Intermediate frequency furnace magnet yoke structure

Abstract

The utility model discloses an intermediate frequency furnace magnet yoke structure, which comprises two symmetrical side plates and a plurality of stacked magnet yoke sheets clamped between the two side plates, the two side plates and the plurality of magnet yoke sheets are connected and fixed through a screw rod and a nut and form a magnet yoke component, the screw rod correspondingly penetrates through the side plates and the magnet yoke sheets, and the screw rod is connected with the magnet yoke sheets through a nut. The radian of the inner cambered surface of the magnet yoke part is the same as that of the outer cambered surface of the induction coil. The upper and lower ends of the magnet yoke part are provided with protruding parts used for restraining magnetic fields at the upper and lower ends of the induction coil. The induction coil is restrained to diverge a magnetic field outwards to the greatest extent, the loss of an outer magnetic circuit is reduced, the induction heating and redness phenomena of the outer magnetic circuit to the steel structure furnace shell are reduced, a short circuit ring is omitted, the electric efficiency is improved, the practicability is high, and the induction coil is suitable for market popularization and use.

Description

Technical Field

[0001] The utility model relates to the technical field of medium frequency furnaces, in particular to a magnetic yoke structure of a medium frequency furnace. Background Art

[0002] The medium frequency furnace is an AC power supply device with a frequency of 100Hz-10000Hz. This AC current is sent into a loop composed of a capacitor and an induction coil, generating high-density magnetic lines of force in the induction coil, cutting the metal material contained in the induction coil, and generating large eddy currents in the metal material. In order to improve the good loop of the magnetic field, a bar yoke (made of a material with good magnetic conductivity) is usually used, close to the periphery of the induction coil to facilitate the formation of a closed loop of the magnetic field of the induction coil, reduce the magnetic field loss and improve work efficiency. At the same time, the constraint of the yoke on the magnetic field greatly reduces the induction heating of the steel structure furnace shell by the magnetic field. The traditional yoke is a straight bar type. Its defect is that the central magnetic field of the induction coil will flow into the yoke in an arc. This arc magnetic line of force will induction heat the steel shell furnace body, which is undesirable. Therefore, two Faraday coils, namely short-circuit rings, are installed at the upper and lower ends of the induction coil. Although the short-circuit ring has a magnetic shielding effect on the upper and lower steel structures of the furnace shell and is not heated, there is a serious consequence of large electrical efficiency loss.

[0003] The patent with authorization announcement number CN210781426U discloses a water-cooled variable frequency furnace inductor, including an induction coil component and a yoke component. The yoke component is installed on the outside of the induction coil component. The induction coil component includes an induction coil. The top and bottom of the induction coil are provided with short-circuit rings for absorbing magnetic fields. It has the above-mentioned problems and defects. Utility Model Content

[0004] The technical problem to be solved by the utility model is to overcome the existing defects and provide a medium frequency furnace yoke structure, which can maximally constrain the induction coil to radiate the magnetic field outward, reduce the external magnetic circuit loss, reduce the induced heating and reddening of the steel structure furnace shell by the external magnetic circuit, eliminate the short-circuit ring, improve the electrical efficiency, have strong practicality, be suitable for market promotion and use, and can effectively solve the problems in the background technology.

[0005] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: a medium frequency furnace yoke structure, comprising two symmetrical side plates and a plurality of stacked yoke sheets clamped between the two side plates, the two side plates and the plurality of yoke sheets are connected and fixed by screw rods and nuts to form a yoke component, the screw rods pass through the side plates and the yoke sheets correspondingly, the curvature of the inner arc surface of the yoke component is the same as the curvature of the outer circle of the induction coil, and the upper and lower ends of the yoke component have protrusions for constraining the magnetic fields at the upper and lower ends of the induction coil.

[0006] Preferably, the protruding parts at the upper and lower ends of the yoke component are correspondingly located above and below the induction coil and are correspondingly attached to the upper and lower ends of the induction coil. The protruding parts extend towards the axis of the induction coil and extend beyond the inner wall of the induction coil.

[0007] Preferably, both the side plate and the yoke sheet are of channel structure.

[0008] Preferably, insulating sleeves are also sleeved at both ends of the lead screw. The nut is threadedly connected to the lead screw and makes the insulating sleeve abut against the side plate. The lead screw and the nut are made of non-magnetic materials.

[0009] Preferably, multiple groups of the lead screws and nuts are provided, and the side plate and the yoke sheet are both provided with through holes for the lead screws to pass through.

[0010] Preferably, the side plate is one of aluminum plate, copper plate, stainless steel or non-magnetic steel.

[0011] Preferably, the yoke sheet is made of silicon steel sheet with high magnetic permeability and low loss.

[0012] Preferably, the yoke sheet is made of silicon steel sheet.

[0013] Compared with the prior art, the beneficial effects of the present utility model are as follows: Two side plates and several yoke sheets are connected and fixed by lead screws and nuts to form a yoke component. The radian of the inner arc surface of the yoke component is the same as the outer arc radian of the induction coil. Both the upper and lower ends of the yoke component have protruding parts, which can make the yoke closely adhere to the outside of the induction coil and wrap the upper and lower ends of the induction coil, maximizing the constraint of the induction coil from emitting magnetic field outwards. There is no need to set a short-circuit ring, reducing the magnetic induction of the magnetic field on the steel structure furnace shell, and at the same time improving the electromagnetic efficiency of the induction coil, with obvious power-saving effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is a schematic structural diagram of the present utility model;

[0015] Figure 2 is a partial structural schematic diagram of the present utility model;

[0016] Figure 3 is a schematic structural diagram of the yoke sheet of the present utility model;

[0017] Figure 4 is an implementation schematic diagram of the present utility model.

