U.S. patent application number 16/713323 was filed with the patent office on 2020-06-18 for gas replacement apparatus.
The applicant listed for this patent is TOYO JIDOKI CO., LTD.. Invention is credited to Tatsuya HIGUCHI, Yasuyuki HONDA, Hideo SAGO, Masaru YOSHIKADO.
Application Number | 20200189780 16/713323 |
Document ID | / |
Family ID | 68887278 |
Filed Date | 2020-06-18 |
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United States Patent
Application |
20200189780 |
Kind Code |
A1 |
SAGO; Hideo ; et
al. |
June 18, 2020 |
GAS REPLACEMENT APPARATUS
Abstract
The side holding drive unit and the mouth holding drive unit
move the side holding unit and the mouth holding unit from a first
processing position to a second processing position while
maintaining a state where the side holding unit holds the side
portion and the mouth holding unit holds the mouth portion. The gas
nozzle drive unit moves the gas nozzle from the first processing
position to the second processing position while maintaining a
state where the ejection port is arranged inside the bag.
Inventors: |
SAGO; Hideo; (Iwakuni-shi,
JP) ; HONDA; Yasuyuki; (Iwakuni-shi, JP) ;
YOSHIKADO; Masaru; (Iwakuni-shi, JP) ; HIGUCHI;
Tatsuya; (Iwakuni-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
TOYO JIDOKI CO., LTD. |
Tokyo |
|
JP |
|
|
Family ID: |
68887278 |
Appl. No.: |
16/713323 |
Filed: |
December 13, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B65B 31/06 20130101;
B65B 31/042 20130101; B65B 43/50 20130101; B65B 3/04 20130101; B65B
43/60 20130101; B29L 2031/7128 20130101; B65B 43/30 20130101; B29C
66/849 20130101; B65B 43/465 20130101 |
International
Class: |
B65B 43/46 20060101
B65B043/46; B65B 43/30 20060101 B65B043/30 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 14, 2018 |
JP |
2018-234587 |
Claims
1. A gas replacement apparatus comprising: a side holding unit that
holds a side portion of a bag; a mouth holding unit that holds a
mouth portion of the bag; a gas nozzle having an ejection port to
eject a replacement gas; a side holding drive unit that moves the
side holding unit; a mouth holding drive unit that moves the mouth
holding unit; a gas nozzle drive unit that moves the gas nozzle;
and a sealing unit that seals the mouth portion, wherein the side
holding drive unit and the mouth holding drive unit move the side
holding unit and the mouth holding unit from a first processing
position to a second processing position while maintaining a state
where the side holding unit holds the side portion and the mouth
holding unit holds the mouth portion, and the gas nozzle drive unit
moves the gas nozzle from the first processing position to the
second processing position while maintaining a state where the
ejection port is arranged inside the bag.
2. The gas replacement apparatus as defined in claim 1, wherein the
side holding drive unit moves the side holding unit from the second
processing position to a third processing position while
maintaining a state where the side holding unit holds the side
portion, and the mouth holding drive unit and the gas nozzle drive
unit move the mouth holding unit and the gas nozzle from the second
processing position to the first processing position without moving
the mouth holding unit and the gas nozzle from the second
processing position to the third processing position.
3. The gas replacement apparatus as defined in claim 1, wherein the
mouth holding drive unit and the gas nozzle drive unit include a
common movement base to which the mouth holding unit and the gas
nozzle are attached, and the mouth holding unit and the gas nozzle
are moved by moving the movement base.
4. The gas replacement apparatus as defined in claim 2, wherein the
mouth holding drive unit and the gas nozzle drive unit include a
common movement base to which the mouth holding unit and the gas
nozzle are attached, and the mouth holding unit and the gas nozzle
are moved by moving the movement base.
5. The gas replacement apparatus as defined in claim 3, wherein a
plurality of side holding units, a plurality of mouth holding
units, and a plurality of gas nozzles are provided, and two or more
mouth holding units and two or more gas nozzles are attached to the
single movement base.
6. The gas replacement apparatus as defined in claim 4, wherein a
plurality of side holding units, a plurality of mouth holding
units, and a plurality of gas nozzles are provided, and two or more
mouth holding units and two or more gas nozzles are attached to the
single movement base.
7. The gas replacement apparatus as defined in claim 1, wherein the
side holding unit holds the bag in a suspended state.
8. The gas replacement apparatus as defined in claim 1, wherein the
side holding drive unit intermittently moves the side holding
unit.
9. The gas replacement apparatus as defined in claim 1, wherein the
side holding drive unit includes a rotary table provided to be
rotatable about a rotation axis, and the side holding unit is
attached to an outer peripheral portion of the rotary table and is
moved in accordance with rotation of the rotary table.
10. The gas replacement apparatus as defined in claim 2, wherein a
plurality of side holding units, a plurality of mouth holding
units, and a plurality of gas nozzles are provided, and the mouth
holding drive unit and the gas nozzle drive unit move the mouth
holding unit and the gas nozzle from the second processing position
to the first processing position after the side holding unit is
arranged at the second processing position.
11. The gas replacement apparatus as defined in claim 10, wherein
the mouth holding drive unit and the gas nozzle drive unit move the
mouth holding unit and the gas nozzle toward the first processing
position during at least a part of time when the side holding unit
moves from the second processing position to the third processing
position.
12. The gas replacement apparatus as defined in claim 10, wherein a
plurality of stations are provided to be continuously adjacent to
each other, the plurality of stations including a first processing
station, a second processing station, a third processing station,
and a fourth processing station, the plurality of side holding
units include a first side holding unit and a second side holding
unit, the plurality of mouth holding units include a first mouth
holding unit and a second mouth holding unit, the plurality of gas
nozzles include a first gas nozzle and a second gas nozzle, for the
first side holding unit, the first mouth holding unit, and the
first gas nozzle, the first processing station corresponds to the
first processing position, the second processing station
corresponds to the second processing position, and the third
processing station corresponds to the third processing position,
and for the second side holding unit, the second mouth holding
unit, and the second gas nozzle, the second processing station
corresponds to the first processing position, the third processing
station corresponds to the second processing position, and the
fourth processing station corresponds to the third processing
position.
13. The gas replacement apparatus as defined in claim 11, wherein a
plurality of stations are provided to be continuously adjacent to
each other, the plurality of stations including a first processing
station, a second processing station, a third processing station,
and a fourth processing station, the plurality of side holding
units include a first side holding unit and a second side holding
unit, the plurality of mouth holding units include a first mouth
holding unit and a second mouth holding unit, the plurality of gas
nozzles include a first gas nozzle and a second gas nozzle, for the
first side holding unit, the first mouth holding unit, and the
first gas nozzle, the first processing station corresponds to the
first processing position, the second processing station
corresponds to the second processing position, and the third
processing station corresponds to the third processing position,
and for the second side holding unit, the second mouth holding
unit, and the second gas nozzle, the second processing station
corresponds to the first processing position, the third processing
station corresponds to the second processing position, and the
fourth processing station corresponds to the third processing
position.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is based upon and claims the benefit of
priority from Japanese Patent Application No. 2018-234587, filed on
Dec. 14, 2018; the entire contents of which are incorporated herein
by reference.
TECHNICAL FIELD
[0002] The present invention relates to a gas replacement apparatus
configured to supply a replacement gas into a bag.
