JP2024059557A - Contact wire - Google Patents

Abstract

[Problem] To provide a trolley wire that is lightweight while suppressing a decrease in wear life. [Solution] In one aspect of the present invention, a trolley wire 1 is provided that has an upper small arc surface 11, a lower large arc surface 12, and an ear groove 13 between the small arc surface 11 and the large arc surface 12, and an ear fitting for a trolley wire having a radial cross-sectional area of 170 mm2 can be used in the ear groove, the radial cross-sectional area being 153.2 to 155 mm2, in the radial cross section of the trolley wire, the curvature of a first circular arc that is the outline of the small arc surface 11 and the curvature of a second circular arc that is the outline of the large arc surface 12 are each constant, the positions of a center O1 of the first circular arc and a center O2 of the second circular arc are different, and the curvature of the first circular arc is smaller than the curvature of the second circular arc. [Selected Figure] Figure 1

Description

The present invention relates to contact wires used in train tracks.

In recent years, the increasing speed of Shinkansen trains has led to a demand for a trolley wire with a high wave propagation velocity. Although the wave propagation velocity can be increased by reducing the mass of the trolley wire, when the trolley wire is replaced with a smaller diameter one (for example, when a trolley wire with a cross-sectional area of 170 ^mm2 is replaced with a trolley wire with a cross-sectional area of 110 ^mm2 or ¹³⁰ mm2), the ear fittings also need to be changed. Therefore, it is preferable to reduce the weight of the trolley wire without changing the shape of the ear groove.

Conventionally, a trolley wire is known that has a hollow portion that is continuous in the longitudinal direction near its center (see Patent Document 1). The trolley wire in Patent Document 1 is lighter in weight due to the provision of the hollow portion, thereby improving the wave propagation speed.

JP 2009-1195 A

However, the trolley wire in Patent Document 1 is lightweight due to the hollow section, and so its cross-sectional area decreases significantly due to wear, and its strength and current capacity reach their allowable limits at an early stage, resulting in a short wear life. In addition, if the shape and size of the large arc surface of the trolley wire are changed from the standard shape of the trolley wire specified in JISE 2101 in order to reduce weight, there is a risk that the visibility of the wear detection groove, which is an indicator of the wear limit position, will decrease.

Therefore, one of the objectives of the present invention is to provide a lightweight trolley wire that minimizes the reduction in wear life.

In order to solve the above-mentioned problems, the present invention provides a trolley wire having a small arc surface at an upper part, a large arc surface at a lower part, and an ear groove between the small arc surface and the large arc surface, in which an ear fitting for a trolley wire having a radial cross-sectional area of ¹⁷⁰ mm2 can be used in the ear groove, wherein the radial cross-sectional area is 153.2 to ¹⁵⁵ mm2, in the radial cross-section of the trolley wire, the curvature of a first arc which is the outline of the small arc surface and the curvature of a second arc which is the outline of the large arc surface are each constant, the positions of the center of the first arc and the center of the second arc are different, and the curvature of the first arc is smaller than the curvature of the second arc.

In addition, for the purpose of solving the above-mentioned problems, the present invention provides a trolley wire having a small arc surface at an upper part, a large arc surface at a lower part, and an ear groove between the small arc surface and the large arc surface, in which an ear fitting for a trolley wire having a radial cross-sectional area of ¹⁷⁰ mm2 can be used in the ear groove, wherein the radial cross-sectional area is 158.5 to ¹⁶⁰ mm2, in the radial cross-section of the trolley wire, the curvature of a first arc which is the contour of the small arc surface and the curvature of a second arc which is the contour of the lower part of the wear detection groove of the large arc surface are each constant, the positions of the center of the first arc and the center of the second arc are different, and the curvature of the second arc is greater than the curvature of the first arc.

In order to solve the above problems, the present invention provides a trolley wire having an upper small arc surface, a lower large arc surface, and an ear groove between the small arc surface and the large arc surface, in which an ear fitting for a trolley wire having a radial cross-sectional area of ¹⁷⁰ mm2 can be used in the ear groove, and the radial cross-sectional area is 163 to 165 mm2. The present invention provides a trolley wire ^comprising : a trolley wire having a recess for reducing the mass of the trolley wire, the recess extending along the length of the trolley wire, located below the large arc surface; in a radial cross section of the trolley wire, the curvature of a first arc which is the contour of the small arc surface, the curvature of a second arc which is the contour of a portion of the large arc surface where the recess is not provided, and the curvature of a third arc which is the contour of a portion of the large arc surface that is curved downward within the recess are all constant; the positions of the centers of the first arc and the second arc and the center of the third arc are different; the curvature of the first arc and the curvature of the second arc are equal; and the curvature of the third arc is greater than the curvature of the first arc and the curvature of the second arc.

