JP6821966B2 - Bag making machine and its control method - Google Patents

Description

In the present invention, a long bag-making film (generally a plastic film) on which at least a reference mark (including a print pattern that can be used as a reference mark) is printed at a constant printing pitch is formed with a length corresponding to the printing pitch. The present invention relates to a bag-making machine that intermittently conveys bags by (distance) and, in a stopped state, applies predetermined processing (seal, punch, cut, etc.) to a bag-making film to produce a bag, and a control method thereof.

In the conventional bag making machine, the misalignment of the seal position due to the expansion and contraction of the plastic film for bag making and the misalignment due to slippage during transportation are visually detected. It is necessary to slightly displace the processing unit that processes the film according to the detected positional deviation, but this was also adjusted manually. Especially in the case of a film in which patterns are repeatedly printed at a constant pitch, the deviation of the seal position cannot be ignored.

Patent Document 1 discloses a bag making machine that automatically solves the problem that the position of the printed pattern and the processing position (particularly the horizontal seal position) are displaced due to the expansion or contraction of the plastic film.

Japanese Patent No. 4819110

In the bag making machine described in Patent Document 1, when the printing pitch fluctuates due to the expansion and contraction of the plastic film, the amount of fluctuation of the printing pitch is obtained based on the detection signal of the optical sensor. Based on the amount of fluctuation in the print pitch and the detection signal, the machining unit is slightly displaced to a position where there is no deviation between the position of the machining unit and the print position. It has been proposed to improve production efficiency by automatically adjusting the position of this processing unit without performing manual adjustment. However, there are problems with the position adjustment accuracy and adjustment speed of the machining unit.

That is, in the bag making machine described in Patent Document 1, the printing pitch is calculated to determine the displacement amount of the processing unit, but the adjustment accuracy is high because the transport error of the plastic film by the bag making machine is not taken into consideration. It doesn't rise. In addition, the processing unit is driven after the transport of the plastic film is stopped, so the production speed cannot be increased.

According to the present invention, in the bag making machine, the accuracy of fine adjustment of the position of the processing unit is improved in consideration of the slippage of the bag making film caused by the conveying device and the conveying error based on the stability of the control device of the conveying device. With the goal.

Next, it is an object of the present invention to increase the production speed of the bag making machine by accelerating the start time of fine adjustment of the processing unit.

Another object of the present invention is to reduce the number of optical sensors and simplify the configuration.

Of course, the present invention can sufficiently cope with the position change due to the expansion and contraction of the bag-making film.

The bag-making machine according to the present invention is a transport device that intermittently transports a long bag-making film on which at least a reference mark is printed at a constant pitch, and a transport direction at each processing position facing the transport path of the bag-making film. A group of a plurality of processing units that are displaceably arranged forward and backward and perform predetermined processing on the bag-making film when the bag-making film is stopped, and each of the processing units is displaced as instructed. The group of machining units so that the reference mark is detected between the stop position of the previous stage and the distance corresponding to the constant pitch of the machining unit drive device and the bag-making film that are displaced in the direction. A single mark sensor located upstream in the transport direction of, and the measured transport amount from the stopped state of the previous stage until the mark sensor detects the reference mark, and the measured transport amount is measured. The unit bag film portion of interest is commonly used for the group of processing units, and the remaining transport amount is obtained based on the measured transport amount and the transport target value output from the control device of the transport device. The displacement control means of the machining unit for controlling the corresponding machining unit drive device by calculating the displacement direction and the displacement amount of the machining unit based on the comparison with the reference remaining transport amount for each machining position is provided. It is something that is.

In a preferred embodiment, the displacement control means of the processing unit controls the processing unit drive device to start driving before the next stage of the bag-making film to be conveyed is stopped.

