening is started. On the other hand, simultaneously with the activation of the feed / back feed stepping motor M ₂ , the constant voltage output device C outputs the signal from the CPU, and an auxiliary current is supplied from the constant voltage output device C to drive the cam. The rotor of the stepping motor M ₁ is held at its stop position.

Next, when the load tension of the band B due to the secondary tightening reaches the set upper limit value (greater than the set upper limit value at the time of the primary tightening), the CPU is controlled by the detection means (operation means T) not shown. Send a signal to the feed
The backfeed stepping motor M ₂ is automatically stopped. Then, at the time of this automatic stop, the CPU operates to switch the current switching device S to the state shown by the dotted line in FIG. 5 and to output the driver D to start the cam driving stepping motor (cam motor) M _1. The band supply end processing means K is operated by operating a cam arm or the like, and binding of the band B after gripping, melting, pressing, cutting, gripping release, slide opening, slide closing, etc. is performed by a conventionally known method. Work is done. During this bundling operation, the constant voltage output device C is generated by a signal from the CPU.
Is not output, the feed / back feed stepping motor M ₂ is in a power-off state.

After that, when the binding work is completed, the CPU issues a signal in response to the signal from the completion detecting means (operating means T) to bring the current switching device S into the state shown by the solid line in FIG.
The cam driving stepping motor (cam motor) M ₁
Is connected to the constant voltage output device C, and the CP
Based on the U signal, the constant voltage output device C outputs an auxiliary current to hold the rotor of the cam motor M ₁ . On the other hand, the feed / back feed stepping motor M ₂ is connected to the driver D to provide a system for supplying the band B for the next packing operation.

As described above, the packing machine according to the present invention is
Two stepping motors M₁, M ₂And means to drive
Drive current by the pulse signal from the pulse generator P.
Driver D that outputs and constant voltage output that outputs auxiliary current
Device C and the current switching device for switching between the two currents
And the two stepping motors M₁, M
₂Each of the drivers through the current switching device S
Since it can be freely connected to D and the constant voltage output device C,
The pulse generator P and the driver D are connected to the two stages.
Pping motor M₁, M₂It can also be used for
Only by providing the current switching device S, the constant voltage output device C
And the current from the driver D can be switched.

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, the control circuit can be changed so that an unused stepping motor that is not pulse-driven is always energized by the auxiliary current of the constant voltage output device to be in the hold state.

[0024]

As can be understood from the above description, the present invention uses the two stepping motors M ₁ and M ₂ for the packing operation, while the pulse oscillator P and the driver D are connected to the two stepping motors. Since the motors M ₁ and M ₂ can be used in common, the cost can be reduced by simplifying the motor drive system. Further, by providing the constant voltage output device for outputting the auxiliary current, the rotor of the unused stepping motor which is not in the rotational driving state can be surely held by the auxiliary current, and when the holding is not necessary, By blocking the output of the auxiliary current,
Power consumption can be reduced by powering off the stepping motor.

[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] Example stepping motors M ₁ and M ₂ for packing machine
FIG. 6 is a time chart for explaining the operating state of FIG.

FIG. 5: Stepping motors M ₁ and M ₂ for driving a cam and for feeding / back feeding of the packing machine according to the embodiment of the present invention.
Schematic of the drive system of FIG.

FIG. 6 is a schematic diagram of a drive system of cam driving and feed / back feed stepping motors M ₁ and M ₂ of a conventional packing machine.

[Explanation of symbols]

B ... Band C ... constant voltage output device CPU ... Computer D ... current supply means (driver) F ... feeding, tightening work mechanism K ... band feed end processing apparatus M ₁ ... stepping motor M ₂ ... feed-back feed drive cam Stepping motor P ... Pulse generator S ... Current switching device T ... Operating means

Claims (2)

[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 object to be packed, and gripping and pressing of the band B. In the packing machine 1 including the cam driving stepping motor M ₁ that drives the band supply end processing means K that performs operations such as melting and cutting, pulse transmission is performed as means for driving the two stepping motors M ₁ and M _2. A driver D that outputs a constant-current drive current based on a pulse signal from the device P, a constant-voltage output device C that outputs a constant-voltage auxiliary current, and a current switching device S that switches between the two output currents are provided. the two stepping motors M _1, M ₂ are each connected freely to any of the current switching device S via said driver D or the constant voltage output device C Packing machine, characterized in that. 2. The pulse oscillator P, the constant voltage output device C, and the current switching device S are each operated by an output signal of a computer CPU based on a signal from an operating means T of the packing machine 1. Claim 1 characterized by the above.
Packing machine described.