The Inventor’s Corner
Wire Rope Flaw Detection Device
A wire rope flaw detection device includes: a base unit including a magnetizer for forming a main magnetic path in the axial direction of a wire rope, and a magnetic sensor for detecting a leakage magnetic flux generated by a wire rope damaged part; and a guide unit including guide members and a guide plate which are formed in U shapes along the outer circumference of the wire rope, wherein the guide unit is fixed to the base unit.
Figure 1 is a perspective view of the wire rope flaw detection device 1 in embodiment 1 of the present invention, in which a wire rope 2 to be examined is also shown. Figure 2 is a perspective view of the wire rope flaw detection device 1 when a guide unit 30 provided at an upper part thereof is detached. Figure 3 is a perspective view of the guide unit 30 separated into a guide plate 21 and guide members 22.
In figure 1, the wire rope flaw detection device 1 includes a base unit 20 and the guide unit 30, and the guide unit 30 is fixed to the base unit 20 by bolts. The wire rope 2 to be examined passes through a substantially U-shaped portion 30a at an upper part of the guide unit 30. As shown in figures 2 and 3, the guide unit 30 includes the guide plate 21 and the guide members 22.
As shown in figure 2, the base unit 20 includes a main circuit portion 15, a column 16, and a base cover 17. The main circuit portion 15 includes a magnetizer 10, a magnetic sensor 11, and a support base 12 for the magnetic sensor 11. The magnetizer 10 includes a back yoke 3, permanent magnets 4a, 4b, and magnetic pole pieces 5a, 5b. The wire rope flaw detection device 1 in the present embodiment 1 forms, by the magnetizer 10, a main magnetic path in the passing wire rope 2 in a predetermined range in the axial direction, and detects, by the magnetic sensor 11, a leakage magnetic flux generated due to breakage of the wire rope 2 and disconnection of an element wire thereof.
The magnetizer 10, in order to form a main magnetic path in the wire rope 2, includes: the back yoke 3 made of a ferromagnetic material such as iron; a pair of permanent magnets 4a, 4b for magnetization, provided on both ends of the back yoke 3 with their magnetic poles opposite to each other; and the magnetic pole pieces 5a, 5b made of a ferromagnetic material and provided on magnetic pole surfaces, of the permanent magnets 4a, 4b, that are opposite to the back yoke 3. The upper parts of the magnetic pole pieces 5a, 5b have substantially U shapes along the outer circumference of the wire rope 2. Columns 16 are provided at both ends of the back yoke 3 of the magnetizer 10, and the guide members 22 are provided above the columns 16. The columns 16 and the back yoke 3 of the main circuit portion 15 are fitted into each other and fixed by bolts. The base cover 17 is provided for protecting a signal processing circuit portion (not shown) for processing a signal detected by the magnetic sensor 11 provided to the main circuit portion 15.
In the state in which the base unit 20 and the guide unit 30 are assembled as shown in figure 1, the guide members 22 are located on the outer sides in the wire rope axial direction of the magnetic pole pieces 5a, 5b. Similarly to the magnetic pole pieces 5a, 5b, the upper parts of the guide members 22 are formed substantially in U shapes along the outer circumference of the wire rope 2 as in the magnetic pole pieces 5a, 5b.
The guide plate 21 is made of a nonmagnetic material such as stainless and is provided substantially in close contact with the cross-section U-shaped parts of the magnetic pole pieces 5a, 5b. That is, the guide plate 21 is provided at upper part of the magnetizer 10 and the magnetic sensor 11 and has a function of protecting the magnetic pole pieces 5a, 5b and the magnetic sensor 11. Further, the guide plate 21 has a guide function for causing the wire rope 2 to pass smoothly. In figure 2, the substantially U-shaped portions formed at the upper parts of the guide plate 21 and the guide members 22 and along the outer circumference of the wire rope 2 are collectively denoted by 30a.
Pat. 10,571,429 U.S. class 1/1 Int. class G01N 27/82
Inventor: Yoshiyuki Terai, Tokyo, JP., Takashi Yoshioka, Tokyo, JP., Tomokazu Hoshinoo, Tokyo, JP., Masao Akashi, Tokyo, JP.
Assignee: Mitsubishi Electric Corp., Chiyoda-Ku, Tokyo, JP.
