JPH09267535A - Internal pressure explosion-proofing structure for printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to maintain the explosion-proofness at a dangerous place with a simple structure by providing a swinging door between a room for accommodating a printer and a sheet discharge chamber, and higher pressure protective gas supply means than the atmospheric pressure, and introducing the part of protective gas by switching a gate capable of passing a printed sheet. SOLUTION: In the case of printing by a printer P, the slit 10a of a gate 10 is previously opened so that the part of the protective gas supplied from a compressor is not introduced to an introducing hole. At this time, an internal pressure chamber A communicates with a dray chamber B via the slit 10a, but since the door 31 of the chamber B is closed, and hence no atmospheric air is invaded into the chamber B. On the other hand, higher pressure protective gas than the atmospheric pressure is continuously supplied by the compressor. Thus, the combustible or explosive gas in the external dangerous atmosphere cannot be invaded into the chamber A, and the explosion-proofness is maintained. The printer P can be used with anxiety at the dangerous place.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an explosion-proof structure for a printer, which allows the printer to be used even in a dangerous atmosphere, and more specifically, to supply a protective gas of a constant pressure into a housing that houses the printer. The present invention relates to an explosion-proof structure for an internal pressure explosion-proof printer that maintains explosion-proof properties.

[0002]

2. Description of the Related Art Explosive gas, flammable gas, etc. may exist in a normal state in a factory, or explosion or fire may occur in a so-called dangerous atmosphere where these gases may leak and accumulate. In order to prevent this, it is required to apply an explosion-proof structure to electrical equipment, electric and electronic equipment in accordance with the factory electrical equipment explosion-proof guideline by the Ministry of Labor, Institute of Industrial Safety.

Therefore, a pressure-resistant explosion-proof structure and an internal pressure explosion-proof structure,
Various explosion-proof structures such as the intrinsically safe explosion-proof structure have already been put into practical use, and one of these explosion-proof structures has been applied depending on the degree of danger of the dangerous place.

By the way, when the printer is to be used in a hazardous area, the discharge tray for receiving the printed paper discharged from the printer is exposed to the outside air. Must be prevented from entering the printer side from the output tray side.

Therefore, in the prior art, an air ejection port is provided near the exit of the ejection passage between the printer and the ejection tray, and air is ejected from the ejection port so that the outside air is ejected from the ejection passage. It is designed to prevent the intrusion to the printer side through the.

[0006]

However, the above-mentioned conventional structure is effective in the case of a small special printer that handles small-sized paper, but in the case of a general printer that can handle relatively large-sized paper. Since the paper discharge passage has a large cross-sectional area, it is difficult to prevent the invasion of outside air only by ejecting air, and it is impossible to maintain the explosion-proof property.

The present invention has been made in view of the above-mentioned conventional circumstances, and provides an internal pressure explosion-proof structure for a printer, which can maintain the explosion-proof property with a simple structure and can use the printer safely in a dangerous place. To aim.

[0008]

An internal pressure explosion-proof structure for a printer according to the present invention is separated from a first chamber for accommodating a printer and the first chamber by a partition wall, and printed sheets from the printer are discharged. A casing having a second chamber discharged to the tray, a door for opening and closing the second chamber, and a gas supply unit for supplying a protective gas having a pressure higher than the atmospheric pressure into the first chamber, A gate provided with the partition wall and having a slit through which a printed sheet from a printer can pass, a diaphragm provided on the gate for opening and closing the slit, and a part of protective gas from the gas supply means. And a gate opening / closing means having a gas introduction portion introduced into the operation surface portion of the diaphragm.

In the present invention, when printing is performed by the printer, the gate slit is opened beforehand by the gate opening / closing means. That is, in this case, the protective gas is not introduced into the diaphragm by the gas introduction part. At this time, the first chamber and the second chamber communicate with each other, but since the door of the second chamber is closed, outside air does not enter the housing.

Further, a protective gas (for example, clean air or an inert gas) having a pressure higher than the external pressure is continuously supplied to the first chamber by the gas supply means, and therefore,
Flammable or explosive gas in the external hazardous atmosphere does not enter the first chamber, and the explosion proof property is maintained.

