JPH04109387U - Locating device for non-metallic buried pipes - Google Patents

Abstract

(57) [Summary] (with modifications) [Purpose] To obtain a locating device with a large magnetic field and small attenuation. [Configuration] Conductor 1 at the tip of locating wire 1
Attach 0. [Effects] Since current flows into the wire 1 via the conductor 10, it is not affected by the coating, a large induced magnetic field can be formed, and there is no attenuation of the current, so detection sensitivity does not decrease with distance. Furthermore, the sensitivity is good even in the low frequency range.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This invention later uses a locator to locate the buried position of non-metallic pipes buried underground. A locating wire is run along this non-metallic underground pipe to enable detection. The present invention relates to a locating device that is designed to be kept in place.

0002

[Conventional technology]

Piping such as gas pipes, such as plastic pipes buried underground. In such a case, the position can be detected using an electromagnetic induction locator like the metal pipe, as shown in Figure 8. Locating wires (copper polyester) are placed along supply pipe 2 and branch pipe 5 as shown (ethylene coated wire) 1 and expose one end 1a above the ground. When performing categorization, connect the output line 6 of the locator's transmitter 3a to one end 1a. , connect the output wire 6a to the metal grounding rod 4 inserted into the ground and connect it to the locating watch. A current is applied to ear 1, which causes a wire to form around locating wire 1. The position of the piping is detected by detecting the induced magnetic field a with the magnetic sensor 7.

0003

[Problem that the idea aims to solve]

However, when using a coated locating wire like this, the following There are problems like this.

0004 a. Because the applied current flows through the high-resistance wire sheath, the current value and its The induced magnetic field is small and the detection sensitivity is reduced. Especially if the extension is short or This tendency becomes more pronounced when a locator with a low frequency of 0 kHz or less is used.

[0005] b. Since the current flows from the entire surface of the locating wire, from the point of inflow The current attenuates at a distance. For this reason, the further away from the grounding rod 4 the induced magnetism becomes. Field a is attenuated and detection becomes difficult.

[0006] In addition, as a means to solve the above problem (a), it is possible to coat the locating wire. There is also a proposal to select a conductive material, but even if this method is adopted, the upper The problem in item b remains the same.

[0007] This invention has been proposed in view of these points, and its first purpose is locating. In the device, the induced magnetic field is increased by increasing the inflow current into the wire. The second purpose is to increase the detection sensitivity of the locator by increasing the distance. The third purpose is to reduce the attenuation of the magnetic field (current), and the third purpose is to reduce the attenuation of the magnetic field (current). The aim is to reduce the influence of differences in frequency.

[0008]

[Means to solve the problem]

The configuration of the present invention is as follows.

[0009] A locating wire with anti-corrosion coating is placed along the non-metallic buried pipe. At the same time, connect the locating wire and the electric wire to the tip of this locating wire. This is a locating device for non-metallic buried pipes, which consists of a conductor that is connected to the surface of the pipe.

0010 Note that the shape and material of the conductor may be arbitrary. Also, the conductor is at the tip of the wire. It may also be attached in the middle instead of at the top. In this case, the interval may be appropriate. However, for practical purposes, an interval of 10 m is sufficient. However, this distance depends on the size of the conductor. It will be different though.

[0011] Next, if zinc is used as a conductor, the current in zinc underground will be reduced by copper (wire). The locating wire This is a preferred example from a practical point of view, as the copper wires in the area are protected from corrosion.

0012

[Effect]

At the ground level, attach the attached locator to one end of the locating wire and the ground rod. Connect the output wire of the transmitter, insert the grounding rod into the ground, and connect the locating wire. Apply voltage between the wire and the ground rod. The current flowing into the ground from the grounding rod is a conductor. flows into the locating wire and is guided around the locating wire. A magnetic field is formed. We will detect this magnetic field with the magnetic sensor attached to the locator. This allows the location and depth of piping to be detected.

[0013]

【Example】

An embodiment of the present invention is shown in FIGS. 1, 2, and 3.

