JP2002332012A - Bag manufacturing and packaging machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a substitution defect and a sealing defect in a bag manufacturing and packaging machine replacing gas within a packaging material while a consumption of inert gas to be replaced is being restricted. SOLUTION: There are provided an oxygen concentration sensor 18 for sensing a concentration of residual oxygen within a bag-like packaging material, and a seal sensor 56 for sensing a sealing defect caused by a biting of packaged item at an upper seal segment of packaging material having the packaged material sealingly enclosed in it. A control signal is outputted at a flow rate control valve 28 installed on a nitrogen gas supplying pipe in response to signals fed from these sensors and a supplied flow rate of nitrogen gas is controlled in such a way that a concentration of residual oxygen enters in a predetermined allowable range and a rate of poor sealing becomes less than a predetermined allowable limit.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bag-making and packaging machine for continuously producing products by putting articles into a packaging material while sealing the packaging material into a bag shape while sealing the packaging material. Belongs to the field of packaging technology.

[0002]

2. Description of the Related Art Generally, a bag making and packaging machine for enclosing an article in a packaging bag while molding the packaging bag is formed by overlapping left and right side edges of a band-shaped packaging material into a cylindrical shape and forming a vertical seal. The overlapping portion of the tubular packaging material is thermally welded in the longitudinal direction by the device, and the tubular packaging material is thermally welded in the width direction orthogonal to the longitudinal direction by a horizontal sealing device to form a bag shape, Thereafter, an article to be packaged is introduced into the bag-shaped packaging material from above through a vertically extending article introducing tube member, and the upper part thereof is sealed by the horizontal sealing device, and the upstream of the packaging material. By separating from the part, a product in which the article to be packaged is enclosed in a packaging bag is generated.

In this type of bag making and packaging machine, when the object to be packaged is food, the air in the bag-like packaging material into which the object to be packaged is introduced is removed with a nitrogen gas in order to prevent spoilage and deterioration. The upper part is sealed after replacing with an inert gas such as argon or argon gas. In that case, in order to increase the processing speed, while introducing the article to be packaged into the bag-like packaging material,
A method is used in which an inert gas is continuously or intermittently fed into the packaging material, and air in the packaging material is exhausted and replaced with the inert gas.

[0004] However, in this method, when a large amount of inert gas is fed into the bag-shaped packaging material in order to obtain a high level of inert gas replacement rate, the consumption of the inert gas increases. , The production cost will increase.

When the flow rate is increased to supply a large amount of inert gas, the inert gas blows vigorously into the bag-like packaging material, and blows up the articles introduced into the packaging material upward. Or, the introduction of the packaged material to the bottom of the packaging material is prevented, and the packaged material blown up above or delayed in the introduction to the bottom is bitten by the horizontal sealing device, and the sealing failure is caused. Will happen.

As a solution to this problem, for example, Japanese Patent Laid-Open No. 10-53217 discloses a packaging machine in which the flow rate of an inert gas is changed during one cycle of a packaging operation.

In other words, according to this packaging machine, while the packaged material is supplied from above through the tube member into the bag-shaped packaging material, the packaging material introduced into the bag-shaped packaging material. An inert gas is supplied into the packaging material at a relatively small first flow rate so as not to blow up the material upward and to prevent introduction of the packaging material into the bottom of the bag-like packaging material. When the supply of the object into the packaging material is completed, the inert gas is supplied into the packaging material at a second flow rate larger than the first flow rate.

Therefore, the consumption of the inert gas is reduced as compared with the case where the inert gas is always supplied at a large flow rate, and
Since the flow velocity is small while the packaged object is being introduced into the bag-shaped packaging material, the occurrence of poor sealing due to the packaged product being blown up or being prevented from being introduced into the packaging material is reduced. .

[0009]

However, even with the packaging machine disclosed in this publication, it is difficult to switch the supply amount of the inert gas from a small first flow rate to a large second flow rate during one cycle. In addition, the behavior of the packaged object in the packaging material becomes unstable, and the packaged object is blown up, thereby causing a sealing failure due to biting of the horizontal sealing device. Also, if the value of the second flow rate is reduced to prevent this, the rate of replacement with the inert gas will be reduced.

Therefore, the present invention provides a bag making and packaging machine in which gas replacement is performed, while maintaining the inert gas replacement rate in the packaging material at a required level while suppressing the consumption of inert gas. It is another object of the present invention to prevent a seal failure due to a bite of an article to be packaged by a horizontal sealing device.

[0011]

Means for Solving the Problems In order to solve the above problems, each invention of the present application is characterized in that it is configured as follows.

First, the invention according to claim 1 of the present application (hereinafter referred to as the invention)
This is referred to as a first invention. ) Is a production method in which a gas supply means for supplying an inert gas into the wrapping material while introducing the wrapped object into the wrapping material while forming the wrapping material into a bag shape is provided. In a bag packaging machine, a residual oxygen detecting means for detecting a residual state of oxygen in a bag-like packaging material, and a flow rate control for controlling a flow rate when the inert gas is supplied by the gas supply means based on a detection result by the detecting means. Means is provided.

The invention according to a second aspect (hereinafter referred to as a second aspect) is characterized in that, in the first aspect, a flow meter for detecting a flow rate of the inert gas supplied by the gas supply means; Display means for displaying the flow rate of the inert gas detected by the meter and the residual state of oxygen detected by the residual oxygen detection means.

