JP5551864B2 - Snow sampler - Google Patents

Description

  The present invention relates to a snow accretion sampler. More specifically, the present invention relates to an apparatus used for, for example, grasping a snowfall situation of an overhead power transmission line or an artificial snowfall test of a power transmission line.

  For overhead power transmission lines, from the viewpoint of snow damage prevention and maintenance, and from the viewpoint of snow damage prevention tests and research by elucidating the snow accretion phenomenon of power transmission lines, accurate observation and accurate observation of power line snowfall conditions are performed. It is very important to collect various kinds of quantitative data. In addition, since it is difficult to observe and measure snow conditions on actual overhead power transmission lines that are energized, short actual wires are used as measurement wires (hereinafter referred to as measurement wires) when observing snow conditions and measuring various quantitative data. A snow sampler provided as a short electric wire is used.

  Here, factors affecting snowfall on the transmission line include weather conditions such as temperature, humidity, precipitation, wind direction and wind speed, and the outer circumference of the wire, wire diameter, span length, wire twist rigidity, wire temperature, etc. The characteristic of an electric wire is mentioned. The span length is the actual length of the transmission line between the steel tower that supports the power transmission line. Further, the electric wire temperature as a snow accretion influencing factor is to consider the temperature rise of the transmission line itself due to energization, and can be replaced with the current value energized to the transmission line.

  In the process of growing snowfall on the transmission line, a phenomenon is observed in which the transmission line is gradually twisted due to the eccentric moment generated by the snowfall. It is known that there is a big difference in the amount of snowfall. Therefore, in order to accurately reproduce the situation of snow accretion on the actual power transmission line in the snow accretion sampler, the torsional rigidity of the short measuring wire is set to the actual overhead power transmission line between the steel tower that supports the power transmission line and the steel tower. It is particularly important to design such that it is equivalent to the torsional rigidity (hereinafter referred to as the actual span).

  In addition, for the purpose of tests and research for the purpose of snow damage prevention and maintenance and the elucidation of snow accretion phenomenon, the snow twist sampler uses the wire twist angle in the overhead transmission line (that is, centering on the axis of the transmission line). It is necessary to be able to accurately observe and measure the angle of rotation of the shaft), snow shape, and snow weight.

  As a conventional snow sampler, for example, as shown in FIG. 4, a shaft 103 rotatably supported via a ball bearing mechanism 102 between a pair of support plates 101, 101 arranged at intervals. And spacers 104, 104 fitted concentrically on the shaft 103 between the support plates 101, 101, and the spacer 104 is encased and one end is locked to the shaft 103 and the other end is a set of supports. A rotation detector that detects a relative rotational displacement angle between a coil spring 105 having a predetermined torsional rigidity that is locked to one of the plates 101 and 101 and a support plate 101 that locks the shaft 103 and the coil spring 105. 106, a protective cover 107 that provides moisture resistance protection between the support plates 101 and 101, and a support plate 101 that locks the shaft 103 and the coil spring 105. A connector 108 that coaxially connects one end of a measurement short electric wire fixed to either one of 101 directly or via another member, and an external mounting member 109 fixed to the other directly or via another member (Patent Document 1).

Reality 2-41558

  However, in the snow sampler of Patent Document 1, the support mechanism in which the ball bearing mechanism 102 and the special coil spring 105 are built in the protective cover 107 is very complicated and takes time to manufacture. In addition, careful attention is required for the axial alignment of both end support portions, and adjustment takes time. For this reason, it is hard to say that it is general purpose. Furthermore, there is a problem that an error occurs in measurement when the alignment is not accurate.

  Further, in the snow sampler, it is necessary to smoothly twist the measuring short electric wire following the eccentric moment due to snow, but the support mechanism via the ball bearing mechanism 102 as in the snow sampler disclosed in Patent Document 1. However, since the smooth twist is hindered by the friction of the bearing portion, there is a problem that accurate observation and measurement cannot be performed. Specifically, the measurement short electric wire does not twist until the eccentric moment increases due to snowfall of a certain level or more, and shows a behavior that it twists rapidly with a snowfall amount of a certain level or more. Observation / measurement cannot be performed. Furthermore, since the smooth movement of the bearing portion is hindered by the occurrence of deflection in the short measuring wire due to the snow weight, accurate observation and measurement cannot be performed.