BACKGROUND ART
[0003] Devices that seal a bag having a desired gas in its inside
have been known. For example, Japanese patent application
publication No. 54-58590 discloses a device that ejects an inert
gas from an inert gas ejection nozzle into a bag to replace a gas
in the bag with the inert gas, and then, seals the bag.
[0004] There are also known devices that cause a gas ejection
nozzle to follow a bag while moving the bag (see Japanese patent
application publication Nos. 2005-255236, 2012-111499, 08-169416
and 55-89022). In particular, the device disclosed in Japanese
patent application publication No. 55-89022 moves in such a manner
that an inert gas supply pipe that supplies an inert gas to the
inside of a bag and a pair of plate members that sandwich a bag
mouth follow the bag.
SUMMARY OF INVENTION
Technical Problem
[0005] In the device of Japanese patent application publication No.
54-58590, a first inert gas supply pipe is withdrawn from the bag,
the bag is moved to the next station, and then, a second inert gas
supply pipe is inserted into the bag. Therefore, outside air may
flow into the bag and the inert gas in the bag may flow out of the
bag after the withdrawal of the first inert gas supply pipe and
before the insertion of the second inert gas supply pipe. In
addition, since it is difficult to supply the inert gas into the
bag while moving the bag from a station where the first inert gas
supply pipe is provided to a station where the second inert gas
supply pipe is provided, the time during which the inert gas can be
supplied into the bag is limited.
[0006] In the devices disclosed in Japanese patent application
publication Nos. 2005-255236, 2012-111499 and 08-169416, a bag
mouth is not closed while supplying a desired gas into the bag.
Therefore, the desired gas is supplied into the bag in a situation
where outside air may flow into the bag, and thus a gas inside the
bag is not always efficiently replaced with the desired gas.
[0007] In the device in Japanese patent application publication No.
55-89022, the inert gas is supplied from the inert gas supply pipe
to the inside of a bag while sandwiching the bag mouth by a pair of
plate members, but the supply of the inert gas is not always
performed stably. Specifically, in the device disclosed in Japanese
patent application publication No. 55-89022, while the upper end
portion (mouth portion) of a bag is supported by a pair of plate
members, the side portions (edges) of the bag are not supported.
Since the bag is conveyed without being supported from the side
portions in this manner, when a force from one side portion to the
other side portion (that is, a force in the width direction) acts
on the bag, there is a possibility that the bag may come off from
the support of the pair of plate members in a relatively easy
manner. For example, when a bag is intermittently moved at a high
speed and a relatively large inertia force acts on the bag in the
width direction, there is a concern that the position and the
posture of the bag may be displaced during conveyance. In such a
case, the supply of the inert gas into the bag becomes unstable,
and further, there is a possibility that it may be difficult to
properly seal the bag mouth.
[0008] This invention has been contrived in view of the
above-described circumstances, and an object thereof is to provide
a technique capable of stably supplying a replacement gas into a
bag.
Solution to Problem
[0009] One aspect of the present invention is directed to a gas
replacement apparatus comprising: a side holding unit that holds a
side portion of a bag; a mouth holding unit that holds a mouth
portion of the bag; a gas nozzle having an ejection port to eject a
replacement gas; a side holding drive unit that moves the side
holding unit; a mouth holding drive unit that moves the mouth
holding unit; a gas nozzle drive unit that moves the gas nozzle;
and a sealing unit that seals the mouth portion, wherein the side
holding drive unit and the mouth holding drive unit move the side
holding unit and the mouth holding unit from a first processing
position to a second processing position while maintaining a state
where the side holding unit holds the side portion and the mouth
holding unit holds the mouth portion, and the gas nozzle drive unit
moves the gas nozzle from the first processing position to the
second processing position while maintaining a state where the
ejection port is arranged inside the bag.
[0010] The side holding drive unit may move the side holding unit
from the second processing position to a third processing position
while maintaining a state where the side holding unit holds the
side portion, and the mouth holding drive unit and the gas nozzle
drive unit may move the mouth holding unit and the gas nozzle from
the second processing position to the first processing position
without moving the mouth holding unit and the gas nozzle from the
second processing position to the third processing position.
[0011] The mouth holding drive unit and the gas nozzle drive unit
may include a common movement base to which the mouth holding unit
and the gas nozzle are attached, and the mouth holding unit and the
gas nozzle may be moved by moving the movement base.
[0012] A plurality of side holding units, a plurality of mouth
holding units, and a plurality of gas nozzles may be provided, and
two or more mouth holding units and two or more gas nozzles may be
attached to the single movement base.
[0013] The side holding unit may hold the bag in a suspended
state.
[0014] The side holding drive unit may intermittently move the side
holding unit.
[0015] The side holding drive unit may include a rotary table
provided to be rotatable about a rotation axis, and the side
holding unit may be attached to an outer peripheral portion of the
rotary table and may be moved in accordance with rotation of the
rotary table.
[0016] A plurality of side holding units, a plurality of mouth
holding units, and a plurality of gas nozzles may be provided, the
mouth holding drive unit and the gas nozzle drive unit may move the
mouth holding unit and the gas nozzle from the second processing
position to the first processing position after the side holding
unit is arranged at the second processing position.
[0017] The mouth holding drive unit and the gas nozzle drive unit
may move the mouth holding unit and the gas nozzle toward the first
processing position during at least a part of time when the side
holding unit moves from the second processing position to the third
processing position.
[0018] A plurality of stations may be provided to be continuously
adjacent to each other, the plurality of stations including a first
processing station, a second processing station, a third processing
station, and a fourth processing station, the plurality of side
holding units may include a first side holding unit and a second
side holding unit, the plurality of mouth holding units may include
a first mouth holding unit and a second mouth holding unit, the
plurality of gas nozzles may include a first gas nozzle and a
second gas nozzle, for the first side holding unit, the first mouth
holding unit, and the first gas nozzle, the first processing
station may correspond to the first processing position, the second
processing station may correspond to the second processing
position, and the third processing station may correspond to the
third processing position, and for the second side holding unit,
the second mouth holding unit, and the second gas nozzle, the
second processing station may correspond to the first processing
position, the third processing station may correspond to the second
processing position, and the fourth processing station may
correspond to the third processing position.
Advantageous Effects of Invention
[0019] According to the present invention, it is possible to stably
supply a replacement gas into a bag.
BRIEF DESCRIPTION OF DRAWINGS
[0020] FIG. 1 is a plan view illustrating an example of a packaging
system;
[0021] FIG. 2 is a side view of a cross section of the packaging
system, and mainly illustrates elements arranged at a sixth station
in a gas replacement apparatus;
[0022] FIG. 3 is a plan view illustrating a partial configuration
of a gas replacement apparatus;
[0023] FIG. 4 is a schematic plan view for describing the operation
of a gas replacement apparatus;
[0024] FIG. 5 is a schematic plan view for describing the operation
of a gas replacement apparatus;
[0025] FIG. 6 is a schematic plan view for describing the operation
of a gas replacement apparatus;
[0026] FIG. 7 is a schematic plan view for describing the operation
of a gas replacement apparatus; and
[0027] FIG. 8 is a schematic plan view for describing the operation
of a gas replacement apparatus.