The present invention makes it possible to provide a trolley wire that is lightweight while minimizing the reduction in wear life.

FIG. 1 is a radial cross-sectional view of a contact wire according to a first embodiment of the present invention. FIG. 2 is a radial cross-sectional view of a contact wire according to a second embodiment of the present invention. FIG. 3 is a radial cross-sectional view of a contact wire according to a third embodiment of the present invention.

First Embodiment
(Contact wire structure)
1 is a radial cross-sectional view of a trolley wire 1 according to a first embodiment of the present invention. The trolley wire 1 is a modified trolley wire having a cross-sectional profile corresponding to a grooved hard copper trolley wire defined in JIS E2101, and has a small arc surface 11 at an upper portion, a large arc surface 12 at a lower portion, and V-shaped ear grooves 13 between the small arc surfaces 11 and the large arc surfaces 12 on both sides.

The shape of the ear groove 13 of the trolley wire 1 is the same as that of a trolley wire with a standard dimension having a cross-sectional area of 170 ^mm2 (sq) (hereinafter referred to as a standard-shaped trolley wire) specified in JIS E 2101. Therefore, ear fittings for a trolley wire with a radial cross-sectional area of ¹⁷⁰ mm2 can be used for the ear groove 13 of the trolley wire 1. The trolley wire 1 is mainly composed of a copper alloy, for example, a Cu-Sn-In alloy.

When power is supplied to a railway vehicle via the trolley wire 1, the bottom of the large arc surface 12 comes into contact with the railway vehicle's current collector, such as a pantograph. As a result, the sliding of the current collector causes the trolley wire 1 to wear away from the bottom of the large arc surface 12. In general, the limit at which a worn trolley wire can maintain its strength for safe use is called the wear limit. If the wear progresses beyond the wear limit position 14, the cross-sectional area falls below the level at which the safe strength can be maintained, increasing the risk of the wire breaking.

The trolley wire 1 may have wear detection grooves 15a, 15b on the large arc surface 12, which are indicators of the wear limit position 14. The wear detection grooves 15a, 15b are continuous grooves along the length of the trolley wire 1. Typically, the wear detection grooves 15a, 15b are provided on both sides of the trolley wire 1, as shown in FIG. 1. Three or more wear detection grooves may be provided on each of the left and right sides of the trolley wire 1. By providing multiple wear detection grooves on each of the left and right sides in this way, even if the shape and size of the large arc surface of the trolley wire are changed from a standard trolley wire shape to reduce weight, the progress of wear can be easily visually confirmed, and it is also advantageous for dealing with uneven wear in which wear occurs faster on only one side.

In the contact wire 1, the position of the wear surface (bottom surface) when wear progresses to the point where the tensile load reaches 54.7 kN is the wear limit position 14. Here, 54.7 kN is the required load when used in a heavy compound overhead line, and is calculated by the overhead line tension of the heavy compound overhead line (22.6 kN) x safety factor (2.2) x tension fluctuation (1.1).

In the trolley wire 1, the contours of the small arc surface 11 and the large arc surface 12 in the radial cross section are deformed from the contours of the small arc surface and the large arc surface in the radial cross section of a standard-shaped trolley wire in order to reduce the mass of the trolley wire 1. As a result, the radial cross-sectional area (calculated cross-sectional area) of the trolley wire 1 is 153.2 to ¹⁵⁵ mm2.

The contours 111 and 121 shown by dotted lines in Fig. 1 indicate the contours of the small and large arc surfaces in a radial cross section of a standard-shaped contact wire. The contours 111 and 121 are circular arcs with the same center position and radius. The height _h0 and width _w0 of the standard-shaped contact wire are 15.49 mm, and the contours 111 and 121 are circular arcs with a radius _r0 of 7.745 mm centered at point _O2 .

Here, in the radial cross section of the trolley wire 1, the curvature of the arc (hereinafter referred to as the first arc) which is the contour of the small arc surface 11 and the curvature of the arc (hereinafter referred to as the second arc) which is the contour of the large arc surface 12 are constant. In addition, the positions of the center _O1 of the first arc and the center _O2 of the second arc are different, and the curvature of the first arc is smaller than the curvature of the second arc (the radius _r1 of the first arc is larger than the radius _r2 of the second arc). Typically, as shown in Fig. 1, the center _O1 of the first arc and the center _O2 of the second arc are both located on the vertical center line indicated by the dashed line. The width _w1 of the trolley wire 1 is smaller than the width _w0 of the trolley wire of the standard shape, and the height _h1 of the trolley wire 1 is smaller than the height _h0 of the trolley wire of the standard shape.

