JPS594467A - Device for holding and immersing cylindrical body in liquid - Google Patents

Abstract

PURPOSE:To prevent blowing off bubbles that impede uniformity of coating film in a holding device that holds a cylindrical body such as a drum for photosensitive body etc. from inside by friction locking, by controlling pressure of a space inside of the cylindrical body. CONSTITUTION:With a rubber bag 5 shrinked, and a valve 10 closed, a cylinder 3 is inserted to the middle of a cylindrical body 7. Air is introduced to the rubber bag 5 by pressure to inflate it. This is brought into close contact with a groove 4 and inner wall of the cylindrical body to shut off circulation of air between the cylinder 3 and the cylindrical body 7. At the same time, hanging of the cylindrical body 7 is made possible by holding with frictional force. When the cylindrical body is immersed vertically into liquid under this condition, the liquid does not go into the space 11 due to sealed air, and only the surface of the cylindrical body comes into contact with the liquid. When pulling up the cylindrical body 7, blowing off bubbles from the space 11 can be prevented by connecting the space 11 to outside by opening the valve 10 just before the bottom leaves the surface of the liquid.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a gripping device for a cylindrical body. Specifically, the present invention provides a method for gripping a cylindrical body and immersing it in a liquid.
The present invention relates to a gripping device that can grip a cylindrical body without contacting the outer surface of the cylindrical body and prevents liquid from wetting the inner surface of the cylindrical body. In particular, the present invention relates to a drum gripping device suitable for applying a photoreceptor layer to the outer surface of a photoreceptor drum during the production of an electrophotographic photoreceptor.

One method for applying a photoreceptor layer to a drum is to suspend and immerse the drum in a photoreceptor solution. In this method, a coating film is not formed at the gripping point of the drum, that is, the contact area between the drum and the gripping device, so if the drum is not gripped at a point other than the outer surface on which the photoreceptor layer is to be formed, the drum will be exposed when immersed. Preferably, the solution does not come into contact with the inner surface of the tube.

As a device that satisfies such requirements, the present inventors have previously proposed (al) rod (b+ mechanism for suspending and supporting the rod (cl) a fluid-tight bag attached to the lower end of the rod and capable of expanding and contracting. A gripping mechanism Fdl having a portion is equipped with a fluid discharger mechanism that introduces and discharges fluid into the bag portion to inflate and deflate it, and the bag portion of the gripping mechanism proposed a device characterized by being able to tightly grip the inner wall of a cylindrical body and at the same time block the flow of gas inside the cylindrical body (June 1981). (Refer to Patent Application No. 190, "Cylinder gripping device") This device grips (chucks) the drum inside, and when the drum is gripped and vertically immersed in liquid, the side wall of the drum and the gripping device The inner surface of the drum is superior in that its lower end is only slightly in contact with the liquid, since the air in the space formed by the drum prevents liquid from entering this space. When the drum is gripped by the device, dipped vertically into the liquid, and then pulled vertically out of the liquid, the air trapped inside the drum becomes bubbles just before the drum leaves the liquid surface. The bubbles may be ejected from the lower end of the drum and adhere to the outer surface of the drum.This adhesion of air bubbles to the outer surface of the drum is undesirable because it impairs the uniformity of the liquid film formed on the outer surface.

It is presumed that this release of air bubbles is due to the liquid evaporating while the drum was immersed in the liquid, increasing the amount of gas in the space inside the drum. That is, although air at atmospheric pressure originally exists in the space inside the drum, the amount of gas in the space inside the drum increases because the vapor generated from the liquid during the dipping operation is added to this air. While the drum is immersed to a sufficient depth in the liquid, the gas is confined in the space because the pressure of the liquid is greater than the pressure of the gas in the space containing the generated vapor. However, as the drum is pulled up, the pressure of the liquid decreases, and eventually the pressure of the gas in the space containing the generated vapor exceeds the pressure of the liquid, and bubbles are released from the space inside the drum to the outside. It is thought that this will lead to

The present invention provides a gripping device that makes it possible to control the pressure in the space inside the drum.

That is, the present invention is a gripping device for a cylindrical body for gripping a cylindrical body and immersing it in a liquid so that only the outer surface of the cylindrical body comes into contact with the liquid. A mechanism for suspending and supporting (cl
A gripping mechanism (dl) is attached to the lower end portion of the rod and has a fluid-tight bag portion that can be inflated and deflated.
A discharger mechanism (θ) for the fluid to be contracted is equipped with a pressure adjustment mechanism having a hole passing through the gripping mechanism up and down, and the bag portion of the gripping mechanism has a cylindrical shape when inflated inside the cylindrical body. It is characterized by being able to tightly grip the inner wall of the body and to prevent the flow of gas inside the cylindrical body through parts other than the pressure adjustment mechanism.

To explain the present invention in more detail, the present invention is an apparatus for gripping a cylindrical body from the inside using a gripping mechanism that engages with the inner wall of the cylindrical body by frictional force.

