JP2505397Y2 - Power line sag measuring device - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tool for measuring the sag of overhead lines between steel towers in power transmission line construction work.

[0002]

2. Description of the Related Art An external shape of a power transmission line draws a catenary curve, and an ideal virtual catenary curve and a virtual sag are calculated in advance by using an elastic catenary formula for appearance and accident prevention. When viewed from the same measurement point, it is ideal that all the tails of the lines should be laid in contact with the same tangent plane of the virtual catenary curve.

Conventional measuring methods include an isometric method, an isometric method, and an angle method. The isometric method and the isometric method use a catenary approximation formula and a parabolic approximation formula, and measuring instruments installed in respective steel towers. The central sag is obtained by setting a sag ruler point and looking through the line tail from a measuring instrument equipped with a telescope. The angle method calculates the vertical angle of the tangent plane of the virtual catenary curve using the above approximation formula, and obtains the central sag by looking through from the measurement point of one steel tower at that angle.

[0004]

When measuring the sag by the above method, the conventional measuring device does not cause a measurement error as long as both suspension points of the transmission line of the multi-line tower are horizontal.
Even if the heights of both suspension points of the power transmission line are different, if the measurement is performed at a position that is lower than the suspension point of each power transmission line by the distance of the virtual sag, no measurement error will occur, but the power transmission line Since it is supported at the tip of the arm, if it is attempted to measure directly under the transmission line as described above, the measurement point will be in the air, and such measurement will be impossible.
Therefore, set a tangent line of one virtual catenary curve between the steel towers, and assume that the position lower than the line segment connecting both transmission line suspension points by the virtual sag distance is just under the overhead line, and the telescope at that position. After setting the angle according to the angle of the tangent line, or looking at the sag ruler installed on the opposing steel tower, the telescope holding that angle is moved to the side between both arms where it is actually erected, and the I was measuring the degree. However, since the telescope horizontally rotates while maintaining the specified angle as described above, the tangent of the line tail of the transmission line as seen from the telescope inevitably exists on the conical surface with the apex at the telescope, and the tangent to the virtual catenary curve. There is a drawback in that an error occurs due to the upward displacement from the plane.

The present invention aims to simplify the overhead line work and to extend the power line to an ideal catenary curve.
It is intended to develop and provide a sag measuring device capable of accurately measuring sag.

[0006]

According to the present invention, there is provided a main body which is horizontally rotatable on a base about a vertical axis, a fixing means for fixing the main body at an arbitrary horizontal rotation angle, and a main body. Level that holds the body horizontally, a support body that is swingable up and down on the main body, fixing means that fixes the support body at an arbitrary elevation angle, and rotatable about a pivot that stands upright from the support body. It is characterized by comprising a telescope provided in. The above-mentioned telescope may be a telescope for transit, and may be the one described above. Further, it is more excellent if the above-mentioned power line sag measuring device is installed in a frame, and a connecting fitting is projected from the frame.

[0007]

According to the sag measuring device of the transmission line of the present invention, the tangent line of the virtual catenary curve is set in advance, the measuring device is installed at a point intersecting with the tangent line of the steel tower, and installed on the opposite steel tower from the telescope. Fix the support by looking at the sag ruler. Alternatively, the support is fixed at the calculated angle toward the opposing tower. Next, the telescope is rotated about a pivot that stands upright from the support, and the central sag is obtained by looking through the line tail of the power transmission line.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A power line sag measuring device according to an embodiment of the present invention will be described in detail with reference to the drawings. A transit 2 is fixed to a frame-shaped frame 1, and the main telescope is used as a support 3. A telescope 4 with a cross hair is provided on the support 3 so as to be rotatable and fixed at a predetermined angle in parallel with the support 3, and a step bolt (not shown) of a steel tower is provided under the frame 1. Project the connecting metal fitting 5 to be attached to
A pair of semi-cylindrical covers 6 and 6 for covering the frame 1 from the left and right are provided on the frame 1 so as to be rotatable and fixed, and both the covers 6 and 6 cover the frame 1 for transportation, and when used, like a roof. It is placed overhang.

The transit 2 is mounted on a base 7 which is adjusted and held so as to be horizontal to the bottom plate of the frame 1.
Is provided so as to be horizontally rotatable with respect to the vertical axis, and a main body fixing means 9 is provided.
A main telescope which has a main telescope 10 and which can swing and adjust in the vertical direction and which can precisely indicate its angle is provided on the upper part of the main body 8. A support fixing means 11 for fixing the main telescope at a predetermined rotation angle. And its structure is similar to the conventional one.

In order to construct the sag measuring device of the present invention using the above-mentioned transit 2, as shown in FIG. 1, the main telescope provided in the transit 2 is used as the support 3, and this support 3 A telescope 4 with a cross hair is rotatably provided horizontally on a pivot 12 provided on the upper side of the support 12, and a sighting device 13 is attached to a side surface of the telescope 4.

However, it is advantageous to use the conventional trancit 2 as it is, but one telescope fulfills its function, and if two telescopes are provided, the weight becomes heavy. Therefore, as shown in FIG. 2, instead of the main telescope of the transit 2, a corner block is provided as the support 3 as described above, and a telescope having a cross hair and having a function capable of precisely measuring the angle for the transit is provided. It may be attached as the telescope 4.