The invention according to claim 3 (hereinafter referred to as a third invention) is characterized in that, in the first invention or the second invention, a packaging state detecting means for detecting a packaging state is provided, and the flow control means is The flow rate of the inert gas is controlled so that the residual oxygen concentration detected by the residual oxygen detection means is equal to or less than a predetermined value and the defective rate of the packaging state detected by the packaging state detection means is equal to or less than a predetermined value. It is characterized by the following.

The invention according to claim 4 (hereinafter referred to as a fourth invention) is characterized in that, in the third invention, depending on the flow rate control by the flow rate control means, the residual oxygen concentration is less than a predetermined value and the packaging state The present invention is characterized in that a packaging ability lowering means is provided for reducing the capacity of the packaging operation when the failure rate does not fall below a predetermined value.

The invention according to claim 5 (hereinafter referred to as a fifth invention) is characterized in that, in any one of the first to fourth inventions, a storage means for storing a predetermined inert gas flow rate;
When the flow rate control means starts controlling the flow rate of the inert gas, an initial value setting means for setting the flow rate read from the storage means to an initial value of the control is provided.

Further, the invention according to claim 6 (hereinafter referred to as sixth invention)
In the fifth aspect of the present invention, in the fifth aspect, there is provided an environment detecting means for detecting at least one of the ambient temperature and the atmospheric humidity of the working environment, and the storage means associates with the working environment detected by the environment detecting means. In addition to storing the flow rate of the inert gas during the packaging operation under the environment, the initial value setting means stores the current flow rate of the inert gas from the storage means when starting the flow rate control of the inert gas by the flow rate control means. A flow rate associated with a work environment equivalent to the work environment is read out, and the flow rate is set as an initial value of control.

The invention according to claim 7 (hereinafter referred to as the seventh invention)
In the fifth invention or the sixth invention,
The storage means stores the flow rate of the inert gas during the packaging operation in association with the type of the article to be packaged, and the initial value setting means starts the flow control of the inert gas by the flow rate control means, The flow rate of the inert gas associated with the article to be processed this time is read out from the storage means, and the flow rate is set as an initial value for control.

With the above arrangement, the following effects can be obtained according to the present invention.

First, according to the first aspect of the present invention, when an inert gas such as a nitrogen gas or an argon gas is supplied while introducing an object to be packaged into the bag-shaped packaging material to replace the oxygen in the packaging material. To
Since the flow rate when the inert gas is supplied by the gas supply means is controlled based on the residual state of oxygen such as the residual oxygen amount and the residual oxygen concentration in the packaging material detected by the residual oxygen detection means, the flow rate is small, Insufficient supply of active gas may leave oxygen in the packaging material in excess of the permissible limit, or the flow rate may be too large to supply more inert gas than necessary even though the gas has been sufficiently replaced. The air inside the packaging material is always replaced to the required level with the minimum supply of inert gas, and this control is performed in real time, so that a constant gas replacement rate is always obtained. Become.

In this case, according to the second invention, the remaining state of oxygen detected by the remaining oxygen detection means and the flow rate of the inert gas supplied by the gas supply means are displayed by the display means. Therefore, the worker can grasp the gas replacement state during the work, and for example, the work can be performed such that preparation for the supply source of the inert gas can be performed without delay or an abnormality in the flow rate can be detected. It will be smoothed.

According to the third aspect of the present invention, in addition to the residual oxygen detecting means, a packaging state detecting means for detecting a packaging state such as the presence or absence of a seal failure is provided, and the packaging state detected by the detecting means is provided. The defective rate is below a predetermined value,
In addition, since the flow rate of the inert gas is controlled so that the residual oxygen concentration detected by the residual oxygen detection means is equal to or less than a predetermined value, the flow rate is small, so that the supply amount of the inert gas is insufficient. This prevents both the generation of a product with insufficient gas replacement and the poor sealing caused by blowing up the packaged object due to the flow rate being too large.

Further, according to the fourth aspect of the present invention, when performing the control of the third aspect of the present invention, if the inert gas is supplied so that the residual oxygen concentration becomes equal to or less than a predetermined value, the packaging state becomes defective due to blowing up of the packaged object. When the inert gas is supplied so that the rate exceeds the permissible limit and the defective rate of the packaging state becomes a predetermined value or less, when the gas replacement rate does not reach the predetermined level, the capacity of the packaging operation is reduced. Therefore, for example, while maintaining the flow rate of the inert gas constant and suppressing the blow-up of the packaged object, by increasing the supply time, a required amount of the inert gas is supplied, and the gas replacement rate at a predetermined level Can be achieved.

According to the fifth aspect, when the supply control means starts controlling the flow rate of the inert gas based on the remaining state of oxygen, the initial value setting means sets the predetermined value stored in the storage means in advance. Is set to the initial value, the supply state of the inert gas is quickly stabilized, and a good product can be obtained immediately after the start of the packaging operation.

In this case, according to the sixth aspect of the invention, the flow rate suitable for the working environment such as the ambient temperature and the atmospheric humidity at the time of this work is set as the initial value. Even if the flow rate fluctuates, the inert gas is always supplied at the optimum flow rate.

