JPH01176470A - Coating method and device therefor - Google Patents

Abstract

PURPOSE:To form a uniform coat on the peripheral surface of a base material by placing an annular pot containing an application liquid with an annular sealing member over a bar-like base material so that the inner peripheral edge of the sealing member comes into close contact with the periphery of the base material and allowing the annular pot to descend along the base material. CONSTITUTION:An annular pot 2 which stores an application liquid with an annular sealing member provided at the bottom is fitted over a cylindrical or bar-like base material 1 to be coated in such a way that the inner peripheral edge of a sealing member 3 comes in close contact with the peripheral surface of the base material 1 along the latter. Then the base material is fixed by setting it upright. Next, the annular pot 2 storing the application liquid 4 is allowed to descend along the base material 1 to form a coat 5 on the peripheral surface of the base material 1. As a result, a uniform coat of synthetic rubber or synthetic resin solution can efficiently be formed on the peripheral surface of a base to be coated such as a roll core. In addition, the thickness of the coat can be set easily and freely.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a coating method and an apparatus therefor which are applied, for example, to manufacturing synthetic rubber coated rolls used as fixing rolls of image forming apparatuses.

2. Description of the Related Art In the past, for example, when manufacturing a fixing roll for an image forming apparatus, methods for coating a metal roll core with synthetic rubber or synthetic resin are mainly known as (i) a spray method and (il) a dipping method. ing.

Here, according to the former spray method, there were problems in that the thickness of the coating film tends to be non-uniform, unevenness occurs, the smoothness is poor, and the performance of the fixing roll is poor. In addition, in order to spray the coating solution uniformly, the viscosity of the solution must be low.
Therefore, there has been a problem that there are restrictions on the types of rubber or resin that can be coated. Moreover, since a sufficiently thick coating film cannot be obtained in one coating operation, this process must be repeated several times to perform so-called overcoating, resulting in poor production efficiency of the fixing roll.

Further, since the solution is scattered by spraying, the working environment is extremely polluted, and the yield rate is extremely poor at 30 to 50%, which in turn increases the manufacturing cost of products such as fixing rolls.

According to the latter dipping method, a synthetic rubber or synthetic resin solution is placed in a relatively large-capacity dipping tank, and the base material such as the roll core is immersed in this solution.
During dipping, oil, dust, dirt, etc. adhering to the substrate are mixed into the solution, and the solution in the bath must be replaced after just a few uses, resulting in a 5% yield.
It is very poor, being less than 0%, and there is a problem in that the cost of products such as fixing rolls becomes high. Moreover, since the dipping tank is large, it requires a large installation space and is not compact.

OBJECT OF THE INVENTION The object of the present invention is to solve the above problems and to efficiently form a uniform coating film of a solution of synthetic rubber or synthetic resin on the outer peripheral surface of a substrate to be coated such as a roll core. Moreover, the thickness of the coating film can be set very easily and freely.
Another object of the present invention is to provide a coating method and an apparatus therefor that do not pollute the working environment, have a good yield, and can coat synthetic rubber or synthetic resin at low cost.

Structure of the Invention The first aspect of the present invention is to attach a coating liquid storage annular pot having an annular sealing member at the bottom to a cylindrical or rod-shaped substrate to be coated, so that the inner peripheral edge of the sealing member runs along the outer peripheral surface of the substrate. A coating film is formed on the outer circumferential surface of the substrate by fitting and covering the substrate in a tight manner, fixing the substrate in a substantially vertical position, and lowering the annular pot containing the coating liquid along the substrate. The gist of this article is a coating method characterized by the following.

Next, a second invention of the present invention is an apparatus for carrying out the method of the first invention, which holds a cylindrical or rod-shaped substrate to be coated in a substantially vertical state and in a removable manner. A base material holding means, a coating liquid storage annular pot having an annular sealing member that is fitted over the base material and whose inner peripheral edge is in close contact with the outer circumferential surface of the base material at the bottom, and an annular pot containing the coating liquid. The gist is a coating device comprising an annular pot lifting means that is lowered along the material and returns the annular pot to its original level after coating.

Example Next, embodiments of the invention will be described based on the drawings.

In this specification, front, rear, right, and left are based on Figure 2, where the front refers to the front side of the paper sheet in Figure 2, the rear refers to the back side, the left refers to the left side of the same figure, and the right refers to the right side of the same figure. shall be.

Note that the embodiments are based on a plain paper copying machine (P P
This figure shows the case of manufacturing a fixing roll used in C).