DESCRIPTION OF EMBODIMENTS
[0028] Hereinafter, an embodiment of the present invention will be
described with reference to the drawings. Hereinafter, a packaging
system to which a gas replacement apparatus and a gas replacement
method are applied will be described as an example. According to
the gas replacement apparatus and the gas replacement method to be
described below, a replacement gas (for example, an inert gas,
steam, oxygen, carbon dioxide, or other gases) is blown inside a
bag containing a content, and a gas inside the bag is replaced with
the replacement gas.
[0029] In the following description, the terms "upstream" and
"downstream" are based on a bag conveyance direction. In addition,
the terms "height direction", "horizontal direction", "upward
direction" and "downward direction" are based on the vertical
direction in which gravity acts. The "height direction" means a
direction parallel to the vertical direction, the "horizontal
direction" means a direction that forms 90 degrees with the
vertical direction, the "upward direction" means a direction
opposite to the vertical direction in the height direction, and the
"downward direction" means the same direction as the vertical
direction.
[Packaging System]
[0030] FIG. 1 is a plan view illustrating an example of a packaging
system 5.
[0031] The packaging system 5 includes: a rotary table 31 installed
on a rack 32, and a plurality of side holding units 30 attached to
an outer peripheral portion of the rotary table 31 at equal
intervals. Each of the side holding units 30 moves along a circular
trajectory along with intermittent rotation of the rotary table 31
about a rotation axis Ax while holding side portions of a bag B to
move around a plurality of stations (a first station S1 to a tenth
station S10 in the illustrated packaging system 5). A bag B held by
each of the side holding units 30 is subjected to corresponding
processing at each station.
[0032] The number and specific configurations of the side holding
units 30 are not limited, and in the illustrated packaging system
5, the plurality of side holding units 30 are constituted by the
same number of gripper units (that is, ten gripper units) as the
number of stations. Each of the gripper units includes two
grippers, and each of the side holding units 30 holds a
corresponding bag B as both side portions of the corresponding bag
B are gripped by these two grippers. The opening and closing of
each of the grippers included in each of the side holding units 30
and a distance between the grippers can be appropriately changed by
a holding adjustment mechanism (not illustrated) under control of a
control unit 11.
[0033] A side holding unit 30 arranged at the first station (bag
feeding station) S1 receives a bag B from a conveyor magazine 12
storing a plurality of bags B (i.e., empty bags) through a bag
feeder (not illustrated), and grips both the side portions of the
bag B to hold the bag B in a suspended state. Each of the
illustrated side holding units 30 (gripper units) grips both side
portions at positions close to a mouth portion of a bag B or a part
of the mouth portion and both side portions of a bag B. Each of the
side holding units 30 adjusts a tension to be applied to a bag B by
changing the distance between the grippers in the state of holding
the corresponding bag B, and can place the bag B, for example, in a
relaxed state where the mouth portion is loosened or in a tense
state where the mouth portion is closed.
[0034] The mouth portion of a bag B is a range including an edge of
the bag B (that is, the upper edge of the bag B that is suspended
by a side holding unit 30). However, various types of processing
for the mouth portion to be described later are not necessarily
performed in the range including the edge of a bag B, and may be
performed in a range of a bag B which does not include the edge but
can form an opening. A portion of a bag B opposite to the mouth
portion (that is, the side opposing the mouth portion) is a bottom
portion, and both the side portions, the front surface, and the
back surface of a bag B extend between the mouth portion and the
bottom portion. Therefore, the bottom portion is formed by the
range including the lower edge of a bag B in a state where the bag
B is suspended by a side holding unit 30, and both the side
portions are formed by the range including the edges extending in
the height direction.
[0035] A printer 13 is provided at the second station (printing
station) S2. The printer 13 prints various types of information
(for example, a date when a packaging process is performed) on a
bag B. The third station (printing inspection station) S3 is
provided with a print inspection unit 14 that inspects a print
state of a bag B. The configuration of the print inspection unit 14
is not limited. For example, the print inspection unit 14 may
include an image sensor that acquires image data of the printed
portion of a bag B, and a processor that can analyze the image data
of the printed portion and determine whether the print is good or
bad. Incidentally, some functions of the print inspection unit 14
may be realized by the control unit 11. For example, image data of
the printed portion of a bag B acquired by the print inspection
unit 14 may be sent to the control unit 11, and the control unit 11
may analyze the image data to determine whether the print is good
or bad.
[0036] The fourth station (opening station) S4 is provided with an
opening unit 15 that opens the mouth portion of a bag B. The
illustrated opening unit 15 includes two suckers that can
reciprocate in the horizontal direction, and causes the suckers to
move in a direction such that the suckers are distanced from each
other in a state of sucking the front surface and the back surface
of a bag B respectively, so that the mouth portion of the bag B can
open. At this time, if necessary, the two grippers (the side
holding unit 30) holding both the side portions of the bag B move
in the horizontal direction so as to approach each other, and the
front surface and back surface of the bag B are bent.
[0037] The fifth station (content injection station) S5 is provided
with an injection unit 16. The injection unit 16 injects a content
(not illustrated) inside a bag B arranged at the fifth station S5
through the opened mouth portion of the bag B. The illustrated
injection unit 16 includes a hopper (funnel), and the content is
injected into the bag B from the hopper. A state of the content to
be stored in a bag B is not limited. For example, the content may
be a solid, a liquid, a paste (fluid), a gel, or a mixture
containing two or more of them.
[0038] The sixth station S6, the seventh station S7, and the eighth
station S8 are gas replacement stations. Each bag B is subject to a
gas replacement process while moving through the sixth station S6
to the eighth station S8, and a gas inside each bag B is replaced
with a replacement gas. The sixth station S6, the seventh station
S7, and the eighth station S8 are provided with a plurality of gas
nozzles 17 (that is, a first gas nozzle 17a and a second gas nozzle
17b), a plurality of mouth holding units 19 (that is, a first mouth
holding unit 19a and a second mouth holding unit 19b), and a
follow-up unit 24 (that is, mouth holding drive units 27 and gas
nozzle drive units 28 to be described later) that moves the gas
nozzles 17 and the mouth holding units 19. Details of these devices
arranged at the sixth station S6, the seventh station S7, and the
eighth station S8 and the gas replacement process will be described
later.
[0039] A sealing unit 21 is provided at the ninth station (sealing
processing station) S9. The sealing unit 21 has two sealing plates
21a that perform heat-sealing while sandwiching the mouth portion
(in particular, a sealing-planned portion) of a bag B.
[0040] The tenth station (cooling and discharge station) S10 is
provided with a cooling unit 22 and a release unit 23. The cooling
unit 22 includes two cooling plates 22a that perform cooling while
sandwiching the mouth portion (in particular, a location
heat-sealed by the sealing unit 21 (that is, the sealing-planned
portion)) of a bag B arranged at the tenth station S10. After the
mouth portion is cooled by the cooling unit 22, a bag (i.e.,
product bag) B is released from a side holding unit 30 at the tenth
station S10 to fall, is guided by the release unit 23 so as to be
sent to the subsequent stage.
[0041] The various devices included in the packaging system 5
described above and a gas replacement apparatus 10 to be described
later are driven while being controlled by the control unit 11 as
necessary. For example, the control unit 11 controls the sealing
unit 21 to open and close the two sealing plates 21a in accordance
with the rotation of the rotary table 31 (that is, the movement of
the side holding units 30). Specifically, the two sealing plates
21a are placed in the open state when a side holding unit 30 moves
from the eighth station S8 to the ninth station S9, and when a side
holding unit 30 moves from the ninth station S9 to the tenth
station S10. As a result, a bag B can move together with a side
holding unit 30 without being obstructed by the two sealing plates
21a. On the other hand, the two sealing plates 21a are placed in
the closed state in a state where a side holding unit 30 is
arranged at the ninth station S9, the mouth portion of a bag B held
by a side holding unit 30 is pressed and sealed by the two sealing
plates 21a.
[Gas Replacement Apparatus]
[0042] The gas replacement apparatus 10, which replaces a gas
inside a bag B with a replacement gas and then seals the mouth
portion of the bag B as described above, is provided at the sixth
station S6 to the ninth station S9 of the illustrated packaging
system 5.
[0043] FIG. 2 is a side view of a cross section of the packaging
system 5, and mainly illustrates elements arranged at the sixth
station S6 in the gas replacement apparatus 10. FIG. 3 is a plan
view illustrating a partial configuration of the gas replacement
apparatus 10.
[0044] The gas replacement apparatus 10 according to the present
embodiment includes the side holding units 30, the mouth holding
units 19, the gas nozzles 17, the side holding drive unit 26, the
mouth holding drive units 27, the gas nozzle drive units 28, and
the sealing unit 21 (see FIG. 1).
[Side Holding Unit and Side Holding Drive Unit]
[0045] As the side holding drive unit 26 moves each of the side
holding units 30, each of the bags B moves around the plurality of
stations S1 to S10 including the sixth station S6 to the ninth
station S9 as described above. The illustrated side holding drive
unit 26 is a so-called rotary type conveyance unit, includes the
rotary table 31 and moves intermittently the plurality of side
holding units 30 attached to the outer peripheral portion of the
rotary table 31.
[0046] The rotary table 31 is installed on the rack 32 via a table
support 33 as illustrated in FIG. 2, is provided to be rotatable
about the rotation axis Ax, and is connected with a rotation shaft
(not illustrated). The illustrated rotary table 31 has a circular
planar shape, and the rotation axis Ax passes through the center of
the rotary table 31. The rotation shaft extends on the rotation
axis Ax at the inner side of the table support 33, and is rotated
intermittently about the rotation axis Ax by a drive source (not
illustrated) (for example, a motor, or the like). The rotary table
31 and each of the side holding units 30 rotate intermittently
about the rotation axis Ax together with the rotation shaft.
[0047] Each of the side holding units 30 moves around the first
station S1 to the tenth station S10 intermittently in accordance
with the rotation of the table support 33 while drawing a circular
trajectory. In this manner, a trajectory of each of the side
holding units 30 is a circular endless trajectory, and each bag B
is conveyed from the upstream side to the downstream side while
being held by the corresponding side holding unit 30 in a suspended
state. Between two side holding units 30 provided to be adjacent to
each other in the illustrated plurality of side holding units 30,
the side holding unit 30 arranged on the upstream side is referred
to as a first side holding unit 30a, and the side holding unit 30
arranged on the downstream side is referred to as a second side
holding unit 30b (see FIGS. 4 to 7 to be described later).
[Gas Nozzle, Gas Nozzle Drive Unit, Mouth Holding Unit, and Mouth
Holding Drive Unit]
[0048] Props 34 extending in the height direction are installed on
the rack 32. A main frame 35 extending in the horizontal direction
is fixed to the props 34. A motor support frame 36 is attached to
the main frame 35. The motor support frame 36 is positioned below
the main frame 35, and a motor (for example, a servo motor) 37 is
attached to the motor support frame 36. The motor 37 has a motor
rotation shaft 38. The motor rotation shaft 38 extends downward so
as to penetrate the motor support frame 36. The central axis of the
motor rotation shaft 38 and the rotation axis Ax coincide with each
other, and the motor rotation shaft 38 rotates about the rotation
axis Ax. A movement base 39 extending in the horizontal direction
is attached to a lower distal end of the motor rotation shaft 38.
Two support blocks 40 and two lifting/lowering drive units (for
example, air cylinders) 43 are attached to the lower surface of the
movement base 39.
[0049] Each of the lifting/lowering drive units 43 has a
lifting/lowering drive rod 44 whose protruding amount in the upward
direction is variable. The gas nozzles 17 (that is, the first gas
nozzle 17a and the second gas nozzle 17b) are connected
respectively to the lifting/lowering drive rods 44 via nozzle
holding units 45 and gas guide units 46.
[0050] Each of the support blocks 40 extends in the horizontal
direction. A first rotation shaft 49 and a second rotation shaft 50
extending in a horizontal direction perpendicular to the extending
direction of each support block 40 are rotatably attached to each
of the support blocks 40 via bearings. A first rotation gear 51 is
fixed to a distal end of the first rotation shaft 49, and a first
pressing lever 53 is fixed to an intermediate portion of the first
rotation shaft 49. The first rotation shaft 49, the first rotation
gear 51, and the first pressing lever 53 rotate integrally about a
common axis (that is, a central axis of the first rotation shaft
49). A second rotation gear 52 is fixed to a distal end of the
second rotation shaft 50, and a second pressing lever 54 is fixed
to an intermediate portion of the second rotation shaft 50. The
second rotation shaft 50, the second rotation gear 52, and the
second pressing lever 54 rotate integrally about a common axis
(that is, a central axis of the second rotation shaft 50).
[0051] The first rotation gear 51 and the second rotation gear 52
are engaged with each other at their outer peripheral portions, and
exhibit symmetrical rotational behaviors. The first pressing lever
53 and the second pressing lever 54 extend downward from the first
rotation shaft 49 and the second rotation shaft 50, respectively,
and swing in accordance with rotation of the first rotation shaft
49 and the second rotation shaft 50. A first pressing support unit
57 and a second pressing support unit 58 are fixed to the lower
ends of the first pressing lever 53 and the second pressing lever
54, respectively. The first pressing support unit 57 and the second
pressing support unit 58 extend in the horizontal direction, and
have a first pressing unit 55 and a second pressing unit 56,
respectively. The first pressing unit 55 and the second pressing
unit 56 extend in the horizontal direction so as to oppose each
other, and are configured using a member (for example, sponge)
having both flexibility and a close contact property.
[0052] An opening/closing drive unit (for example, an air cylinder)
41 is rotatably attached to each of the support blocks 40. The
opening/closing drive unit 41 has an opening/closing drive rod 42
extending in parallel with the corresponding support block 40. The
protruding amount of the opening/closing drive rod 42 from the main
body of the opening/closing drive unit 41 (in particular, the
protruding amount of the opening/closing drive rod 42 in a
direction parallel to the extending direction of the corresponding
support block 40) is variable, and a connecting unit 48 is
rotatably attached to a distal end of the opening/closing drive rod
42. The connecting unit 48 is fixed to the first rotation shaft 49.
In accordance with the protruding amount of the opening/closing
drive rod 42, the connecting unit 48 swings about the first
rotation shaft 49, and the first rotation shaft 49 rotates about
its own central axis.
[0053] The gas replacement apparatus 10 according to the present
embodiment having the above-described configuration includes the
plurality of gas nozzles 17 (specifically, the two gas nozzles 17).
Among these gas nozzles 17, the gas nozzle 17 arranged on the
upstream side is referred to as the first gas nozzle 17a, and the
gas nozzle arranged on the downstream side is referred to as the
second gas nozzle 17b.
