JP2821057B2 - Wire release agent coating method and apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for applying a release agent to an electric wire and an applicator for the method.

[0002]

2. Description of the Related Art An electric wire is roughly classified into a single-core covered wire in which a copper single wire or a twisted wire is covered with an insulator, and a double-core wire in which two or more single-core covered wires are covered with another insulator. There is a covered wire.

When connecting an electric wire to a connection end, it is necessary to remove a part of the insulation covering the end of the electric wire to expose the copper wire. At this time, the covering insulator removing operation is performed manually by a tool using a tool or automatically by a machine. In any case, in order to increase the efficiency of the removal operation and improve the finish, during the production of electric wires, a mineral such as talc is placed between the copper wire and the coated insulation and between the single-core covered wires. Powder is always applied as a release agent. The device used at this time is an electric wire release agent coating device.

[0004] A conventional wire release agent coating apparatus is generally composed of a wet method in which water is added to mineral powder such as talc to form a slurry into a storage tank, and a copper wire or an electric wire is passed therethrough. It is what is called so-called "dobske". In this conventional method, the amount of the release agent applied becomes uneven, a drying device and a device for peeling off the excess are required, and various drawbacks that the working environment becomes dirty due to the use of water cannot be avoided.

[0005]

SUMMARY OF THE INVENTION The present invention proposes a method for applying a wire release agent by a dry method and an apparatus therefor, which solves the above-mentioned drawbacks of the conventional apparatus for applying a wire release agent by a wet method. As an issue.

[0006]

SUMMARY OF THE INVENTION The above object is achieved by flowing compressed release agent powder contained in a release agent storage tank by blowing compressed air from below a perforated plate provided below the release agent storage tank. A certain amount of the powder, which has been formed into a layer and thus becomes a fluidized bed, is sucked by an injector-type powder pump, sent to a release agent coating gun arranged so as to face the spraying section, and is provided near the coating gun. Static electricity is supplied from a static electricity generator to the electric electrode, and the release agent is uniformly applied to the electric wire passing through the spraying part by the action of the static electricity, and the residual powder not attached to the electric wire is sprayed with compressed air. From the dust collector box, the residual powder is separated from the clean air by the dust collector filter by the negative pressure generated by the exhaust fan, and compressed air is sent to the filter for a short time instantaneously at regular time intervals. Thereby peeling off the filter. Returning the particles obtained by the said release agent reservoir is solved by the method of the present invention.

[0007] Further, the above-mentioned problems are caused by a perforated plate provided below the release agent storage tank, a first compressed air supply device for supplying compressed air below the perforated plate, and compressed air blown out from the perforated plate. Injector-type powder pump that sucks and sends a fixed amount of powder that has become a fluidized bed, and a release agent that is arranged so as to face the spraying part, to which the powder that has become a fluidized bed is supplied by the powder pump. A coating gun, a static electricity generator for supplying static electricity to an electrostatic electrode provided near the coating gun,
A spraying part for uniformly applying the release agent to the electric wire passing by the electrostatic action, and a second part for sending the residual powder not adhering to the electric wire from the spraying part with compressed air to the filter in the dust collector box. A compressed air supply device, an air blower for separating the residual powder from clean air by negative pressure in the filter, and a filter for removing the separated powder to the release agent storage tank at regular time intervals. This is solved by the device according to the invention, which comprises a third compressed air supply for delivering compressed air to the body in a short time.

[0008]

According to the present invention, the compressed air for flow supplied below the perforated plate provided at the lower part of the release agent storage tank is blown out from the perforated plate, so that the release agent powder stored in the release agent storage tank is in a flowing state. And The release agent powder in the fluidized state is then sucked in a fixed amount by an injector type powder pump supplied with compressed air for a pump, and sent to a release agent application gun.
At the same time, static electricity is supplied to an electrostatic electrode provided in the vicinity of the release agent application gun to give a charge to the release agent powder. Thus, the required amount of the release agent powder is uniformly applied to all of the upper, lower, and both side surfaces of the electric wire passing through the spray portion.