In the drawing, the coating apparatus according to the present invention has a cylindrical coated base material (1) made of an aluminum roll core erected approximately vertically on the front right side of a plate-like base (10), and is detachably attached. Base material holding means (11)
is provided on the front left side of the base (10), and a coating liquid storage annular pot (2) fitted and covered with a roll core (1) serving as a base material to be coated is lowered along the roll core (1). Annular pot lifting means (31) are provided for returning the annular pot (2) to its original level after application.

The base material holding means (11) includes a pair of upper and lower holding members (12).
)(13) are provided. Here, the upper clamping member (
12) is a connecting member (15) attached to the lower surface of the lifting block (14).
), and two-step tapered portions (12a) (12b) are provided at the tip thereof so as to fit into the upper ends of a plurality of roll cores (1) having different diameters. A pair of upper and lower legs (14a) and a pair of left and right legs (14a) are provided on the back surface of the lifting block (14), and these legs (14a) (14a) extend vertically to the front surface of the base (10). It is fitted from both left and right sides into a guide rail (1B) with a T-shaped horizontal cross section. Also, the top of the lifting block (14) has a hanging wire (1
7) is connected, and the middle part of this wire (17) is wrapped around two pulleys (18) (1g) attached to the top of the base (10), and the same ends are connected at the back of the base (10). A balance weight (19) is suspended from the other end of the wire (17).

The front of the lifting block (14) has a vertically long elongated hole (
A rod-shaped lever (21) is made to protrude from this elongated hole (20).
) to move the lifting block (14) to a predetermined height and then releasing the lever (21), the lifting block (14) is stopped at that height by a stopper mechanism (not shown).

In addition, the lower holding member (13) includes a horizontal bracket (24)
(24) and the base (10) via the connecting member (25).
) is fixed upward to the front surface of the upper clamping member (12), and a two-step tapered part (13a) (13b) is attached to the tip of the upper clamping member (12).
It is set up in the same way as in the case of .

The upper end of the roll core (1) as the base material to be coated has a small tapered part (
12b) (13b) with spacers (22) and (2), respectively.
8) is fitted and attached through the roll core (1)
is held in a vertical position. Upper and lower spacers (22)
(23) is for applying the coating liquid (4) to the end of the roll core (1);
It has approximately the same outer diameter as the outer diameter, and has a roll core (1) at the tip.
A small-diameter portion (22a) (23a) is provided to be inserted into the end of the tube.

The coating liquid storage annular pot (2) fitted over the roll core (1) is made of stainless steel, and the bottom of the pot is made of silicone rubber whose inner periphery is in close contact with the outer peripheral surface of the roll core (1). An annular sealing member (3) is provided, and a small-diameter leg (2a) is annularly provided at the bottom of the annular pot (2>).

The annular seal member (3) is held down by a stainless steel annular holding fitting (6) fitted into the annular pot (2) from above, and is sealed with the bottom wall outside the leg (2a) of the pot (2). The tips of the plurality of countersunk screws (7) passing through the member (3) from below are screwed into the threaded holes of the holding fitting (B), whereby the pot (2) and the sealing member (3) are screwed together.
) and the presser fitting (6) are integrally coupled.

The inner diameter of the annular seal member (3) is usually 1 to 4 a+m smaller in radius than the outer diameter of the roll core (1), and as shown in FIGS. ) is bent slightly upward and brought into close contact with the outer peripheral surface of the roll core (1). A required amount of a coating liquid (4) made of a silicone rubber raw material is injected into the annular pot (2) having the sealing member (3).

On the other hand, the annular pot holding means (31) is equipped with a block-shaped moving body (32), and a female threaded portion (33) is provided in the center of this moving body (32) and penetrates vertically. Guide rod insertion holes (34) on both left and right sides of
(34) are opened in parallel.

Then, the upper and lower brackets (37) (
The male threaded rod (35) is vertically attached via the
) are screwed to the female threaded portion (33) of the moving body (S2), and the left and right rods are attached to the plate-shaped base (10) in parallel with the male threaded rod (35) via the upper and lower brackets (38), respectively. A pair of guide rods (3B) (3B
) are inserted into the insertion holes (34) (34) of the movable body (32). In addition, a transmission sprocket (3) is attached to the lower end of the male threaded rod (35) beyond the lower bracket (37).
9) is attached, and this sprocket (39) and the sprocket (39) provided at the tip of the drive shaft (41) of the reversible motor (40) attached to the plate-shaped base (10).
42), a power transmission chino (43) is wound around it.