Therefore, when a cylindrical body is gripped and suspended in the liquid using the apparatus according to the present invention, since the gripping mechanism does not contact the outer surface of the cylindrical body, the entire outer surface can be brought into contact with the liquid. In addition, in the inner space of the cylindrical body below the gripping mechanism,
Due to the pressure of the gas trapped in this part, almost no liquid enters, so neither the inner wall of the cylindrical body nor the gripping mechanism itself comes into contact with the liquid. Furthermore, since the pressure in the inner space of the lower cylindrical body can be adjusted from the gripping mechanism,
Air bubbles can be prevented from being released from the inner space when the cylindrical body is pulled up from the liquid.

To explain the present invention in detail based on the drawings, FIG. 1 shows seven examples of a gripping device according to the present invention.

In the figure, (11 is a rod, and the inside is hollow. (2) is the bottom plate of the cylinder (3). The cylinder (3) has almost the same shape as the inner surface of the cylindrical body (7). , can be freely inserted into the cylindrical body (7). (4) is an annular groove provided on the outer surface of the cylinder (3), and (5) is an annular rubber bag accommodated in this groove. Yes. (6) is a rod (1) and a rubber bag (5)
This is the supply and exhaust pipe that connects the (8) is a hole penetrating the bottom plate (2). (9) is a pipe communicating with the hole (8), and (lO) is a valve provided in the middle of the pipe (note that the means for controlling the opening and closing of the valve is omitted in the figure. ).

To explain how to use this device, with the rubber bag (5) deflated and the valve (10) closed, the cylinder (31
vertically inserted halfway into the cylindrical body (7). Next, when air is forced into the rubber bag (5) through the rod (1), the rubber bag (5) expands and comes into close contact with the groove (4) and the inner wall of the cylindrical body (7), thereby forming a contact with the cylinder (3). The flow of air between the tubular body (7) is blocked. When the air pressure inside the rubber bag (5) is raised sufficiently, the cylindrical body can be suspended by the rod (1) due to the frictional force between the rubber bag (5) and the inner wall of the cylindrical body. In this state, the cylindrical body is suspended and vertically immersed in the liquid. Since air is confined in the space (marked) at the bottom of the cylindrical body, almost no liquid can enter this space, and as a result, only the outer surface comes into contact with the liquid.

Next, when the cylindrical body is vertically pulled out from this state, the pressure in the space (11) gradually decreases, so that
The liquid level that has entered the inside of the cylindrical body against the air pressure in the space part (marked) gradually decreases. Just before this liquid level reaches the bottom end of the cylindrical body, the valve (10) is opened and the space part ( 11) is communicated with the outside to equalize both pressures.At this point, the cylindrical body is only slightly immersed in the liquid, so even if the valve is opened, the liquid will not flow inside the cylindrical body. It only penetrates slightly.If you continue to pull up the cylindrical body in this state,
The cylindrical body can be pulled above the liquid surface without air bubbles being released from the space (11).

In the above method, the selection of the opening timing of the valve (10) is important; if it is too early, a large amount of liquid will enter the inside of the cylindrical body and come into contact with the inner wall. Conversely, if this is too slow, bubble release may occur. Normally, the valve is opened when the immersion depth of the tubular body reaches a predetermined value.

This value may be determined by the immersion time and the vapor pressure of the liquid, but is usually 10@m or less. One of the preferred operating methods is to pull up the cylindrical body at a constant speed (or, fix the rod and lower the container containing the liquid at a constant speed).
, an automatic control means is provided to open the valve (10) when the immersion depth reaches a predetermined value calculated from the pulling speed.

Another method of using the device shown in Figure 1 is to connect the tube (9) with pressure-reducing means so that when the cylindrical body is immersed in a liquid, a space is removed from the pressure source depending on its depth. Air is forced into the space (11), and when the cylindrical body is pulled up from the liquid, the tube (9) is connected to a decompression source, and the space (11) is
1) Exclude the air so that the liquid level is always slightly inside the lower end of the cylindrical body. According to this method, it is possible to limit the contact of the liquid to the inside of the cylindrical body only in the very vicinity of the lower end.

Another way to use the device shown in Figure 1 is to suspend the cylindrical body with the valve (10) open, lower it vertically, and close the valve 00) just before the cylindrical body contacts the liquid level. This is the way to close it. According to this method, the air in the space of the cylindrical body (marked) is replaced one after another during its descent at the liquid level, and finally has almost the same composition as the air near the liquid surface. -7S
As described in O'l/, if the side wall of the container extends from the liquid surface to one side and the air near the liquid surface is saturated with liquid air, this method Since the air in the space (marked) contains a considerable amount of liquid vapor when it reaches the liquid surface, the vapor generated from the liquid during immersion is suppressed from accumulating in the space.This suppression Depending on the extent of this, air bubbles will not be released from the space (11) even if the valve (10) is not opened when the cylindrical body is pulled up from the liquid.

In the device shown in Fig. 1, annular rubber bags (5) are housed in the upper and lower grooves of the cylinder (3), but instead of the rubber bags, the openings of the grooves may be airtightly covered with a rubber membrane. It has a similar effect. In addition, in order to hold the cylindrical body vertically in this device, it is preferable to make the distance between the cylinder () and the cylindrical body (7) as small as possible.

