JPH082131B2 - Coanda flow line device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a Coanda flow wire passing device. More specifically, the present invention is particularly useful for wiring work in which a conductor is passed through a pipe having a relatively short distance of up to about 100 m, which has a large number of bends, and is capable of conducting the wire with high efficiency. It relates to the device.

[0002]

2. Description of the Related Art Conventionally, in office buildings, factories, communication facilities, etc., it has been common to pass a conductor or the like through a pipe, and many ways have been devised for the wiring method therefor. ing. For example, the known wire passing methods include: a) a method using a compressed fluid;
B) There is a method that does not use compressed fluid. As an example of the former, a method of supplying a compressed fluid to a conduit to convey a conductor is known, and as an example of the latter, a method of forcibly manually pushing in the conductor with a wire or the like is known. Has been.

However, in the former method, in a conduit having a large number of bends, the compressed fluid in the pipe chokes, especially at the bends, so that the flow does not become smooth and, therefore, the conductors, etc. The carrying force for carrying is reduced and it becomes extremely difficult to pass the wire. For this reason, it is generally conceivable that the pressure inside the pipe will be very low, but in this case too, the carrying force for carrying the conductors, etc. is also very low, and in practice it is very ineffective.

Furthermore, in the generally used turbulent pipe flow in the former method, the turbulence is very large, and therefore friction between the conductor and the pipe wall occurs.
Particularly in piping having a bent portion, it is very difficult to run the wire. Further, in the latter method, since the conductor wire is pushed in manually, it is difficult in many cases to carry the conductor wire, and even if the conductor wire can be managed in a short distance, the work labor is great.

In such a situation, even in a long-distance pipe having a large number of bends, a new type of line which reduces friction between a conductor or the like and a pipe wall and allows the line to be easily and efficiently conducted. The device has already been proposed by the inventor. The device uses the Coanda spiral flow, which the inventor of the present invention has been actively studying for application to various application fields, as a principle method for the wiring.

That is, this Coanda spiral flow exhibits a so-called steeper velocity distribution in which the velocity difference between the axial flow of the fluid and its surroundings and the density difference are large, the pipe axis flow is fast and the outside flow is slow. . Further, for example, the turbulence shows a value of 0.09, which is less than half the value of 0.2 of normal turbulence, and has a characteristic of forming a state different from normal turbulence. Moreover, there is a feature that a unique spiral flow is formed by combining the axial vector and the radial vector.

Therefore, by utilizing the fact that this Coanda spiral flow is a flow converging on the pipe axis in the pipe flow, even if it is a long-distance pipe having a large number of bent portions, the conductor wire can be easily and efficiently passed. Passing devices have already been developed. In this wiring device, a Coanda spiral flow unit is connected to a predetermined conduit for conducting a conductor, with or without a flexible hose or the like. Compressed fluid is supplied to the Coanda spiral unit from the compressed fluid supply means through the annular Coanda slit in the passage direction of the conduit. In this state, a predetermined conducting wire, cable or the like is inserted into the suction inlet of the Coanda spiral flow unit.

The conductor wire is automatically conveyed by the flexible hose and the spiral flow in the pipe line, and the friction between the conductor wire and the pipe wall is small, and the conductor wire progresses at high speed. In this case, an air compressor or a cylinder of compressed fluid such as nitrogen can be used as the compressed fluid supply means. Even when using a cylinder, it is sufficient that the supply pressure of the compressed fluid can be maintained at about 10 kg / cm2.

The Coanda spiral flow unit includes an annular Coanda slit between a connection port to a conduit and a suction introduction port for introducing a lead wire, a gradually reducing pipe in the vicinity thereof, a compressed fluid distribution chamber, and a compressed fluid supply unit. With the road. As the ejected annular jet passes through the gradually reducing pipe, a spiral flow converging on the pipe axis is formed, and a strong negative pressure suction force is generated at the suction inlet, and as a result, the negative pressure suction force causes the conductor wire to flow. The lead wire is guided at a high speed while converging on the pipe axis by the Coanda spiral flow in the pipe passage.

The wire passing device as described above enables easy and efficient wire passing even in long-distance piping of 1000 m or more having a large number of bends, and is extremely effective as compared with the conventional method. Show. However, subsequent studies by the inventors have revealed that there is a point to be further improved also in the case of this wire passing method by Coanda spiral flow and its device. With a Coanda spiral flow line such as this, it is possible to run lines up to several thousand meters, and even if the pressure is low enough not to cause choke in the pipe, the line runs sufficiently efficiently. However, it is necessary to raise the pressure of the supply fluid in order to improve efficiency in the relatively short distance wire running from 30m to 100m. There is a weak point that choking of the flow in the road occurs, the flow does not become smooth, and as a result, the passage efficiency decreases. In other words, it is better to prevent choke inside the pipe, rather than to prevent friction between the conductor and the pipe wall, for high efficiency in conducting a relatively short distance of about 30 m to 100 m. I got the conclusion.

The present invention has been made in view of the above-mentioned circumstances, and in a comparatively short distance of about 30 to 100 m, even if the pressure of the supply fluid is increased, the bent portion of the pipe is It is an object of the present invention to provide a new wire passage device that allows more efficient wire passage without choking of pipe flow.