The constant curvature of the first and second arcs facilitates winding the trolley wire around a drum and inspection of the wear state by an inspection vehicle. The fastening shape of the ear fittings attached to the ear grooves 13 is determined, and the shape of the trolley wire needs to be matched to the determined shape. Therefore, it is preferable that the shape of the trolley wire 1 is close to the shape of a standard trolley wire. In order to reduce the cross-sectional area while maintaining a shape close to the standard trolley wire, it is preferable that the center _O1 of the first arc is located below the center _O2 of the second arc (on the large arc surface 12 side). More specifically, by positioning the center _O1 of the first arc below the center _O2 of the second arc, the cross-sectional area of the trolley wire ₁ can be reduced while sufficiently securing the length t1 of the upper part of the ear groove 13 and the length _t2 of the lower part. By sufficiently securing the lengths _t1 and _t2 , the fit with the ear fittings is improved. In the example shown in Fig. 1, the length _t1 , which is particularly important in terms of fitting with the ear fitting, is made the same as that of the standard-shaped trolley wire, and the length _t2 is made shorter than that of the standard-shaped trolley wire within a range of 10% or less. In addition, when the height _h1 and width _w1 of the trolley wire 1 are equal, it becomes easier to wind the trolley wire 1 around the drum, and the shape of the trolley wire 1 becomes closer to that of the standard-shaped trolley wire.

Compared to trolley wires in which the cross-sectional area is reduced by providing a hollow section, as described in the above-mentioned Patent Document 1, the cross-sectional area of the trolley wire 1 decreases more slowly due to wear, making it possible to reduce weight while suppressing the decrease in wear life.

For example, when the trolley wire 1 has the shape shown in FIG. 1, the radius _r1 of the first arc is 9.195 mm, the radius _r2 of the second arc is 7.25 mm, the height _h1 is 14.50 mm, and the width _w1 is 14.50 mm, the position of the center _O2 of the second arc coincides with the center of the arcs of the contour 111 and the contour 121, and the center _O1 of the first arc is located 1.945 mm vertically downward from the center _O2 , the cross-sectional area of the trolley wire 1 is ^153.62 mm2.

(Characteristics of contact wire)
Hereinafter, the characteristics of the trolley wire 1 according to the first embodiment of the present invention will be described with reference to an example in which the trolley wire 1 shown in FIG. 1 is used in a heavy compound overhead line.

When the contact wire 1 is strung in a heavy compound catenary with a tension of 2.3 tons (22.6 kN), in order to accommodate the Shinkansen running at a commercial speed of 360 km/h, and in particular when high-speed performance is prioritized (the β value is set higher and the wear allowance is set smaller within a range that can accommodate the Shinkansen running at a commercial speed of 360 km/h), it is preferable that the β value be 0.782 or less when the Shinkansen runs at 360 km/h, and that a wear allowance (height from the bottom of the contact wire 1 to the wear limit position 14) _h2 of 4 mm is secured. Here, the β value is the ratio (V/C) of the running speed V of the Shinkansen to the wave propagation speed C of the contact wire.

The wear allowance _h2 is set in increments of 0.5 mm as a limit value of the wear height that can secure the necessary cross-sectional area required to maintain the strength when the wear of the trolley wire 1 progresses. Here, the tensile strength per unit area of the trolley wire 1 is set to 470 MPa, and the necessary load of 54.7 kN is divided by this tensile strength per unit area to calculate the necessary cross-sectional area as 116 mm2. The wear _allowance ^h2 for securing the necessary cross-sectional area of 116 mm2 of the trolley wire 1 is calculated as 4 mm. The reason why the tensile strength per unit area of the trolley wire ¹ is set to 470 MPa is that the strength of the trolley wire increases due to work hardening as the cross-sectional area decreases, and therefore the tensile strength per unit area can be set to 470 MPa or more.

The following Table 1 shows the relationship between the mass, cross-sectional area, wave propagation velocity, and β value of the contact wire when the Shinkansen runs at 360 km/h, in the case where the contact wire 1 is suspended in a heavy compound contact wire with a tension of 2.3 tons (22.6 kN). Here, the density of the contact wire 1 is set to 8.92 g/ ^cm3 .

According to Table 1, when the cross-sectional area of the trolley wire 1 is 155 ^mm2 or less, the β value is 0.782 or less when the Shinkansen train runs at 360 km/h.

Table 2 below shows the characteristics of a trolley wire 1 with a cross-sectional area of 151 to ¹⁵⁶ mm2 when it is worn 4 mm in the height direction from its bottom. Here, the remaining cross-sectional area in Table 2 is the cross-sectional area of the part remaining after the wear of the trolley wire 1. Also, the values of the tensile load, mass, wave propagation velocity, and β value are the values of the trolley wire 1 after the wear.