The control method of the bag making machine according to the present invention is a transfer device that intermittently conveys a long bag making film on which at least a reference mark is printed at a constant pitch, and each processing position facing the carrying path of the bag making film. , A group of multiple processing units that are displaceably arranged forward and backward in the transport direction and perform predetermined processing on the bag-making film when the bag-making film is stopped, and each of the processing units is instructed. The reference mark is detected between the stop position of the previous stage and the distance corresponding to the constant pitch of the displacement amount, the processing unit drive device for displacement, and the bag making film in the displacement direction. In a bag making machine equipped with a single mark sensor located upstream of the transport direction of a group of processing units, the actual measurement transport amount from the stop state of the previous stage to the detection of the reference mark by the mark sensor. The measured transport amount is used in common for the group of processing units for the unit bag film portion, and the remaining transport is based on the measured transport amount and the transport target value output from the control device of the transport device. The amount is calculated, and the displacement direction and displacement amount of each processing unit are calculated based on the comparison between the remaining transfer amount and the reference remaining transfer amount for each processing position, and the next stage of the bag-making film to be conveyed. It is controlled so that the driving of the processing unit drive device is started before the stop of the above.

The control device of the transport device acquires data related to the actual transport amount, preferably for each intermittent transport or every few intermittent transports, and updates and outputs the transport target value based on this data.

According to the present invention, the actual measurement amount of film transferred from the stopped state to the start of film transfer until the mark sensor detects the reference mark of the film to be conveyed is measured. Then, the remaining transfer amount is obtained based on the measured actual transfer amount and the transfer target value output from the control device of the transfer device, and the displacement direction of the processing unit is obtained based on the comparison between the remaining transfer amount and the reference remaining transfer amount. And the displacement amount is calculated, and the displacement of the machining unit is controlled based on the calculated displacement direction and displacement amount.

The transport error due to slippage and instability in the transport device is reflected in the transport target value output from the control device of the transport device. Since this transfer target value is used as one parameter for fine adjustment of the position of the processing unit, fine adjustment of the position of the processing unit in consideration of the transfer error can be realized and its accuracy can be improved. In addition, the measured transport amount from the stop position to the start of film transport until the mark sensor detects the reference mark is measured, and this measured transport amount is also used as one of the parameters for fine adjustment of the position of the processing unit. .. Since the elongation and contraction of the film are reflected in the measured transport amount, the position of the processing unit can be finely adjusted in consideration of the fluctuation of the stop position of the film due to the expansion and contraction of the film. Furthermore, since the displacement drive of the machining unit based on the calculated displacement direction and displacement amount is started before the stop of the next stage of the film, the start time of fine adjustment of the machining unit is earlier, and faster production is possible. Bag production becomes possible.

Since a single mark sensor is used for a group of machining units consisting of multiple machining units, the number of mark sensors should be reduced and the configuration should be simplified compared to the case where a mark sensor is provided for each machining unit. Can be done.

Preferably, the reference remaining transfer amount is updated in the displacement control means based on the average value of the remaining transfer amount over an appropriate range for each machining unit after an appropriate number of repetitions in an intermittent manner.

The overall configuration of the bag making machine is shown. The bag making process is shown. (A), (B), (C), (D), (E), (F), (G) use a certain unit bag to measure and calculate various quantities for displacement control of the machining unit. It is shown focusing on the film part. The processing procedure by the control device is shown.

FIG. 1 is a perspective view of the outline of the overall configuration of the bag making machine, and FIG. 2 is a plan view showing the bag making process by the bag making machine shown in FIG.

The bag making machine is provided with a conveying device 10 that intermittently conveys a long bag making film (or sheet) 1. The transport device 10 rewinds the raw film 1 wound around a roll or the like (not shown) and transports it in the longitudinal direction thereof. Two films 1 are stacked and conveyed in a horizontal plane in this embodiment. Generally, the film 1 is a plastic film, and a pattern (including characters and the like) (not shown) is repeatedly printed at a constant pitch (printing pitch). There is a reference mark 2 in a part of this pattern. The reference mark 2 is also provided at the above-mentioned constant pitch, and is used for transport control of the transport device 10, minute displacement control of the processing unit described later, and the like.