  In addition, the snow-covered sampler disclosed in Patent Document 1 has a problem that maintenance such as injection of lubricating oil needs to be periodically performed in order to ensure the operability of the bearing portion, and maintenance work is required.

  Furthermore, it is important to make the torsional rigidity of the short electric wire for measurement equivalent to the torsional rigidity between the actual diameters in order to accurately reproduce the state of snow accretion on the actual power transmission line in the snow accumulating sampler. In the snow accretion sampler, the torsional rigidity of the short measuring wire cannot be adjusted unless the coil spring 105 is replaced. Therefore, every time the condition between the actual diameters to be observed changes, the complicated support mechanism must be disassembled, the coil springs must be replaced and reassembled, and the axis alignment of both end support parts must be performed again, so preparation for measurement There is a problem that it takes time and effort.

  Further, in order to accurately observe the snow accretion shape, it is desirable to photograph snow accretion from the axial front of the measuring short electric wire. However, in the snow accumulating sampler of Patent Document 1, since the support mechanism including the ball bearing mechanism 102 obstructs the visual field in the electric wire axial direction (that is, the axial direction of the shaft 103), it is possible to photograph the snow accumulating from the front in that direction. There is a problem that it is impossible to observe the snowfall shape in an optimal manner.

  Accordingly, an object of the present invention is to provide a snow-covering sampler that can accurately observe and measure snow-covering conditions on a transmission line with a simple configuration and can reduce the trouble of measurement and maintenance. . Furthermore, an object of the present invention is to provide a snow accretion sampler capable of observing the snow accretion shape on the transmission line in an optimum manner.

In order to achieve this object, the snow-covering sampler according to claim 1 includes a measuring short electric wire, a pair of wires fixedly connected to both ends of the measuring short electric wire, and a measuring short electric wire for each wire. wires are coupled the ends of the combined side opposite to have a pair of struts for supporting by fictitious measurement for short wire through the wire, the diameter and length of the wire, measuring short wire The diameter and length are set so as to reproduce the torsional rigidity between the actual diameters .

  Therefore, according to this snow accretion sampler, the measurement short electric wire is simply suspended and supported by the linear suspension member, so the structure of the measurement short electric wire support mechanism is very simple, No need to make and adjust

  In addition, according to this snow accumulating sampler, the measurement short electric wire is simply suspended by the linear suspension member and supported, so when the measurement short electric wire is twisted, friction is generated between the measurement mechanism and the support mechanism. Thus, smooth and continuous twisting is realized from the beginning of snowfall, and the wire twist angle accompanying snowfall can be accurately reproduced. In addition, since the measuring short electric wires are supported by the linear suspension members coupled to both ends, smooth twisting is hindered even when the measuring short electric wires are bent due to snow. The wire twist angle accompanying snowfall can be accurately reproduced.

  Also, according to this snow accretion sampler, the torsional rigidity of the short measuring wire and the torsional rigidity between the actual diameters can be matched by adjusting the diameter and length of the linear suspension member. The sampler can easily reproduce the torsional rigidity between the actual diameters. And if the conditions between the actual diameters of the observation objects change, the torsional rigidity of the short measuring wires can be matched to the torsional rigidity between the actual diameters only by replacing the suspension members, making it easy to prepare for measurement. Can be done.

  Furthermore, according to this snow accretion sampler, the mechanism to reproduce the torsional rigidity between the actual diameters is very simple, and the operability of the mechanism to reproduce the torsional rigidity between the actual diameters without requiring special maintenance. Is secured.

  According to a second aspect of the present invention, there is provided a snow-covered sampler comprising a pair of linear suspended wires coupled to one end of each of the plurality of measurement short electric wires and each of the measurement short electric wires located at both ends of the plurality of measurement short electric wires. A suspension member, one or a plurality of coupling members that couple a plurality of short measuring wires to each other, and a suspension member in which the end of each hanging member opposite to the side where the measurement short wires are joined is joined And a pair of support columns for supporting the measurement-use short electric wire by aerial.