[0054] Each of the gas nozzles 17 extends in the height direction
and is connected to a gas supply source (not illustrated) via a gas
guide unit 46. A lower distal end of each of the gas nozzles 17 has
an ejection port 20. A replacement gas, sent from the gas supply
source to each of the gas nozzles 17 via the gas guide unit 46, is
ejected from the ejection port 20. The replacement gas is blown
into a bag B by ejecting the replacement gas from the ejection port
20 in a state where the ejection port 20 is arranged inside the bag
B. The ejection of the replacement gas from the ejection port 20
can be controlled by an arbitrary method. For example, when the
control unit 11 switches on and off the gas supply source to open
and close a valve (not illustrated) provided in a gas supply pipe
connecting the gas supply source and a gas guide unit 46 under the
control of the control unit 11, it is possible to eject the
replacement gas from the ejection port 20, to stop such ejection of
the replacement gas, and to adjust the ejection amount of the
replacement gas from the ejection port 20.
[0055] Each of the gas nozzles 17 is moved by a gas nozzle drive
unit 28. Specifically, a gas nozzle drive unit 28 includes a nozzle
lifting/lowering drive unit that moves each of the gas nozzles 17
in the height direction and a nozzle horizontal drive unit that
moves each of the gas nozzles 17 in the horizontal direction.
[0056] The nozzle lifting/lowering drive unit moves each of the gas
nozzles 17 in the height direction. Each of the gas nozzles 17 is
lifted and lowered by the nozzle lifting/lowering drive unit to be
arranged at an outer position and an inner position. When a gas
nozzle 17 is arranged at the outer position, a distal end (in
particular, the ejection port 20) of the gas nozzle 17 is
positioned above a bag B held by a side holding unit 30. When a gas
nozzle 17 is arranged at the inner position, a distal end of the
gas nozzle 17 (especially the ejection port 20) is arranged at a
position lower than the mouth portion and higher than the bottom
portion of a bag B held by a side holding unit 30. Therefore, in a
state where a bag B whose mouth portion is opened is arranged below
a gas nozzle 17, the ejection port 20 is positioned outside the bag
B by arranging the gas nozzle 17 at an upper position, and the
ejection port 20 is positioned inside the bag B by arranging the
gas nozzle 17 at a lower position.
[0057] The nozzle horizontal drive unit moves each of the gas
nozzles 17 so as to move around the plurality of stations (in
particular, the sixth station S6 to the eighth station S8). In
particular, the nozzle horizontal drive unit of the present
embodiment reciprocates each gas nozzle 17.
[0058] The illustrated gas nozzle drive units 28 include the
movement base 39. Each of the gas nozzles 17 is connected to the
movement base 39 via a lifting/lowering drive unit 43 (including a
lifting/lowering drive rod 44), a nozzle holding unit 45, and a gas
guide unit 46. The illustrated nozzle horizontal drive unit
includes the motor 37 (including the motor rotation shaft 38), the
movement base 39, the lifting/lowering drive units 43 (including
the lifting/lowering drive rods 44), the nozzle holding units 45,
and the gas guide units 46. In particular, the movement base 39
moves the gas nozzles 17 and the mouth holding units 19 in the
horizontal direction in such a manner that the gas nozzles 17 and
the mouth holding units 19 follow corresponding side holding units
30 and bags B only in a partial section among the first station S1
to the tenth station S10 (that is, only a section from the sixth
station S6 to the eighth station S8) in the present embodiment as
will be described later. On the other hand, the illustrated nozzle
lifting/lowering drive unit includes the lifting/lowering drive
units 43 (including the lifting/lowering drive rods 44), the nozzle
holding units 45, and the gas guide units 46.
[0059] In the present embodiment, the plurality of mouth holding
units 19 (specifically, the two mouth holding units 19) are
provided. Between these mouth holding units 19, the mouth holding
unit 19 arranged on the upstream side is referred to as the first
mouth holding unit 19a, and the mouth holding unit 19 arranged on
the downstream side is referred to as the second mouth holding unit
19b. The illustrated mouth holding units 19 each include a first
pressing unit 55 and a second pressing unit 56.
[0060] The mouth portion of each bag B is held by a mouth holding
unit 19 by being pressed while being sandwiched between the first
pressing unit 55 and the second pressing unit 56. The mouth holding
drive units 27 move the respective mouth holding units 19.
Specifically, each of the mouth holding drive units 27 includes: a
holding opening/closing drive unit that causes the first pressing
unit 55 and the second pressing unit 56 of each of the mouth
holding units 19 to be close to or away from each other; and a
holding horizontal drive unit that moves each of the mouth holding
units 19 in the horizontal direction.
[0061] The holding opening/closing drive unit moves the first
pressing unit 55 and the second pressing unit 56 between a position
where the first pressing unit 55 and the second pressing unit 56
sandwich the mouth portion of a bag B (i.e., the closed position;
see a location indicated by the solid line in FIG. 2) and a
position where the first pressing unit 55 and the second pressing
unit 56 do not come into contact with a bag B (i.e., the open
position; see a location indicated by the dotted line in FIG. 2).
The mouth portion of a bag B is arranged in a space between the
first pressing unit 55 and the second pressing unit 56 arranged at
the open position, and then, the first pressing unit 55 and the
second pressing unit 56 are arranged at the closed position.
Accordingly, the bag B is frictionally held by the first pressing
unit 55 and the second pressing unit 56 while being pressed in such
a manner that the mouth portion is closed.
[0062] The holding opening/closing drive unit in the illustrated
example includes, the opening/closing drive units 41 (including the
opening/closing drive rods 42), the connecting units 48, the first
rotation shafts 49, the first rotation gears 51, the first pressing
levers 53, the first pressing support units 57, the second rotation
shafts 50, the second rotation gears 52, the second pressing levers
54, and the second pressing support units 58. Power corresponding
to the protruding amount of an opening/closing drive rod 42 is
transmitted to a first rotation shaft 49 via a connecting unit 48,
and the first rotation shaft 49 rotates about the central axis. In
accordance with the rotation of the first rotation shaft 49, a
first pressing lever 53, a first pressing support unit 57, and a
first pressing unit 55 swing around the first rotation shaft 49 (in
particular, the central axis). Meanwhile, the power is transmitted
from the first rotation shaft 49 to a second rotation shaft 50 via
a first rotation gear 51 and the second rotation gear 52, and the
second rotation shaft 50 rotates about its own central axis. In
accordance with the rotation of the second rotation shaft 50, a
second pressing lever 54, a second pressing support unit 58, and a
second pressing unit 56 swing around the second rotation shaft 50
(in particular, the central axis). In this manner, the first
pressing unit 55 and the second pressing unit 56 move symmetrically
around the first rotation shaft 49 and the second rotation shaft
50, respectively, according to the protruding amount of the
opening/closing drive rod 42.
[0063] On the other hand, the holding horizontal drive unit in the
illustrated example includes the motor 37 (including the motor
rotation shaft 38), the movement base 39, the support blocks 40,
the opening/closing drive units 41 (including the opening/closing
drive rods 42), the connecting units 48, the first rotation shafts
49, the first pressing levers 53, the first pressing support units
57, the first rotation gears 51, the second rotation shafts 50, the
second pressing levers 54, the second pressing support units 58,
and the second rotation gears 52.