A large number of a pair of upper and lower nip rolls 13 (only a part thereof is shown) are arranged along the transport path (transport path) of the transport device 10. The pair of upper and lower nip rolls 13 sandwich and convey two stacked films 1 between them. The nip roll 13 is rotationally driven by the drive device (motor) 12 via, for example, a timing belt. The transport device 10 further includes its control device 11, an encoder 14, and an optical sensor 15. The encoder 14 is attached to, for example, the rotating shaft of the nip roll 13 (or the rotating shaft of the motor, or any other shaft that rotates in synchronization with the rotating shaft), and is used to measure the amount of rotation, that is, the amount of film 1 conveyed by the nip roll 13. Will be done. The output signal of the encoder 14 is given to the control device 11. The optical sensor 15 detects the reference mark 2 printed on the film 1, and is arranged at an appropriate position on the transport path, for example, on the downstream side of the transport path. The optical sensor 15 outputs a detection signal (for example, a pulse representing the tip of the reference mark 2 with a rising edge) every time the reference mark 2 passes through the mounting position, and gives the detection signal to the control device 11.

The control device 11 controls the drive motor 12 (hence, the nip roll 13) to be rotationally driven intermittently. That is, the transfer of the film 1 is repeated intermittently, and the film 1 is stopped between the transfer and the transfer. During this stop time, processing (sealing, punching, cutting, etc.) into the film 1 for making the bag is performed. The amount of intermittent transfer by the transfer device 10 at one time corresponds to the printing pitch, that is, the distance (length) between the adjacent reference marks 2.

In the transfer control by the control device 11, the transfer target value L (corresponding to the printing pitch) is set, and the motor 12 is driven (started and stopped) until the transfer amount (measured by the output of the encoder 14) reaches this target value. It is something to do. Then, the control device 11 is transported from the time when the output signal is generated from the optical sensor 15 to the time when the next output signal is generated, which is the transfer amount and the printing pitch of one intermittent transfer measured based on the output of the encoder 14. , Or the length that will be transported), and based on this comparison result, the transfer target value L for the next intermittent transfer is generated (the transfer target value L is updated). If the measured transfer amount is smaller than the print pitch (for example, the optical sensor 15 does not generate the next output signal even after the intermittent transfer is completed), a value slightly larger than the previous transfer target value is set as the next transfer target. Output as the value L. On the contrary, if the measured transfer amount is larger than the print pitch (the reference mark 2 passes the position of the optical sensor 15), a value slightly smaller than the previous transfer target value is output as the next transfer target value L. To do. The amount to increase or decrease the transport target value is not necessarily proportional to the difference between the measured transport amount and the print pitch in order to prevent the occurrence of overshoot and the phenomenon that the transport target value L frequently increases and decreases. It is preferable to set the value to a very small value so that the value gradually increases or decreases (gradually). The transfer control itself is a known technique. The updated transfer target value L is given from the control device 11 to the displacement control device 21 of the machining unit.

Along the transport path of the transport device 10, the vertical seal unit is directed from the upstream side (rear in the transport direction; right side in FIGS. 1 and 2) to the downstream side (front in the transport direction; left side in FIGS. 1 and 2). It is arranged in the order of 31, cooling unit 34, horizontal seal unit 41, 44, 47, cooling unit 51, 52, punch unit 61, and cutter unit 71. These units are collectively called a machining unit (machining device), and the position on the transport path where the machining unit is located is called the machining position. Each processing unit is supported so as to be movable (positionally adjustable) in the direction along the transport direction (front-back direction). Since the processing (sealing, cooling, punching, cutting) by these processing units is performed when the transportation of the film 1 to be intermittently conveyed is stopped, each processing unit is suitable for processing at the stop position of the film 1. It is placed in a position and is fine-tuned to the optimum position as described later.