  Therefore, according to this snow accumulating sampler, in addition to the operation of the invention of claim 1, a plurality of short electric wires for measurement are provided, so that it is possible to reproduce snow accumulating conditions at a plurality of locations on an actual power transmission line. .

  According to a third aspect of the present invention, in the snow accumulating sampler according to the first or second aspect of the present invention, the snow sampler further includes a photographing device for photographing the short measuring wire from the front in the axial direction. In this case, since only a linear suspension member is coupled to both ends of the measurement short electric wire, it can be taken from the front in the axial direction of the measurement short electric wire. An image of the twisted state of the electric wire and the snow-covered state from the axial front is obtained at the center position.

The invention of claim 4, wherein the wherein the accretion sampler to claim 1, opposite to the end connected to the side where the measuring short wire of each wire are coupled together is supported on each of the pair of posts The load cell is further provided. According to a fifth aspect of the present invention, there is provided the snow sampler of the second aspect, wherein the end of the suspension member is supported by each of the pair of struts and is opposite to the side where the measuring short electric wires of each hanging member are coupled. Are further connected to each other. In the case of these, the accretion weight of the measuring short wire is measured.

  According to the snow-covered sampler of claim 1, the structure of the support mechanism for the measuring short electric wire is very simple, and the labor for manufacturing and adjusting the apparatus can be reduced, so that the versatility of the apparatus can be improved. It becomes possible.

  In addition, according to the snow accumulating sampler according to claim 1, no friction is generated between the short measuring wire and the support mechanism, and smooth and continuous twisting is realized from the beginning of snowing. Because the wire twist angle that accompanies snowfall can be accurately reproduced, it is possible to create a situation similar to that between actual diameters and accurately reproduce the snowfall conditions between actual diameters, and the reliability of the equipment・ Usefulness can be improved. In addition, smooth twisting is not obstructed even if the measurement short wire is bent due to snowfall, and the wire twist angle associated with snowfall can be accurately reproduced. Thus, it is possible to accurately reproduce the snowfall situation between the actual diameters and improve the reliability and usability of the device.

  In addition, according to the snow landing sampler of the first aspect, the torsional rigidity between the actual diameters can be easily reproduced in the snow landing sampler, and furthermore, the preparation for measurement can be easily performed. This effort can be reduced and the operability can be improved.

  In addition, according to the snow sampler of claim 1, since the operability of the mechanism for reproducing the torsional rigidity between the actual diameters can be ensured without requiring special maintenance, the labor of maintenance is reduced. This makes it possible to improve operability.

  Moreover, according to the snow accretion sampler according to the second aspect, it is possible to reproduce the snow accretion situation at a plurality of locations on the actual power transmission line, so that the reproducibility of the situation on the actual power transmission line can be improved.

  Further, according to the snow accumulating sampler according to claim 3, since the image of the twisting state and the snow accumulating state of the electric wire from the axial front is obtained at the axial center position of the measurement short electric wire, the electric wire twisting accompanying the snow accretion is obtained. The turning angle can be accurately measured, and the snowfall shape of the electric wire can be accurately observed in an optimum manner, so that the reliability and usefulness of the apparatus can be improved.

Further, according to the snow landing sampler according to claims 4 and 5 , in addition to the wire twist angle and the snow accumulating shape that can be grasped also in the inventions according to claims 1 and 2, the snow landing weight of the short measuring wire can be reduced. Since it can be measured, it becomes possible to grasp more diverse data about the snowfall situation.

  Hereinafter, the configuration of the present invention will be described in detail based on the best mode shown in the drawings.

  FIG. 1 shows a first embodiment of the snow accretion sampler of the present invention. This snow accretion sampler includes a measuring short electric wire 1, a pair of linear hanging members 2, 2 coupled to both ends of the measuring short electric wire 1, and each of the hanging members 2, 2. A pair of load cells 3 and 3 to be connected, a photographing device 4 for photographing the measurement short electric wire 1 from the front in the axial direction, and a measurement short electric wire via the suspension members 2 and 2 that support the load cells 3 and 3 respectively. It has a pair of support columns 6 and 6 for supporting 1 by aerial.

