JPS5847429Y2 - metal detection coil device - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to a metal detection coil device.

Conventional means for non-contact detection of metal pieces or objects containing metal (hereinafter referred to as metal) uses a detection coil to generate an electromagnetic field, and detects metal from changes in the impedance or induced voltage of the detection coil. It is something.

A conventional coil supporter for a detection coil is made of ceramic such as alumina oxide or magnesia oxide in a cylindrical shape, and a coil wire is wound around the cylindrical coil supporter to form a detector. .

By the way, ceramic insulating materials have a negative temperature characteristic of specific resistance value.

Therefore, compared to low temperatures such as 100 to 200 degrees Celsius, the specific resistance value decreases to several tenths of a liter or several hundredths at high temperatures, such as 900 to 1000 degrees Celsius, so the impedance of the detection coil changes. do.

Therefore, temperature changes will generate noise, reduce the signal-to-noise ratio, and may even not function as a detection coil at all.

Based on the above, in order to detect metal during a hot processing process using a conventional detection coil, for example, the detection coil itself must be forcibly cooled, or a heat insulating plate must be installed to prevent deterioration of detection accuracy. However, the detection work becomes complicated and the detection accuracy inevitably deteriorates.

Furthermore, when detecting molten steel level in a ladle where the detection coil cannot be cooled, or detecting steel in a heating furnace under high-precision adverse environments, for example, a ceramic coil supporter produces large thermal noise and is difficult to detect. Moreover, it caused insulation deterioration and had problems with durability.

The present invention eliminates these drawbacks and provides a detection coil device that is capable of always stable detection and has high durability.

In other words, the detection coil device of the present invention is constructed by intersecting one or more auxiliary plates made of a heat-resistant material so as to be perpendicular to both sides of a substrate made of a heat-resistant material, and at the same time, the metal edges of the substrate and the auxiliary plate are A coil winding frame is formed by providing a plurality of concave or mountain-shaped notches on each edge in a direction parallel to each other, and the coil strand is wound several times around the notches of the coil winding frame. This is a metal detection coil device.

The present invention will now be described in detail with reference to an illustrative embodiment.

FIG. 1 is a diagram showing an embodiment of the present invention, in which A is a front view, the mouth is a plan view, and C is a side view.

In the figure, 1 is the substrate of the coil winding frame 3, a plan view of which is shown in FIG.
, 1-b and the intermediate part 1-c, and the intermediate part 1
-c is provided with a plurality of mountain-shaped (or concave-shaped) cuts 1-d.

Note that the collar portions 1-a and 1-b are provided to facilitate the winding work when winding the coil wire 4, which will be described later, and for convenience when the usage is as shown in FIG. However, it is not required.

Further, the number of cuts 1-d may be a number corresponding to the number of turns of the coil wire 4.

1-e is a rectangular notch for engaging an auxiliary plate 2, which will be described later, and in this embodiment three rectangular notches are provided.

Reference numeral 2 denotes an auxiliary plate of the coil winding frame 3, whose plan view is shown in FIG. (may be concave) cut 2-
d is provided, and a notch 2-e for engaging with the notch 1e of the substrate 1 from one of both edges on the other side toward the center part.
is provided.

However, in this embodiment, the three auxiliary plates 2 are
By engaging the notches 2-e with the three notches 1-e of the board 1 and assembling the coil, a coil winding frame 3 is constructed in which the auxiliary plates intersect perpendicularly to both sides of the board. Ru.

Both the substrate 1 and the auxiliary plate 2 for constructing the coil winding frame 3 of the present invention are made of a heat-resistant material, and examples of the heat-resistant material include a mica plate and a recrystallized plate whose specific resistance value changes little due to temperature changes. Aluminous ceramics or quartz are suitable.

Reference numeral 4 denotes a coil wire, such as a heat-resistant wire such as a nichrome wire, and the substrate 1 is framed as the coil winding frame.
The detection coil device 5 is constructed by winding one thread in each groove of the notch 1-d of the auxiliary plate 2 and the notch 2d of the auxiliary plate 2.

In the detection coil device 5, the coil wire 4 is connected to the coil winding frame 3.
The area in contact with the coil is extremely small, and most of it is floating in the air, so even if there is a slight change in the resistivity of the coil winding frame due to temperature changes, the effect (change in coil impedance) is minimized. I rarely receive it,
In addition, since cuts 1-d and 2-d for winding the coil wire 4 are provided in the substrate 1 and the auxiliary plate 2 of the coil winding frame 3, respectively, the coil wire 4 is prevented from thermal distortion etc. at high temperatures. Even if this occurs, phase-to-phase short circuit between the coil wires 4 can be prevented, and further,
Since the coil winding frame is made of a heat-resistant material such as a mica plate, recrystallized alumina ceramic, or quartz, which has a small change in specific resistance value with respect to temperature changes, impedance changes and functional deterioration of the detection coil device 5 at high temperatures are prevented. This allows for extremely stable detection even at unprecedentedly high temperatures and in locations where forced cooling is not possible.

FIG. 4 shows a detection coil loading frame 6 made of a fireproof material such as firebrick, one side of which is open and lower.
Inner walls 8-a and 8-b of the open lower portion are provided with cuts 8-C in the depth direction.

The notch 8-C is for inserting and supporting the detection coil device 5.

That is, the collar 1-a of the detection coil device 5. 1-b is inserted into the notch 8-C to support the detection coil device 5.

Thus, for example, in order to detect the level of molten steel in a ladle (not shown), a detection coil insertion frame 6 equipped with a detection coil device 5 is assembled into the inner wall of the ladle to detect the level of molten steel.

In addition to the above-mentioned functions, the present invention also has (coil element wire 4
) The coil winding frame is made of a heat-resistant material such as mica plate, which has a small change in resistivity due to temperature changes, and the contact area with the coil winding is small, so that carbon in the molten metal object is reduced during long-term use. Even if some amount of other impurities are present in the detection coil device 5, it does not cause insulation defects and has high durability, which is extremely effective in terms of maintenance.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention, in which A is a front view, the mouth is a plan view, and C is a side view. Fig. 2 is a plan view of a coil winding frame substrate in an embodiment of the present invention, Fig. 3 is a plan view of a coil winding frame auxiliary plate in an embodiment of the present invention, and Fig. 4 is a detection coil insertion frame. FIG. In the figure, 1: board, 1-d: notch, 2: auxiliary plate, 2-d:
3: coil winding frame; 4: coil wire; 5: detection coil device.

Claims (1)

[Scope of utility model registration request] One or more auxiliary plates made of heat-resistant material are crossed and framed perpendicularly to both sides of the substrate made of heat-resistant plates, and each edge in a direction parallel to each other among all edges of the substrate and auxiliary plates A metal detection coil device characterized in that a coil winding frame is formed by providing a plurality of concave or mountain-shaped notches in the coil winding frame, and a coil wire is wound a plurality of times around the notches of the coil winding frame.