In the case where there is a geographical difference in elevation between the two or more multi-line towers 14, the virtual catenary curve n and its sag d are set by the catenary approximation formula, and the virtual catenary curve n and one of the towers 14 are set. The position lower than the intersection point by the sag d is set as the measurement point O, and the other steel tower 14
The focus P is defined as a position that is lowered by the above d from the intersection with the point P, or the point on the steel tower when viewed at the elevation angle a calculated by the catenary approximation formula.

As shown in FIG. 3B, the conventional measuring method using a measuring instrument is such that when the high-position steel tower 14 is viewed from the low-position steel tower 14, the elevation angle a is maintained. When the telescope is rotated about the vertical axis OQ of the steel tower 14 as a central axis, the telescope moves along a circular locus k1 having a radius of the line segment QP as shown in FIG. Looking at this circular locus k1 by the diagram (b) of FIG.
A line segment k at the bottom of a cone having a generatrix line segment OP that vertices
2 (horizontal line passing through the focal point P).

Therefore, as shown in FIG.
When the line tail R1 of the power transmission line m1 to be erected from above is viewed, the focal point is located at the point P1 on the circular locus k1 and the point P1 is taken at the line segment k2 in the (b) diagram of FIG. The focus moves to the position of point P1. When the line tail R1 of the power transmission line m1 is measured in this state, the line segment R1 of the power transmission line m1 comes into contact with the line segment O-P1 indicated by the dotted line. Is shorter than the length of the
The line tail R1 of 1 comes to a position higher than the line tail R of the virtual catenary curve n, which causes a large error.

The measuring method using the sag measuring device of the power transmission line of the present invention is as follows. The measuring device is fixed at the measuring point O to the step bolt of the steel tower with the mounting bracket 5, as shown in FIG. As shown, the steel tower 1 facing the main telescope, which is the support 3.
When the support body 3 is fixed at the elevation angle a while looking at the focal point P on the lens 4 and the telescope 4 provided on the support body 3 is rotated to the left and right, as shown in FIG. Moves on a circle k3 drawn with a radius O-P, but when the circle k3 is viewed from the side of FIG. 4B, it should be drawn on a line segment k4 indicated by a dotted line drawn at an elevation angle a. Therefore, the focal point P moves along the line segment k4. Further, when the telescope 4 is rotated 90 degrees from the direction in which the opponent's tower 14 is seen, the elevation angle of the telescope 4 becomes zero.

Therefore, as shown in FIG. 4A, the focus P2 when looking at the line tail R2 of the power transmission line m2 is at the intersection of the extension line of the line segment O-R2 and the circumference k3, and this intersection is shown in FIG. In (b) of Figure, since it is located at the point P2 on the line segment k4, the transmission line m
The line tail R2 of 2 is the same as the line tail R of the virtual catenary curve n, the sag d of the virtual catenary curve n and the sag d2 of the power transmission line m2 match, and no error occurs in the sag d2.
The power transmission line m2 can be accurately installed.

[0017]

[Effects of the Invention] By using the sag measuring device of the transmission line according to the present invention, there is no need to go through many steps as in the conventional case.
Only a small number of workers can work. In addition, the telescope can be accurately displaced on the tangential plane of the line end of the calculated virtual catenary curve, so the sag can be accurately measured, and the catenary curve can be quickly and accurately formed into a beautiful ideal catenary curve. can do.

[Brief description of drawings]

1 is a perspective view of a power line sag measuring device according to the present invention;

FIG. 2 is a perspective view showing the basic structure of the present invention.

3 (a) and (b) are explanatory views showing a measuring method by a conventional measuring device.

4 (a) and (b) are explanatory views showing a measuring method of the transmission line sag measuring device of the present invention.

[Explanation of symbols]

 1 frame 3 support 4 telescope 5 connecting metal fittings 7 base 8 body 9 body fixing means 10 level 11 support body fixing means 12 pivot

Front page continuation (72) Eiji Yanase Eiji Yanase 1-1-1, Higashida district town, Toyama city, Toyama prefecture Hokuriku Electric Works Co., Ltd. (56) Reference JP-A-58-167908 (JP, A) JP-A-3 -222615 (JP, A)

Claims (3)

(57) [Scope of utility model registration request] 1. A main body (8) provided on a base (7) so as to be horizontally rotatable about a vertical axis, and a main body fixing means (9) for fixing the main body (8) at an arbitrary horizontal rotation angle. , Body (8)
(10) for holding the body horizontally, a support (3) provided on the main body (8) so as to be vertically swingable, and a support fixing means (11) for fixing the support (3) at an arbitrary angle. And a telescope (4) rotatably provided around a pivot (12) standing upright at a right angle from a support (3). 2. The sag measuring device for a power transmission line according to claim 1, wherein the telescope (4) is a transit telescope. 3. A slack measuring device for a power transmission line according to claim 1 or 2 is installed in a frame (1), and a connecting metal fitting (5) is projectingly provided on the frame (1). Power line sag measuring device characterized by