According to Table 2, when the cross-sectional area of the trolley wire 1 is 153.2 ^mm2 or more, a tensile load of 54.7 kN or more, which is the required load, can be secured when the trolley wire 1 is worn by ⁴ mm. In other words, when the cross-sectional area of the trolley wire 1 is 153.2 mm2 or more, a wear allowance _h2 of 4 mm can be secured.

Second Embodiment
(Contact Wire Structure)
2 is a radial cross-sectional view of a trolley wire 2 according to a second embodiment of the present invention. The trolley wire 2 is a modified trolley wire having a cross-sectional profile corresponding to a grooved hard copper trolley wire defined in JIS E2101, and has a small arc surface 21 at the top, a large arc surface 22 at the bottom, and V-shaped ear grooves 23 between the small arc surfaces 21 and the large arc surfaces 22 on both sides.

The shape of the ear groove 23 of the trolley wire 2 is the same as that of a standard-shaped trolley wire (a trolley wire with a standard dimension of a cross-sectional area of ¹⁷⁰ mm2 (sq) as specified in JIS E2101). Therefore, ear fittings for a trolley wire with a radial cross-sectional area of ¹⁷⁰ mm2 can be used for the ear groove 23 of the trolley wire 2. The trolley wire 2 is mainly composed of a copper alloy, for example, a Cu-Sn-In alloy.

The trolley wire 2 has wear detection grooves 25a, 25b on the large arc surface 22, which are indicators of the wear limit position 24. Typically, the wear detection grooves 25a, 25b are provided on both sides of the trolley wire 2, as shown in FIG. 2. Three or more wear detection grooves may be provided on each of the left and right sides of the trolley wire 2. By providing multiple wear detection grooves on each of the left and right sides in this way, even if the shape and size of the large arc surface of the trolley wire are changed from a standard trolley wire shape to reduce weight, the progress of wear can be easily visually confirmed, and it is also advantageous for dealing with uneven wear where wear occurs faster on only one side.

In the contact wire 2, the position of the wear surface (bottom surface) when wear progresses to the point where the tensile load reaches 54.7 kN is the wear limit position 24. Here, 54.7 kN is the required load when used in a heavy compound overhead line, and is the value calculated by the overhead line tension of the heavy compound overhead line (22.6 kN) x safety factor (2.2) x tension fluctuation (1.1).

In order to reduce the mass of the trolley wire 2, the contours of the small arc surface 21 and the large arc surface 22 in the radial cross section are deformed from the contours of the small arc surface and the large arc surface in the radial cross section of a standard-dimension trolley wire (a trolley wire of a standard shape) having a cross-sectional area of ^{170 mm2} specified in JISE 2101. As a result, the radial cross-sectional area (calculated cross-sectional area) of the trolley wire 2 is 158.5 to 160 mm2.

The contour 221 shown by the dotted line in Fig. 2 indicates the contour of the large arc surface in the radial cross section of the standard-shaped trolley wire. The contour 211 of the small arc surface in the radial cross section of the standard-shaped trolley wire coincides with the contour of the small arc surface 21. The contours 211 and 221 are arcs with the same center position and radius. The height _h0 and width _w0 of the standard-shaped trolley wire are 15.49 mm, and the contours 211 and 221 are arcs with a radius _r0 of 7.745 mm centered at point _O1 .

Here, in the radial cross section of the trolley wire 2, the curvature of the arc (hereinafter referred to as the first arc) which is the contour of the small arc surface 21 and the curvature of the arc (hereinafter referred to as the second arc) which is the contour of the lower (bottom) part of the wear detection grooves 25a, 25b of the large arc surface 22 are constant. In addition, the positions of the center _O1 of the first arc and the center _O2 of the second arc are different, and the curvature of the second arc is larger than the curvature of the first arc (the radius _r2 of the second arc is smaller than the radius _r1 of the first arc). Typically, as shown in FIG. 2, the center _O1 of the first arc and the center _O2 of the second arc are both located on the vertical center line indicated by the dashed line. The width _w1 of the trolley wire 2 is smaller than the width _w0 of the standard shape trolley wire, and the height h1 of the trolley wire ₂ is typically equal to the height _h0 of the standard shape trolley wire.

The contour of the upper portion of the wear detection grooves 25a, 25b of the large-arc surface 22 is inside the contour 221, like the contour of the lower portion of the wear detection grooves 25a, 25b of the large-arc surface 22, and preferably is connected to the contour of the lower portion of the wear detection grooves 25a, 25b of the large-arc surface 22 with almost no step between them, as shown in Fig. 2. In the example shown in Fig. 2, part of the contour of the upper portion of the wear detection grooves 25a, 25b of the large-arc surface 22 consists of an arc of radius _r3 (hereinafter referred to as the third arc) centered at point _O3 , which is located at a different position from points _O1 , _O2 .