In the apparatus according to the present invention, as shown in FIG. 1, it is advantageous to provide the rubber bags in one layer above and below, from the viewpoint of vertically holding the cylindrical body. However, it is not impossible to make the rubber bag 7-tiered.

Figure 1 shows seven examples of such devices, in which a shallow and wide annular groove (4) is provided on the side surface of the cylinder (3), and a comb membrane (
12) is attached. Of course, a disk-shaped hollow body (16) having a rubber membrane (15) and a side wall formed of a comb membrane (I2) is provided, and an attitude control member (16) is provided above it.
3). This member has a layer shape on the outer surface of the lid that fits into the cylindrical body, and has a layer shape on the outer surface. When inserting the holding mechanism into the cylindrical body and gripping the cylindrical body, the shoulder portion contacts the two ends of the cylindrical body, and the portion reaching the shoulder serves as a guide, and the cylindrical body and the rod are coaxial. (18) is a through hole for ventilation provided in the attitude control member.

In the device of FIG. 3, gripping of the cylindrical body is achieved by expansion of the hollow body. Further, since the relative relationship between the rod and the cylindrical body is controlled by both the hollow body and its ten attitude control members, the cylindrical body can be gripped vertically. In addition,
The hollow body (16) has a gas discharge pipe (
9) is provided.

The device according to the present invention gripped the cylindrical body as described above!
! This allows the air at the bottom of the cylindrical body to communicate with the outside or to block it. Therefore, when the cylindrical body is immersed in liquid, the space (marked at the bottom of the cylindrical body) 1
1), and when the cylindrical body is pulled up from the liquid, air bubbles can be prevented from being released from the space (11).

[Brief explanation of drawings]

1 to 3 are schematic cross-sectional views of different examples of entertainment equipment according to the present invention. (110nd (2) Cylinder bottom plate (3) Cylinder (4)
Annular groove (5) Annular rubber bag (6) Supply and exhaust pipe (7)
Cylindrical body (8) Through hole in bottom plate (9) Gas release pipe (10
) Valve (11) Space '(+21 Rubber membrane (13) Attitude control part benefit' (+41 Upper bottom plate of hollow body (15) Lower bottom plate of hollow body (1G) Hollow body (17) Support of hollow body (18) Ventilation hole vj Revised applicant Mitsubishi Chemical Industries, Ltd. Figure 1 Figure 2 Figure 3121

Claims (6)

[Claims] (1) A cylindrical body entertainment device for holding a cylindrical body and immersing it in a liquid so that only the outer surface of the cylindrical body comes into contact with the liquid, comprising: (a) Orad (b + the rod); A mechanism for suspending and supporting the rod (c+) A gripping mechanism (dl) that is attached to the lower end of the rod and has a fluid-tight bag that can be expanded and contracted (dl) Adjusts the inflation pressure by letting fluid flow in and out of the bag. The bag portion of the gripping mechanism, when inflated inside the cylindrical body, comes into close contact with the inner wall of the cylindrical body to hold it in place, and also prevents air from passing through parts other than the pressure adjustment mechanism. A device characterized in that it is capable of making it possible to clearly prevent the flow of gas inside a cylindrical body. (2) The gripping mechanism includes a bottomed cylindrical body that can be freely inserted into the inside of the cylindrical body, an annular groove provided in at least two upper and lower stages on the outer surface of the side wall, and an annular groove accommodated in the groove. Rubber bag'!
! It is characterized by having a rubber membrane covering the opening of the rubber bag or groove, and a communication conduit connecting the space formed by the rubber membrane and the inner wall of the rubber bag or groove and a fluid discharge mechanism. An apparatus according to claim 1. (3) The gripping mechanism includes a bottomed cylindrical body that can be freely inserted into the inside of the cylindrical body, and a wide annular groove provided on the outer surface of the side wall thereof;
Communication between a wide annular rubber bag accommodated in this groove or a rubber membrane covering the opening of the groove, a space formed by the rubber membrane and the inner wall of this rubber bag or groove, and a fluid discharge mechanism. 2. A device according to claim 1, further comprising a conduit. (4) The gripping mechanism includes a hollow body that can be freely inserted into the inside of the cylindrical body and at least the side wall of the hollow body is made of rubber, and this hollow body and a fluid discharge mechanism. 2. The apparatus according to claim 1, further comprising a communication conduit connecting the hollow body and a posture-side leg member located above the hollow body. (5) The pressure adjustment mechanism has a hole that vertically penetrates the bottom plate of the cylinder, a pipe that communicates with the hole and has a valve in the middle, and a means for controlling the opening and closing of the valve. An apparatus according to claim 1 or 3, characterized in that: (6) A pressure adjustment mechanism includes a pipe that vertically penetrates the hollow body;
2. The device according to claim 1, further comprising a valve provided in the middle of the pipe and means for controlling opening and closing of the valve.