The male threaded rod (35) is then rotated by the drive of the motor (40) through these transmission mechanisms, and the moving body (
32) is adapted to be lowered or raised. A limit switch (44) for stopping the moving body is attached to the lower end of the left guide rod (38).

A projecting portion (45) is provided on the front surface of the movable body (32), and a horizontal hole (4) formed in this projecting portion (45) is provided.
8), the proximal end (46a) of the pot holding member (46) having the annular pot holder portion (47) at the tip is inserted;
The two fasteners are fixed by bolts (48). The annular pot holder has a leg portion (47) of the annular pot (2).
2a) is fitted from above, and the pot holder is attached to the part (47).
) The three bolts screwed through are bolts (49).
The annular pot (2) is fixed by.

In the above, the cylindrical roll core (1) as the substrate to be coated
A coating liquid storage annular pot (2) equipped with a silicone rubber annular seal member (3) at the bottom is fitted so that the inner peripheral edge of the seal member (3) closely follows the outer peripheral surface of the base material (1). At the same time, spacers (22) and (23) are fitted to both the upper and lower ends of the roll core (1), and these are sandwiched between the upper and lower holding members (12) and (13) to hold the roll core (1) approximately vertically. Stand it up and fix it. Next, the motor (40) is operated to rotate the male threaded rod (35), and the annular pot (2) containing the coating liquid (4) made of silicone rubber raw material is lowered along the roll core (1). When the moving body (32), which forms the coating film (5) of the silicone rubber raw material on the outer peripheral surface of the roll core (1), reaches the bottom dead center, the motor (40) is activated by the action of the limit switch (44). It is automatically stopped.

The thickness of the coating film (5) formed on the outer peripheral surface of the roll core (1) is usually 20 to 250 p. It is desirable to apply an undercoat to the outer circumferential surface of the roll core (1) in advance to improve adhesion. Further, the descending speed of the annular pot (2) is usually 2 to 20 seconds/sec, preferably 4 to 17 fflI
Il/sec, and the viscosity of the coating liquid (4) is usually 50 to 1
000 cp, preferably 300-600 cp.

The faster the annular pot (2) descends, the faster the application liquid (
The higher the viscosity of 4), the thicker the coating film (5) becomes.

Therefore, by appropriately setting these pot lowering speeds and coating liquid viscosity values, a coating film (5) of a desired thickness can be formed.

The annular seal member (3) usually has a hardness of 3 in JIS hardness.
It has a hardness of 0 to 70°, preferably 40 to 60''.The inner diameter of this sealing member (3) is usually 1 to 411 mm smaller in radius than the outer diameter of the roll core (1), preferably 2 to 4 mm. Here, if the inner diameter of the seal member (3) is smaller than 41 in radius, the seal member (3) is
2) When the inner peripheral edge is brought into close contact with the outer surface of the roll core (1), the resistance becomes too large, which causes pulsations and uneven coating, which is not preferable.

Further, if the difference between the inner diameter of the sealing member (3) and the outer diameter of the roll core (1) is less than 1 m11 in radius, it is not preferable because there is a risk of liquid leakage due to machining errors or the like. In addition,
The material of the annular sealing member (3) is not limited to silicone rubber, but may also be other materials such as fluororesin, EPDM, so-called ultra-high molecular weight polyethylene, etc. When the hardness of the sealing member (3) is low, its inner diameter It is also possible to make the radius smaller than the outer diameter of the roll core (1) by more than 4 mm.

In addition, since the coating liquid (5) can be applied as long as it is in liquid form, the coating liquid (5) is not limited to the silicone rubber raw material mentioned above.
A solvent diluted solution or emulsion solution of other synthetic rubber or synthetic resin raw materials can be used. The annular pot (2) is filled with an amount of coating liquid (5) that can form a coating film (5) of a predetermined thickness on the surface of the roll core (1).
If the entire amount does not initially enter, lower the annular pot (2) and add the coating solution (
5) should be refilled quietly.

After forming the coating film (5), the roll core (1) with the coating film (5) is removed and placed in an oven (path shown), for example at 80°C.
The silicone rubber coating (5) is vulcanized by heating at 150° C. for 10 minutes, at 150° C. for 1 hour, and then at 200° C. for 2 hours to produce a fixing roll. The hardness of the silicone rubber coating layer of the fixing roll obtained in this way is usually 30.
~70°, preferably 45-60''.