[0012]

In order to solve the above-mentioned problems, the present invention solves the above-mentioned problems by introducing a suction inlet of a conductor, a Coanda slit for supplying compressed fluid behind the conductor, and a fluid ejected from the Coanda slit and a suction inlet. A Coanda flow through line comprising a Coanda unit unit having a Coanda curved surface which is a flow path for a fluid sucked from a mouth and a straight pipe unit, and a diffuser which is gradually expanded in the straight pipe unit. Provide a device.

FIG. 1 shows an example of the wire passage device of the present invention. For example, as illustrated in FIG. 1, for the Coanda flow wire passage device (1) in the wire passage device of the present invention, the suction introduction port (2) and the annular Coanda slit (3) behind the suction introduction port (2), the Coanda slit ( 3) Coanda curved surface (4) which is a flow path between the fluid ejected from the fluid and the fluid sucked from the suction inlet (2), and the straight pipe portion (5)
Furthermore, the diffuser (6) of the progressive expansion connected to the tip
A structure having and can be shown as a typical example. It also has a compressed fluid distribution chamber (7) and a compressed fluid supply path (8).

In this structure, the angle (θ) from the Coanda slit (3) to the Coanda curved surface (4) can be, for example, about 5 to 70 °. At this angle (θ), the compressed fluid supplied from the Coanda slit (3) is jetted from the Coanda curved surface (4) to the straight pipe section (5). At this time, the velocity distribution inside the straight pipe portion (5) is such that the pipe wall is very fast and the pipe axis is very slow. Once in the diffuser (6), the flow spreads and the dynamic pressure can be reduced.

In other words, the diffuser (6) forms a smooth flow without generating chokes in the pipe flow.
Then, as a result, the negative pressure suction force of the suction introduction port (2) becomes very large, the conductive wire (9) and the like are efficiently sucked, and the conveyance force is increased. The opening angle (ψ) of the diffuser (6) is preferably about 3 ° to 15 °, and the diameter of the straight pipe portion (5) is d,
When the diameter of the pipe (10) is D, d = (1/6 to 4 /
6) It is desirable to set it to about D. By optimizing the opening angle (ψ) and the pipe diameter ratio, separation of the flow in the diffuser (6) is suppressed, and high-efficiency wiring is possible.

Further, in the present invention, the inner wall of the diffuser (6) is formed by a clothoid curve, trochoid curve, 2
The curved surface may be formed using a smooth curve such as a higher-order curve such as quadratic or quartic, an exponential curve, or a logarithmic curve. By connecting with such a smooth curved surface, it becomes possible to further suppress the separation of the flow in the diffuser (6). Improve to.

Hereinafter, the present invention will be described in more detail with reference to examples.

[0018]

[Examples] Actually, in the apparatus shown in FIG. 1, the diameter (d) of the straight pipe portion is 18 mm, and the diameter (D) of the diffuser jet port is 54 m.
m, the inner wall of the diffuser has a smooth curved surface made by a clothoid curve, the opening angle (ψ) of the diffuser is 4 °, and the angle (θ) from the Coanda slit to the Coanda curved surface is 45 °. Using a wire passing device, an optical fiber having a diameter of 1.8 mm was passed through a plastic tube having an inner diameter of 54 mm and a length of 30 m having two bent portions.

The length (L) from the suction inlet to the diffuser outlet was 15.0 cm, and the diameter of the suction inlet was 20.0 mm. Compressed air with a pressure of 2 kg / cm ² was supplied from an annular Coanda slit to run the wire. As a result, the passage was completed in 2 seconds. For the purpose of comparison, when the same wire was run using the wire passing device using the Coanda spiral flow unit already proposed by the inventor, it took about 4 seconds to run the wire.

[0020]

As described in detail above, according to the present invention, choking does not occur even in a bent portion, and highly efficient wiring can be performed by a large suction force and a conveyance force.

[Brief description of drawings]

FIG. 1 is a cross-sectional view illustrating a device of the present invention.

[Explanation of symbols]

 1 Coanda Flow Passing Device 2 Suction Inlet 3 Coanda Slit 4 Coanda Curved Surface 5 Straight Pipe 6 Diffuser 7 Compressed Fluid Distribution Chamber 8 Compressed Fluid Supply Channel 9 Conductor 10 Piping

Claims (4)

[Claims] 1. A straight pipe and a Coanda curved surface, which is a suction inlet of a conductor wire, a Coanda slit for supplying compressed fluid behind the conductor, and a passage for a fluid ejected from the Coanda slit and a fluid sucked from the suction inlet. A Coanda flow wire passing device, wherein a diffuser of gradually expanding is disposed in a straight pipe portion of a Coanda unit portion having a portion. 2. The Coanda flow through wire device according to claim 1, wherein the relationship between the diameter d of the straight pipe portion and the jet diameter D of the diffuser is about d = (1/6 to 4/6) D. . 3. The spread angle (ψ) of the diffuser is 3
2. The Coanda flow wire connection device according to claim 1, wherein the angle is about 35 ° to 35 °. 4. The Coanda flow wire passing device according to claim 1, wherein the inner wall of the diffuser is a curved surface that is smooth toward the ejection port side.