JPS58125539A - Sucton device - Google Patents

Abstract

PURPOSE:To have an attraction which is suitable for high speed operation by furnishing a suction hole for air, separately from the suction hole provided in a vent of the piston but in the neighborhood of it, and by controlling the pressure in the cylinder's upper chamber regardless of the pressure in lower chamber. CONSTITUTION:A lid 15 having a hole at its center is installed at the bottom of the cylinder 10 equipped with a vent 19 in communication with the source of vacuum or atmosphere, and a cylinder lower chamber 25 in communication with this vent 19 is furnished in the cylinder. A suction pipe 16, whose suction hole 17 at the lower part is stretching till the bottom of the lid, is fixed to the cylinder's central part both at its top and bottom, and the upper part of its central hole is put in communication with the vent 19. The lid is equipped with a suction hole 12 protruding downward, and a piston 13 slidable and airtight against the surrounding of the lid's central hole is furnished movable vertically in such a way as enclosing the surroundings of the pipe 16 with a gap reserved. In the chamber 25 is installed a spring 14 having a force capable of heaving the piston against the weight of a possible sheet-shaped object attracted at the suction hole 12 while a cylinder upper chamber 26 iis furnished in communciation with the gap around the pipe 16.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a suction device that is effective when applied to automatic abandonment paper feeders, vacuum suction devices for plate-shaped objects, and the like.

Conventionally, there are various types of suction devices A for plate-shaped objects B that utilize vacuum pressure and are used in automatic sheet feeders such as printing machines. I will explain about it. When a vacuum is applied to this suction device A, air flows from the suction port (1) through the ventilation hole (,?) and the restriction (ri) of the piston (c) as shown by the arrow, and the inside of the cylinder (y) becomes negative pressure. However, due to the action of the throttle (4'), the piston lower chamber (
The pressure in 6) becomes lower than the pressure in the upper chamber of the piston (7).

This differential pressure pushes the piston (C) downward against the splash (S), and when it comes into contact with the paper (9) below,
Air from the suction port (i) is blocked and the upper chamber of the piston (7)
, the pressure in the lower chamber (B) becomes equal, and the paper (9) is placed in the suction port (1).
) is raised by the piston (C) and spring Cg) while adsorbing it. The force that holds the paper (9) to the suction opening (1) by suction is the pressure difference that acts on the upper and lower surfaces of the paper (9) at the suction part, and the force that presses the paper (9) against the suction opening (1); This is the frictional force caused by this. Both of them are the upper chamber of the piston (
7) Pressure is the main factor.

As is clear from the above operating principle, if the throttle (4) is small, the amount of air flowing into the piston lower chamber (6) will be small.
Therefore, the differential pressure between the upper and lower piston chambers (7) (A) increases, and the downward speed of the piston (A) increases. Paper (9
) comes into contact with the suction port (1), the differential pressure disappears, but the change over time is gradual, and not only does it take a long time to securely adsorb the paper (9), but it also takes a long time to lift the paper (9). The rising speed of the piston (2) is also slow.

Conversely, if the orifice (!I) is increased, the piston lower chamber (!
The amount of air flowing into the upper and lower chambers of the piston (7) is large.
) The differential pressure in (A) is small, and the downward speed of the piston (A) is slow. On the other hand, after the eye (1) comes into contact with the paper (9), the degree of temporal decrease in the pressure in the upper chamber of the piston (7) becomes rapid.
The time it takes to achieve reliable adsorption becomes shorter and the piston rises faster. In this way, the performance of the adsorption device is determined by the diaphragm (4
'), and there is a contradictory relationship between the piston descending speed, the time required for adsorption, and the piston rising speed.

Moreover, the drawbacks of this device become noticeable when adsorbing at high speed. In other words, the number of times the piston (k) falls to contact the paper (9) at high speed, the time to ensure suction, and the rise time of the piston (k) to lift the paper (9). Both must be short, but
It was theoretically impossible to satisfy these points with this device.

The present invention has been proposed in order to solve the above-mentioned conventional drawbacks, and includes providing a separate air suction port near the suction port in the piston vent hole to control the pressure in the upper chamber of the piston regardless of the pressure in the lower chamber of the piston. The object of the present invention is to provide a suction device that enables suction suitable for high speed.

Embodiments of the present invention will be described below with reference to the drawings. Figure R shows an embodiment of the present invention, in which a piston (13) having a suction port (/) for adsorbing paper (l/) is built into a cylinder (/) so as to be able to move up and down. The piston (/3) is a spring (/II) with enough force to push up against the weight of the piston (/3) and the paper (l/).
is supported by

In addition, the lower part of the cylinder (l) is covered with a lid (/!f), and the suction port (17) at the tip of the suction tube (/A) installed through the upper part of the cylinder (/) is a suction port (/!f). 12).The area of one gap between the outer diameter D2 of the suction pipe (/A) and the inner diameter D1 of the ventilation chamber (7g) of the piston (13) is equal to the inner diameter d1 of the suction port (/). Furthermore, the area of the inner diameter d2 of the suction port (/) is several times larger than the area of the aperture of the conventional device.