On the other hand, the residual powder that has not adhered to the electric wire is
It is sent to the inside of the dust collector box from the spraying part by the compressed air for blowing down. Here, a negative pressure from the exhaust fan acts, and the residual powder is separated from the clean air by the dust collector filter. The powder collected on the surface of the filter body is separated from the filter body by sending compressed air for wiping off to the filter body for a short period of time at a constant time interval, and then released from the filter body by gravity. Return inside.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The components of an electric wire release agent coating apparatus according to the present invention are shown in a block diagram in FIG. 1 and specifically in FIG. 2. The components will be described below with reference to these drawings.

An electric wire release agent coating device 1 includes a release agent storage tank 2 containing release agent powder, an injector type powder pump 3 for sucking the release agent powder from the release agent storage tank 2, and an electric wire. Release agent coating gun 4 for applying release agent powder to the surface, electrostatic electrode 5, static electricity generator 6, spraying unit 7 for supplying release agent powder to passing electric wire by said application gun 4, dust collector box 8, a dust collector 9, an exhaust fan 10, and first to fourth compressed air supply devices shown in FIG. A perforated plate 11 is arranged below the release agent storage tank 2.

In FIG. 3, a compressed air for flow is supplied from a first compressed air supply device 12 below a perforated plate 11 provided below a release agent storage tank 2, and the compressed air is blown out from the perforated plate 11. Accordingly, the release agent powder stored in the release agent storage tank 2 is in a fluid state. The release agent powder in the fluidized state is then sucked in a fixed amount by the injector type powder pump 3 to which compressed air for pump is supplied from the fourth compressed air supply device 15 and is sent to the release agent application gun 4. Can be At the same time, the static electricity generated by the static electricity generator 6 is supplied to the electrostatic electrode 5 provided near the release agent application gun 4,
This gives a charge to the release agent powder. Thus, the required amount of the release agent powder is uniformly applied to all of the upper and lower sides and both side surfaces of the electric wire passing through the spraying section 7.

On the other hand, the residual powder which has not adhered to the electric wire is sent from the blowing unit 7 into the dust collecting box 8 by the compressed air for blowing down from the second compressed air supply device 13.
Here, the negative pressure generated by the exhaust fan 10 acts, and the residual powder is separated from the clean air by the dust collector filter. The powder collected and collected on the surface of the filter is sent from the third compressed air supply device 14 to the filter at a constant time interval and a short time instantaneously sends compressed air to the filter. , And then returns to the release agent storage tank 2 by gravity. In this case, a foreign matter removing device 16 such as a fixed sieve or a revolving sieve is provided between the spraying unit 7 and the dust collector box 8 along a path for feeding the powder from the spraying unit 7 to the filter in the dust collector box 8. Place and remove foreign matter.

As described above, when the release agent powder in the release agent storage tank 2 forms a fluidized bed, the release agent powder is sucked by the injector type powder pump 3 in a certain amount. It becomes possible. In addition, by supplying static electricity to the electrostatic electrode 5 provided in the vicinity of the release agent application gun 4 and applying a charge to the release agent powder, the release agent powder can be uniformly applied to the back side of the electric wire. Can be attached.

Next, as a powder pump used in the present invention,
When a conventionally known powder pump manufactured by Nordson is used, since the powder suction direction and the discharge direction of the powder pump form a right angle, the powder adheres to the inside of the pump and the amount of ejected powder increases. The pumps did not survive continuous use, as well as reduced clogging and frequent blockages.

Therefore, the injector type powder pump 3 was used. This powder pump will be described with reference to FIG.