[0064] As described above, the movement base 39 is attached to the
gas nozzles 17 and the mouth holding units 19 and constitutes a
part of each of a mouth holding drive unit 27 and a gas nozzle
drive unit 28. In this manner, the mouth holding drive units 27 and
the gas nozzle drive units 28 include the common movement base 39.
As the movement base 39 is moved, the mouth holding unit 19 and the
gas nozzle 17 are integrally moved in the horizontal direction. In
particular, in the present embodiment as illustrated in FIG. 3, the
two or more mouth holding units 19 (in the present embodiment, the
first mouth holding unit 19a and the second mouth holding unit 19b)
and the two or more gas nozzles 17 (in the present embodiment, the
first gas nozzle 17a and the second gas nozzle 17b) are attached to
the single movement base 39, and thus the plurality of gas nozzles
17 and the plurality of mouth holding units 19 are integrally
moved.
[0065] In the illustrated example, a connection structure between
the first mouth holding unit 19a and the movement base 39 and a
connection structure between the second mouth holding unit 19b and
the movement base 39 are formed to be symmetric with respect to a
symmetry axis Ar (see FIG. 3) extending in a radial direction from
the rotation axis Ax. Accordingly, the elements constituting the
gas replacement apparatus 10 can be arranged in a space-efficient
manner.
[Behaviors of Side Holding Unit, Gas Nozzle, and Mouth Holding
Unit]
[0066] In the gas replacement apparatus 10 having the
above-described configuration, a side holding unit 30, the gas
nozzles 17, and the mouth holding units 19 exhibit the following
behaviors.
[0067] Specifically, the side holding drive unit 26 and the mouth
holding drive unit 27 move a side holding unit 30 and a mouth
holding unit 19 from a first processing position to a second
processing position while maintaining a state where the side
holding unit 30 holds the side portions of a bag B and the mouth
holding unit 19 holds the mouth portion of the bag B. At this time,
a gas nozzle drive units 28 moves a gas nozzle 17 from the first
processing position to the second processing position while
maintaining a state where the ejection port 20 of the gas nozzle 17
is arranged inside the bag B.
[0068] In addition, the side holding drive unit 26 moves a side
holding unit 30 from the second processing position to a third
processing position while maintaining a state where the side
holding unit 30 holds the side portions of a bag B. On the other
hand, a mouth holding drive unit 27 and a gas nozzle drive unit 28
move a mouth holding unit 19 and a gas nozzle 17 from the second
processing position to the first processing position without moving
the mouth holding unit 19 and the gas nozzle 17 from the second
processing position to the third processing position. In this case,
it is preferable that the mouth holding drive unit 27 and the gas
nozzle drive unit 28 move the mouth holding unit 19 and the gas
nozzle 17 from the second processing position to the first
processing position after the side holding unit 30 is arranged at
the second processing position. In addition, it is preferable that
the mouth holding drive unit 27 and the gas nozzle drive unit 28
move the mouth holding unit 19 and the gas nozzle 17 toward the
first processing position during at least a part of time when the
side holding unit 30 moves from the second processing position to
the third processing position.
[0069] In the gas replacement apparatus 10 of the present
embodiment including the plurality of gas nozzles 17 and the
plurality of mouth holding units 19, the above first to third
processing positions are determined with respect to each of the gas
nozzles 17 and each of the mouth holding units 19. The illustrated
packaging system 5 is provided with the plurality of stations S1 to
S10 that are continuously adjacent to each other, and the plurality
of stations include the four processing stations (the sixth station
S6 to the ninth station S9) in which the gas replacement apparatus
10 is installed. For the first side holding unit 30a, the first
mouth holding unit 19a, and the first gas nozzle 17a, the sixth
station S6 (first processing station) corresponds to the above
first processing position, the seventh station S7 (second
processing station) corresponds to the above second processing
position, and the eighth station S8 (third processing station)
corresponds to the above third processing position. On the other
hand, for the second side holding unit 30b, the second mouth
holding unit 19b, and the second gas nozzle 17b, the seventh
station S7 (second processing station) corresponds to the above
first processing position, the eighth station S8 (third processing
station) corresponds to the above second processing position, and
the ninth station S9 (fourth processing station) corresponds to the
above third processing position.
[Gas Replacement Method]
[0070] Next, the flow of an example of the gas replacement method
performed by the above-described gas replacement apparatus 10 will
be described.
[0071] FIGS. 4 to 8 are schematic plan views for describing an
operation of the gas replacement apparatus 10. The illustration of
some (for example, the nozzle holding unit 45 and the like) of the
elements constituting the gas replacement apparatus 10 are omitted
from FIGS. 4 to 8.
[0072] According to the illustrated gas replacement apparatus 10, a
replacement gas injection process is simultaneously performed on
two bags B at three stations (that is, the sixth station S6 to the
eighth station S8). On the other hand, a sealing process (in
particular, a heat-sealing process) for each of the bags B is
performed at one station (that is, the ninth station S9). In the
present embodiment, the plurality of mouth holding drive units 27
and the plurality of gas nozzle drive units 28 (that is, two sets
of the mouth holding drive units 27 and the gas nozzle drive units
28) are provided as described above, and the mouth holding drive
units 27 exhibit substantially the same behavior at substantially
the same timing as each other and the gas nozzle drive units 28
exhibit substantially the same behavior at substantially the same
timing as each other. However, the mouth holding drive units 27 may
exhibit substantially the same behavior at different timings from
each other, and the gas nozzle drive units 28 may exhibit
substantially the same behavior at different timings from each
other.
[0073] First, side holding units 30 are moved by the side holding
drive unit 26, and the two bags B each storing a content are
arranged at the sixth station S6 and the seventh station S7,
respectively, as illustrated in FIG. 4. Immediately after having
moved to the sixth station S6 and the seventh station S7, the two
bags B have not received a replacement gas and each mouth portion
thereof is open.
[0074] While these bags B are moving from the fifth station S5 and
the sixth station S6 to the sixth station S6 and the seventh
station S7, each of the gas nozzles 17 is arranged at the outer
position and does not collide with the bags B. Each of the mouth
holding units 19 is arranged at the open position, and a space in
which the bag B in the state of storing the content with the mouth
portion open can be arranged is formed between the first pressing
unit 55 and the second pressing unit 56. In the present embodiment,
each of the mouth holding units 19 (that is, the first pressing
unit 55 and the second pressing unit 56) arranged at the open
position does not come into contact with the bags B in the state
where the mouth portion is open. However, the mouth holding units
19 arranged at the open position may come into contact with the
bags B in the state where the mouth portion is open. In this case,
as will be described later, the mouth holding units 19 come into
contact with the bags B so as to secure an open state of the mouth
portions to such an extent that enables the gas nozzles 17 moving
from the outer position to the inner position to appropriately
enter the inside of the bags B.
[0075] Incidentally, the bag B arranged at the eighth station S8
illustrated in FIG. 4 is arranged in a state where the replacement
gas has been already injected therein and the mouth portion is
closed by the tension applied to the bag B from the side holding
unit 30.
