JPH09288023A - Detection structure for abnormality of tensioning apparatus for overhead wire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a detection structure by which whether the tension of an overhead wire is proper or not is always monitored, by which an abnormality can be detected at an early stage so as to take measures and which prevents the disconnection of the overhead wire by a method wherein a gas for a spring or a pressure is monitored and a change in the tension of the overhead wire is monitored. SOLUTION: When a moving cylinder 2 is pulled to the right side by an overhead wire L via a moving rod 3, a fixed rod 4 is going to rush further into a liquid chamber 2b, a gas chamber 2a is pressurized via a liquid, and proper tension is generated by a springy action due to a gas pressure against it. At this time, the tension of the overhead wire L has a constant relationship with the pressure of a gas sealed in the gas chamber 2a and of a liquid sealed in the liquid chamber 2b. P.V/T=constant. That is to say, since a pressure P and/or a volume V are changed according to a change in a temperature, the tension of the overhead wire can act in a direction in which the change portion of the volume of the gas chamber due to the change in the temperature and an amount at which the overhead wire is expanded and contracted due to the change in the temperature are offset.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an overhead wire tensioning device used for equipment or the like for keeping the tension of a power line constant, and more particularly to a structure for detecting an abnormality in the overhead wire or the tensioning device. It is about.

[0002]

2. Description of the Related Art Overhead wires, especially electric wires (suspension overhead wires, auxiliary suspension overhead wires, trolley wires), expand and contract due to temperature changes, and elastic elongation due to creep and trolley wire wear, and tilting of the support over time. Since the sag tension is affected by such factors, it is necessary to keep the tension of the power line constant. Further, it is desirable that the adjustment be automatically performed to be maintenance-free.

Conventionally, as the automatic tension adjusting device capable of constantly maintaining the above tension, there are known a pulley type in which a pulley is used to apply tension by a weight and a spring type in which a spring is used. The pulley type is excellent in the ability to keep the tension constant, but it has problems such as complicated installation work and regular maintenance to prevent wire deterioration, so the device is compact. A spring-type tensioning device that can be reduced in weight and weight and can be maintenance-free has attracted attention. This spring type uses a coil spring or is disclosed in, for example, Japanese Patent Laid-Open No. 6-
There is one using an air spring as disclosed in Japanese Patent No. 16068.

[0004]

In the above-mentioned various types of overhead wire tensioning devices, although tension control is conventionally performed during installation, tension measurement is not performed during actual traveling thereafter. . Therefore, if the tension of the overhead wire changes due to some cause (Joule heat, snow accumulation on the tensioning device, etc.), the amount of friction increases due to the bending, and in some cases, a problem such as disconnection may occur.

Therefore, for example, in Japanese Utility Model Publication No. Sho 49-35049, a signal line which is disconnected when tension is weakened due to abnormal extension of an overhead wire is provided in a spring tensioning device. An inspection device for detecting an abnormality in tension by monitoring the energization state of a signal line is described.

However, since the inspection device described in the above publication detects an abnormal tension from the amount of movement of the spring or overhead wire, it must be individually adjusted or designed according to the length of the overhead wire or the size of the spring. It had to be versatile. Further, the above-mentioned inspection device is destroyed due to its structure once the abnormal tension is detected, which makes maintenance difficult.

The present invention has been made in view of the above-mentioned problems of the prior art, and its main purpose is to conveniently monitor the tension of the overhead line, and also to have high versatility and easy maintenance. An object of the present invention is to provide an abnormality detection structure for a tensioning device for a vehicle.

[0008]

According to the present invention, there is provided an abnormality detecting structure for a gas spring type overhead wire tensioning device for applying a predetermined tension to an overhead wire,
It has a means for detecting the pressure of the gas for the spring of the tensioning device or the pressure of its transmission medium by a pressure sensor or a pressure switch, and means for monitoring the tension of the overhead wire based on the detection result of the pressure detecting means. It is achieved by providing an abnormality detection structure for an overhead wire tensioning device. As described above, by monitoring the change in the overhead wire tension by monitoring the pressure, it is possible to detect the abnormality early.