In the above embodiment, a case was shown in which a fixing roll used in a plain paper copying machine (PPC) was manufactured according to the present invention, but the present invention is not limited to this. This applies to all cases in which a coating liquid such as synthetic rubber or synthetic resin raw material is applied to the coating substrate (1).

Further, the substrate holding means (31) for holding the cylindrical or rod-shaped substrate to be coated (1) in a substantially vertical state, and the elevating means (31) for the coating liquid storage annular pot (2) are as shown in the figure. However, the present invention is not limited to this, and other configurations may be used as appropriate.

Effects of the Invention As described above, the coating method of the present invention includes sealing a coating liquid storage annular pot (2) equipped with an annular sealing member (3) at the bottom onto a cylindrical or rod-shaped substrate to be coated (1). The member (3) was fitted over the base material (1) so that its inner circumferential edge was in close contact with the outer circumferential surface of the base material (1), and the base material (1) was fixed in a substantially vertical position, and the coating liquid (4) was contained therein. By lowering the annular pot (2) along the base material (1), the coating film (5) is formed on the outer peripheral surface of the base material (1). A uniform coating film (5) of a solution of synthetic rubber or synthetic resin can be formed very efficiently on the outer circumferential surface of 1). By adjusting the lowering speed of the annular pot (2), it can be freely set. In addition, compared to the conventional spray coating method, it does not pollute the working environment at all, and there is very little loss of the coating solution (4), making it possible to secure a yield of approximately 80% or more. (4) can be used effectively, coating with synthetic rubber or synthetic resin can be performed at low cost, and products such as fixing rolls can be mass-produced at low cost.

Further, as described above, the coating apparatus of the present invention includes a substrate holding means (11) that holds the cylindrical or rod-shaped substrate to be coated (1) in a substantially vertical state and in a removable manner.
and an annular seal member (3) that is fitted over the base material (1) and whose inner peripheral edge is in close contact with the bottom portion along the outer peripheral surface of the base material (1).
An annular pot containing a coating liquid (2) and a coating liquid (4)
The device comprises an annular pot lifting means (31) for lowering the annular pot (2) containing the coating material along the substrate (1) and returning the annular pot (2) to the original level after coating. The method can be carried out extremely smoothly, and a uniform coating film of synthetic rubber or synthetic resin solution can be efficiently formed on the outer peripheral surface of the substrate (1) to be coated, such as a roll core, and the quality can be improved. This has the effect that products such as fixing rolls with excellent quality can be manufactured at low cost.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a partially enlarged sectional view of a substrate to be coated and an annular pot containing a coating liquid, showing the middle of coating. Fig. 2 is a partially cutaway front view of the device of the present invention, Fig. 3 is a right side view of the device, and Fig. 4 is a partially cutaway front view of the device of the present invention.
FIG. 2 is an enlarged cross-sectional view taken along line IV-IV in FIG. (1)... Substrate to be coated (roll core), (1)... Annular pot containing coating liquid, (3)... Annular sealing member, (
4)...Coating liquid, (5)...Coating film, (11)...
Coated substrate holding means, (12) (13)...Upper and bottom holding member, (14)...Elevating block, (22) (23)
)... Spacer, (31)... Annular pot elevating means, (32)... Moving body, (35)... Male threaded rod, (
36)... Guide rod, (4B)... Pot holding member, (47)... Annular pot holder is part. Patent applicant: Yamauchi Co., Ltd. @Figure 1

Claims (2)

[Claims] (1) A cylindrical or rod-shaped substrate to be coated (1) and a coating liquid storage annular pot (2) equipped with an annular seal member (3) at the bottom.
) is fitted over the base material (1) so that the inner peripheral edge of the seal member (3) closely fits along the outer peripheral surface of the base material (1), and the base material (1) is fixed in a substantially vertical position, and the coating liquid (4) By lowering the annular pot (2) containing the material along the base material (1),
A coating method characterized by forming a coating film (5) on the outer peripheral surface of a base material (1). (2) a base material holding means (11) for holding the cylindrical or rod-shaped base material (1) to be coated in a substantially vertically erected state and detachably; An annular pot (2) containing a coating liquid, the bottom of which is provided with an annular seal member (3) whose inner peripheral edge is in close contact with the outer circumferential surface of the base material (1); and an annular pot (2) containing the coating liquid (4). A coating device comprising an annular pot lifting means (31) for lowering the annular pot (2) along the substrate (1) and returning the annular pot (2) to its original level after coating.