JPH06323369A - Tension adjusting device - Google Patents

Abstract

PURPOSE:To enable the early abnormality detection of parts by providing a rotating member having a female screw and a male screw in the mutually different directions at both ends and also connecting members to be screwed with the rotating member, and providing at least one of the rotating member and connecting members with a tension sensor. CONSTITUTION:In the case of being executed to a wire turnbuckle, the joints 11, 21 of connecting members 1, 2 are connected to a tension adjusted object, and a rotating cylinder 5, a rotating member, is rotated to contract the spacing of both connecting members 1, 2. Tension is thereby generated to a shank 12, and distortion is generated to a magnetostrictive film, a part of a tension sensor 6, provided at the shank 12. Since the magnetostrictive film 61 changes according to this distortion, the impedance of a coil 62 changes. This change is proportional to tension, so that tension is obtained by detecting the impedance of the coil 62 in an electric circuit, and the abnormality of parts forming a tension adjusting device is detected to prevent damage caused by corrosion and the like.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tension variable device used for various tension adjustments.

[0002]

2. Description of the Related Art Conventionally, when adjusting the tension of an overhead wire, for example, a manual tension varying device is usually used. There is a wire turnbuckle as a typical example of the tension varying device, and this wire turnbuckle applies the principle of the screw, and its structure is shown in FIG. A right male screw part 3 and a left male screw part 4 are respectively formed at the base ends of the connecting members 1 and 2 for connecting the objects whose tension is to be changed, and the right female screw is formed in almost half of the inside of the cylindrical member in the longitudinal direction and the other is formed in the other. A rotary cylinder 5 that is a rotary member having a left female thread is provided. By rotating the rotary cylinder 5, the length between the right male screw portion 3 and the left male screw portion 4 is changed to adjust the tension. The connecting members 1 and 2 including the left and right male screw portions 3 and 4 are made of SUS304 in order to improve corrosion resistance.

For the purpose of roughly grasping the tension of the wire turnbuckle in use, a wire turnbuckle incorporating a spring tension meter is commercially available. Its structure is shown in FIG. This is a method in which a spring 7 is installed in series with the wire turnbuckle in FIG. 2, and the expansion and contraction amount of the spring 7 expands and contracts in proportion to the load to display the expansion and contraction amount in color and to divide the tension in stages. .

[0004]

When a tension variable device such as a wire turnbuckle is used by connecting it to an overhead wire,
The tension is always applied. The SUS304 stainless steel used for this wire turnbuckle is subjected to solution heat treatment to prevent intergranular corrosion and stress corrosion cracking when used in a chloride atmosphere under tension. However, when the solution heat treatment is incomplete, corrosion occurs, and although no abnormality is apparently observed, it suddenly cracks, which may cause a major accident due to a broken wire. Therefore, there has been a demand for a method of detecting an abnormality in the initial process when a crack starts to occur due to corrosion.

However, not only in the conventional wire turnbuckle but also in the wire turnbuckle incorporating the tensiometer, even if cracks due to corrosion start to occur in the used state, the tensiometer does not change at all. No detection was possible. The reason is that in FIG. 3, even if a crack is generated in the shaft portion of the connecting member 1, the load applied to the spring 8 does not change.

The problem to be solved by the present invention is not only to measure the tension at all times, but also to detect an abnormality in the initial state even if cracks start to occur during use due to corrosion or the like during use due to quality problems in production control. It is to provide a variable tension device that can be used.

[0007]

In order to solve the above-mentioned problems, the tension varying device of the present invention has a rotating member having female threads or male threads in different directions at both ends, and one screw at each end of the rotating member. A tension variable device having a male or female screw to be screwed and a connecting member for connecting an object to the other end, wherein a strain gauge type or magnetostrictive type tension sensor is provided on at least one of the rotating member or the connecting member. It is equipped with.

[0008]

In the structure of the wire turnbuckle, a tension sensor for detecting the tension from the change in strain is incorporated in the outer peripheral surface of the SUS304 member which is susceptible to stress corrosion cracking. Therefore, when stress corrosion cracking starts to occur, the stress applied to the SUS304 member changes as shown in FIG. 4 to FIG. 5, so that the strain on the surface of the cylindrical part is reduced. As a result, the output of the tension sensor drops abnormally, and it can be seen that a crack has occurred.

[0009]

EXAMPLES The present invention will be specifically described below based on examples. FIG. 1 is a view showing the structure of a wire turnbuckle according to an embodiment of the present invention. In the figure, 6 is a magnetostrictive tension sensor. The tension sensor 6 has a magnetostrictive film 61 provided on the shaft portion 12 of the connecting member 1 made of SUS304.
The coil 62 is arranged around the unit 1. The magnetostrictive film 61 is formed of 90% Ni-Fe by the sputtering method.

FIG. 6 shows an example of the configuration of an electric circuit for extracting the change in the impedance of the coil 62 as a voltage signal. An exciting current is supplied to the coil 62 from the exciting power supply 8. The voltage induced on the secondary side of the coil 62 is converted into direct current by the direct current conversion circuit 9, amplified by the amplifier 10, and output.