[0009]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a partial sectional view showing the structure of a gas spring tensioning device for overhead lines to which the present invention is applied. This tensioning device has a bottomed cylindrical casing 1 having one end fixed to a support P, and a movable cylinder 2 movably supported in the casing 1 in the axial direction.
A U-shaped movable rod 3 fixed to the side of the movable cylinder 2 and extending to the other end of the casing 1 and connected to the overhead line L, and an end of the casing 1 on the side of the overhead line L. And a movable cylinder 2 which is provided so as to project in the axial direction on the
And a fixed rod 4 that rushes into. The movable cylinder 2 is divided into a gas chamber 2a filled with a spring gas and a liquid chamber 2b filled with a liquid as a transmission medium with a bellows 5 which is expandable and contractible in the axial direction. The fixed rod 4 projects into the liquid chamber 2b. Movable rod 3
A pressure switch 7 is attached to this via a passage 2c communicating with the liquid chamber 2b. The pressure switch 7 is connected to the monitor 10 via a cable 8 and a strain amplifier 9.

FIG. 2 shows a schematic structure of the pressure switch 7.
FIG. 3 shows the circuit configuration. The pressure switch 7 has, for example, a diaphragm 7a made of stainless steel, and four semiconductor strain gauges 7b attached to the diaphragm 7a via an insulating film. These semiconductor strain gauges 7b are bridge-connected, and the output of the semiconductor strain gauges 7b is differentially amplified by the differential amplifier A, and the output is obtained by comparing with a predetermined voltage by the comparator C. Therefore,
The strain of the diaphragm 7a caused by the pressure is detected as a change in the resistance value, the output is differentially amplified, and when it is changed from the predetermined pressure by, for example, 10% or more, this is output. By changing the predetermined voltage by the variable resistor R, the set value (threshold value) to be output can be changed.

When the movable cylinder 2 is actually pulled to the right side in FIG. 1 by the overhead line L via the movable rod 3, the fixed rod 4 does not further enter the liquid chamber 2b and the gas chamber 2a is inserted through the liquid. An appropriate tension is generated by the spring action of the gas pressure that is applied and resists the pressure.

Here, the tension of the overhead line L has a certain relationship with the pressure of the gas enclosed in the gas chamber 2a and the liquid enclosed in the liquid chamber 2b (P · V / T = constant). That is, since the pressure P and / or the volume V changes according to the change of the temperature T, the volume change of the gas chamber due to the temperature change and the amount of expansion and contraction of the overhead wire due to the temperature change can be offset. it can.

On the other hand, because of the characteristics as described above, by appropriately setting the expansion / contraction amount of the overhead wire and the volume change amount of the gas chamber due to the temperature change, a substantially constant tension can be obtained regardless of the temperature change. It is possible to maintain. However, in reality, the temperature and the temperature change between the overhead wire and the gas chamber are not the same, so that some tension change occurs. The setting value of the pressure sensor is determined by considering the operation error of the pressure switch 7 due to this as described below.

An example of the relationship between temperature and change in tension is shown in FIG. Here, the standard tension is 1000 kgf and the temperature change is −
20 to 40 ° C (10 ° C ± 30 ° C), and the maximum temperature difference between the overhead wire and the tensioning device is 15 ° C. At this time, the tensioning device is
If the temperature of the tensioning device is the same as that of the overhead line, the tensioning device always changes by 15 ° C below the temperature of the overhead line. When the temperature is always 40 ° C, indicates the tension change when the tensioning device is always 10 ° C regardless of the temperature change of the overhead line, and indicates the tension change when the tensioning device is always -20 ° C regardless of the temperature change of the overhead line. At the maximum expected temperature difference of ± 15 ° C (hatched portion), the change in tension is ± 7%. On the other hand, if the operation error of the pressure switch 7 is ± 3%, the pressure switch 7
The output set value of is set to, for example, ± 10% of the set tension, and within this range, it is determined that the tensioning device is operating normally.