[0014] The code 1 is a locating wire using polyethylene coated wire. The locating wire 1 includes a resin branch pipe 5 branched from a metal main pipe 8, It runs along the resin supply pipe 2 branched from this branch pipe 5, and one end 1a is a rotor. It is exposed above the ground for catering.

[0015] 10 is a conductor attached to the tip of the locating wire 1. The size of the iron piece (coupon) is 10 x 10 cm.

[0016] The locating work using the above locating device is as shown in Fig. 8. Same as the example, but the iron piece 10 is attached to the tip of the locating wire 1. Therefore, the current emitted underground from the grounding rod 4 is transferred from this iron piece 10 to the location. It flows efficiently into the fining wire 1.

[0017] As a result, the induced magnetic field a becomes very large, making it easy to detect with the magnetic sensor 7. Therefore, the position and direction of the supply pipe 2 and branch pipe 5 can be easily and quickly detected using a locator. It becomes like this.

[0018] Figure 4 shows when using polyethylene coated locating wire and when using iron piece 10. The frequency characteristics of the sheathing resistance (in tap water) of the locating wire are shown. This is what I did.

[0019] From this figure, 1. The coating resistance (marked with ○) of a fully coated wire increases as the transmission frequency increases. The longer the lower.

[0020] 2. The one with the tip cut off (marked with ◆) shows a slightly lower resistance value in the low frequency range. , it is no different from a fully covered one in the high frequency range.

[0021] 3. Coupons (iron pieces) connected to wires (●, ▲, ■ marks) are frequency The resistance value is 1 to 3 orders of magnitude lower regardless of the Depends on the product.

[0022] I understand that.

[0023] Figures 5 and 6 show changes in locating current depending on distance, and the conditions are shown in the figure. As shown in 7.

[0024] From this figure, a. In the case of wire only (marked with ○), the locating current is small, especially at 10 Attenuation due to distance is observed at high frequencies of 0 kHz.

[0025] b. On the other hand, when a conductor is attached (□, ●, ■, × mark), the frequency The current value increases significantly regardless of the current value.

[0026] c. The appearance of current attenuation differs depending on the location where the conductor is installed, but if it is installed in only one place far away, Attenuation is minimized when it is attached (marked □). Especially in the low frequency range It is almost 0.

[0027]

[Effect of the idea]

As described above, the present invention is based on attaching a conductor to the locating wire. Therefore, regardless of the position, the induced magnetic field formed along the locating wire is growing.

[0028] As a result, it is easy to detect with a magnetic sensor, and the position and direction of the resin pipe can be detected easily. This has the effect of making it very easy to use even from a certain position.

[Brief explanation of drawings]

FIG. 1 is a plan view of a locating device implementing the present invention.

FIG. 2 is a front view of a locating device implementing the present invention.

FIG. 3 is a side view of a locating device implementing the present invention.

FIG. 4 is an explanatory diagram of frequency characteristics of coated resistance.

FIG. 5 is an explanatory diagram of changes in locating current depending on distance.

FIG. 6 is an explanatory diagram of changes in locating current depending on distance.

FIG. 7 is an explanatory diagram of the conditions of FIGS. 4 and 5.

FIG. 8 is an explanatory diagram of a conventional locating device.

[Explanation of symbols]

1 Locating wire 2 Supply pipe 3 Receiver attached to locator 3a Transmitter attached to locator 4 Ground rod 5 Branch pipe 6, 6a output line 7 Magnetic sensor 8 Mains 10 Iron piece

Claims (2)

[Scope of utility model registration request] [Claim 1] A structure in which a locating wire coated with an anti-corrosion coating is placed along a non-metallic buried pipe, and a conductor is attached to the tip of the locating wire by electrically connecting it to the locating wire. locating device for non-metallic buried pipes. 2. The locating device for a non-metallic buried pipe according to claim 1, wherein conductors are attached at regular intervals at the tip and middle of the locating wire.