JPH0567340B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a quantitative coating device for uniformly and stably applying varnish to a filament in the production of enamelled wire.

[Prior art] To manufacture enameled wire, varnish is applied to the outer periphery of the filament, passed through a baking oven and baked, and this application and baking are repeated a required number of times to form an enamel film of the required thickness. form.

Therefore, in applying varnish to the striatum,
For normal-sized filaments, it is common to use a vertical furnace to pass the filament through a varnish bath to adhere varnish, and then squeeze it with a die to coat it uniformly. The above method is not necessarily appropriate depending on the size, and a roll felt method using a horizontal furnace is often adopted.

That is, a portion of the strip is immersed in varnish and passed through it in contact with the rotating roll surface, and the varnish on the roll surface is attached to the strip, and then the strip is placed in the direction of travel of the strip. The filament is sandwiched between the felt and squeezed to ensure uniform adhesion.

FIG. 2 shows a coating device of this kind of conventional construction.

1 is a roll that is partially immersed in varnish 7 in varnish tank 6 and rotates in the direction of the arrow in the figure. Grooves 1a, 1a are formed in the roll 1, and the filament bodies 10, 10 for each pass are accommodated in each groove 1a, 1a, and are configured to advance in the direction of the arrow while contacting the roll. Felts 2 and 3 held by a felt holder 4 are provided in front of the progress of the striated bodies 10 and 10, and the felts 2 and 3 sandwich the striated bodies 10 and 10, while a weight 5
Appropriate clamping pressure is applied.

Since the varnish 7 is configured as described above, the varnish 7 in the tank 6 adheres to the outer surface of the rotating roll 1 and is supplied toward the filament bodies 10, 10. The stripes 10, 10 moving forward in contact with the roll 1 cause the varnish 7 supplied by the roll 1 to adhere to the surface, but this alone causes uneven adhesion, so the felts 2, 3 spread the varnish 7 evenly over the entire stripe. The purpose is to apply a varnish of a certain thickness. After this,
The filament 10 with the varnish attached passes through a baking furnace, where the varnish is baked, and then it returns to the roll 1 side again, where the baked varnish is coated with varnish again, and this pass is repeated. to form an enamel layer of desired thickness.

FIG. 3 shows another conventional configuration example,
The varnish 7 is not supplied by the rotation of the roll, but the varnish 7 sent through the supply pipe is sent through the supply hole 8 as shown by the white arrow in the figure, and is directly supplied to the felt 2, so that the overflowing varnish 7 is fed to the felt. It is applied to the striatum 10 between 2 and 3. Other than that, there is no particular difference from the case in FIG. 2, as the same reference numerals are given.

[Problems to be Solved by the Invention] In the case of the roll supply method shown in FIG. 2, the amount of varnish attached to the filament 10 always changes, and the amount of varnish supplied to the felts 2 and 3 is not constant. Therefore, the thickness of the varnish film changes and the wire diameter is not stable.

Further, as already explained, V-shaped grooves 1a, 1a are formed in the roll 1 for each pass, and the filament 1
The varnish is easily attached to the striatum 10, but the striatum 10
Since varnish application is repeated for each pass, the outer diameter of the filament 10 increases with each pass, and the amount of varnish that adheres to the surface within the groove 1a changes each time the pass changes. However, since the roll 1 is a single piece, it is not possible to take measures such as making the rotation of the varnish variable and changing the amount of varnish supplied depending on the pass to adjust the amount of varnish deposited.

In addition, in the direct feeding method shown in Fig. 3, the varnish 7 is absorbed by the capillary action of the felts 2 and 3, but the suction force due to the capillary action is not constant, and as a result, the felt absorbs the varnish 7. The amount of varnish supplied through the striatum is not constant, and the amount of varnish that adheres to the striatum also fluctuates.
As in the case shown in the figure, unevenness in the thickness of the varnish film and variations in the wire diameter due to this are unavoidable.

In recent years, there has been remarkable development in the field of electronics, and demands for higher performance and higher precision of the equipment itself are becoming more severe day by day. There is a strong demand for quality assurance of the ultra-fine precision enameled wire used in such devices, and it is becoming difficult to meet such strict customer demands with the varnish coating device of the conventional configuration.

The present invention has been made in view of the above-mentioned circumstances, and uses a roll method while being able to sufficiently control the supply of varnish, thereby stably forming a high-quality enamel film with a uniform wire diameter. The present invention aims to provide a novel quantitative varnish coating device.

[Means for Solving the Problems] The present invention has a configuration in which a part of a rotating roll is immersed in a varnish and rotated, while a felt for sandwiching a filament is brought into contact with the surface of the roll, By being configured so that a fixed amount of varnish can always be supplied by a roll that rotates toward the felt, it is possible to supply a fixed amount of varnish in an extremely stable manner compared to conventional methods that rely on capillary action.At the same time, the roll itself does not directly supply varnish. This eliminates the uneven adhesion of varnish to the striatum.

[Example] The present invention will be described below with reference to the drawings of the example.

FIG. 1 is an explanatory diagram showing a specific example of the configuration of an apparatus according to the present invention.