Since the curvature of the first and second arcs is constant, it is easy to wind the wire around a drum and to inspect the wear condition using an inspection vehicle. Also, since the centers of the first and second arcs are located at different positions, it is possible to reduce the cross-sectional area while keeping the curvature of the first and second arcs constant.

The height _h1 of the trolley wire 2 is greater than the width _w1 , and the ratio _h1 / _w1 of the height _h1 to the width _w1 is about 1.05 to 1.15 (e.g., 1.1), which ensures a wear allowance h2 of 4.5 _mm or more (the height from the bottom of the trolley wire 2 to the wear limit position 24). In addition, the radius _r2 is about 10 to 20% (e.g., 15%) smaller than the radii _r0 and _r1 , which makes it possible to suppress the degree of reduction in the cross-sectional area of the lower part of the trolley wire 2 when it is worn, and to suppress the decrease in mechanical strength due to wear of the trolley wire 2.

Compared to trolley wires in which the cross-sectional area is reduced by providing a hollow section, as described in the above-mentioned Patent Document 1, the cross-sectional area of the trolley wire 2 decreases more slowly due to wear, making it possible to reduce weight while suppressing the decrease in wear life.

For example, when the trolley wire 2 has a shape shown in FIG. 2, the radius _r1 of the first arc is 7.745 mm, the radius _r2 of the second arc is 6.61 mm, the radius _r3 of the third arc constituting a part of the contour of the upper part of the wear detection grooves 25a, 25b of the large arc surface 22 is 7.745 mm, the height _h1 is 15.49 mm, and the width _w1 is 13.89 mm, the position of the center _O1 of the first arc coincides with the center of the arc of the contour 211 and the contour 221, the center _O2 of the second arc is located at a distance of 1.135 mm vertically downward from the center _O1 , and the center _O3 of the third arc is located at a distance of 0.8 mm on the opposite side of the third arc in the horizontal direction from the center _O1 and a distance of 0.3 mm vertically upward from the center O1, the cross-sectional area of the trolley wire 2 is 159.2 ^mm2 .

(Characteristics of contact wire)
The characteristics of the trolley wire 2 according to the second embodiment of the present invention will be described below by taking an example in which the trolley wire 2 shown in FIG. 2 is used in a heavy compound overhead line.

When the trolley wire 2 is strung in a heavy compound strut with a strut tension of 2.3 tons (22.6 kN), in order to accommodate the operation of a Shinkansen at a commercial speed of 360 km/h, and in particular when priority is given to maintenance-free operation (the β value is set small and the wear allowance large within a range that can accommodate the operation of a Shinkansen at a commercial speed of 360 km/h), it is preferable that the β value be 0.795 or less when the Shinkansen is operated at 360 km/h, and that a wear allowance h2 of 4.5 mm (the height from the bottom of the trolley wire ₂ to the wear limit position 24) be secured.

The wear allowance _h2 is set in increments of 0.5 mm as a limit value of the wear height that can secure the necessary cross-sectional area required to maintain the strength when the wear of the trolley wire 2 progresses. Here, the tensile strength per unit area of the trolley wire 2 is set to 470 MPa, and the necessary load of 54.7 kN is divided by this tensile strength per unit area to calculate the necessary cross-sectional area as 116.4 mm2. The wear _allowance ^h2 for securing the necessary cross-sectional area of 116.4 mm2 of the trolley wire ² is calculated as 4.5 mm. The reason why the tensile strength per unit area of the trolley wire 2 is set to 470 MPa is that the strength of the trolley wire increases due to work hardening as the cross-sectional area decreases, and therefore the tensile strength per unit area can be set to 470 MPa or more.

The following Table 3 shows the relationship between the mass, cross-sectional area, wave propagation velocity, and β value when the Shinkansen runs at 360 km/h, in the case where the contact wire 2 is suspended in a heavy compound overhead wire with a tension of 2.3 tons (22.6 kN). Here, the density of the contact wire 2 is 8.92 g/ ^cm3 .

According to Table 3, when the cross-sectional area of the trolley wire 2 is 160 ^mm2 or less, the β value is 0.795 or less when the Shinkansen train runs at 360 km/h.

Table 4 below shows the characteristics of a trolley wire ² with a cross-sectional area of 156 to 161 mm2 when it is worn 4.5 mm in the height direction from its bottom. Here, the remaining cross-sectional area in Table 4 is the cross-sectional area of the part remaining after the wear of the trolley wire 2. The tensile load, mass, wave propagation velocity, and β value are the values of the trolley wire 2 after the wear.

According to Table 4, when the cross-sectional area of the trolley wire 2 is 158.5 ^mm2 or more, a tensile load of 54.7 kN or more, which is the required load, can be secured when the trolley wire 2 is worn by 4.5 mm. That is, when the cross-sectional area of the trolley wire 2 is ^158.5 mm2 or more, a wear allowance _h2 of 4.5 mm can be secured.