The vertical seal unit 31 is driven by a drive device (machining unit drive device) 32 including a motor with a slight displacement (position adjustment) in the direction along the transport direction (in the front-rear direction). Similarly, the lateral seal units 41, 44, and 47 can be slightly displaced in the front and rear directions by the drive devices 42, 45, and 48, respectively. The punch unit 61 is slightly displaced forward or backward in the transport direction by the drive position 62 and the cutter unit 71 by the drive device 72, respectively. Since the cooling positions of the cooling units 34, 51, and 52 do not necessarily have to be exact, these cooling units are not provided with a drive device, but may be provided with a drive device.

In the arrangement of each unit in the bag making machine of this embodiment shown in FIG. 1, each unit provided with a drive device is divided into two groups. The first group includes the vertical seal unit 31. Although one processing unit is included in the first group, this is also referred to as a group for convenience. The second group includes the horizontal seal units 41, 44, 47, the punch unit 61, and the cutter unit 71. A dancer roll (not shown) is arranged between the first group and the second group (the part indicated by the broken line of the film 1). One optical sensor 33 is arranged on the upstream side of the processing unit of the first group, and one optical sensor 43 is arranged on the upstream side of the processing unit of the second group. These optical sensors 33 and 43 detect the reference mark 2 printed on the film 1 (for example, like the output signal of the optical sensor 15, the reference mark 2 is rising at the rising edge of the output signal of these optical sensors. The timing of detection). The punch unit 61 and the cutter unit 71 may be separated from the second group to form the third group, and one optical sensor for the third group may be arranged on the upstream side of the punch unit 61.

As described above, the film 1 is intermittently fed by a distance corresponding to the printing pitch. The optical sensors 33 and 43 are arranged so as to detect the reference mark 2 which has reached a position a predetermined distance from the stop position of the previous stage of the film 1 with respect to the processing unit on the most upstream side of each group. Preferably, it is placed approximately in the middle between adjacent stop positions. The detection signals of the optical sensors 33 and 43 are given to the displacement control device 21 of the machining unit. The displacement control device 21 is a machining unit drive device 32 for each machining unit group based on the detection signals from these optical sensors, the transport target value L given by the control device 11 of the transport device 10, and the actually measured transport amount y described later. , 42, 45, 48, 62, 72 are controlled to fine-tune the front-back position of the machining units 31, 41, 44, 47, 61, 71 along the transport direction.

The vertical seal unit 31 heats both side portions of the two-layered film 1 by a length corresponding to one printing pitch and fuses (welds) them (formation of the vertical seal portion 3). The cooling unit 34 cools the fused vertical seal portion 3. The horizontal seal units 41, 44, and 47 heat and fuse the two layers of film 1 in the width direction at intervals of one printing pitch (formation of the horizontal seal portion 4). The same location is heated by these lateral seal units 41, 44, 47. The cooling units 51 and 52 cool the horizontal seal portion 4. The punch unit 61 forms two cuts (notches for opening the bag) 6 at substantially the center of the horizontal seal portion 4. The cut unit 71 cuts the horizontal seal portion 4 along its center line (cut line 7). The film 1 may be cut along the center line (cut line 8) in the width direction by the cut unit 71, or may be cut along the cut line 8 by a cutter (not shown) arranged on the downstream side. Good. In this way, two bags having three sides sealed from the two-layer film 1 are produced for each printing pitch. For convenience of explanation regarding the control of fine adjustment of the front-rear position of the unit drive device, the portion having a length corresponding to the printing pitch in the longitudinal direction of the film 1 is referred to as a unit bag film portion. It is indicated by reference numeral U in FIG. The unit means one bag, or two bags as in this embodiment. The number of bags that make up the unit varies depending on how the film is sealed and cut.

The control of each unit drive device, that is, the fine adjustment of each machining unit is performed for each group as follows, and within each group, for each unit drive device.