  The measurement-use short electric wire 1 is obtained by cutting the same electric wire that is actually used as a power transmission line to be observed in a snow accretion state into a short length. The length of the short measuring wire 1 is not limited to a specific length. For example, it is about several meters in accordance with the size of the place where the snow landing sampler is installed for the observation at the site, the scale of the experimental facility, etc. Use a piece cut to a length of.

  The pair of linear suspension members 2 and 2 are respectively attached to both ends of the measurement-use short electric wire 1 on the front side in the axial direction. As the suspension member 2, a thin linear member and a flexible material is used in order to reduce the influence of snowfall on itself as much as possible. Specifically, for example, a stainless wire is used.

  The suspension member 2 and the short measuring wire 1 are fixedly coupled to each other so that one does not rotate relative to the other. That is, the measurement short electric wire 1 is not free to rotate (that is, twisted) about the axis, and the measurement short electric wire 1 is fixedly coupled to the suspension member 2 when twisting. Receive.

  In the first embodiment, the suspending member 2 plays a role of reproducing the torsional rigidity between the actual diameters in the measurement short electric wire 1. For this reason, the diameter and length of the suspension member 2 are set so that the torsional rigidity between the actual diameters is reproduced in the short measuring wire 1.

  The method for determining the diameter and length of the suspension member 2 for reproducing the torsional rigidity between the actual diameters in the short measuring wire 1 is not limited to a specific method, and is obtained from, for example, the balance of material mechanics. Alternatively, it may be obtained by using a simulation. Specifically, the diameter and length of the suspension member 2 for reproducing the torsional rigidity between the actual diameters in the measurement short electric wire 1 are obtained by the following procedure, for example.

  Assume that the actual distances to be observed in this embodiment are as shown in FIG. Specifically, it is assumed that the span length (that is, the actual wire length) is 2 L [m], and snow is generated in a section (hereinafter referred to as a snowfall section) having a length of 2 La in the center section of the span. To do. Note that it is assumed that snowing is in an initial state where the twisting angle of the electric wire is small, the snowfall shape is the same throughout the snowing section, and the twisting moment generated by the snowfall is equal.

  Let Mu [N m / m] be the moment due to snow acting per unit length of electric wire in the snow accumulating section. The electric wire twist angle at the position x due to the moment generated by the snowfall to the unit length of the position x from the end of the span in the snow accumulating section is expressed by Equation 1.

  Here, kx is as shown in Equation 2.

ここに、θxx：位置ｘの電線捻回角，Ｍu：モーメント〔Ｎ ｍ／ｍ〕，ｋx：位置ｘの捻りバネのバネ定数〔Ｎ ｍ／rad〕，ＧＪ：電線の捻り剛性〔Ｎ ｍ^２〕（なお、Ｇ：横弾性係数，Ｊ：断面二次極モーメント），２Ｌ：径間長（即ち電線実長）〔ｍ〕，ｘ：径間端部からの位置〔ｍ〕をそれぞれ表す。

Here, θxx: wire twist angle at position x, Mu: moment [N m / m], kx: spring constant [N m / rad] of torsion spring at position x, GJ: twist rigidity of wire [N m ² (G: transverse elastic modulus, J: cross-sectional secondary pole moment), 2L: span length (ie, actual wire length) [m], x: position [m] from the span end.

  At this time, the wire twist angle θLx at the center of the span (that is, x = L) due to snowfall per unit length of the position x is expressed by Equation 3.

  Therefore, the wire twist angle θL at the center of the span (ie, x = L) caused by the snowfall on the snowfall section (length 2La) at the center of the span is expressed by Equation 4.

  On the other hand, the length of the measurement short electric wire 1 of the snow landing sampler is set to 2Ls. Then, it is assumed that a moment Mu due to snowfall per unit length equal to the above-described actual diameter occurs in the measurement short electric wire 1. The spring constant of the torsion spring of the suspension member 2 that supports the measurement short electric wire 1 is ks. At this time, the wire twist angle θs due to snowfall of the measurement short electric wire 1 is expressed by Equation 5.