When the printer completes printing, the printed paper is discharged to the paper discharge tray of the second chamber through the slit of the gate. When the discharge of the printed paper is completed, a part of the protective gas from the gas supply means is introduced into the working surface portion of the diaphragm by the gas introduction unit. This deforms the diaphragm and closes the slit.

On the other hand, after confirming the discharge of the printed paper, the operator opens the door of the second chamber and takes out the printed paper from the paper discharge tray. By opening this door, the second chamber is opened to the outside air, but since the slit is closed at this time, the outside air does not enter the first chamber.

When the operator closes the door after taking out the printed paper, the introduction of the protective gas into the diaphragm by the gas introduction portion is stopped, whereby the diaphragm returns to its original shape and the slit is opened. Hereinafter, the same operation is repeated.

In this case, since the slit of the gate is opened and closed by the diaphragm, the explosion-proof structure can be realized with a simple structure. Moreover, since the diaphragm is deformed by utilizing a part of the protective gas supplied from the gas supply means into the first chamber, it is not necessary to separately provide the gas supply means, thereby further simplifying the structure. it can.

Further, since the diaphragm is generally composed of a thin film elastic member, it can be brought into close contact with the inner wall of the slit when it is deformed. 1 can be surely prevented from entering the room and the explosion proof property can be maintained. As a result, the printer can be used safely in a dangerous place.

[0016]

Embodiments of the present invention will be described below with reference to the accompanying drawings. 1 to 9 are views for explaining an internal pressure explosion-proof structure for a printer according to an embodiment of the present invention, FIG. 1 is a front view of an explosion-proof device having the internal pressure explosion-proof structure, and FIG. 2 is a side view thereof. 1 of FIG. 1), FIG. 3 is a side view of the internal structure of the device body of the explosion-proof device, FIG. 4 is a plan view of the device body (view of line IV-IV of FIG. 1), and FIG. FIG. 6 is an enlarged view of a sheet discharging portion in the apparatus body, FIG. 7 is a front view of a gate portion in the apparatus body, and FIG. 8 is a sectional view taken along line VIII-VIII of FIG. 9 is a sectional view taken along line IX-IX in FIG. 7.

As shown in FIGS. 1 to 6, the explosion-proof device 1 is arranged on a base 2 and above the device body 3 via a device body (housing) 3 for accommodating a printer P and a support column 4. And the monitoring board 5 arranged in the.

In the apparatus main body 3, the printer P is arranged on the shelf plate 6 (FIG. 3). On the paper discharge side of the printer P, a guide 7 for guiding the discharged printed paper downward is disposed. Below the guide 7, a gate 10 having a slit 10a through which a printed sheet can pass is provided, and below the gate 10, a discharge tray 30 for receiving a printed sheet is provided. The front panel 8 of the apparatus body 3 is omitted in FIG.

On the other hand, on the front panel 8 of the apparatus body 3,
A door 31 that can be opened and closed (see FIG. 4) is provided. Door 3
A partition wall 9 is provided around the discharge tray 30 inside the opening of the apparatus main body 1 to which the apparatus 1 is attached, and the partition wall 9 forms a space in the apparatus main body 3 as a compartment for storing the printer P. It is partitioned into a certain internal pressure chamber (first chamber) A and a tray chamber (second chamber) B on the side of the discharge tray.

The gate 10 is screwed and fixed onto the partition wall 9, and a slit 9a extending in the direction perpendicular to the plane of FIG. 6 is formed in the gate mounting portion of the partition wall 9. The internal pressure chamber A and the tray chamber B are divided into the slit 9 a of the partition wall 9 and the gate 10.
It communicates only via the slit 10a.

The tray 30 is provided with a photoelectric switch 36 for detecting the discharge of the printed paper on the tray. In the vicinity of the door 31, the partition wall 9 is provided with a proximity switch 38 for detecting opening / closing of the door.

A flange 40 connected to a compressor (gas supply means) not shown is provided in the lower portion of the apparatus main body 3.
(FIG. 3) and a stop valve 41 connected thereto are provided. A pipe and a pressure reducing valve (not shown) are connected to the stop valve 41, and the tip of the pipe is arranged in the internal pressure chamber A.

With this structure, the protective gas (for example, clean air or inert gas) supplied from the compressor and having a pressure higher than the atmospheric pressure is supplied to the flange 40 and the stop valve 4.
1, is continuously introduced into the internal pressure chamber A through a pipe and a pressure reducing valve. As a result, the internal pressure chamber A is kept at a pressure slightly higher than the atmospheric pressure.