If the tension is within the set range, the pressure switch 7 does not operate, and the monitor 10 indicates that it is in a normal state. If the tension exceeds the range of ± 10%, it is judged that some kind of abnormality has occurred in the tensioning device or the overhead wire, and the pressure switch 7 is activated to display an abnormality and an alarm on the monitor 10. And the tensioning device and overhead line that are displayed as abnormal are easily limited, so you can quickly inspect, replace, etc., and if the tensioning device is not abnormal, continue to use the tensioning device you are using. Can be used.

In the above example, the liquid pressure equivalent to the gas pressure is detected, but the gas pressure may be directly detected by connecting a pressure switch to the gas chamber, or a known pressure sensor may be used to continuously detect the gas pressure. The pressure may be monitored to see changes over time.

[0018]

As is apparent from the above description, according to the abnormality detecting structure for the overhead wire tensioning device of the present invention, the change in the overhead wire tension is monitored by monitoring the gas or pressure for the spring. Thus, the appropriateness / absence of the tension of the overhead wire can be constantly monitored, and the abnormality can be detected and dealt with early, so that the wear amount of the overhead wire can be suppressed and the disconnection of the overhead wire can be prevented. Moreover, by using a pressure switch or sensor whose output setting value can be easily adjusted, various overhead wire structures can be supported and its versatility is improved. In addition, the tension abnormality can be detected nondestructively, the maintainability is high, and the cost is reduced.

[Brief description of drawings]

FIG. 1 is a partial sectional view showing the configuration of a gas spring tensioning device for overhead lines to which the present invention is applied.

FIG. 2 is a sectional view showing a schematic structure of a pressure switch.

FIG. 3 is a diagram showing a circuit configuration of the pressure switch of FIG.

FIG. 4 is a graph showing an example of the relationship between temperature and change in tension.

[Explanation of symbols]

 1 Casing 2 Movable Cylinder 2a Gas Chamber 2b Liquid Chamber 2c Passage 3 Movable Rod 4 Fixed Rod 5 Bellows 7 Pressure Switch 7a Diaphragm 7b Semiconductor Strain Gauge 8 Cable 9 Strain Amp 10 Monitor L Overhead Line P Strut A Differential Amplifier C Comparator

Front Page Continuation (72) Inventor Masahiko Kobayashi 1-4-1, Mei Station, Nakamura-ku, Nagoya, Aichi Tokai Passenger Railway Co., Ltd. (72) Inventor Yoshio Narumiya 1-1-1, Mei Station, Nakamura-ku, Aichi Prefecture No. 4 in Tokai Passenger Railway Co., Ltd. (72) Toru Uchikoshi Toru Uchikoshi 1-1-4, Mei Station, Nakamura-ku, Aichi Prefecture Tokai Passenger Railroad Co., Ltd. (72) Inventor Shoji Imada Takaida Naka, Higashi-Osaka City, Osaka Prefecture 2-5-25 In Denki Co., Ltd. (72) Inventor Yuetsu Wakabayashi 2-5-25 Takai Tanaka, Higashi-Osaka City, Osaka Prefecture 72-5 In Denki Co., Ltd. (72) Inventor Takeshi Shinbori Kanazawa-ku, Yokohama-shi, Kanagawa 3-10 Fukuura Nihon-baru Co., Ltd. (72) Inventor Ken Uchida 3-10-10 Fukuura, Kanazawa-ku, Yokohama-shi, Kanagawa Nihon-baru Co., Ltd.

Claims (1)

[Claims] 1. An abnormality detecting structure for a gas spring type overhead wire tensioning device for applying a predetermined tension to an overhead wire, comprising the pressure of a gas for spring of the tensioning device or a pressure sensor or pressure switch for detecting the abnormality. An abnormality detecting structure for an overhead wire tensioning device, comprising: a means for detecting the pressure of a transmission medium; and a means for monitoring the tension of the overhead wire based on the detection result of the pressure detecting means.