  Therefore, the spring constant ks for matching the assumed wire twist angle θL at the center of the actual diameter with the wire twist angle θs of the short measuring wire 1 is solved for ks assuming that Equation 4 and Equation 5 are equal. Thus, Equation 6 is obtained.

  Here, when the snow falls uniformly over the entire span, La = L, and Equation 6 becomes Equation 7.

  In other words, the spring constant ks of the torsion spring for reproducing the situation where snow falls over the entire span between the actual spans is the torsional rigidity GJ and span of the actual transmission line to be simulated, which is the observation target of the snowfall situation. It depends on the value of the length L and the length Ls of the short electric wire 1 for measurement.

  On the other hand, when the length of the suspension member 2 of the snow-covered sampler is Lw and the torsional rigidity is GwJw, the short measuring wire 1 is supported by a torsion spring having a spring constant ksw expressed by Equation 8. Become.

  Therefore, in order to reproduce the situation of snowfalling over the entire span between actual spans by the snow landing sampler, the length of the suspension member 2 is set so that the spring constant ks of Formula 7 and the spring constant ksw of Formula 8 match. What is necessary is just to set thickness and torsional rigidity.

  Specifically, for Equation 7, if an actual power transmission line that is an observation target of a snowfall situation and is to be simulated is selected, the torsional rigidity GJ and the span length 2L are determined. If the length 2Ls is set, the spring constant ks is calculated. Then, regarding Formula 8, when the calculated value of the spring constant ks is substituted into the spring constant ksw and the value of the torsional rigidity GwJw determined by setting the material and diameter of the suspension member 2 is substituted, The length Lw of the lowering member 2 is determined.

  The load cell 3 is for measuring the snowfall weight of the short measuring wire 1. Specifically, the suspension members 2 and 2 are coupled to both ends of the measurement short electric wire 1 in the axial direction, and the side of the suspension member 2 and 2 to which the measurement short electric wire 1 is coupled; The opposite ends are connected to the load cells 3 and 3, respectively, so that the snow weight of the measuring short electric wire 1 is measured.

  Both load cells 3 and 3 are supported by support columns 6 and 6, respectively. In this embodiment, the column 6 includes a vertical member 6a and a horizontal member 6b that protrudes toward the mating column 6 and is attached to the top of the vertical member 6a. The load cell 3 is attached to the horizontal member 6b. ing. In addition, the distance between both the columns 6 and 6 is adjusted so that the measurement short electric wire 1 is suspended via the both suspension members 2 and 2, and the load cells 3 and 3 of the both suspension members 2 and 2 are connected to each other. The distance D between the connecting end portions is adjusted so as to be at least longer than the length 2Ls of the measuring short electric wire 1.

  One column 6 is attached with an imaging device 4 for imaging the measurement-use short electric wire 1 from the front in the axial direction of the electric wire. For example, a digital camera is used as the photographing device 4. Moreover, in this embodiment, the imaging device 4 is attached to the axial direction front of the axial center position of the measurement short electric wire 1 by the fixing member 6 c attached to the vertical member 6 a of the support 6.

  By photographing the electric wire from the front side in the axial direction of the measuring short electric wire 1 using the imaging device 4, that is, in an optimal manner, the snow accretion shape of the measuring short electric wire 1 can be accurately observed and measured. The wire twist angle of the short electric wire 1 can be measured. The wire twist angle can be measured by, for example, attaching a line corresponding to the radius of the wire in advance to the end surface of the measurement short wire 1 on the photographing device 4 side, and measuring the inclination of the wire.

  Next, a second embodiment of the snow landing sampler of the present invention will be described with reference to FIG. In addition, in 2nd embodiment demonstrated below, about the component similar to the above-mentioned 1st embodiment, the same code | symbol is attached | subjected and the detailed description is abbreviate | omitted.

  The snow-covering sampler of the second embodiment includes three short measuring wires 1a, 1b, 1c and the short measuring wires 1b, 1c located at both ends of the short measuring wires 1a, 1b, 1c. A pair of linear suspension members 2, 2 coupled to one end of the wire, a pair of load cells 3, 3 to which each of the suspension members 2, 2 is connected, and the short measuring wires 1 a and 1 b and 1 a and Two connecting members 5 and 5 for connecting 1c, a photographing device 4 for photographing the measurement-use short electric wire 1a from the front in the axial direction, and the load cells 3 and 3 are supported through the suspension members 2 and 2, respectively. It has a pair of support columns 6 and 6 for supporting the short electric wire 1 by aerial.