Now, when the joints 11 and 21 of the connecting members 1 and 2 are connected to an object whose tension is to be adjusted and the rotary cylinder 5 which is a rotating member is rotated to reduce the distance between the connecting members 1 and 2,
Tension is applied to the shaft portion 12. When tension is applied, strain is generated in the magnetostrictive film 61, and the magnetic characteristic (permeability) of the magnetostrictive film 61 changes according to the strain. As a result, the impedance of the coil 62 changes. Since this change is proportional to the tension,
The tension can be known from this value.

Although an example in which a magnetostrictive tension sensor is used is shown here, a commonly used strain gauge or the like may be used. The tension can be changed by rotating the rotary cylinder 5, which is a rotary member, as is conventionally done.

SU used in this wire turnbuckle
The connection member made of S304 was heated to 750 ° C. in advance for sensitization treatment, and then the magnetostrictive film was formed by the sputtering method. 5 kgf / mm for this wire turnbuckle
^{When the} output of the signal of the tension sensor 6 was monitored in the electric circuit shown in FIG. 6 by leaving it in a saline solution at 80 ° C. with the load of ² applied, as shown in FIG. The output started to drop sharply. After 20 hours, the test was stopped and the cross section of the SUS304 member was observed with a microscope. As a result, it was found that stress corrosion and intergranular corrosion occurred.

In the embodiment, the member made of SUS304 is shown, but it is obvious that other materials such as SUS316 and steel material may be used. Further, although the wire turnbuckle is used as the tension varying device, it is clear that the same effect can be obtained with other tension varying devices.

[0015]

As described above, since the tension variable device according to the present invention is provided with the strain sensor based on the strain detection, it is possible to detect the abnormality of the parts constituting the tension variable device. Therefore, for example, when used in a state where tension is applied for a long period of time, damage due to corrosion or the like can be prevented.

[Brief description of drawings]

FIG. 1 is a front view showing the structure of a wire turnbuckle with a tension sensor of the present invention.

FIG. 2 is a front view showing the structure of a conventional wire turnbuckle.

FIG. 3 is a front view showing a structure of a conventional wire turnbuckle with a tension sensor.

FIG. 4 is an explanatory diagram showing a stress distribution in a wire turnbuckle.

FIG. 5 is an explanatory diagram showing a stress distribution in a wire turnbuckle in which corrosion has occurred.

FIG. 6 is an electric circuit diagram of a tension sensor used in the present invention.

FIG. 7 is a diagram showing an abnormality detection characteristic of the tension variable device of the present invention.

[Explanation of symbols]

1, 2 connection member, 11, 21 joint, 12, 22 shaft part, 3 right male screw part, 4 left male screw part, 5 rotary cylinder, 6
Tension sensor, 61 magnetostrictive film, 62 coil, 7 spring, 8
Excitation power supply, 9 DC conversion circuit, 10 amplifier

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Koji Nakajima No. 2 Shiroishi Kurosaki, Yawatanishi-ku, Kitakyushu City, Fukuoka Prefecture Yasukawa Electric Co., Ltd. (72) Koji Uemura No. 2 Kurosaki Shiroishi, Hachimannishi-ku, Kitakyushu, Fukuoka Prefecture Yasukawa Electric Co., Ltd. (72) Inventor Hidenori Hasegawa No. 2 Kurosaki Shiroishi, Hachimannishi-ku, Kitakyushu City, Fukuoka Prefecture (72) Inventor, Iwa Kakudaira Ichome, Nakamura-ku, Aichi Prefecture No. 4 Tokai Passenger Railway Co., Ltd. (72) Inventor Banwa Sowa Ai Prefecture, Nagoya City, Nakamura-ku 1-chome, No. 1-4, Tokai Passenger Railroad Co., Ltd. (72) Inventor Masataka Yamaguchi Nakamura-ku, Aichi Prefecture 1-14, Meieki Tokai Passenger Railway Co., Ltd. (72) Inventor Toshinori Miyazaki 1-4-1 Meieki, Nakamura-ku, Aichi Prefecture Tokai Passenger Railroad Inside the ceremony company (72) Inventor Yutaka Ito 1-4-1, Mei Station, Nakamura-ku, Aichi Prefecture Tokai Passenger Railway Co., Ltd. (72) Yoshio Ishii 6-5-19 Minami-Shinagawa, Shinagawa-ku, Tokyo 3 (72) Inventor Tsugio Takagi 6-5-19 Minami-Shinagawa, Shinagawa-ku, Tokyo Sanwa-Techk Ltd.

Claims (1)

[Claims] 1. A rotating member having female threads or male threads in mutually different directions at both ends, and a connecting member for connecting an object to one end with male threads or female threads to be engaged with the respective screws of the rotating member. And a strain gauge type or magnetostrictive type tension sensor in at least one of the rotating member and the connecting member.