Third embodiment
(Contact Wire Structure)
3 is a radial cross-sectional view of a trolley wire 3 according to a third embodiment of the present invention. The trolley wire 3 is a deformed round trolley wire corresponding to a grooved hard copper trolley wire defined in JISE 2101, with a recess 35 (described later) provided therein, and has a small arc surface 31 at the top, a large arc surface 32 at the bottom, and V-shaped ear grooves 33 between the small arc surfaces 31 and the large arc surfaces 32 on both sides.

The shape of the ear groove 33 of the trolley wire 3 is the same as that of a standard-shaped trolley wire (a trolley wire with a standard dimension of a cross-sectional area of ¹⁷⁰ mm2 specified in JIS E2101). Therefore, ear fittings for a trolley wire with a radial cross-sectional area of ¹⁷⁰ mm2 can be used for the ear groove 33 of the trolley wire 3. The trolley wire 3 is mainly composed of a copper alloy, for example, a Cu-Sn-In alloy.

In the contact wire 3, the position of the wear surface (bottom surface) when wear progresses and the tensile load becomes 65.3 kN is defined as the wear limit position 34. Here, 65.3 kN is the required load when used in a heavy simple overhead line, and is calculated by the overhead line tension of the heavy simple overhead line (27.0 kN) x safety factor (2.2) x tension fluctuation (1.1).

The trolley wire 3 has a recess 35 for reducing the mass of the trolley wire 1 at the lower part of the large arc surface 32 (including the bottom part on the bottom side of the trolley wire 1). The recess 35 is a part recessed from the large arc surface of a standard-shaped trolley wire. As a result, the radial cross-sectional area (calculated cross-sectional area) of the trolley wire 3 is 163 to ¹⁶⁵ mm2. The recess 35 can also be used as a wear detection groove that serves as an indicator of the wear limit position 34. In the trolley wire 3, the shape and size of the part of the large arc surface 32 where the recess 35 is not provided are the same as those of the large arc surface of the standard-shaped trolley wire, so that the recess 35 has good visibility as a wear detection groove.

A contour 321 shown by a dotted line in Fig. 3 indicates the contour of the large arc surface in the radial cross section of the standard-shaped trolley wire. A contour 311 of the small arc surface in the radial cross section of the standard-shaped trolley wire coincides with the contour of the small arc surface 31. The contours 311 and 321 are arcs with the same center position and radius. The height _h0 and width _w0 of the standard-shaped trolley wire are 15.49 mm, and the contours 311 and 321 are arcs with a radius _r0 of 7.745 mm centered at point _O1 . The width _w1 of the trolley wire 3 is equal to the width _w0 of the standard-shaped trolley wire, and the height _h1 of the trolley wire 3 is typically equal to the height _h0 of the standard-shaped trolley wire. Also, typically, the height _h1 and width _w1 of the trolley wire 3 are equal.

In the radial cross section of the trolley wire 3, the curvature of the arc (hereinafter referred to as the first arc) which is the contour of the small arc surface 31, the curvature of the arc (hereinafter referred to as the second arc) which is the contour of the portion of the large arc surface 32 where the recess 35 is not provided, and the curvature of the arc (hereinafter referred to as the third arc) which is the contour of the portion 351 curved downward in the recess 35 of the large arc surface 32 are all constant. In addition, the positions of the center _O1 of the first arc and the center _O3 of the third arc are different, the curvature of the first arc and the curvature of the second arc are equal (the radius _r1 of the first arc and the radius _r2 of the second arc are equal), and the curvature of the third arc is larger than the curvature of the first arc and the curvature of the second arc (the radius _r3 of the third arc is smaller than the radius _r1 of the first arc and the radius _r2 of the second arc). Typically, as shown in FIG. 3, the center _O1 of the first and second arcs and the center _O3 of the third arc are both located on the vertical center line indicated by the dashed line.

The constant curvature of the first arc, the second arc, and the third arc makes it easy to wind the wire around a drum and to inspect the wear condition using an inspection vehicle. In addition, the provision of the recess 35 makes it possible to reduce the cross-sectional area while keeping the curvature of the first arc, the second arc, and the third arc constant.

The trolley wire 3 has a radius _r3 that is approximately 15 to 25% (e.g., 20%) smaller than the radii _r0 , _r1 , and _r2 , thereby suppressing the degree of reduction in the cross-sectional area of the lower part of the trolley wire 3 when it wears, and suppressing the decrease in mechanical strength due to wear of the trolley wire 2.

Compared to trolley wires in which the cross-sectional area is reduced by providing a hollow section, as described in the above-mentioned Patent Document 1, the cross-sectional area of the trolley wire 3 decreases more slowly due to wear, making it possible to reduce weight while suppressing the decrease in wear life.

