JPS5822413B2 - Method for preventing overheating of the heat sealing section of a hydrous explosive packaging machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for preventing overheating of a packaging film heat-sealing section in a hydrous explosive packaging machine.

Conventionally, in order to package slurry-like hydrous explosives into cartridges, a band-shaped film made of synthetic resin is usually transferred and rolled into a cylinder shape, and the edges of the film are overlapped and heated by hot air sprayed from a hot air nozzle. It was heat-sealed to form a cylindrical body, and after pouring a hydrous explosive into this cylindrical body, it was ligated with clip wire at predetermined intervals and cut to form a medicine package.

Conventionally, in this type of packaging machine, if the belt-shaped film is cut during machine operation, or slips during transport, etc., and the transport stops or the transport speed becomes abnormally slow,
The hot air heats the same part of the film heat sealing part for a long time.

Normally, the temperature of the hot air sent to heat seal the resin film is around 300°C, and under normal conditions, there is no risk that a hydrous explosive containing a large amount of water will ignite immediately with such hot air.

However, it cannot be said that there is no possibility that the moisture attached to the machine surface will gradually evaporate and dry due to long-term heating, resulting in deterioration, decomposition, and even ignition.

Furthermore, if an explosive with an abnormal mixture ratio is sent to this loading section due to a mix-up of explosive components, the risk of ignition will further increase.

The present invention relates to a method for safely packaging hydrous explosives by preventing overheating of the heat sealing section.

The present invention converts the transfer speed of a strip film used for packaging hydrous explosives into an intermittent current, and when the circuit of the intermittent current closes, a timer is used to generate a signal that is slightly longer than the intermittent period at the normal transfer speed of the strip film. When the transfer speed is normal, the solenoid valve circuit is continuously energized, and when the transfer of the strip film has stopped or the transfer speed has abnormally decreased, the intermittent current cycle is turned on. When the time is longer than the timer setting, the solenoid valve circuit is opened, and the solenoid valve is operated to cause the air cylinder to change the jetting direction of the hot air nozzle from the heat sealing section to the safe direction.

The method of the present invention will be explained below with reference to the drawings.

FIG. 1 shows the principle of the method of the present invention. A strip film 1 wound around a strip film roll 14 passes through a feed roller 2 and is rolled up into a cylindrical shape while being transferred. They are combined and heat sealed by hot air jetted from the hot air nozzle 3 to form a cylindrical body 4.

The hydrous explosive is pushed out into the cylindrical body through the hydrated explosive feed pipe 5, and the cylindrical body 4 loaded with the hydrated explosive is ligated with a clip wire 6 and cut to become a hydrous explosive cartridge 7. .

As a means for converting the transport speed of the strip film into an intermittent current, the feed roller 2 is provided with a light shielding plate 3 perpendicular to the rotation axis, and a light projecting section 9 arranged parallel to the rotation axis of the feed roller 2. , the light-shielding plate 8 can periodically block light from the optical path between the light-receiving section 10 and the light-receiving section 10 as the feed roller rotates.

That is, by the light shielding plate 8, the light projecting section 9, and the light receiving section 10,
The transport speed of the strip film 1 is converted into an intermittent current,
The intermittent period will be inversely proportional to the transfer speed.

FIG. 2 shows the current waveform in the method of the present invention,
A is the waveform of the intermittent photocurrent when the film strip 1 is transported at a normal speed.

Here, T is an intermittent period, that is, a light shielding period.

B is the waveform of the solenoid valve circuit, and the timer installed in the solenoid valve circuit is activated when the intermittent (photo) current circuit of A is closed, and this timer is set to T', which is slightly longer than T. Therefore, when the strip film 1 is transferred at a normal transfer speed (intermittent period T), the solenoid valve circuit is intermittently energized.

C is a waveform when the conveyance of the strip film 1 stops or the conveyance speed decreases abnormally, and the timer setting time T
′ is longer.

In this case, the solenoid valve circuit is opened by a timer after T' and is no longer energized, as shown in D.

FIG. 3 is an example of a wiring diagram for carrying out the method of the present invention. When a main switch (not shown) is turned on, the amplifier 16 of the photoelectric switch 21 is energized, forming a photoelectric circuit.

When the on-single push button switch 18 is pressed, the film motor relay 19 and relay contacts 19' and 19'' are closed, the film motor 20 is rotated, and the strip of film is transported.

15 is a fuse, and 17 is an OFF single push button switch.

When the amplifier 16 is on, the amplifier contact 16' is turned on, the electromagnetic contactor 22 is activated, and the contact 22' of the electromagnetic valve 23 is activated.

The timer installed in the solenoid valve circuit operates when the intermittent current circuit closes, and is set slightly longer than the intermittent cycle of the intermittent current, so if the strip film is being transferred normally, Since the contact 22' of the electromagnetic valve and the amplifier contact 16' are in contact, the electromagnetic circuit is continuously energized.

If the transport speed of the strip film becomes abnormally low, that is, the intermittent cycle becomes long, the intermittent cycle will be longer than the timer set time, so after the timer set time elapses, the solenoid valve contact 22' and the amplifier contact 16' When the solenoid valve circuit is separated, the solenoid valve circuit is not energized.

In FIG. 1, hot air is injected from a hot air nozzle toward the heat sealing part 11, but the direction of this hot air nozzle is
When the solenoid valve circuit is closed, the heat-sealing part 11 is oriented, and when the solenoid valve circuit is open, it is oriented in a safe direction. When the hot air nozzle 3 is being transferred, the direction of the hot air nozzle is directed toward the heat sealing section, but if a trouble occurs during the transfer, the direction of the hot air nozzle 3 is changed to a safe direction to avoid overheating of the heat sealing section 11. is prevented.

In the method of the present invention, in order to convert the transport speed of the strip film 1 into an intermittent current, in addition to the above-mentioned method of intermittent photocurrent using the light shielding plate 8, for example, using a metal plate instead of the light shielding plate 8, This periodic rotation may be captured by a proximity switch.

The method of the present invention detects abnormalities in the transport of the strip film in the packaging machine for hydrous explosives and prevents overheating in the heat sealing section, thereby preventing deterioration, decomposition, and ignition of the hydrous explosives, which is extremely desirable in terms of safety. It is.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram of a specific example of the method of the present invention, Figure 2 is a current waveform diagram in normal and abnormal conditions in the method of the present invention, and Figure 3 is a wiring diagram for carrying out the method of the present invention. It is. 1... Band-shaped film, 3... Hot air nozzle, 4... Cylindrical body, 11... Heat sealing part,
12...Solenoid valve, 13...Air cylinder.

Claims (1)

[Claims] 1 Roll the film strip into a tube while transporting it, overlay the edges on both sides and heat seal it with hot air to form a tube. The transfer speed of the film is converted into an intermittent current, and when the intermittent current circuit is closed, a timer is used to energize the solenoid valve circuit for a slightly longer period than the intermittent cycle at the normal transfer speed of the film strip. A water-containing explosive characterized in that when the transfer is stopped or the transfer speed is abnormally reduced, a solenoid valve circuit is opened and the solenoid valve is operated to cause an air cylinder to change the injection direction of the hot air nozzle from the heat-sealed part to the safe direction. Method for preventing overheating in the heat sealing section of a packaging machine.