A relief valve (not shown) is connected to the internal pressure chamber A so that the internal pressure chamber A does not exceed the set pressure. A pressure gauge 43 (FIG. 1) for measuring the pressure in the internal pressure chamber A is provided at the bottom of the device body 3.

A part of the protective gas supplied from the compressor is introduced into the gate 10 through another pressure reducing valve, solenoid valve and piping tube 45 (FIG. 6).

A transparent window 50 made of tempered glass, for example, which allows an operator to observe the inside of the apparatus body 3 is attached to the upper portion of the front panel 8 of the apparatus body 3. A similar transparent window 51 is attached to the lid 31. A lid 35 that can be opened and closed is provided on the upper surface of the device body 3.
A transparent window 52 (FIG. 4) similar to the above is also attached.
In addition, each lid 31, 35 has a handle 5 with a key for opening and closing.
4, 55 are provided respectively.

At the center of the upper portion of the front panel 8 of the apparatus main body 3, there is provided a lamp 60 (FIG. 1) for informing the operator of the completion of paper discharge. A fluorescent lamp 61 is provided above the printer P inside the apparatus body 3.

Various indicators 62 are arranged on the monitor board 5. The indicator light 62 is adapted to be turned on, for example, when the internal pressure of the internal pressure chamber A decreases.

Next, details of the gate 10 will be described with reference to FIGS. As shown in these figures, the gate 10 has two side surfaces 11a of a block 11 having a rectangular cross section.
The plate-shaped members 12 and 13 are screwed and fixed to the block 11, and the block-shaped member 14 is screwed to the lower surface 11b of the block 11.
It is configured to be fixed by 5.

The mating surface 14a of the block-shaped member 14 is formed with a recess 16 extending in the longitudinal direction (the horizontal direction in FIG. 7), and inclined surfaces 16a are formed at both ends of the recess 16. The lower surface 11b of the block 11 and the recess 16 form a slit 10a through which the printed paper w from the printer P (FIG. 6) can pass.

Both side surfaces 11a and the lower surface 1 of the block 11
A diaphragm 20 made of, for example, a urethane sheet is attached to 1b. The diaphragm 20 is a member extending in the longitudinal direction, and includes the block 11 and the plate-shaped member 12,
It is sandwiched between 13 and the block-shaped member 14.

A groove 18 extending in the longitudinal direction is formed on the lower surface 11b of the block 11. Further, the upper surface 11c of the block 11 is provided with an introduction hole 19 for introducing a part of the protective gas from the compressor into the gate 10 through the piping tube 45, and the lower end of the introduction hole 19 is a groove. It opens in 18.

With this structure, the protective gas introduced from the introduction hole 19 spreads in the groove 18 and acts on the operating surface 20a of the diaphragm 20 to bend the diaphragm 20 downward, thereby closing the slit 10a. (See the chain double-dashed line in FIG. 9). Therefore, the diaphragm 20 and the introduction hole 19 constitute a gate opening / closing means 25 for opening / closing the slit 10 a of the gate 10.

Next, the operation of this embodiment will be described. When printing is performed by the printer P, the slit 10a of the gate 10 is opened beforehand. That is, by turning off the electromagnetic valve, a part of the protective gas supplied from the compressor is prevented from being introduced into the introduction hole 19. At this time, the internal pressure chamber A and the tray chamber B are separated by the slit 10
Although they communicate with each other via a, the outside air does not enter the tray chamber B because the door 31 of the tray chamber B is closed.

On the other hand, to the internal pressure chamber A, a protective gas (for example, clean air or inert gas) having a pressure higher than the external pressure is continuously supplied by the compressor. For this reason, flammable or explosive gas in the external dangerous atmosphere cannot enter the internal pressure chamber A, and the explosion proof property is maintained.

When the printer P completes the printing, the printed paper w passes through the slit 10a of the gate 10 and the slit 9a of the partition wall 9 and is discharged to the discharge tray 30 of the tray chamber B (see FIG. 6). Then, the photoelectric switch 36 detects the paper w and is turned on, and as a result, the lamp 60 is turned on.