  That is, when the first embodiment and the second embodiment are compared, in the first embodiment, there is one measuring short electric wire 1, whereas in the second embodiment, the measuring short electric wire. Both are greatly different in that 1 is a plurality. And in 2nd embodiment, it has the connection member 5 for connecting the short electric wires 1 for measurement. In the second embodiment, the suspension members 2 and 2 and the short measuring wires 1b and 1c are fixedly coupled to each other so that one does not rotate relative to the other. Furthermore, each of the connecting members 5 and 5 and each of the short measuring wires 1a, 1b, and 1c are fixedly coupled to each other so that one does not rotate relative to the other. That is, the measurement short electric wires 1a, 1b, and 1c are not free to be twisted, and are fixedly coupled to the suspension member 2 and the connecting member 5 when the measurement short electric wires 1a, 1b, and 1c are twisted. Affected.

  Here, between the actual diameters, the wire twist angle of the power transmission line is the largest in the central portion between the steel tower supporting the power transmission line, and the wire twist angle is smaller in the vicinity of the steel tower. That is, the magnitude of the wire twist angle of the transmission line varies depending on the position within the actual span. Therefore, by providing a plurality of short measuring wires as in the second embodiment, it becomes possible to reproduce the wire twist angle and the snowfall situation for each position within the actual span. The reproducibility of the situation on the transmission line can be further improved.

  And in 2nd embodiment, the suspending member 2 and the connection member 5 play the role which reproduces the torsional rigidity between real diameters in each measurement short length electric wire 1a, 1b, 1c. For this reason, the diameter and length of the suspending member 2 and the connecting member 5 are set so that the torsional rigidity between the actual diameters is reproduced in each of the short measuring wires 1a, 1b, and 1c.

  The method for determining the diameter and length of the suspension member 2 and the connecting member 5 for reproducing the torsional rigidity between the actual diameters in each of the short measuring wires 1a, 1b, 1c is not limited to a specific method, For example, it may be obtained from the balance of material mechanics or may be obtained using simulation. Specifically, the diameters and lengths of the suspension member 2 and the connecting member 5 for reproducing the torsional rigidity between the actual diameters in each of the short measuring wires 1a, 1b, and 1c are obtained, for example, by the following procedure.

  First, the snow-covering sampler of the second embodiment is a simulation target in a situation where snow is applied over the entire span of the actual span of the span length of 2 L [m]. The twist angle θL at the center of the span at this time is as shown in Equation 9. Equation 9 is obtained by substituting L for La in Equation 4, and the meaning of each symbol is as described in connection with Equation 4. In the second embodiment as well, it is assumed that the snowfall is in an initial state and the snowfall shape is the same over the entire span and the twisting moments generated by the snowfall are the same.

  On the other hand, the lengths of the measurement short electric wires 1a, 1b, and 1c of the snow accretion sampler are all 2Ls. Then, it is assumed that a moment of Mu [N m / m] is acting per unit length of the electric wire.

  The lengths of the suspension member 2 and the connecting member 5 are Lw, and the torsional rigidity is GwJw. At this time, Formula 10 is established with respect to the wire twist angle θbb of the measurement short electric wire 1b due to snow on the measurement short electric wire 1b. The diameters of the hanging member 2 and the connecting member 5 are smaller than those of the measuring short electric wires 1a, 1b, 1c, and the measuring short electric wires 1a, 1b, 1c are smaller than the twisting of the hanging member 2 and the connecting member 5. It is assumed that the twist is negligible (that is, each measurement short electric wire 1a, 1b, 1c is treated as a rigid body). In addition, Formula 10 and Formula 11 are based on the same concept as Formula 1 and Formula 2.

  Therefore, the wire twist angle θbb of the measurement short electric wire 1b due to snow on the measurement short electric wire 1b is expressed by Equation 11.