According to the seventh aspect of the present invention, the flow rate stored for the type of the article to be processed in the current packaging operation is set as the initial value at the start of the inert gas flow rate control. Even if the optimal flow rate at the time of inert gas supply differs depending on the type of package, that is, the properties and weight of the packaged object, the dimensions of the packaging material, the packaging speed, etc., the inert gas is always supplied at the optimal flow rate immediately. Will be supplied.

[0027]

Embodiments of the present invention will be described below.

As shown in FIG. 1, a bag making and packaging machine 1 according to this embodiment has a machine base 2, and a roll supporting portion (shown in the figure) above a rear portion thereof for rotatably supporting a roll of packaging material. Z)
Is provided, and a former 10 is disposed above a front portion of the machine base 2.

The former 10 has a structure in which a sailor member 12 and a tube member 13 penetrating vertically through the sailor member 12 are attached to a frame 11 (FIG. 2).
), And the left and right side edges are superimposed while being detachably attached to the upper surface of the front part of the machine base 2 and guiding the band-shaped packaging material fed forward from the roll support part downward. To form a cylindrical shape.

The upper part 14 of the tube member 13 projecting upward from the sailor member 12 is formed in a substantially conical shape having a wide open upper end for receiving a packaged material to be put therein. The lower portion 15 extending below the upper portion 12 protrudes into a bag-shaped packaging material, and introduces an article to be packaged into the packaging material.

Further, on both left and right sides of the lower portion 15 of the tube member 13, belt-type feeding devices 3, 3 for feeding the packaging material downward while pressing the packaging material against the left and right side surfaces 15a, 15a of the tube member lower portion 15 are arranged. At the front of the tube member lower part 15, the support member 4 is provided on the front of the machine base 2.
A vertical sealing device 5 is provided, which is supported through the base material and welds the left and right side edges of the packaging material which are overlapped with each other to form the packaging material into a cylindrical shape.

Further, slightly below the lower end of the tube member lower portion 15 on the front surface of the machine base 2, a cylindrically formed packaging material is sandwiched from both front and rear sides so that a predetermined position of the packaging material is set in the horizontal direction. By welding and cutting the substantially central portion of the welded portion in the lateral direction, a bottom portion is formed in a cylindrical packaging material to form a bag, and a portion of the bag-shaped packaging material into which a packaged object is introduced. A horizontal sealing device 6 that seals the upper part is provided. An unloading device 7 that unloads the product formed as described above to the outside of the machine is disposed below the horizontal sealing device 6.

Further, the bag making and packaging machine 1 is provided with a replacement gas passage 16 inside the front side of the tube member 13 for replacing the air in the packaging material with an inert gas. As shown in FIGS. 2, 3, and 4, the replacement gas passage 16 extends from the upper portion 14 to the lower portion 1 of the tube member 13.
A vertically long plate 17 is attached over the lower end of the tube 5 to form a space extending vertically between the plate 17 and the front surface of the tube member 13.

The upper end of the replacement gas passage 16 is
The plate 1 is bent and connected to the inner surface of the tube member 13 so as to be closed, and the inlet 1 communicating with the replacement gas passage 16 at the upper front surface of the tube member 13.
6a is provided, and a supply pipe 2 for the replacement gas is provided at the inlet 16a.
5 (see FIG. 5) are connected. Also,
The lower end of the replacement gas passage 16 is opened to serve as a replacement gas outlet 16b.

A gas intake pipe 19 led from an oxygen concentration sensor 18 (see FIG. 6) is provided in the replacement gas passage 16, and a lower end thereof is connected to an outlet 16 b of the replacement gas passage 16. The tube member 13 protrudes downward, has a distal end serving as a gas inlet 19a, and is opened near the lower end of the tube member 13. The upper portion of the pipe 19 escapes from the replacement gas passage 16, is led outward from the opening at the upper end of the tube member 13, and is connected to the oxygen concentration sensor 18.

In addition to the above configuration, a gas supply device 20 for supplying nitrogen gas to the replacement gas passage 16 as an inert gas for replacement is provided outside the bag making and packaging machine 1.

As shown in FIG. 5, this gas supply device 20
A nitrogen gas tank 21 in which nitrogen gas is stored under pressure, a main valve 22 for supplying nitrogen gas supplied from the tank 21 to the downstream side, and removing impurities contained in the nitrogen gas. And a regulator 24 having a flow meter for adjusting the flow rate of the nitrogen gas supplied from the filter 23 and measuring the flow rate of the nitrogen gas. In other words, the nitrogen gas supplied from the nitrogen gas tank 21 through the main valve 22 is filtered to remove impurities and then adjusted to a predetermined flow rate by the regulator 24 and supplied to the downstream side. become.

The replacement gas supply pipe 25 in which the tank 21, the main valve 22, the filter 23 and the regulator 24 are disposed is provided downstream of the regulator 24 at a high pressure side supply pipe 25 a and a low pressure side supply pipe 25. 25b and a blowing-side supply pipe 25c, and among these branched supply pipes, a high-pressure supply pipe 25a and a low-pressure supply pipe 25c.
b again merges into the inlet 16 of the replacement gas passage 16.
a. Further, the blowing-side supply pipe 25
As shown in FIG. 2, the tip of c is arranged so as to blow nitrogen gas from the upper end of the upper portion 14 of the tube member 13.

The high-pressure supply pipe 25a is provided with a high-pressure solenoid valve 26. When the high-pressure solenoid valve 26 is ON, nitrogen gas supplied from the nitrogen gas tank 21 is supplied to the high-pressure side solenoid valve 26a. The gas is supplied to the replacement gas passage 16 of the packaging machine 1 through the supply pipe 25a.