[0076] Each of the gas nozzles 17 is driven by the corresponding
gas nozzle drive unit 28 to be moved from the outer position to the
inner position. Accordingly, the first gas nozzle 17a is inserted
inside the bag B positioned at the sixth station S6, and the second
gas nozzle 17b is inserted inside the bag B positioned at the
seventh station S7. Therefore, the ejection ports 20 of the first
gas nozzle 17a and the second gas nozzle 17b are arranged inside
the bags B arranged at the sixth station S6 and the seventh station
S7, respectively. While these gas nozzles 17 are moving from the
outer position to the inner position, the mouth portion of each of
the bags B is maintained at the open state, and each of the
bags
[0077] B does not come into contact with the corresponding gas
nozzle 17 moving from the outer position to the inner position.
[0078] In the present embodiment, the movement of the gas nozzles
17 from the outer position to the inner position is performed after
the bags B are stopped at the sixth station S6 and the seventh
station S7. However, the movement of the respective gas nozzles 17
from the outer position to the inner position may be started before
these bags B completely stop at the sixth station S6 and the
seventh station S7. In addition, these gas nozzles 17
simultaneously move from the outer position to the inner position
in the present embodiment, but may move at different timings.
[0079] As illustrated in FIG. 5, the first pressing unit 55 and the
second pressing unit 56 of each of the mouth holding units 19 are
arranged at the closed position by the mouth holding drive unit 27
in a state where the ejection port 20 of each of the gas nozzles 17
is arranged inside the corresponding bag B. Accordingly, each of
the mouth holding units 19 closes the mouth portion of the bag B in
a state where the gas nozzle 17 is inserted into the bag B.
Although each of the gas nozzles 17 is pressed by the corresponding
mouth holding unit 19 via the front surface and back surface of the
bag B at this time, a gap is formed between each of the gas nozzles
17 and the corresponding mouth holding unit 19. It is possible to
circulate a gas between the inside and the outside of the bag B
through the gap formed in this manner.
[0080] Then, a replacement gas is ejected into the corresponding
bag B from the ejection port 20 of each of the gas nozzles 17
arranged at the inner position, and a gas inside each of the bags B
is gradually replaced with the replacement gas. Specifically, the
gas existing in the bag B flows out of the bag B through the gap
between the gas nozzle 17 and the mouth holding unit 19 along with
the supply of the replacement gas from the ejection port 20 into
the bag B, and a ratio of the replacement gas relative the gas in
the bag B gradually increases. At this time, the timing to start
the ejection of the replacement gas from the ejection port 20 is
not limited, and may be after the ejection port 20 is arranged
inside the corresponding bag B or before the ejection port 20 is
arranged inside the corresponding bag B. Each of the gas nozzles 17
may have an exhaust path (not illustrated). When one end of the
exhaust path is arranged inside the bag B and the other end thereof
is arranged outside the bag B in a state where the ejection port 20
is arranged inside the bag B, the gas inside the bag B can be
efficiently discharged out of the bag B.
[0081] As illustrated in FIG. 6, the bags B, the side holding units
30, the gas nozzles 17, and the mouth holding units 19 are moved
from the sixth station S6 and the seventh station S7 to the seventh
station S7 and the eighth station S8. Specifically, when the rotary
table 31 is rotated, the two bags B are moved from the sixth
station S6 and the seventh station S7 to the seventh station S7 and
the eighth station S8 together with the side holding units 30,
respectively. In addition, as the motor rotation shaft 38 is
rotated, the movement base 39 is rotated about the rotation axis
Ax, and the two gas nozzles 17 and the two mouth holding units 19
are moved from the sixth station S6 and the seventh station S7 to
the seventh station S7 and the eighth station S8, respectively.
[0082] At this time, each of the gas nozzles 17 and each of the
mouth holding units 19 are moved so as to follow the corresponding
bag B. Specifically, the movement base 39 is rotated according to
the rotation of the rotary table 31, and a rotation timing and
angular velocity of the rotary table 31 are set to coincide with
the rotation timing and the angular velocity of the movement base
39, for example. Accordingly, it is possible to maintain the state
where the ejection port 20 of each of the gas nozzles 17 is
arranged inside the corresponding bag B, and the replacement gas
can be continuously blown into each of the bags B from each of the
gas nozzles 17 even during movement between the stations. In
addition, the mouth holding units 19 each can maintain the state of
sandwiching the bag B and can close the mouth portion of each of
the bags B to prevent inflow of outside air from the outside to the
inside of the bag B even during movement between the stations.
[0083] As illustrated in FIG. 7, the bags B, the side holding units
30, the gas nozzles 17, and the mouth holding units 19 are arranged
at the seventh station S7 and the eighth station S8. Even after the
bags B, the side holding units 30, the gas nozzles 17, and the
mouth holding units 19 are arranged at the seventh station S7 and
the eighth station S8 (in intermittent stop in the present
embodiment), the replacement gas can be continuously ejected from
the ejection port 20 of each of the gas nozzles 17 into the bag B.
In addition, it is possible to continue the ejection of the
replacement gas from the ejection ports 20 of the respective gas
nozzles 17 into the bags B until the bags B and the side holding
units 30 start moving from the seventh station S7 and the eighth
station S8 to the eighth station S8 and the ninth station S9.
[0084] Then, the mouth holding drive units 27 and the gas nozzle
drive units 28 drive the respective gas nozzles 17 and the
respective mouth holding units 19 in such a manner that, when the
bags B and the side holding units 30 start moving from the seventh
station S7 and the eighth station S8 toward the eighth station S8
and the ninth station S9, respectively, each of the gas nozzles 17
is arranged at the outer position and each of the mouth holding
units 19 is arranged at the open position. Specifically, before the
bags B and the side holding units 30 start moving from the seventh
station S7 and the eighth station S8 to the eighth station S8 and
the ninth station S9, respectively, the gas nozzle drive units 28
arrange the respective gas nozzles 17 at the outer position, and
the mouth holding drive units 27 arrange the respective mouth
holding units 19 at the open position.
[0085] In addition, the side holding units 30 arranged at the
seventh station S7 and the eighth station S8 are driven by the
holding adjustment mechanism (not illustrated) so as to adjust the
tension to be applied to the corresponding bags B in such a manner
that the mouth portions of the corresponding bags B are closed.
This tension adjustment can be performed at an arbitrary timing.
For example, the tension adjustment may be performed before each of
the gas nozzles 17 is arranged at the outer position (that is,
before or during the movement of each of the gas nozzles 17 from
the inner position to the outer position) or after each of the gas
nozzles 17 is arranged at the outer position. In addition, the
tension adjustment may be performed before each of the mouth
holding units 19 is arranged at the open position (that is, before
or during the movement of each of the mouth holding units 19 from
the closed position to the open position) or after each of the
mouth holding units 19 is arranged at the open position.
[0086] In this manner, since the plurality of gas nozzles 17 and
the plurality of mouth holding units 19 are provided, the
replacement gas can be blown into a bag B while the bag B stays at
the first processing position (the sixth station S6 or the seventh
station S7), while the bag B is moving from the first processing
position to the second processing position (the seventh station S7
or the eighth station S8), and while the bag B stays at the second
processing position. On the other hand, when only the single gas
nozzle 17 and only the single mouth holding unit 19 are provided,
it is necessary to return the gas nozzle 17 and the mouth holding
unit 19 from the second processing position to the first processing
position after the gas nozzle 17 and the mouth holding unit 19 are
moved from the first processing position to the second processing
position together with the bag B and the side holding unit 30
before a new bag starts moving from the first processing position
to the second processing position. In this case, a time for which
the gas nozzles 17 and the mouth holding units 19 can stay at the
second processing position is very limited, and thus, it is
difficult to secure a sufficient time to blow the replacement gas
from the gas nozzles 17 into the bags B at the first processing
position and/or the second processing position.