[0018] In the figure: 1 yoke sheet, 2 side plate, 3 lead screw, 4 nut, 5 insulating sleeve. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0019] The present invention can be explained in detail through the following embodiments. The purpose of disclosing the present invention is to protect all technical improvements within the scope of the present invention. In the description of the present invention, it should be understood that if there are terms such as "upper", "lower", "front", "back", "left", "right", etc. indicating directions or positional relationships, they only correspond to the drawings of the present application for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific direction.

[0020] See also Figures 1-4 The utility model provides a technical solution: a medium frequency furnace yoke structure, comprising two symmetrical side plates 2 and a plurality of stacked yoke sheets 1 clamped between the two side plates 2, the two side plates 2 and the plurality of yoke sheets 1 are connected and fixed by screw rods 3 and nuts 4 to form a yoke component, the screw rods 3 pass through the side plates 2 and the yoke sheets 1 correspondingly, the curvature of the inner arc surface of the yoke component is the same as the curvature of the outer circle of the induction coil, and the upper and lower ends of the yoke component are provided with protrusions for constraining the magnetic fields at the upper and lower ends of the induction coil;

[0021] Since the curvature of the inner arc surface of the yoke component is the same as the curvature of the outer circle of the induction coil, the upper and lower ends of the yoke component are provided with protrusions, so that the yoke can be closely attached to the outer side of the induction coil and wrap the upper and lower ends of the induction coil, eliminating the short-circuit ring, reducing the magnetic induction of the magnetic field to the steel structure furnace shell, and at the same time improving the electromagnetic efficiency of the induction coil, which has a significant power saving effect;

[0022] Specifically, the protrusions at the upper and lower ends of the yoke component are correspondingly located above and below the induction coil and correspondingly fit with the upper and lower ends of the induction coil, and the protrusions extend toward the axis of the induction coil and exceed the inner wall of the induction coil, ensuring that the protrusions can cover the magnetic field constraining the upper and lower ends of the induction coil;

[0023] It should be noted that, in this embodiment, the side plate 2 and the yoke sheet 1 are both groove-shaped structures, that is, after a plurality of yoke sheets 1 are stacked, the upper and lower ends thereof are both protruding, and the induction coil is located inside the plurality of yoke sheets 1, which constrains the induction coil to radiate a magnetic field outward to the maximum extent;

[0024] Furthermore, both ends of the screw rod 3 are sleeved with insulating sleeves 5, the nut 4 is threadedly connected to the screw rod 3 and the insulating sleeve 5 is in contact with the side plate 2, the screw rod 3 and the nut 4 are made of non-magnetic material to reduce the induced eddy current heating phenomenon; the screw rod 3 and the nut 4 are provided with multiple groups, and the side plate 2 and the yoke sheet 1 are provided with through holes for the screw rod 3 to pass through;

[0025] In addition, the side plate 2 is made of aluminum plate, copper plate, stainless steel or non-magnetic steel to avoid heating due to induced eddy currents, and no water cooling sleeve is required, thus reducing costs; the yoke plate 1 is made of silicon steel sheet.

[0026] The parts not detailed in this utility model are prior arts. For those skilled in the art, it is obvious that this utility model is not limited to the details of the above-mentioned exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or basic characteristics of this utility model. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-restrictive, aiming to encompass all changes falling within the meaning and scope of equivalent elements in the content of this utility model.

Claims

1. A medium frequency furnace yoke structure, comprising two symmetrical side plates (2) and a plurality of stacked yoke sheets (1) clamped between the two side plates (2), characterized in that: The two side plates (2) and the plurality of yoke sheets (1) are connected and fixed by means of a screw rod (3) and a nut (4) to form a yoke component. The screw rod (3) passes through the side plates (2) and the yoke sheets (1) respectively. The curvature of the inner arc surface of the yoke component is the same as the curvature of the outer circle of the induction coil. The upper and lower ends of the yoke component both have protrusions for constraining the magnetic fields at the upper and lower ends of the induction coil.

2. The medium frequency furnace yoke structure according to claim 1, characterized in that: The protrusions at the upper and lower ends of the yoke component are correspondingly located above and below the induction coil and correspondingly fit with the upper and lower ends of the induction coil. The protrusions extend toward the axis of the induction coil and exceed the inner wall of the induction coil.

3. The medium frequency furnace yoke structure according to claim 1, characterized in that: The side plate (2) and the yoke plate (1) are both groove-shaped structures.

4. The medium frequency furnace yoke structure according to claim 1, characterized in that: Insulating sleeves (5) are sleeved on both ends of the screw rod (3); the nut (4) is threadedly connected to the screw rod (3) so that the insulating sleeve (5) contacts the side plate (2); and the screw rod (3) and the nut (4) are made of non-magnetic material.

5. The medium frequency furnace yoke structure according to claim 1, characterized in that: The screw rod (3) and the nut (4) are provided in multiple groups, and the side plate (2) and the yoke plate (1) are both provided with through holes for the screw rod (3) to pass through.

6. The medium frequency furnace yoke structure according to claim 1, characterized in that: The side plate (2) is an aluminum plate, a copper plate, stainless steel or non-magnetic steel.

7. The medium frequency furnace yoke structure according to claim 1, characterized in that: The yoke sheet (1) is made of silicon steel sheet.

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