JPS6236723Y2 - - Google Patents

Description

[Detailed description of the invention] This invention uses a pair of support arms whose opening and closing operations are controlled to grip the vertical edges of the packaging bag on both sides and transport the bag, passing through an opening station that blows air into the bag from the opening of the bag. In a packaging machine that sequentially transfers packages to a filling station, a bag opening sealing station, a discharging station, etc., if the opening of the packaging machine fails at the opening station, or if the packaging bag is sent to the station. In some cases, such as when only pressurized air is ejected without being opened, an electric signal for opening detection is not generated, and a detection signal is generated when the packaging bag expands properly due to pressurized air being blown into the bag opening and is opened. This invention relates to an improvement of a packaging bag opening detection device for a packaging machine that sends out a bag.

Conventionally, a structure is known in which a switch actuator is provided to detect the bulge when pressurized air is blown into an unopened packaging bag to cause the opening. However, if excessive pressurized air is blown into the packaging bag at the opening station, the bulge will become unnecessarily large, leading to an accident in which the bag comes off the support arm pair and falls.

The purpose of the present invention is to detect the opening of a packaging bag and to prevent the above-mentioned accidents from occurring.

An embodiment of the present invention will be described with reference to the accompanying drawings.

Reference numeral 1 denotes a pair of support arms, and a large number of such support arm pairs are provided in the packaging machine at regular intervals, and are connected to a packaging bag supply station (not shown), an opening station (not shown), a packaging material supply station (not shown), and a bag opening melter. The sealing station, discharge station, etc. are stopped sequentially in a known manner by intermittent driving. The pair of support arms 1 are automatically controlled in opening and closing operations such as approaching and separating from each other in the horizontal direction and moving the movable gripping pieces 2, 2, and the pair of support arms 1 are automatically controlled to open and close operations such as approaching and separating from each other in the horizontal direction and moving the movable gripping pieces 2, 2. The bag is fed with the mouth b facing upward, and the bag is stopped at the opening station by grasping the vertical edges b and b on both sides. At that time, the bags are moved a little in the horizontal direction toward each other to make the opening b of the packaging bag a slacken a little.

The opening station is provided with a pair of movable suction cups 4, 4 corresponding to the sides of the bag opening b and a pressurized air blowing nozzle 5, as is known in the art. 4 are in contact with both sides of the bag opening b as shown by the chain lines in Figure 1, and the bag opening b is slightly opened with suction and movement in the direction of the arrow X in Figure 2, and pressurized air is blown there from the nozzle 5 into the bag. Pressurized air is blown into the opening of the bag, and when the air is blown into the bag, the nozzle 5 is lowered and a pair of bars (not shown) press the outer surface of the bag opening except for the nozzle 5, and the blown pressure is released. Some have a structure that prevents air from escaping.

In this embodiment, guide plates 6 and 7 corresponding to the sides of the unopened packaging bag a are provided at the opening station on the immovable machine stand 3 of the packaging machine. These guide plates 6 and 7 are spaced apart so that the swollen sides of the packaging bag a, which has been opened by blowing in pressurized air, come into contact with each other. Further, an arm 11 projecting outward is attached to the support column 9 of one of the guide plates 7 via a bracket 10, and when a magnetic piece serving as a switch operation piece approaches a right-angled bent portion 11a of the projecting end, an ON operation is generated. Case 1 with built-in electrical signal generation switch SW
3 is passed through so that its movement in the direction of the guide plate 7 can be adjusted and is fixed by a nut 12. Further, the screw 15 of the shaft support plate 14 protruding outward is screwed into the support column 9 and fixed with a lock nut 16, and an inverted swing bracket 17 is placed over the shaft support plate 14 and supported by the shaft 18. , the swing bracket 17 is provided with a swing arm 19 projecting upward, and the horizontal leg 21 of the detection piece 20 projects horizontally through the elongated hole 8 of one guide plate 7 at the upper end of the arm 19. to be fixed. The detection piece 20 includes bent pieces 20 bent diagonally downward on the front and rear sides.
a, 20a are formed. In addition, the swing bracket 1
A switch actuation piece 22 made of a magnetic piece corresponding to the front side of the case is attached to 7, and a spring hook piece 23 provided on the support column 9 and a switch actuation piece 22 immediately below it are attached.
A tension spring 24 is hung between the The spring 24 moves the switch operation piece 22 to the non-operation position shown by the solid line in FIG. This generates a biasing force that causes the unopened packaging bag a to move closer to the side, and the swing arm 19 abuts against the adjustment screw stopper 25 of the support column 9 to adjust the above-mentioned positions. Second
The chain line position in the figure is the position where the switch SW is turned on, and this chain line position is the position where the detection piece 20 detects the opening of the packaging bag a, as will be described in detail later.