In the powder pump 3 shown in FIG. 4, compressed air from a compressed air supply port 18 flows into a linear pipe 20 through a plurality of pores 19, and a release agent The powder sucked from the storage tank 2 is transported to the powder discharge unit 22 at a high speed. Each of the pores 19 is inclined and disposed so as to be directed from the upstream side of the pipeline 20 to approximately one point on the downstream side,
In this case, the angle θ between the center line of each pore and the center line of the flow path in the conduit 20 is 5 to 20 °. 23 is a powder suction unit 21
The suction rubber hose connected to the
2 is a discharge rubber hose connected to 2.

The pipe 20 has a circular cross section, and its inner diameter and the inner diameter of the pore 19 are 4 to 6 mm and 0.8 to 2 mm, respectively. Then, compressed air having a pressure of 1 to 5 kgf / cm ² G is supplied from the compressed air supply port 18. The number of pores is two to four, and the pores are arranged at substantially equal intervals along the circumferential direction.

This injector type powder pump is connected to a pipe 2
Since the cross section of 0 is circular, has a certain dimension, and is linear and has no bending, all the drawbacks of the conventional powder pump described above have been solved, and continuous use has become possible. Further, by adjusting the pressure of the compressed air supplied from the compressed air supply port 18, the amount of ejected powder can be easily changed and set.

Furthermore, when the temperature of the compressed air supplied from the compressed air supply port 18 is increased to a temperature equal to or higher than the room temperature, the temperature drop due to the adiabatic expansion of the compressed air is suppressed. Powder adhesion inside was completely eliminated.

As shown in FIG. 5, a material 25 having high wear resistance, such as tungsten carbide, alumina, silicon nitride, silicon carbide, is used for the inner wall of the pipe 20 having a circular cross section, particularly, the inner wall of the powder contact portion. However, a decrease in the amount of powder ejected due to wear was suppressed, and the powder could be used stably for a long period of time.

Conventionally, a bag filter, which is widely used as a dust collector, is a filter inside a fiber in a fibrous filter cloth. Therefore, a so-called clogging phenomenon in which powder particles are clogged in a filter body with time occurs, The pressure loss gradually increases to reduce the dust collecting effect. If the filter is not replaced, the filter cannot withstand continuous use, and the dust collector itself has a large volume.

On the other hand, a surface filtration type dust collector comprising a filter formed by coating the surface of a fine-grained synthetic resin sintered compact with a fluororesin and then processing the surface, such as a Sinter Lamella filter manufactured by Nittetsu Mining Co., Ltd. Are small, the dust collection efficiency is very large, and the pressure loss of the filter immediately after operation becomes constant, so that the filter can be used continuously without having to be replaced. Therefore, it is desirable to use the above-mentioned surface filtration type dust collector in order to make the wire release agent coating device withstand continuous use for a long time.

[0024] The wire release agent coating device is
Although insignificant, it is inevitable that foreign substances are drawn into the apparatus from the outside. In other words, there is a foreign substance that adheres to the material to be applied and invades it. In order to prevent dust from being discharged into the work environment, the entire device is operated under a slightly negative pressure state. Fine foreign substances such as wood dust, synthetic resin, cotton, fiber, paper and the like, which are generally referred to as trash, may be sucked in. If such foreign matter adheres to the inside of the powder pump, the ejection state may become unstable, and eventually the pump may be blocked.

On the other hand, in the case of the injector type powder pump, as described above, since the cross-sectional shape is constant and there is no bending, the obstacle due to the foreign matter is very small, but the foreign matter removing device is prepared in case of emergency. Is desirably provided.

For this reason, in the present invention, as illustrated and described in FIG. 3, the residual powder that has not adhered to the electric wire is sent from the blowing unit 7 to the filter in the dust collecting box 8 by compressed air. When a foreign matter removing device 16 such as a fixed sieve or a revolving sieve provided with a woven mesh having a mesh of 1 to 5 mm was arranged between the spraying section 7 and the dust collecting box 8, the influence of the foreign matter was completely eliminated. The size of the mesh in this case must be large enough to remove foreign matter and allow the powder to pass easily. If the mesh is too fine, the mesh will be clogged. .