The low-pressure side supply pipe 25b is provided with a low-pressure solenoid valve 27 similar to the high-pressure solenoid valve 26, a flow control valve 28 such as an electro-pneumatic proportional valve, and a flow meter 29. When the low pressure solenoid valve 27 is ON, the nitrogen gas is supplied to the replacement gas passage 16 through the low pressure side supply pipe 25b, and the flow rate thereof is adjusted by the flow control valve 28. The total is measured by a total 29.

The blowing supply pipe 25c is provided with a blowing solenoid valve 30 similar to the high-pressure solenoid valve 26 and the low-pressure solenoid valve 27.
0 is turned on and off, so that the tube member 1
Nitrogen gas is supplied from the upper end side of the upper portion 14 of the fuel cell 3 as needed.

Next, a gas supply control system in the bag making and packaging machine 1 will be described.

As shown in FIG. 6, the bag making and packaging machine 1 is provided with a control unit 40. The control unit 40 is manually operated by an operator, and a start signal a from a start button 51 at which the operation of the bag making and packaging machine 1 is started by the operation, and a stop signal for stopping the operation of the bag making and packaging machine 1 And an end signal for ending the operation of the bag making and packaging machine 1.

When a start signal a from the start button 51 is input to the control unit 40, the control unit 40 operates the main motor (not shown), the feed device 3, the vertical seal device 5, and the vertical seal device 5 shown in FIG. The drive signal b is output to the operating section 52 of the bag making and packaging machine 1 such as the horizontal sealing device 6 and the like, and these are operated.

The stoppage of the bag making and packaging machine 1 is such that the operation of the packaging machine 1 is restarted when the cause of the stoppage is released, and the stop signal is provided in the regulator 24 of the gas supply device 20. A gas flow rate reduction signal c transmitted when the flow rate of the nitrogen gas supplied from the nitrogen gas tank 21 is reduced by the flow meter provided, and a stop signal from the downstream equipment 53 disposed downstream of the bag making and packaging machine 1. d, there is a metal detection signal e from the metal detector 54 that is transmitted when a metal object is detected in the product in which the package is enclosed.

The operation of the bag making and packaging machine 1 is not restarted unless the operator performs a start operation. The end signal includes an end signal from an end button 55 manually operated by the operator. f is included. When the stop signal and the end signal are input to the control unit 40, the control unit 40
A stop signal g is output to the operation unit 52 such as the main motor, and the operation unit 52 is turned off.

Further, in addition to the stop signal and the end signal,
As the flow rate control signal of the nitrogen gas, the flow rate signal h from the flow meter 29, the oxygen concentration signal i from the oxygen concentration sensor 18 described above, and the state of the sealing portion of the packaging material in which the package is enclosed are detected. Seal state signal j from the seal sensor 56
And a temperature signal k and a humidity signal 1 from a temperature sensor 57 and a humidity sensor 58 for detecting an ambient temperature and an atmospheric humidity, respectively, as a work environment, and a packaged object supplied from the measuring device 59 into the bag-shaped packaging material. A weight signal m indicating the weight, a seal state signal n from the seal checker as the downstream implement 53, and a weight signal o from the weight checker as the downstream implement 53 are input to the control unit 40. I have.

Here, the flow signal h is output as a voltage proportional to the flow rate. The seal sensor 56 detects the biting of the packaged object in the seal by detecting the pressing force of the seal of the bag-like packaging material in which the package is sealed by a weight sensor such as a load cell. Some of them detect the state of biting of the seal by a camera or the like. Further, the seal checker detects a decrease in airtightness due to biting of the seal portion by pressing the bag-like packaging material in which the packaged object is sealed from above, and furthermore, the weight checker detects the sealed packaged material. Are individually weighed for the entire weight of the bag-like packaging material in which the is enclosed.

The start signal a, the gas flow rate reduction signal c, the stop signal d from the downstream equipment 52, the metal detection signal e,
When the end signal f or the like from the end button 55 is input to the control unit 40, the elapsed time is started to be measured by the timer 41 provided in the control unit 40. Then, based on the elapsed time measured by the timer 41, the control unit 40 transmits control signals p and q to the high-pressure solenoid valve 26 and the low-pressure solenoid valve 27, and outputs these control signals p and q. Based on the solenoid valve 2
ON and OFF of 6, 27 are switched.

When nitrogen gas is supplied to the bag making and packaging machine 1 with only the low-pressure solenoid valve 27 being ON, the type of the article to be packaged stored in the memory 42 provided in the control unit 40 is controlled. Permissible range of residual oxygen concentration and permissible limit of defective sealing rate, ambient temperature, atmospheric humidity, packaging capacity of the bag making and packaging machine 1, weight of the packaged object, bag size, etc. Data such as the nitrogen gas supply amount, the weight signal m from the measuring instrument 59 and the weight signal o from the weight checker as the downstream device 53, the oxygen concentration signal i from the oxygen concentration sensor 18, and the seal sensor 56 Seal state signal j and downstream equipment 5
The flow control signal r is output to the flow control valve 28 based on the seal state signal n from the seal checker 3.

The flow control signal r is also output based on the flow signal h. Further, a speed control signal s is output to the operating section 52 such as the main motor as part of the control of the nitrogen gas supply amount.

Further, when it is determined based on the oxygen concentration signal i that the oxygen concentration remaining in the bag-like packaging material exceeds a predetermined allowable range, the control unit 40 outputs a warning signal t to the warning device 60. , So that a warning is issued.

The control unit 40 also controls the packaging capacity of the bag making and packaging machine 1, the state of supply of nitrogen gas by the gas supply device 20, the flow rate of nitrogen gas based on the flow signal h from the flow meter 29, and the control of the oxygen concentration sensor 18. Oxygen concentration signal i
A display signal u for displaying on the monitor 61 the remaining oxygen ratio based on the above is output to the monitor 61.
Thereby, the operator can easily know the gas supply state to the bag making and packaging machine 1.

The overall operation of the above embodiment will be briefly described. First, when the bag making and packaging machine 1 is operated, a band-shaped packaging material is provided from a roll supporting portion provided at the rear of the machine base 2. Is fed forward, and while being sent downward above the front of the machine base 2, the packaging material is bent by the sailor member 12 constituting the former 10 so that the left and right side edges overlap. Further, the left and right side edges of the packaging material stacked as described above are welded by the vertical sealing device 5 on the front side of the lower part 15 of the tube member 13 by the feeding devices 3 and 3, State.

At this time, as shown in FIG.
Is closed by the horizontal sealing device 6 to form a bag during the previous packaging operation. Then, after the bag-shaped packaging material A is sent further downward, the objects to be packaged XX are loaded into the packaging material A from above through the tube member 13.

In parallel with the introduction of the articles to be packaged X... X, nitrogen gas is supplied from the gas supply device 20 into the bag-shaped packaging material A through the replacement gas passage 16. The air in the material A is discharged to the outside from the upper end portion of the tube member 13 or the bent portion of the packaging material by the sailor member 12, and the air in the bag-shaped packaging material A is replaced with nitrogen gas. After that, the upper part of the bag-shaped packaging material A into which the object to be packaged is inserted and the lower part of the next part to be packaged are sealed by the horizontal sealing device 6 and cut at the center of the sealing part. Is done.

In this manner, bagged products in which the articles to be packaged are enclosed and the air inside is replaced with nitrogen gas are continuously produced, and are sequentially carried out of the machine by the carry-out device 7 shown in FIG. Is done.

Next, the replacement gas supply control in the bag making and packaging machine 1 according to the embodiment of the present invention will be specifically described with reference to the flowchart of FIG.

First, in step S1, the control unit 40 determines whether or not the bag making and packaging machine 1 has started operating. When the packaging machine 1 starts to operate, the high-pressure electromagnetic valve 26 and the low-pressure electromagnetic valve 27 are first turned on and the timer 41 is started in steps S2 and S3.

Thus, the nitrogen gas tank 2 shown in FIG.
After the nitrogen gas supplied from 1 is adjusted to a predetermined flow rate by the regulator 24, it is supplied to the inlet 16a of the replacement gas passage 16 via the high pressure solenoid valve 26 and the low pressure solenoid valve 27. . At this time, the flow rate of the nitrogen gas supplied to the inlet 16a is set to a relatively large initial flow rate L1 as shown in FIG.

When the time measured by the timer 41 started in step S3 reaches the initial supply time T1, the control unit 40 proceeds to step S4.
Then, the high pressure solenoid valve 26 is turned off. As a result, only the nitrogen gas supplied to the inlet 16a of the replacement gas passage 16 passes through the low-pressure solenoid valve 27, and its flow rate is controlled by the flow rate control valve 28 as shown in FIG. It is adjusted to a smaller normal flow rate L2. Therefore, the nitrogen gas at the normal flow rate L2 is supplied into the bag-like packaging material into which the article to be packaged is introduced.

When the blow solenoid valve 30 is ON, the nitrogen gas is supplied from the opening at the upper end of the tube member 13 in addition to the nitrogen gas at the initial flow rate L1 or the normal flow rate L2. Become. The timer 41 is reset when the measurement time reaches the initial supply time T1.

Next, the control unit 40 determines whether or not a stop signal has been input to the control unit 40 in step S5. Also, in step S6,
It is determined whether an end signal for ending the operation of the packaging machine 1 has been input. When neither signal is input, the state where the nitrogen gas is supplied at the normal flow rate L2 is maintained while repeatedly executing steps S5 and S6, and the packaging operation is repeatedly and continuously performed in this state. .

On the other hand, if a stop signal is input in this state, the control unit 40 proceeds to step S5.
From step S7, the timer 41 is restarted, and at step S8, it is determined whether or not the measured time T from the restart has exceeded a preset extended supply time T2.

If the stop release signal for releasing the stop is input before the elapse of the extended supply time T2 and the end signal has not been input, the control unit 40 starts from step S9. Step S
5. Returning to the state where S6 is repeatedly executed, the state where the low-pressure solenoid valve 27 is turned on, that is, the state where the nitrogen gas is supplied at the normal flow rate L2, is continued as it is.

That is, even if the stop signal is input, if it is canceled relatively quickly, the state in which the nitrogen gas is supplied at the normal flow rate L2 is continued. A gas-substituted product is produced immediately at the required substitution rate when the packaging operation is resumed without wasting gas.

On the other hand, even if the extended supply time T2 has elapsed or has not elapsed, if the end signal is input,
The control unit 40 executes an end process from step S8 or step S10 to step S11 and subsequent steps.

In this case, first, in step S11, the control unit 40 switches off the low-pressure solenoid valve 27. Thereby, the supply of the nitrogen gas to the bag making and packaging machine 1 is completely stopped.

Then, in step S12, the timer 4
After resetting 1 and restarting, the elapsed time from when the low-pressure solenoid valve 27 is turned off is measured, and in step S13, the elapsed time T exceeds the preset supply standby time T3. Is determined.
If the elapsed time T exceeds the supply standby time T3, the control unit 40 determines that the packaging machine 1 has completely stopped, ends the control, returns to step S1, and returns to the next start signal. Wait for input.

On the other hand, the elapsed time T is equal to the supply standby time T3.
If the work start signal is input again before elapses, steps S14 to S15 are executed, the low-pressure solenoid valve 27 is turned ON, and the above steps S5 and subsequent steps are executed again. As a result, in this case, the bag making and packaging machine 1
Is supplied with the nitrogen gas at the normal flow rate L2 again.

That is, even after the operation of the bag making and packaging machine 1 is completed and the supply of nitrogen gas to the packaging machine 1 is stopped,
Thereafter, if the operation is restarted before the predetermined supply standby time T3 elapses, since the nitrogen gas is sufficiently remaining in the tube member 13 of the packaging machine 1, the low-pressure solenoid valve 27 at the start of the operation. Turn ON only a relatively small amount of normal flow L
The work is resumed in Step 2. Thereby, the supply of unnecessary nitrogen gas is suppressed. When the start signal is input after the supply standby time T3 has elapsed, both the high-pressure solenoid valve 26 and the low-pressure solenoid valve 27 are turned on, as indicated by the dashed line in FIG. Is started with the initial flow rate L1.

As described above, the nitrogen gas is supplied at the initial flow rate L1 or the normal flow rate L2 according to the continuous state of the packaging operation. Such control is performed, and this control will be described below.

As shown in FIG. 3, in the nitrogen gas passage 16 of the tube member 13, a gas intake pipe 19 whose tip is opened in a bag-shaped packaging material to take in the gas in the packaging material is provided.
Is provided, and the gas introduced from the inlet 19 a of the pipe 19 is guided to the oxygen concentration sensor 18. The oxygen concentration detected by the sensor 18 is sent to the control unit 40 as a signal h, so that the control unit 40 is constantly input with the residual oxygen concentration in the bag-shaped packaging material. .

On the other hand, the control unit 40 reads from the memory 42 a preset allowable range of the residual oxygen concentration for the package currently being processed. Further, a seal state signal i from a seal sensor 56 for detecting whether or not the packaged object is caught in the upper seal portion of the product in which the packaged product is enclosed, and a seal checker as a downstream device 53 Is input. Further, if biting occurs, the weight becomes insufficient. Therefore, a weight signal o from the weight checker as the downstream equipment 53 is also input, and based on these signals i, o, n, biting in all products occurs. Calculate the seal failure rate that indicates the percentage of products that are in use. Then, the normal flow rate L2 of the nitrogen gas is controlled based on the information.

That is, as shown in FIG. 10, the upper limit of the allowable range of the residual oxygen concentration read from the memory 42 is now 2
Assuming that the remaining oxygen concentration indicated by the signal h from the oxygen concentration sensor 18 exceeds 2%, the control unit 40 causes the flow control valve 28 to increase the flow rate of the nitrogen gas. To output a control signal n. As a result, as shown by the arrow A in FIG. 10, the flow rate of the nitrogen gas is increased, and the residual oxygen concentration is adjusted within an allowable range.

On the other hand, if the flow rate of the nitrogen gas is too large, the residual oxygen concentration is kept within the allowable range, but the flow rate of the nitrogen gas into the bag-like packaging material increases, and the nitrogen gas is introduced into the packaging material. The article to be packaged or being introduced is blown up, so that the lateral sealing device 6 is likely to be bitten. As a result, it is assumed that, for example, the seal failure rate has exceeded the allowable limit of 1%.

In this case, the control unit 40
The control signal n is output to the flow control valve 28 so as to reduce the flow rate of the nitrogen gas. As a result, as shown by the arrow A in FIG. 10, the flow rate of the nitrogen gas is reduced, and the defective sealing rate converges below the allowable limit.

In this way, the normal flow rate L2 is adjusted according to the residual oxygen concentration and the defective sealing rate, the residual oxygen concentration falls within the allowable range, and a gas replacement rate higher than a required level is obtained. The rate will be kept below a predetermined tolerance limit.

In this embodiment, when the residual oxygen concentration falls within the allowable range and the seal failure rate falls below the predetermined allowable limit as described above, the nitrogen gas measured by the flow meter 29 is used. Gas flow rate and temperature sensor 5
7, the ambient temperature and humidity at that time indicated by the signals k and l from the humidity sensor 58, the weight of the packaged object indicated by the weight signal from the measuring instrument 59, and the type of the packaged object, the packaging speed and the bag size. Are stored in the memory 42 in association with each other. Therefore, this memory 4
2 stores data of the nitrogen gas flow rate associated with each combination of the type of the article to be packaged, the ambient temperature, the ambient humidity, the weight, the packaging speed, and the bag size.