On the other hand, in response to the detection signal of the photoelectric switch 36, the solenoid valve is turned on, and a part of the protective gas is introduced from the compressor into the introduction hole 19 through the piping tube 45 (see FIG. 9). The introduced protective gas spreads in the groove 18 and acts on the operating surface 20a of the diaphragm 20, and the pressure thereof causes the diaphragm 20 to bend downward, closing the slit 10a (see the chain double-dashed line in FIG. 9).

After confirming the lighting of the lamp 60, the operator opens the door 31 and takes out the printed paper w from the paper discharge tray 30. By opening this door 31, the tray chamber B
Is opened to the outside air, but since the slit 10a is closed at this time, the outside air does not enter the internal pressure chamber A.

On the other hand, the proximity switch 38 detects that the door 31 is opened, and the lamp 6 receives the detection signal.
The number 0 changes to blinking to call the operator's attention.

Next, when the operator closes the door 31, the timer is activated and the solenoid valve is turned off again after a few seconds. Then, the introduction of the protective gas into the gate 10 is stopped, and the exhaust port of the solenoid valve is opened to the outside air, whereby the diaphragm 20 returns to its original shape by its elasticity and the slit 10a is opened. Further, the lamp 60 is also turned off by closing the door 31. In this way, the next sheet is discharged.

As described above, in this embodiment, since the slit 10a of the gate 10 is opened and closed by the diaphragm 20, the explosion-proof structure can be realized with a simple structure. Moreover, since the diaphragm 20 is deformed by utilizing a part of the protective gas supplied from the compressor into the internal pressure chamber A, it is not necessary to separately provide a gas supply means for the diaphragm, which further improves the structure. Can be simplified.

Further, since the diaphragm 20 is generally composed of a thin film elastic member, it can be brought into close contact with the inner wall of the slit 10a when it is deformed, which allows it to be flammable or explosive in an external dangerous atmosphere. The gas can be surely prevented from entering the internal pressure chamber A, and the explosion proof property can be maintained. As a result, the printer P can be used safely in a dangerous place.

[0043]

As described above, in the internal pressure explosion-proof structure for a printer according to the present invention, the diaphragm is deformed by utilizing a part of the protective gas supplied from the gas supply means, and
Since the diaphragm that opens and closes the slit through which the printed paper passes is opened and closed with this simple structure, the explosion-proof property can be maintained, and the printer can be used safely in hazardous areas.

[Brief description of drawings]

FIG. 1 is a front view of an explosion-proof device having an internal pressure explosion-proof structure for a printer according to an embodiment of the present invention.

FIG. 2 is a side view of the explosion-proof device (a view from the arrow II in FIG. 1).

FIG. 3 is a side-side internal structure diagram of a device body portion of the explosion-proof device.

FIG. 4 is a plan view of the device body of the explosion-proof device (see FIG.
IV-IV line arrow view).

FIG. 5 is a front side internal structural diagram of a device body portion of the explosion-proof device.

FIG. 6 is an enlarged view of a paper discharge portion in the apparatus body of the explosion-proof device.

FIG. 7 is a front view of a gate portion in the device body of the explosion-proof device.

8 is a sectional view taken along line VIII-VIII of FIG.

9 is a sectional view taken along line IX-IX in FIG. 7.

[Explanation of symbols]

 1 Explosion proof device 3 Device body (housing) 9 Partition 10 Gate 10a Slit 19 Introduction hole (gas introduction part) 20 Diaphragm 20a Operating surface 25 Gate opening / closing means 30 Paper ejection tray 31 Door A Internal pressure chamber (first chamber) B tray Room (second room) P Printer w Printed paper

Claims (1)

[Claims] 1. An internal-pressure explosion-proof structure for a printer, comprising: a first chamber for accommodating the printer and a first partition separated from the first chamber, and printed sheets from the printer are discharged to a discharge tray. A housing having a second chamber and a door that opens and closes the second chamber, a gas supply unit for supplying a protective gas having a pressure higher than the atmospheric pressure into the first chamber, and the partition wall. A gate having a slit through which printed paper from the printer can pass, a diaphragm for opening and closing the slit, and a part of protective gas from the gas supply means for operating the diaphragm. An internal pressure explosion-proof structure for a printer, comprising: a gate opening / closing means having a gas introducing portion introduced into the portion.