In this embodiment, when the packaging bag a gripped by the support arms 1 and 1 pair moves to the opening station and stops, the movable suction cups 4 and the pressurized air blowing nozzle 5 operate as shown in the chain line in FIG. When a swollen opening is generated, the detection piece 20 is opened by one side c.
is pressed, the swinging arm 19 swings around the shaft 18 against the elasticity of the tension spring 24, and the switch operating piece 22 is moved along the chain line to approach the case 13, and the electrical signal generation switch is activated. Turn on the SW to generate a sensing electrical signal. As the packaging bag a bulges, its flanks on both sides come into contact with the corresponding inner surfaces of the guide plates 6 and 7 as shown by the chain lines in FIG. be done.

When the packaging bag a moves away from the opening station, the detection piece 20 and the switch actuation piece 22 are activated by the tension spring 2.
4 returns to the original position and turns off the electrical signal generation switch SW. At that time, the next packaging bag moves to the open position.

As exemplified above, the device of the present invention is provided with a detection piece 20 corresponding to the side of an unopened packaging bag moving to the opening station, attached to a swinging arm 19 that is linked to the detection piece 20. Guide plates 6 and 7 are provided to allow the unopened packaging bag a to enter the station and match the sides thereof, and as the packaging bag a swells due to the above-mentioned blowing of pressurized air, the corresponding surfaces of the guide plates 6 and 7 When the bag comes into contact with the bag, it expands by blowing in excessive pressurized air to prevent it from falling off the support arm pair 1, and the unopened packaging bag is held by the support arm pair 1. Even when the bag is moved to the opening station, there is no risk that the guide plates 6 and 7 will hit the packaging bag and impede the movement, and pressurized air is blown into the station to create the bulge. Therefore, even if the side of the packaging bag a comes into contact with the corresponding surfaces of the guide plates 6 and 7, the guide plates 6 and 7 are not prevented from moving to the next station, and due to the swelling of the packaging bag a. This has the effect of completely preventing the accident of the bag falling immediately after the opening is detected.

[Brief explanation of the drawing]

The accompanying drawings show an embodiment of the present invention, with FIG. 1 being a plan view and FIG. 2 being a partially cutaway sectional view. ...Opening station, 1...Support arm, 6,
7... Information board, 9... Support column, 11... Arm
SW...Electric signal generation switch, 18...Axis, 1
9... Swing arm, 20... Detection piece, 24... Pull spring.

Claims (1)

[Scope of utility model registration request] A pair of supporting arms 1 whose opening/closing operations are controlled grip the vertical edges b and b on both sides of the packaging bag a and transport it, passing through an opening station that blows pressurized air into the packaging bag from the bag opening. In the packaging machine,
An unopened packaging bag a is entered into the opening station, and the guide plates 6 and 7 are fixed at a position adjustable so that the bag bulges out due to the blowing of pressurized air into the bag and is spaced apart so that the sides of the bag come into contact with each other. and a switch operating piece 22 corresponding to the electrical signal generation switch SW.
At the same time, the swinging arm 19, which is moved to the non-operating position by the biasing force, is attached to the shaft 18 on the outside of one guide plate 7.
The packaging machine is characterized in that the detection piece 20, which is pivotally supported by the arm 19 and connected to the arm 19, is passed through one of the guide plates 7 and made to correspond to the side of the unopened packaging bag a by the aforementioned urging force. Packaging bag opening detection device.