  Further, the wire twist angle θab of the measurement short wire 1a and the wire twist angle θcb of the measurement short wire 1c caused by twisting of the measurement short wire 1b due to snow on the measurement short wire 1b are for measurement. Since it is proportional to the total length of the suspension member 2 and the connection member 5 from the connection point 2a with the load cell 3 of the suspension member 2 on the short electric wire 1c side, Equations 12 and 13 are obtained, respectively.

  Next, Formula 14 is established with respect to the wire twist angle θaa of the short measurement wire 1a due to snow on the short measurement wire 1a.

  Therefore, the wire twist angle θaa of the measurement short electric wire 1a due to snow on the measurement short electric wire 1a is expressed by Equation 15.

  Further, the wire twist angle θba of the measurement short wire 1b and the wire twist angle θca of the measurement short wire 1c caused by the twist of the measurement short wire 1a due to snow on the measurement short wire 1a It becomes like this.

  Further, with regard to the wire twist angle θcc of the measurement short electric wire 1c due to snow on the measurement short electric wire 1c, in consideration of the symmetry of the system, the measurement short electric wire 1b due to snow attachment to the measurement short electric wire 1b. It is expressed in the same manner as the wire twist angle θbb. That is, Equation 17 is obtained.

  Further, the wire twist angle θac of the measurement short wire 1a and the wire twist angle θbc of the measurement short wire 1b caused by the twisting of the measurement short wire 1c due to snow on the measurement short wire 1c are respectively expressed by Equation 18. , Equation 19 is obtained.

  From the above, the wire twist angles θa, θb, and θc of the short measuring wires 1a, 1b, and 1c are expressed by Equation 20, respectively.

  Therefore, in order to reproduce the situation where snow falls over the entire span between actual spans by the snow landing sampler, the lengths of the suspension member 2 and the connecting member 5 are set so that θL in Formula 9 and θa in Formula 20 match. What is necessary is just to set thickness and torsional rigidity. That is, it is sufficient to satisfy Equation 21.

  Then, if an actual power transmission line that is to be simulated and is to be simulated based on Equation 21 is selected, the torsional rigidity GJ and the span length 2L are determined, and the length 2Ls of the short measuring wire 1 is calculated. By setting the value of the torsional rigidity GwJw determined by setting the material and diameter of the suspension member 2 and the connection member 5 to the formula 22, the lengths of the suspension member 2 and the connection member 5 are set. Lw is determined.

  As shown in Formula 20, in the second embodiment shown in FIG. 2, the twisting angles θb and θc of the measurement short electric wires 1b and 1c at both ends are the twists of the central measurement short electric wire 1a. It becomes 3/4 of the angle θa. That is, when the twist angle increases with the development of snowfall on the electric wire, a difference in the snow landing shape appears due to the difference in the twist angle. According to the second embodiment, a difference in the twisting angle occurs between the measuring short electric wire 1a and the measuring short electric wires 1b and 1c, and the difference in snow-covering shape depending on the span position can be reproduced.

  When a plurality of short measuring wires are provided as in the second embodiment, it is preferable that the measuring short wires 1b and 1c at both ends are not particularly inclined. For this reason, based on the total length 2Ls of each measurement short wire and the length Lw of the suspension member 2 and the connecting member 5, both suspensions are made so that the measurement short wires 1b and 1c at both ends are not extremely inclined. It is preferable that the distance D (that is, the distance between the pair of struts 6 and 6) between the ends of the lowering members 2 and 2 connected to the load cells 3 and 3 is adjusted. And, in order to more accurately reproduce the situation of snow accretion on the actual power transmission line with the snow accretion sampler, a pair of measurement cables are arranged so that the inclination of each measurement short wire is close to the inclination of each part of the overhead power transmission line between actual diameters. More preferably, the interval between the columns 6 and 6 is adjusted.

  According to the snow accretion sampler configured as described above, it is possible to accurately observe and measure the snow accretion situation on the transmission line with a simple configuration, and to reduce the trouble of measurement and maintenance. Furthermore, according to the snow sampler of the present invention, it is possible to photograph the snow accretion shape on the transmission line in an optimum manner.