When the flow rate is switched from the initial flow rate L1 to the normal flow rate L2 at the start of the next and subsequent packaging operations, the ambient temperature, the atmospheric humidity, the type of the object to be packaged, the weight, the packaging speed, and the packaging speed are changed. The data of the nitrogen gas flow rate associated with the combination of temperature and humidity of the combination closest to the size is read from the memory 42, and the flow rate is set to the initial value of the normal flow rate L2. Therefore, an appropriate amount of nitrogen gas is supplied immediately after the start of the packaging operation, and the occurrence of defective gas replacement or defective sealing immediately after the start of the operation is suppressed.

Further, in parallel with the above control, irrespective of whether or not the residual oxygen concentration is within an allowable range, the residual oxygen concentration, sealing failure, type and weight of the packaged object, packaging speed, bag size, and The ambient temperature and the ambient humidity are stored in association with each packaging operation.

That is, for example, when the packaged product is fried with oil, the amount of oxygen varies depending on the type of the packaged product. Since the weight supplied from the measuring instrument 59 varies within an allowable range, the amount of oxygen varies depending on the weight, and accordingly, the flow rate of the nitrogen gas for keeping the residual oxygen concentration within the allowable range also differs. . Also, when the packaging speed is high or when the bag size is large, the supply amount of nitrogen gas is large, so the flow rate at the time of supply is large. Since the ease of blowing is different and the viscosity of the nitrogen gas is changed, the flow rate is different even at the same pressure. Therefore, by storing the flow rate for each of these parameters and using this in the control shown in FIGS. 10 and 11, it becomes possible to perform these controls more appropriately.

By controlling the nitrogen gas flow rate as shown in FIG. 10, if the nitrogen gas flow rate is increased so that the residual oxygen concentration falls within the allowable range, the seal failure rate exceeds the allowable limit, and conversely, the seal failure If the flow rate of the nitrogen gas is reduced so that the rate becomes lower than the allowable limit, the case where the residual oxygen concentration exceeds the allowable range may occur.

In this case, the control unit 40
A speed control signal s is output to the operating section 52 of the bag making and packaging machine 1 so as to reduce the operation speed. As a result, as shown in FIG. 11, for example, when the work is being performed with a processing capacity of 120 times per minute, the seal failure rate is suppressed to below the allowable limit, and as a result, the residual oxygen concentration becomes the upper limit of the allowable range. If it exceeds 2%, the operation speed of the drive source 59 is reduced, and the processing capacity is set to, for example, 100 times per minute, as shown by reference numeral c in FIG. As a result, the nitrogen gas supply time to one bag-like packaging material becomes longer by an amount corresponding to the reduction in the processing capacity. The concentration can be reduced to within an allowable range.

Also, when the nitrogen gas supply amount is increased so that the residual oxygen concentration falls within the allowable range, and the sealing failure rate exceeds the allowable limit, the operating speed of the operating part 52 may be reduced. By extending the time of one packaging cycle, the time required for the blown-up article to fall can be secured, so that the required amount of nitrogen gas is supplied to maintain the gas replacement rate at a predetermined level, and the sealing is performed. This makes it possible to reduce the defective rate below the allowable limit.

Here, in the above embodiment, the normal flow rate L2 on the low pressure side is to be controlled, so that more precise control is possible. In addition, real-time control based on various signals becomes possible.

Further, in this embodiment, a voltage corresponding to the flow rate is input from the flow meter 29 to the control unit 40 as the flow rate signal h, and the difference between the flow rate indicated by the signal h and the desired set flow rate is obtained. The feedback control of the nitrogen gas flow rate is performed by outputting the control signal r to the flow control valve 28 based on That is, the bag making and packaging machine 1
This feedback control is performed when the nitrogen gas is supplied at the initial flow rate L1 at the start of the operation or when the nitrogen gas is supplied at the time of restarting the work after the stop, whereby the flow rate of the nitrogen gas at the start of the work or the like is rapidly increased. It will be adjusted to the optimal flow rate.

FIG. 12 shows another embodiment of the nitrogen gas supply control system. In this system 20 ', the high-pressure solenoid valve 26 and the low-pressure solenoid valve 27 in the above embodiment do not exist. Replacement gas supply pipe 25 'from the nitrogen gas tank 21' to the inlet 16a 'of the replacement gas passage.
A main valve 22 ', a filter 23', a flow control valve 28 'composed of an electropneumatic proportional valve and the like and a flow meter 29' are arranged. The blowing solenoid valve 3 is placed on the blowing-side supply pipe 25c 'branched from the replacement gas supply pipe 25'.
The point where 0 'is arranged is the same as in the above embodiment. The flow control valve 28 'is controlled by a control signal from a control unit. Therefore, also in this embodiment, control is performed such that the residual oxygen concentration converges within an allowable range and the sealing failure rate is equal to or lower than a predetermined allowable limit, similarly to the above-described embodiment.

In this embodiment, the flow rate may be continuously controlled based on the oxygen concentration signal i without performing the control shown in FIG. 8 in the above embodiment. That is, instead of controlling only the normal flow rate L2 shown in FIG. 9, the entire range from the flow rate 0 to a large flow rate corresponding to the initial flow rate L1 in FIG. 9 is controlled based on the oxygen concentration signal i.