[0087] As illustrated in FIG. 8, the side holding units 30 move
from the seventh station S7 and the eighth station S8 to the eighth
station S8 and the ninth station S9 together with the bags B into
which the replacement gas has been injected, and the respective gas
nozzles 17 arranged at the outer position and the respective mouth
holding units 19 arranged at the open position move from the
seventh station S7 and the eighth station S8 to the sixth station
S6 and the seventh station S7.
[0088] In FIG. 8, the "bag B moving from the eighth station S8 to
the ninth station S9" and the "bag B moving from the seventh
station S7 to the eighth station S8" are bags each storing the
replacement gas therein with the mouth portion closed (that is, the
bags into which the gas has been blown). On the other hand, in FIG.
8, the "bag B moving from the sixth station S6 to the seventh
station S7" and the "bag B moving from the fifth station S5 to the
sixth station S6" are bags each having the open mouth portion and
into which no replacement gas has been blown.
[0089] The gas nozzles 17 and the mouth holding units 19 (see FIG.
4) having returned to the sixth station S6 and the seventh station
S7 repeat the above series of operations to inject the replacement
gas into the new bags B arranged at the sixth station S6 and the
seventh station S7, respectively.
[0090] On the other hand, the mouth portion of the bag B in which
the replacement gas has been stored is sealed by the sealing unit
21 at the ninth station S9. Accordingly, the bag B is sealed in a
state of being filled with the replacement gas.
[0091] As described above, according to the gas replacement
apparatus 10 and the gas replacement method of the present
embodiment, the replacement gas can be stably supplied into a bag B
in a state where the side portions and the mouth portion of the bag
B are held by the side holding unit 30 and the mouth holding unit
19. Since the bag B is supported from a plurality of directions as
described above, the bag B can be stably held, and it is possible
to prevent a position shift of the bag B when an unintended force
acts on the bag B. When the position of the bag B with respect to
the side holding unit 30 is shifted, there is a possibility that
the replacement of the gas inside the bag B with the replacement
gas may be insufficient, and further, there is a possibility of
causing defective sealing of the bag B. For example, when a bag B
is conveyed at a high speed, a large inertia force may act on the
bag B. According to the gas replacement apparatus 10 and the gas
replacement method of the present embodiment, it is possible to
prevent the positional shift of the bag B by the side holding unit
30 and the mouth holding unit 19 even when such a large inertial
force acts on the bag B.
[0092] In addition, the gas nozzles 17 and the mouth holding units
19 are moved to reciprocate, and thus gases in the plurality of
bags B can be continuously replaced with the replacement gases
using the limited number of gas nozzles 17 and the limited number
of mouth holding units 19. By preventing the increase in the number
of gas nozzles 17 and the number of mouth holding units 19 in this
manner, it is possible to suppress the increase in device cost.
[0093] In addition, the mechanism for moving the gas nozzles 17 and
the mouth holding units 19 in the horizontal direction using the
common movement base 39 is adopted, and thus the drive source can
be shared, and the gas nozzles 17 and the mouth holding units 19
can be moved synchronously with the simple configuration while
suppressing the cost. In particular, the plurality of gas nozzles
17 and the plurality of mouth holding units 19 are attached to the
common movement base 39, and thus it is possible to more
effectively promote the cost reduction and simplification of the
configuration.
[0094] In addition, the plurality of gas nozzles 17 and the
plurality of mouth holding units 19 are installed so as to be
continuously adjacent to each other, and thus it is easy to secure
the sufficient time for the replacement gas to be blown into the
bags B, and it is possible to improve a replacement ratio of the
gas inside the bag B with the replacement gas. In particular, since
the two gas nozzles 17 and the two mouth holding units 19 are
provided, it is possible to secure the sufficient time to blow the
replacement gas while suppressing the increase in device cost.
[Variations]
[0095] Although each of the gas nozzles 17 and each of the mouth
holding units 19 are moved in the horizontal direction using the
common movement base 39 and the common drive source (that is, the
motor 37) in the above-described embodiment, the gas nozzle 17 and
the mouth holding unit 19 may be moved using separate drive
mechanisms and separate drive sources. In such a case, the control
unit 11 can control the drive mechanisms and the drive sources in
such a manner that each of the gas nozzles 17 and each of the mouth
holding units 19 appropriately follow the corresponding bag B.
[0096] In addition, in the above-described embodiment, the gas
nozzles 17 and the mouth holding units 19 are provided so as to
reciprocate, and the number of gas nozzles 17 and the number of
mouth holding units 19 are fewer than the number of stations and
the number of side holding units 30. However, the number of gas
nozzles 17 and the number of mouth holding units 19 are not
limited, and may be the same as the number of stations and the
number of side holding units 30, for example. In this case, a
unique gas nozzle 17 and a unique mouth holding unit 19 can be
associated with each of the side holding units 30, and a side
holding unit 30, a gas nozzle 17 and a mouth holding unit 19 that
are associated with each other can be integrally moved in the
horizontal direction. Such a device configuration can be easily
realized by applying, for example, the device illustrated in FIG. 1
of Japanese patent application publication No. 55-89022. In this
case, it is possible to use a common drive source configured to
move the side holding unit 30, the gas nozzle 17 and the mouth
holding unit 19 in the horizontal direction.
[0097] Although the rotary table 31 and the side holding units 30
move intermittently in the above-described embodiment, the side
holding drive unit 26 may continuously move the side holding units
30 (including the rotary table 31) without stopping the side
holding units 30. When the rotary table 31 and the side holding
units 30 continuously move, the mouth holding drive units 27 and
the gas nozzle drive units 28 can continuously move the gas nozzles
17 and the mouth holding units 19 according to the moving speed of
the bags B and the side holding units 30 in such a manner that the
gas nozzles 17 and the mouth holding units 19 appropriately follow
the side holding units 30 and the bags B.
[0098] In the above-described embodiment, each of the side holding
units 30 holds a bag B in a suspended state, but the bag B may be
held in another posture. For example, each of the side holding
units 30 may move around the first station S1 to the tenth station
S10 while holding bags B in a lying posture (that is, the bags B in
a state of extending in the horizontal direction).
[0099] In addition, a movement trajectory of each of the side
holding units 30 and a movement trajectory of each of the bags B
are not limited to the above circular trajectory, and may be other
curved trajectories, straight trajectories, or trajectories
combining both the curved trajectory and the straight trajectory
(for example, an endless trajectory whose both ends are
semicircular trajectories (that is, a racetrack trajectory)).
[0100] In addition, a method for sealing the mouth portion of a bag
B is not limited, and the sealing unit 21 may seal the mouth
portion of a bag B by means other than heating.
[0101] The present invention is not limited to the above-described
embodiments and variations. For example, various modifications may
be made to each element of the embodiments and the variations
described above. Further, the effects exerted by the present
invention are not limited to the above-described effects, and
specific effects according to the specific configuration of each
embodiment can be exerted. As described above, various additions,
modifications, and partial deletions can be made to the elements
described in the claims, the specification, the abstract, and the
drawings without departing from a technical idea and a gist of the
present invention.
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