FIG. 3 shows how the bag-making film 1 that is intermittently fed is intermittently conveyed. FIG. 3A shows a state in which transportation is stopped. For convenience of explanation, one of the reference marks 2 for each print pitch is represented by reference numeral 2A, and the reference mark represented one print pitch away from the front (downstream side) in the transport direction is represented by reference numeral 2O. It is represented by. The film portion between the reference marks 2O and 2A is the unit bag film portion (since the boundary of the printing pitch and the position of the reference mark 2 are misaligned, the unit bag film separated by the printing pitch as shown in FIG. 2). The part and the unit bag film part separated by the reference mark 2 are slightly different, but it does not matter in the following explanation). The unit bag film portion between the reference marks 2O and 2A is particularly referred to as the unit bag film portion U1 of interest. FIG. 3 shows an operation in which the unit bag film portion U1 of interest is repeatedly processed by the processing unit at the stop position and then conveyed by one pitch. Of the processing units of the second group, the horizontal seal units 41, 44, and 47 are shown (also referred to as S1, S2, and S3 in the meaning of the first stage, the second stage, and the third stage), and the upstream side of these processing units. The optical sensor 43 arranged in is illustrated in FIG. The stop state before the reference mark 2A in the rearward (upstream side) in the transport direction related to the unit bag film portion U1 of interest is detected by the optical sensor 43 is set as the previous stop position (FIG. 3 (A)).

FIG. 3 (B) shows the state at the moment when the film 1 starts to be conveyed from the stopped state of FIG. 3 (A) and the reference mark 2A is detected by the optical sensor 43 (the rising edge of the output signal of the optical sensor 43). ing. The film 1 continues to be conveyed. The measured amount (length, distance) of the film 1 (unit of interest bag film portion U1) measured from the stop position in the previous stage until the reference mark 2A is detected by the optical sensor 43. And. The measured transfer amount y is measured by the control device 11 or the displacement control device 21 based on the output signal of the encoder 14. The output signal of the encoder 14 may be directly input to the displacement control device 21. Preferably, the installation position of the optical sensor 43 is determined so that the actually measured transfer amount y is about half (before and after) the transfer target value L.

The displacement control device 21 is based on the following equation (Equation (1)) based on the transfer target value L given by the transfer control device 11 (the transfer target value at this point is L1) and the measured transfer amount y. ， Calculate the remaining transport amount x1.

x1 = L1-y ... Equation (1)

The remaining transport amount x1 indicates how long (conveyed amount) should be transported in order for the transport device 10 to transport the film 1 by a distance (length) corresponding to the transport target value L1.

Further, the displacement control device 21 uses the given reference remaining transfer amount xo (S1) and the remaining transfer amount x1 to obtain the position of the processing unit (horizontal seal unit 41) according to the following equation (Equation (2)). The fine adjustment displacement amount Δx1 of is calculated.

Δx1 = x1-xo (S1) ... Equation (2)

The reference remaining transport amount xo (S1) is a value peculiar to the horizontal seal unit 41 or its driving device 42. The initial values of the reference remaining transfer amount xo (S1) are the standard printing pitch (printing pitch in a film without expansion and contraction), the film setting stop position (setting reference position of the horizontal seal unit 41), and the optical sensor 43. It is determined based on the installation position of. After the bag making machine is put into operation, the standard remaining transport amount xo (S1) is updated by the average value of the remaining transport amount x1 of 10 to 50 times before and after every 100 to 1000 intermittent transports.

The calculated displacement amount Δx1 is used for finely adjusting the position of the processing unit (horizontal seal unit 41) (of the first stage (stage) S1 of the second group) related to (belonging to) the optical sensor 43. When Δx1 is positive (x1> xo (S1)), the film portion (printed pattern) corresponding to the printing pitch advances slightly to the downstream side, so that the processing unit is moved to the downstream side in the transport direction, Δx1. The amount of displacement corresponding to the absolute value of is moved. On the contrary, when Δx1 is negative (x1 <xo (S1)), the machining unit is moved to the upstream side by a displacement amount corresponding to the absolute value of Δx1. The displacement of the machining unit is performed by the corresponding drive device (drive device 42 in the case of the horizontal seal unit 41) under the control of the control device 21. In this way, the film is processed by the processing unit at a position that matches the printing pitch, regardless of the expansion and contraction of the film 1 and the transfer error by the transfer control device 11.

FIG. 3 (C) shows a state in which the film is stopped again after being conveyed by the amount of transfer corresponding to the transfer target value L1 from the stopped state (FIG. 3 (A)). At this stop position, processing (horizontal sealing by the horizontal sealing unit 41) is performed on the unit bag film portion U1 of interest. What is important is the remaining transfer amount x1 and displacement between the detection of the reference mark 2A by the optical sensor 43 (Fig. 3 (B)) and the stop of the next (next stage) film (Fig. 3 (C)). The calculation of the quantity Δx1 and the start of the displacement drive of the machining unit by the drive device are performed. The displacement drive of the processing unit may end after the film has stopped (FIG. 3 (C)). Of course, the film is processed after the fine adjustment of the processing unit is completed.

When the processing of the film 1 by the processing unit is completed, the film 1 is conveyed again as shown in FIG. 3 (D). In the process of this transfer, what is detected by the optical sensor 43 is the reference mark 2B located one print pitch upstream of the reference mark 2A, and is not the reference mark 2A related to the unit bag film portion U1 of interest.

The measured transfer amount y measured when the reference mark 2A related to the bag film portion U1 of interest is detected earlier in (FIG. 3 (B)) is stored in the memory of the displacement control device 21, and is the unit of interest. The previously measured transfer amount y is also used for finely adjusting the position of the processing unit 44 for processing in the second stage S2 of the bag film portion U1, the following calculation corresponding to the equation (1) is performed, and the rest. The transport amount x2 is calculated.

x2 = L2-y ... Equation (3)

L2 is the transport target value of the film 1 at the time of this calculation (as described above, the transport target value L is updated every moment in the transport control device 11).

In the displacement control device 21, the finely adjusted displacement amount Δx2 for the position of the machining unit (horizontal seal unit 44) is calculated by the following equation using the reference remaining transfer amount xo (S2) peculiar to the second stage S2.

Δx2 = x2-xo (S2) ‥‥‥ Equation (4)

Then, while the film 1 is being conveyed, the above calculation and the displacement drive of the processing unit are started, and when the film 1 is stopped (FIG. 3 (E)), the horizontal seal unit 44 to the film portion U1 of the unit of interest (Horizontal seal processing) is performed. Regarding the next unit bag film portion U2 (see FIG. 3 (A)) that continues to the rear (upstream side) in the transport direction of the unit bag film portion U1 of interest, the method described above for the unit bag film portion U1 of interest (actual measurement transport). It goes without saying that the processing is performed in the first stage S1 (the value of the quantity will be different).

When the processing of the film 1 by the processing unit is completed, the film 1 is conveyed again as shown in FIG. 3 (F). In the process of this transfer, the optical sensor 43 detects the reference mark 2C located one print pitch upstream of the reference mark 2B, and the reference mark 2A related to the unit bag film portion U1 of interest also has the same. It is also not the reference mark 2B associated with the next unit bag film portion U2.

The measured transfer amount y measured when the reference mark 2A related to the unit bag film portion U1 of interest was detected earlier (FIG. 3 (B)) is still stored in the memory of the displacement control device 21, and the attention is paid. The previously measured transfer amount y is also used for finely adjusting the position of the processing unit 47 for processing in the third stage S3 of the unit bag film portion U1, and the following calculation corresponding to equations (1) and (3) Is performed, and the remaining transport amount x3 is calculated.

x3 = L3-y ... Equation (5)

L3 is the transport target value of the film 1 at the time of this calculation.

In the displacement control device 21, the finely adjusted displacement amount Δx3 for the position of the machining unit (horizontal seal unit 47) is calculated by the following equation using the reference remaining transport amount xo (S3) peculiar to the third stage S3.

Δx3 = x3-xo (S3) ‥‥‥ Equation (6)

Then, while the film 1 is being conveyed, the above calculation and the displacement drive of the processing unit are started, and when the film 1 is stopped (FIG. 3 (G)), the horizontal seal unit 47 to the film portion U1 of the unit of interest. (Horizontal seal processing) is performed. The next unit bag film portion U2 (see FIG. 3 (A)) following the unit bag film portion U1 in the transport direction (upstream side) and the unit bag film portion following the unit bag film portion U2 are also described above (as described above). It goes without saying that the processing is performed in the first stage S1 and the second stage S2 (the values of the actually measured transfer amounts are different).

In this way, based on the detection signal of the single optical sensor 43, the calculation for fine adjustment in the front-rear direction of the plurality of processing units arranged in front (downstream side) in the transport direction and the calculation result are obtained. Based on the fine adjustment operation is performed. Fine adjustment of the punch unit 61 and cutter unit 71 may also be performed based on the detection signal of the optical sensor 43, or another optical sensor is arranged on the upstream side of the punch unit and based on the output of this optical sensor. You may go there.

As described above, the control device 11 of the transfer device updates the transfer target value L for each intermittent transfer. This is to correct the transfer error due to slippage and the transfer error due to the instability of the transfer control. Therefore, the printing pitch of the film (the position of the printed pattern including the reference mark 2) may be slightly different from the position of the processing apparatus. This is corrected by fine-tuning the position of the processing unit so that processing is always applied where the processing unit matches the print pitch of the film. As described above, when the transport target value L becomes large (assuming that the actual transport amount y is constant), the print pitch of the film (reference mark 2) becomes excessive, so that the processing unit also moves downstream (assuming that the actual transport amount y is constant). Move (albeit a very small amount). On the contrary, when the transport target value L becomes small, the print pitch (reference mark 2) does not reach the position of the processing unit, so the position of the processing unit is moved to the upstream side. In this way, in the bag making machine, the accuracy of fine adjustment of the position of the processing unit can be improved in consideration of the slippage of the bag making film caused by the conveying device and the conveying error based on the stability of the control device of the conveying device. it can.

It can also handle the expansion and contraction of the film. For example, when the film is stretched, the measured transport amount y becomes large (the transport target value L is constant for simplicity), and the remaining transport amount x becomes small, so that the processing unit is moved to the upstream side (for simplicity). Although it is a slight amount of displacement). On the contrary, when the film shrinks, the measured transport amount y becomes small and the remaining transport amount x becomes large, so that the processing unit is moved to the downstream side.

Furthermore, since the calculation based on equations (1) to (6) is performed from the time when the optical sensor detects the reference mark, and the fine adjustment of the position of the processing unit is started based on the result (film transfer is stopped). The processing unit drive device is started before the film is driven), and the bag making can be realized more quickly than when the processing unit is started to move after the film transfer is stopped.

The optical sensor and the machining unit group (which may include one machining unit) arranged in front (downstream side) of the transport direction are paired with the optical sensor, and are in the vicinity of the machining unit group, preferably on the upstream side. Since the above calculation is performed based on the detection signal of the optical sensor arranged at the nearest position (preferably within one printing pitch, and may be about two printing pitches), partial expansion and contraction of the film can be dealt with.

FIG. 4 shows a control processing procedure by the control devices 11 and 21. S11, S16, and S18 are processed by the control device 11 of the transport device, and the rest are processed by the displacement control device 21. The processing by the displacement control device 21 is performed separately for each pair of the optical sensor and the processing unit group.