In this case, since the configurations of the gas supply device and the control system are simplified and stepless continuous control is performed, the initial flow rate L1, the normal flow rate L2, and the flow rate 0 in the above-described embodiment are not changed. Switching control becomes unnecessary, and unnecessary supply of nitrogen gas at the time of switching from the initial flow rate L1 to the normal flow rate L2, for example, is suppressed.

In this embodiment, it goes without saying that control similar to that of the above embodiment may be performed based on the signals a, c to f, and h to o shown in FIG.

[0092]

As described above, according to the bag making and packaging machine of the present invention, an inert gas such as a nitrogen gas or an argon gas is supplied while introducing an article to be packaged into the bag-like packaging material. When replacing the oxygen in the packaging material, the flow rate of the inert gas is controlled in real time based on the remaining state of the oxygen in the packaging material. Insufficient amount of oxygen remains in the packaging material due to insufficient supply amount, or the flow rate is too large, so that more than necessary inert gas may be supplied even though gas is sufficiently replaced. This prevents the air in the packaging material from being replaced to a required level with a minimum supply of inert gas at all times.

In this case, according to the third and fourth aspects of the present invention, in addition to the above-described effects, the defective rate of the packaged state is controlled to a predetermined value or less, and according to the fifth and sixth aspects of the present invention. For example, immediately after the start of the work, the inert gas supply control is performed satisfactorily.

[Brief description of the drawings]

FIG. 1 is a schematic front view of a bag making and packaging machine according to an embodiment of the present invention.

FIG. 2 is an enlarged side view of a former in the bag making and packaging machine.

FIG. 3 is an enlarged sectional view around a lower end portion of a replacement gas passage.

FIG. 4 is a sectional view taken along line xx of FIG. 3;

FIG. 5 is a block diagram illustrating a configuration of a gas supply device.

FIG. 6 is a block diagram illustrating a configuration of a gas supply control system.

FIG. 7 is an explanatory diagram of a packaging operation.

FIG. 8 is a flowchart showing an operation of gas supply control.

FIG. 9 is a time chart showing an inert gas supply state under the same control.

FIG. 10 is an explanatory diagram of flow rate control during gas supply.

FIG. 11 is an explanatory diagram of control of the processing capacity.

FIG. 12 is a block diagram showing another embodiment of the gas supply device.

[Explanation of symbols]

1 Bag-making and packaging machine 18 Remaining oxygen detection means (oxygen concentration sensor) 20 Gas supply means (gas supply device) 28, 40 Flow rate control means (flow rate control valve, control unit) 57, 58 Environment detection means (temperature sensor, humidity sensor) )

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3E050 AA02 AB02 BA11 CA02 CB01 DC02 DC09 DD05 DF01 FA01 FB01 FB07 GA06 GB05 GC09 JA04 3E053 AA06 AA09 BA05 DA03 FA01 JA03 JA04 3E118 AA07 AB12 BA10 BB08 CA03 CA12 EA10

Claims (7)

[Claims] 1. A gas supply means for introducing an object to be packaged into a bag-shaped packaging material while forming the band-shaped packaging material into a bag shape, and supplying an inert gas into the packaging material is provided. A bag making and packaging machine, comprising: a residual oxygen detecting means for detecting a residual state of oxygen in the bag-shaped packaging material; and a flow rate at the time of supplying an inert gas by the gas supplying means, based on a detection result by the detecting means. A bag making and packaging machine provided with flow rate control means for controlling. 2. A flowmeter for detecting a flow rate of an inert gas supplied by the gas supply means, a flow rate of the inert gas detected by the flowmeter, and a residual state of oxygen detected by the residual oxygen detection means. 2. A bag making and packaging machine according to claim 1, further comprising a display means for displaying the following. 3. A packaging state detecting means for detecting a packaging state, wherein the flow rate control means includes a means for detecting a packaging state when the residual oxygen concentration detected by the residual oxygen detecting means is equal to or less than a predetermined value. 3. The flow rate of the inert gas is controlled such that the defective rate of the packaging state detected by the method is equal to or less than a predetermined value.
2. The bag making and packaging machine according to 1. 4. The method according to claim 1, wherein the control of the flow rate by the flow rate control means causes a reduction in the packaging capacity when the residual oxygen concentration is lower than a predetermined value and the defective rate of the packaging state does not become lower than the predetermined value. 4. A bag making and packaging machine according to claim 3, further comprising means. 5. A storage means for storing a predetermined flow rate of an inert gas, and when the flow rate control means starts controlling the flow rate of the inert gas, the flow rate read out from the storage means is set to an initial value of the control. The bag making and packaging machine according to any one of claims 1 to 4, further comprising an initial value setting unit. 6. An environment detecting means for detecting at least one of an ambient temperature and an atmospheric humidity of a working environment, wherein the storage means associates the working environment detected by the environment detecting means with the environment. In addition to storing the flow rate of the inert gas during the packaging operation, the initial value setting means, when starting the flow control of the inert gas by the flow rate control means, from the storage means, the same as the current working environment The bag making and packaging machine according to claim 5, wherein a flow rate associated with the working environment is read out, and the flow rate is set as an initial value of the control. 7. The storage means stores the flow rate of the inert gas during the packaging operation in association with the type of the article to be packaged, and the initial value setting means controls the flow rate of the inert gas by the flow rate control means. 7. The method according to claim 5, wherein when starting, the flow rate of the inert gas associated with the package to be processed this time is read from the storage means, and the flow rate is set to an initial value of control. The bag making and packaging machine as described.