If the recess 35 is provided below the wear limit position 34, as wear of the trolley wire 3 progresses, the recess 35 disappears before the wear reaches the wear limit position 34. This makes it possible to suppress a rapid decrease in the remaining cross-sectional area of the trolley wire 3 as wear progresses.

For example, when the trolley wire 3 has the shape shown in FIG. 3, the radius _r1 of the first arc and the radius _r2 of the second arc are 7.745 mm, the radius _r3 of the third arc is 6.17 mm, the height _h1 and the width _w1 are 15.49 mm, the positions of the centers _O1 of the first arc and the second arc coincide with the center of the arc of the contour 321, and the center _O2 of the third arc is located 1.575 mm vertically downward from the center _O1 , the cross-sectional area of the trolley wire 3 is ¹⁶⁵ mm2.

(Characteristics of contact wire)
The characteristics of the trolley wire 3 according to the third embodiment of the present invention will be described below with reference to an example in which the trolley wire 3 shown in FIG. 3 is used in a heavy simple overhead line.

When the contact wire 3 is strung in a heavy simple overhead line with a strut tension of 2.75 tons (27 kN), in order to accommodate the Shinkansen's commercial speed of 360 km/h, it is required that the β value when the Shinkansen is run at 360 km/h be 0.737 or less, and that a wear allowance h2 of 3 mm (the height from the bottom of the contact wire ₃ to the wear limit position 34) be secured.

The wear allowance _h2 is set in increments of 0.5 mm as a limit value of the wear height at which the necessary cross-sectional area required to maintain the strength can be secured when the wear of the trolley wire 3 progresses. Here, the tensile strength per unit area of the trolley wire 3 is set to 460 MPa, and the necessary cross-sectional area of 142 mm2 is calculated by dividing the necessary load of 65.3 kN by this tensile strength per unit area. Then, the wear _allowance ^h2 for securing the necessary cross-sectional area of 142 mm2 of the trolley wire 3 is calculated to be 3 mm. The reason why the tensile strength per unit area of the trolley wire ³ is set to 460 MPa is that the tensile strength per unit area of a trolley wire with a cross-sectional area of ¹⁶³ mm2 or more is set to 460 MPa or more.

Table 5 below shows the relationship between the mass, cross-sectional area, wave propagation velocity, and β value when the Shinkansen runs at 360 km/h, in the case where the contact wire 3 is suspended in a heavy simple overhead line with a tension of 2.75 tons (27 kN). Here, the density of the contact wire 3 is set to 8.92 g/ ^cm3 .

According to Table 5, when the cross-sectional area of the contact wire is ¹⁶⁵ mm2 or less, the β value is 0.737 or less when the Shinkansen runs at 360 km/h.

Table 6 below shows the characteristics of a trolley wire 3 with a cross-sectional area of 160 to ¹⁶⁵ mm2 when it is worn 3 mm in the height direction from its bottom. Here, the remaining cross-sectional area in Table 6 is the cross-sectional area of the part remaining after the wear of the trolley wire 1. Also, the values of the tensile load, mass, wave propagation velocity, and β value are the values of the trolley wire 1 after the wear.

According to Table 6, when the cross-sectional area of the trolley wire 3 is 163 ^mm2 or more, a tensile load of 65.3 kN or more, which is the required load, can be secured when the trolley wire 3 is worn by 3 mm. In other words, when the cross-sectional area of the trolley wire 3 is ¹⁶³ mm2 or more, a wear allowance _h2 of 3 mm can be secured.

(Effects of the embodiment)
According to the first to third embodiments, the cross-sectional area of the trolley wire is reduced by modifying the cross-sectional contour of the trolley wire, so that a rapid decrease in the remaining cross-sectional area of the trolley wire when wear progresses can be suppressed. In addition, in the first and second embodiments, a plurality of wear detection grooves are provided on each of the left and right side surfaces of the trolley wire, and in the third embodiment, the shape and size of the large arc surface of the trolley wire are made the same as those of a standard-shaped trolley wire, so that the visibility of the wear detection groove is improved. As a result, the weight of the trolley wire can be reduced while suppressing a decrease in wear life and a decrease in the visibility of the wear detection groove, and the wave propagation speed can be improved. In addition, according to the first to third embodiments, the weight of the trolley wire is reduced without changing the shape of the ear groove, so that there is no need to change the ear fitting when replacing the trolley wire.

(Summary of the embodiment)
Next, the technical ideas grasped from the above-described embodiment will be described by using the reference numerals and the like in the embodiment. However, the reference numerals and the like in the following description do not limit the components in the claims to the members and the like specifically shown in the embodiment.