The film transfer is started from the state in which the transfer is stopped (FIGS. 3 (A), (C), (E)) (S11). When the detection signal from the optical sensor is input (S12), the remaining transfer amount x is calculated for each set of the processing unit and the optical sensor of the processing unit group (S12), and the displacement amount Δx of each processing unit is further calculated. Is calculated, the displacement direction is determined (S14), and the drive of the drive device of each processing unit is started based on this result (S15).

Then, when the transfer of the transfer target value L is completed from the start of transfer (S11), the transfer of the film is stopped (S16) (FIGS. 3 (C), (E), (G)), and the processing by each processing unit is started. (S17). The processing of S11 to S17 is repeated until the film wound on the roll is exhausted (S18).

1 Bag making film 2, 2A, 2B, 2C, 2O Reference mark 3 Vertical seal part 4 Horizontal seal part 6 Notch 7, 8 Cut line
10 Transport device
11 Transport device control device
14 encoder
21 Displacement control device
31 Vertical seal unit (processing unit)
32, 42, 45, 48, 62, 72 Drive
33, 43 Optical sensor
34, 51, 52 Cooling unit
41, 44, 47 Horizontal seal unit (processing unit)
61 Punch unit (processing unit)
71 Cutter unit (processing unit)

Claims (4)

A transport device that intermittently transports a long bag-making film with at least a reference mark printed at a constant pitch.
The long bag-making film is displaceably arranged forward and backward in the transport direction at each processing position facing the transport path of the long bag-making film, and when the long bag-making film is stopped, the long bag-making film is used. A group of multiple processing units that perform predetermined processing on a film,
A machining unit drive device that displaces each of the machining units in the designated displacement direction by the amount of displacement.
The long bag-making film was arranged on the upstream side in the transport direction of the group of processing units so as to detect the reference mark between the stop position of the previous stage and the transport of the film for a distance corresponding to the constant pitch. One mark sensor and the measured transfer amount until the mark sensor detects the reference mark after starting the transfer from the stopped state in the previous stage, and the measured transfer amount is the unit of interest for the bag film part of the group. Commonly used for machining units, the remaining transport amount is obtained based on the measured transport amount and the transport target value output from the control device of the transport device, and the remaining transport amount and the unique reference remaining for each machining position. Displacement control means for a machining unit that calculates the displacement direction and displacement amount of each machining unit based on a comparison with the transport amount and controls the corresponding machining unit drive device.
A bag making machine equipped with. The displacement control means of the processing unit controls so that the processing of the processing unit driving device is started before the next stage of the long bag-making film to be conveyed is stopped.
The bag making machine according to claim 1. The bag making machine according to claim 1 or 2, wherein the control device of the transfer device acquires data related to the actual transfer amount and outputs a transfer target value based on the data. A transport device that intermittently transports a long bag-making film with at least a reference mark printed at a constant pitch, and is displaced forward and backward in the transport direction at each processing position facing the transport path of the long bag-making film. capable disposed respectively, the elongated bag film a group of a plurality of processing units for performing predetermined processing on the elongated bag film while stopped, the respective processing units, respectively, indicated The reference mark is detected between the stop position of the previous stage and the distance corresponding to the constant pitch of the displacement amount, the processing unit drive device that displaces the film in the displacement direction, and the film for long bag making. In a bag making machine equipped with one mark sensor arranged on the upstream side in the transport direction of the group of processing units.
Transport is started from the stopped state in the previous stage, the measured transport amount until the mark sensor detects the reference mark is measured, and the measured transport amount is commonly used for the unit bag film portion of the group of processing units. , The remaining transport amount is obtained based on the measured transport amount and the transport target value output from the control device of the transport device, and based on the comparison between the remaining transport amount and the specific reference remaining transport amount for each processing position. The displacement direction and the amount of displacement of each processing unit are calculated, and the processing unit drive device is controlled to start driving before the next stage of the long bag-making film to be conveyed is stopped.
How to control the bag making machine.

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