Reference numeral 1 denotes a varnish supply roll, which is partially immersed in varnish 7 in a varnish tank 6 and configured to be rotatable in the direction of the solid line arrow in the figure. 2 and 3
is a felt capable of sandwiching the filament bodies 10, 10, and the lower felt 2 is placed in contact with the roll 1. 4 is a felt holder, 5 is a felt 2,
It is a weight that applies appropriate clamping pressure to 3, and 10,10
is the striatum to be varnished.

Since the present invention is configured as described above, when the roll 1 rotates in the direction of the solid line arrow, the varnish 7 adheres to the outer surface of the roll 1, and as the roll 1 rotates, the varnish 7 moves as indicated by the white arrow in the figure. The varnish 7 is supplied to the felt 2 that is in contact with the varnish 7. Although it is omitted in the figure,
It is desirable to install something such as a shielding plate during the rotation of the roll 1 to provide a mechanism that can adjust the amount of varnish that adheres to the roll surface.

The varnish 7 supplied toward the felt 2 in the above manner infiltrates between the felts 2 and 3 and reaches the striated bodies 10 and 10 which are sandwiched between the felts 2 and 3 and are moving in the direction of the arrow. Apply the specified amount of varnish. Varnished striatum 10,10
As in the conventional case, the varnish is fed into a baking furnace, where the applied varnish is baked, and then returned to the coating device. By repeating this process, the filament 10 is gradually repositioned in the longitudinal direction of the felts 2 and 3 with each pass.

According to the apparatus according to the present invention, the method of supplying the varnish 7 to the felts 2 and 3 is not by the capillary action shown in FIG. The possibility of uneven supply is largely eliminated. Furthermore, since the felts 2 and 3 are in contact with the roll 1 under the same conditions over the entire length of the felts 2 and 3, the amount of varnish 7 supplied to the felts 2 and 3 is the same throughout the length of the felts 2 and 3. . This is why the device of the present invention is called a quantitative coating device.

If the varnish is supplied in a constant amount and under the same conditions in the longitudinal direction of the felt as described above, even if the filamentary body 10 changes its position in the longitudinal direction of the felt for each pass, the The amount of varnish applied is constant regardless of the position. Therefore, as shown in Fig. 2 above, there is no fear that the amount of varnish applied changes with each pass, and a fixed amount of varnish can be applied stably under the same conditions, and it is always uniform and uneven thickness can be avoided. It is possible to obtain enameled wire of good quality with no uneven wire diameter.

In the apparatus according to the present invention, the felt is brought into contact with the varnish supply roll, and the contact position of the felt with the roll is as shown in FIG. 1 as a typical example. It is preferable that the vicinity of the entrance side to the roll be brought into contact with the roll.
That is, depending on the type and material of the felt or the characteristics of the felt itself, the amount of varnish absorbed by the felt is not necessarily constant in its longitudinal direction and tends to vary. If this variation occurs in the longitudinal direction, it becomes impossible to maintain a constant amount of varnish applied to the filament in each pass as described above, and the applied film becomes unstable, resulting in poor appearance and the like. In order to avoid this, it has been confirmed through experiments that it is very effective to make contact near the inlet side of the striatum and place the varnish supply point there.

However, this is one of the conditions confirmed in the above experiment, and as a means of supplying a uniform and fixed amount of varnish in the longitudinal direction of the felt, for example, piping is provided for each pass of the filament to supply varnish in the longitudinal direction of the felt. Of course, it is possible to take appropriate measures, such as controlling the amount of varnish to be constant, or making a hole in the felt holder for each pass so that a constant amount of varnish can be supplied through the hole. Therefore, it is possible to more easily uniformly and quantitatively supply the varnish.

In addition, although Fig. 1 shows an example of supplying varnish to the lower felt 2, the design can be changed as necessary, such as a method of supplying the varnish to the upper felt 3 side, a method of supplying the varnish to both the upper and lower felts 2 and 3 at the same time, etc. be. The number of felts is not limited to one each for the top and bottom, but can be configured as appropriate, such as using multiple felts for one or both of the top and bottom, and making use of the varnish uniformity phenomenon at the interface to make the overall varnish absorption effect uniform. It goes without saying that you may change the .

[Effects of the Invention] As described above, according to the apparatus according to the present invention, it is possible to supply a uniform and constant amount of varnish in the longitudinal direction to the felt on which the varnish is applied to the striatal body, so that the varnish can be applied in each pass. This makes it possible to maintain a constant amount of varnish, and to manufacture enameled wires that have a cross-sectional shape close to a perfect circle after application and a uniform coating thickness, and quality requirements are becoming increasingly strict. The present invention has great significance as a timely proposal today.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing an embodiment according to the present invention,
2 and 3 are explanatory diagrams showing two types of conventional devices, respectively. 1: roll, 2, 3: felt, 6: varnish tank, 7: varnish, 10: striatum.

Claims (1)

[Scope of Claims] 1. A rotatable roll is installed with a part of it immersed in varnish in a varnish tank, a felt for sandwiching the filament is provided in contact with the surface of the roll, and the roll surface is changed by rotation of the roll. A roll-supplied quantitative coating device configured such that varnish adhering to the roll can be transferred to the felt side that is in contact with the roll. 2. The quantitative coating device according to claim 1, wherein the position where the felt is brought into contact with the roll is close to the entrance of the filament.