[1] A trolley wire (1) having a small arc surface (11) on an upper side, a large arc surface (12) on a lower side, and an ear groove (13) between the small arc surface (11) and the large arc surface (12), in which an ear fitting for a trolley wire having a radial cross-sectional area of ¹⁷⁰ mm2 can be used in the ear groove, the large arc surface (12) on each of the left and right sides has a plurality of wear detection grooves (15a, 15b) that are indicators of a wear limit position ( ¹⁴ ), the radial cross-sectional area is 153.2 to 155 mm2, in a radial cross-section of the trolley wire, the curvature of a first circular arc that is a contour of the small arc surface ( ₁₁ ) and the curvature of a second circular arc that is a contour of the large arc surface (12) are each constant, the positions of the center (O1) of the first circular arc and the center ( _O2 ) of the second circular arc are different, and the curvature of the first circular arc is smaller than the curvature of the second circular arc.

[2] A trolley wire having an upper small arc surface (21), a lower large arc surface (22), and an ear groove (23) between the small arc surface (21) and the large arc surface (22), in which an ear fitting for a trolley wire having a radial cross-sectional area of ¹⁷⁰ mm2 can be used in the ear groove, the large arc surface (22) on each of the left and right sides has a plurality of wear detection grooves (25a, 25b) on the large arc surface (22) that are indicators of a wear limit position (24), the radial cross-sectional area being 158.5 to ¹⁶⁰ mm2, in a radial cross-section of the trolley wire, the curvature of a first circular arc that is a contour of the small arc surface (21) and the curvature of a second circular arc that is a contour of a portion of the large arc surface (22) below the wear detection grooves (25a, 25b) are each constant, and the center (O ₁ ) of the first circular arc and the center (O _{2 )} of the second circular arc are each constant. ) are at different positions, and the curvature of the second arc is greater than the curvature of the first arc.

[3] A trolley wire having an upper small arc surface (31), a lower large arc surface (32), and an ear groove (33) between the small arc surface (31) and the large arc surface (32), in which an ear fitting for a trolley wire having a radial cross-sectional area of ¹⁷⁰ mm2 can be used in the ear groove, and the radial cross-sectional area is 163 to 165 mm2. a trolley wire ⁽³ ) having a recess (35) for reducing the mass of the trolley wire, the recess (35) extending along the length direction of the trolley wire, at a lower part of the large arc surface (32); in a radial cross section of the trolley wire, a curvature of a first arc which is the contour of the small arc surface (31), a curvature of a second arc which is the contour of a portion of the large arc surface (32) where the recess (35) is not provided, and a curvature of a third arc which is the contour of a portion (351) of the large arc surface (32) that is curved downwardly within the recess (35) are all constant; the positions of the centers (O ₁ ) of the first and second arcs are different from the position of the center (O ₃ ) of the third arc; the curvature of the first arc and the curvature of the second arc are equal; and the curvature of the third arc is greater than the curvature of the first arc and the curvature of the second arc.

[4] The trolley wire described in [3] above, having the recess (35) below the wear limit position (34).

Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications are possible within the scope of the gist of the invention.

Furthermore, the embodiments described above do not limit the invention according to the claims. It should be noted that not all of the combinations of features described in the embodiments are necessarily essential to the means for solving the problems of the invention.

1, 2, 3 Contact wire 11, 21, 31 Small arc surface 12, 22, 32 Large arc surface 13, 23, 33 Ear groove 14, 24, 34 Wear limit position 15a, 15b, 25a, 25b Wear detection groove 35 Recess 351 Downwardly curved portion

Claims (2)

A trolley wire having an upper small arc surface, a lower large arc surface, and an ear groove between the small arc surface and the large arc surface, wherein an ear fitting for a trolley wire having a radial cross-sectional area of ¹⁷⁰ mm2 can be used in the ear groove,
The radial cross-sectional area is 153.2 to ¹⁵⁵ mm2,
In a radial cross section of the contact wire, a curvature of a first circular arc which is a contour of the small arc surface and a curvature of a second circular arc which is a contour of the large arc surface are each constant,
a center of the first arc and a center of the second arc are located at different positions;
The curvature of the first arc is smaller than the curvature of the second arc.
Trolley wire. A trolley wire having an upper small arc surface, a lower large arc surface, and an ear groove between the small arc surface and the large arc surface, wherein an ear fitting for a trolley wire having a radial cross-sectional area of ¹⁷⁰ mm2 can be used in the ear groove,
The radial cross-sectional area is 158.5 to ¹⁶⁰ mm2,
a curvature of a first arc which is a contour of the small arc surface in a radial cross section of the contact wire;
and a second arc, which is a contour of a lower portion of the wear detection groove of the large arc surface, have a constant curvature.
a center of the first arc and a center of the second arc are located at different positions;
The curvature of the second arc is greater than the curvature of the first arc.
Trolley wire.

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