  In addition, although the above-mentioned form is an example of the suitable form of this invention, it is not limited to this, A various deformation | transformation implementation is possible in the range which does not deviate from the summary of this invention. For example, in the first embodiment and the second embodiment, the load cell 3 is provided to measure the snowfall weight, but the present invention is not limited to this, and when it is not necessary to measure the snowfall weight, that is, For the purpose of measuring the snow accretion shape and the wire twist angle, the suspension member 2 may be directly coupled to the column 6 without the load cell 3.

  In the second embodiment, three short electric wires for measurement are provided. However, the present invention is not limited to this, and the reproducibility of the wire twist angle and the snow-covered state at each position within the actual diameter is improved. If so, it is sufficient to provide two or more short electric wires for measurement. In the second embodiment, the number of short measuring wires is set to an odd number to reproduce the central portion between the steel tower and the steel tower where the wire twisting angle is the largest, and to twist the electric wire in the central portion. Corners can be measured.

  An example of setting the diameter and length of the measurement-use short electric wire 1 and the suspension member 2 in the snow-covered sampler of the present invention will be described. In this example, a case where the snow landing sampler (see FIG. 1) of the first embodiment described above is used will be described as an example.

In the present embodiment, it is assumed that the actual diameter of 240 mm ² single conductor and span length 2L = 300 [m] is simulated.

  A stainless steel wire having a diameter of 1.5 [mm] was used as the suspension member 2. Further, the length 2Ls of the measurement short electric wire 1 was set to 2 [m].

The stainless steel wire had a wire structure similar to that of a power transmission line, and the transverse elastic modulus Gw was considered to be about 3 times that of aluminum ACSR 240 mm ² . Further, since the diameter of the stainless steel wire is 1.5 [mm] with respect to the diameter 22.4 [mm] of ACSR 240 mm ² , the cross-sectional secondary pole moment Jw is 1.5 / 22 with respect to J of ACSR 240 mm ^2. .4) ^Four times. Based on this, it was considered that GwJw = GJ × 3 × (1.5 / 22.4) ⁴ .

  At this time, Equation 9 is obtained assuming that the torsion spring constant ks for simulating the actual diameter represented by Equation 7 is equal to the torsion spring constant ksw for supporting the short measuring wire 1 represented by Equation 8. It was.

Substituting GwJw = GJ × 3 × (1.5 / 22.4) ⁴ , L = 150, 2Ls = 2 into Equation 9, Lw = 0.67 [m] was obtained.

It is a figure which shows 1st embodiment of the snow accretion sampler of this invention. It is a figure which shows 2nd embodiment of the snow accretion sampler of this invention. It is a figure explaining the space | interval between the actual diameters assumed in description of the spring constant of the torsion spring in this invention. It is a block diagram of the support structure of the conventional snow accretion sampler.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Short electric wire for a measurement 2 Hanging member 3 Load cell 4 Imaging device 6 Prop

Claims (5)

A measuring short electric wire, a pair of wires fixedly connected to both ends of the measuring short electric wire, and an end portion of each wire opposite to the side where the measuring short electric wire is connected are combined. the short wire for the measuring through the wire have a pair of struts for supporting by imaginary Te, diameter and length of the wire, to reproduce the torsional rigidity of real span in the measuring short wire diameter And a snow accumulating sampler characterized by being set to a length .   A plurality of measurement short wires, a pair of linear suspension members coupled to one end of each measurement short wire located at both ends of the plurality of measurement short wires, and the plurality of measurement short wires One or a plurality of connecting members for connecting the measuring wire and the end of the hanging member opposite to the side to which the measuring short wire is connected, and the measuring short wire through the hanging member A snow-covered sampler comprising: a pair of support columns that support and support the vehicle.   The snow accretion sampler according to claim 1 or 2, further comprising a photographing device for photographing the short electric wire for measurement from the front in the axial direction.   The snow accretion according to claim 1, further comprising a load cell that is supported by each of the pair of support columns and to which an end portion on the opposite side to the side where the short electric wires for measurement of each wire are coupled is connected. Sampler.   3. The load cell according to claim 2, further comprising a load cell that is supported by each of the pair of struts and that is connected to an end of the suspension member opposite to the side to which the measurement short electric wire is coupled. A snow sampler.

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