There is an air hole (19) at the bottom of the cylinder (/), a joint (20), a hose (C1) and a joint (C2).
It has been passed down to The joint (U) is a three-way joint, and one of the remaining a sides is connected to the suction pipe (/6) with a hose (U), and the other is connected to the vacuum pipe (/6) installed separately with a hose (J4'). This is connected to a valve (not shown) that switches between the action of Indicates the operation and piston upward movement (paper lifting completed).

Mari (#) Get the lower chamber of the piston, (Mu) is the upper chamber of the piston.

Next, the operation will be explained. As shown in FIG. 3, when a vacuum is applied by switching the pulp, the pressure in the lower piston chamber (O) rapidly decreases. On the other hand, vacuum also acts on the suction tube (/6), but the outer diameter D2 of the suction tube [/6] and the inner diameter D of the piston (13)
The area of the inner diameter d of the suction port (/2) is larger than the area of the gap between the suction tube (/A) and the suction port [17
] extends to the suction port (1), and the suction port (/7) is facing the suction port (12), so that most of the air that is sucked is from the suction port (12). The pressure in the upper chamber (roller) of the piston decreases slowly.

As a result, the pressure difference between the upper and lower chambers of the piston becomes large, and the piston (/3) quickly descends. From the state shown in Figure 9, the piston (/3) further descends and the paper ( ///
When the suction port (12) touches the tube as shown in Figure 5-, the suction port (/
2) Atmospheric suction from the piston upper chamber (λA
) pressure decreases rapidly. At this time, the paper (ll) and the mouthpiece (
12) Even if atmospheric suction is not completely blocked due to contact with The decrease in pressure in the chamber (/S) is rapid. For this reason, paper (
//) can be reliably held in a short time.

To express this phenomenon intuitively, conventional devices have no suction (
It looks like the paper comes into contact with the paper (/l) and is absorbed, but
In this device, the paper (ll) appears to be attracted to the suction port (/, 2).

When the paper (//) is attracted to the suction port (12), the pressure in the upper chamber of the piston (mu) decreases, but the degree of this decrease is several times greater than in conventional devices, and the piston must be raised quickly. It will be done. In addition, to release the paper (//) from the restriction of the suction port (/, 2), switch the valve to open the upper chamber of the piston (2A).
All you have to do is open the lower chamber (lieutenant) to the atmosphere.

Since the present invention is configured as explained in detail above,
The pressure in the lower piston chamber is determined solely by the effect of the vacuum from the valve and is not affected by the condition in the upper piston chamber. In addition, the pressure in the upper chamber of the piston is determined by the inner diameter D1 of the internal ventilation chamber of the piston, the outer diameter 7 of the suction pipe, the inner diameter d2 of the suction port,
The inner diameter d of the suction port, the position and orientation of the suction port, etc. are determined only by what is inside the piston upper chamber, and are not influenced or influenced by the state of the piston lower chamber. Moreover, not only is the suction of the paper to the suction port the same, but also the suction can be carried out more reliably and quickly.

As described above, according to the present invention, it is possible to solve at once the problems that were achieved in the conventional device by the effect of the throttle that connects the lower piston chamber, the upper piston chamber, and the ventilation hole.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram showing how a conventional suction device takes out stacked papers one by one, Fig. 2 is a detailed sectional view of the suction device of Fig. 7, and Fig. 3 shows an embodiment of the present invention. A cross-sectional view of the suction device, FIG. D and FIG. Description of the main parts of the diagram

Claims (1)

[Claims] A cylinder having a ventilation hole communicating with a vacuum source or an atmospheric source and having a lid member having a hole in the center attached to the lower end, a lower cylinder chamber provided within the cylinder and communicating with the ventilation hole, and a central portion of the cylinder. The upper part of the central hole communicates with the ventilation hole, and the lower suction port has a suction pipe that extends to the lower end of the lid member, and the suction port can be moved up and down to surround the suction pipe through a gap. A piston that is freely provided and has a suction port that protrudes downward from the lid member and that can slide around the central hole of the lid member while maintaining airtightness, and a seal that attracts the piston to the suction port. A cylinder top that has enough force to push up by overcoming the weight of the upper object, is isolated from the cylinder bottom chamber by a spring and the piston provided in the cylinder bottom chamber, and communicates with the gap around the suction pipe. An adsorption device comprising a chamber, wherein the area of the gap between the outer diameter of the suction pipe and the inner diameter of the ventilation chamber of the piston is smaller than the area of the inner diameter of the suction port.