[0027]

According to the present invention, there are various drawbacks such as the uneven amount of the release agent applied in the conventional electric wire release agent application method, the necessity of a drying device and an excess stripping device, and the contamination of the working environment due to the use of water. Can be eliminated.

[Brief description of the drawings]

FIG. 1 is a block diagram of components of a wire release agent coating device according to the present invention.

FIG. 2 is an explanatory view showing an arrangement of each component of the electric wire release agent coating device.

FIG. 3 is a block diagram for explaining the operation of each component of the wire release agent coating device.

FIG. 4 is a sectional view of an injector-type powder pump used in the present invention.

FIG. 5 is a sectional view showing a modification of the powder pump.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 wire release agent application device 2 release agent storage tank 3 injector type powder pump 4 release agent application gun 5 electrostatic electrode 6 static electricity generator 7 spraying unit 8 dust collector box 9 dust collector 10 exhaust fan 11 perforated plate 16 foreign matter removal Equipment 19 Pores 20 Pipelines 25 Wear-resistant materials

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H01B 13/16 B05B 5/025 B05C 19/04 B05D 1/06 B05D 7/20

Claims (6)

(57) [Claims] A compressed air is blown out from under a perforated plate provided at a lower portion of a release agent storage tank, so that the release agent powder stored in the release agent storage tank is formed into a fluidized bed, thus forming a fluidized bed. A certain amount of powder was sucked by an injector type powder pump and sent to a release agent coating gun arranged so as to point to the spraying part,
Static electricity is supplied from a static electricity generator to an electrostatic electrode provided in the vicinity of the coating gun, and the release agent is uniformly applied to an electric wire passing through a spraying portion by the action of the static electricity. The powder is sent into the dust collector box from the blowing section with compressed air, and the residual powder is separated from the clean air by the dust collector filter by the negative pressure generated by the exhaust fan,
A method of applying an electric wire release agent, wherein compressed air is instantaneously sent to the filter at a fixed time interval for a short period of time, whereby powder separated from the filter is returned to the release agent storage tank. 2. The method for applying an electric wire release agent according to claim 1, wherein said compressed air is supplied while being heated to room temperature or higher. 3. A fluidized bed formed by a perforated plate provided below the release agent storage tank, a first compressed air supply device for supplying compressed air below the perforated plate, and compressed air blown out from the perforated plate. An injector-type powder pump that sucks and sends a fixed amount of powder, a release agent application gun that is arranged to face the spraying part and is supplied with the powder that has become a fluidized bed by the powder pump, A static electricity generator for supplying static electricity to an electrostatic electrode provided in the vicinity of the coating gun, a spraying unit for uniformly applying the release agent to an electric wire passing by the electrostatic action, and residual powder not attached to the electric wire A second compressed air supply device for sending compressed air into the dust collector box from the blowing section, a blower for separating the residual powder from clean air by negative pressure by the dust collector filter, Return the body to the release agent tank Wire release agent application device, characterized in that a third compressed air supply device for feeding the short momentarily compressed air into the filter body at a constant time interval. 4. The injector type powder pump has a diameter of 0.8 to 2 mm on a side wall of a circular cross-section pipe having an inner diameter of 4 to 6 mm.
At an angle of 5 ° to 20 ° with respect to the center line of the circular section tube.
And two to four holes are formed in a conformal arrangement so that the holes intersect at one point of the center line, and compressed air having a pressure of 1 to 5 kgf / cm ² G is applied to the holes. The electric wire release agent coating device according to claim 3, wherein a powder pump for feeding is used. 5. The electric wire release agent applying apparatus according to claim 4, wherein a material having high wear resistance is used for the inner wall of the powder contact portion of said circular cross section tube. 6. A foreign matter removing device, such as a fixed sieve or a revolving sieve, is disposed between the spraying part and the dust collector box in a path for sending the residual powder from the spraying part to the filter in the dust collector box. The wire release agent coating device according to any one of claims 3 to 5, which is characterized in that: