Forming mold for increasing magnetic declination of magnetic ring for microwave oven magnetron

Abstract

A forming die for increasing magnetic declination of a magnetic ring for a microwave oven magnetron comprises an upper die, a lower stamping die, a non-magnetic core rod, a green body, an alloy sleeve and a magnetic conducting ring, the green body is placed in the alloy sleeve, the non-magnetic core rod penetrates through the green body and limits the green body together with the alloy sleeve, the magnetic conducting ring is arranged on the alloy sleeve in a sleeving mode, and the magnetic declination of the magnetic ring is increased. The side surfaces of the non-magnetic core rod, the green body, the alloy sleeve and the magnetic conductive ring are simultaneously propped against the upper die, the lower punching die is positioned in the alloy sleeve and is propped against the green body together with the upper die, and the inner diameter of the magnetic conductive ring is the same as the outer diameter of the alloy sleeve and is coaxial with the outer diameter of the alloy sleeve. Therefore, the magnetic field during forming is optimized, and the magnetic declination of the magnetic ring is improved.

Description

Technical Field

[0001] The utility model relates to the field of magnetic ring production, in particular to a forming die for increasing the magnetic deflection angle of a magnetic ring used for a microwave oven magnetron. Background Art

[0002] A microwave oven magnetron primarily consists of a magnetic ring, pole piece, and bracket, which together form the magnetron's magnetic field circuit. The magnetic ring, acting as the source of the magnetic field, has a magnetic property that directly affects the magnitude and uniformity of the magnetic field, thereby influencing the magnetron's output frequency, spectral characteristics, and efficiency.

[0003] Among all magnetic rings, ferrite magnetic rings are mainly made by wet pressing. In order to increase the central Gauss of the magnetic ring, it is necessary to make the magnetic circuit more convergent toward the center during the wet pressing process of the magnetic ring, that is, to increase the magnetic deflection of the magnetic ring.

[0004] The wet pressing mold usually consists of an upper mold, a cavity, and a lower punch. The currently commonly used method to adjust the magnetic deflection angle is to change the thickness and shape of the non-magnetic conductive layer of the lower punch. However, this method has many restrictions on the thickness and shape of the Stellite layer. An unreasonable Stellite layer design can easily cause the magnetic ring to crack, reducing the product qualification rate and performance. Utility Model Content

[0005] The technical problem to be solved by the present invention is to overcome the defects of the prior art that there are many restrictions on the thickness and shape of the Stellite layer, and unreasonable Stellite layer design can easily lead to cracking of the magnetic ring, thereby reducing the product qualification rate and performance, and to provide a forming mold for increasing the magnetic deflection angle of the magnetic ring used in microwave oven magnetrons.

[0006] The utility model solves the technical problem by adopting a technical solution, which is a forming die for increasing the magnetic deflection angle of a magnetic ring for a microwave oven magnetron, comprising an upper die, a lower punch, a non-magnetic core rod, a green embryo, an alloy sleeve and a magnetic conductive ring, wherein the green embryo is placed in the alloy sleeve, the non-magnetic core rod passes through the green embryo and limits the green embryo together with the alloy sleeve, the magnetic conductive ring sleeve is arranged on the alloy sleeve, the side surfaces of the non-magnetic core rod, green embryo, alloy sleeve and magnetic conductive ring simultaneously abut against the upper die, the lower punch is located in the alloy sleeve and abuts against the green embryo together with the upper die, and the inner diameter of the magnetic conductive ring is the same as the outer diameter of the alloy sleeve and is coaxial.

[0007] Furthermore, the height of the magnetic conductive ring is lower than the height of the green body.

[0008] Furthermore, the magnetic ring is made of magnetic material or a permanent magnet.

[0009] Furthermore, the magnetic conductive material is 45 steel, hard alloy or copper.

[0010] Furthermore, the permanent magnet is a radially magnetized AlNiCo permanent magnet.

[0011] The utility model has the following beneficial technical effects:

[0012] The introduction of the magnetic ring allows the magnetic circuit to enter the lower punch die obliquely through the magnetic ring, thereby optimizing the magnetic field during forming and increasing the magnetic deflection of the magnetic ring. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 A structural diagram of a first embodiment of a forming die for increasing the magnetic deflection angle of a magnetic ring for a microwave oven magnetron according to the utility model;

[0014] Figure 2 This is a structural schematic diagram of Example 2 of a forming die for increasing the magnetic deflection angle of a magnetic ring for a microwave oven magnetron according to the present invention.

[0015] Description of reference numerals:

[0016] 1. Upper die; 2. Lower punch; 3. Non-magnetic core rod; 4. Green blank; 5. Alloy sleeve; 6. Magnetic ring; 7. Non-magnetic layer. DETAILED DESCRIPTION

[0017] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0018] Reference Figure 1 and Figure 2 This embodiment includes an upper die 1, a lower punch 2, a non-magnetic core rod 3, a green embryo 4, an alloy sleeve 5, and a magnetic ring 6. The green embryo 4 and the non-magnetic core rod 3 are both placed in the alloy sleeve 5, and the middle of the green embryo 4 is hollow. The non-magnetic core rod 3 passes through the green embryo 4 and limits the green embryo 4 together with the alloy sleeve 5. The magnetic ring 6 is sleeved on the alloy sleeve 5. The side surfaces of the non-magnetic core rod 3, the green embryo 4, the alloy sleeve 5, and the magnetic ring 6 simultaneously abut against the upper die 1. The lower punch 2 is located in the alloy sleeve 5 and abuts against the green embryo 4 together with the upper die 1. The inner diameter of the magnetic ring 6 is the same as the outer diameter of the alloy sleeve 5 and is coaxial.

[0019] The height of the magnetic ring 6 is lower than that of the green body. The magnetic ring 6 is made of a magnetic material or permanent magnet, including but not limited to 45 steel, cemented carbide, copper, and the like. The permanent magnet is a radially magnetized alnico permanent magnet with low coercivity. This reduces the magnetic attraction of the forming coil after power is removed, thus preventing magnetic attraction of powder to the cavity surface during filling and affecting mold closing. The number of magnetic rings 6 can be one or more, and their height is lower than that of the green body.

[0020] In addition, a non-magnetic conductive layer 7 is provided between the lower punch 2 and the green body 4 .

[0021] In Example 1, the outer diameter, inner diameter, and height of the magnetic ring green body were 72.0 mm, 24.82 mm, and 20.5 mm, respectively. The introduced magnetic ring 6 was made of 45-grade steel, with corresponding outer diameters, inner diameters, and heights of 104.6 mm, 81.6 mm, and 8 mm, respectively. Without the magnetic ring 6, the maximum declination angle of the forming magnetic field was 30°, and the Gaussian intensity at the center of the magnetic ring was 158.6 mT. With the 45-grade steel magnetic ring 6, the declination angle of the forming magnetic field was 32.5°, and the Gaussian intensity at the center of the magnetic ring was 161.2 mT, an increase of 2.6 mT.

[0022] In Example 2, the outer diameter, inner diameter, and height of the magnetic ring green body are 72.0 mm, 24.82 mm, and 20.5 mm, respectively. The introduced magnetic ring 6 is made of a radially magnetized alnico permanent magnet with a remanence of 1.26 T and an intrinsic coercive force of 50929 A / m. The corresponding outer diameter, inner diameter, and height dimensions are 104.6 mm, 81.6 mm, and 20 mm, respectively. Without the introduction of the magnetic ring 6, the maximum magnetic deflection angle of the formed magnetic field is 30°, and the Gaussian intensity at the center of the magnetic ring is 158.6 mT. After the introduction of the alnico permanent magnet magnetic ring 6, the magnetic deflection angle of the formed magnetic field is 58°, and the Gaussian intensity at the center of the magnetic ring is 163.8 mT, an increase of 5.2 mT in the center Gaussian intensity.

[0023] The above are all preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Identical parts are denoted by the same reference numerals. It should be noted that the terms "front," "rear," "left," "right," "up," and "down" used in the following description refer to directions in the accompanying drawings, and the terms "inside" and "outside" refer to directions toward or away from the geometric center of a specific component, respectively. Therefore, any equivalent changes made based on the structure, shape, and principle of the present invention should be included within the scope of protection of the present invention.

Claims

1. A forming die for increasing the magnetic deflection angle of a magnetic ring for a microwave oven magnetron, characterized in that: The invention comprises an upper die (1), a lower punch (2), a non-magnetic core rod (3), a green embryo (4), an alloy sleeve (5) and a magnetic ring (6), wherein the green embryo (4) is placed in the alloy sleeve (5), the non-magnetic core rod (3) passes through the green embryo (4) and limits the green embryo (4) together with the alloy sleeve (5), the magnetic ring (6) is sleeved on the alloy sleeve (5), the side surfaces of the non-magnetic core rod (3), the green embryo (4), the alloy sleeve (5) and the magnetic ring (6) simultaneously abut against the upper die (1), the lower punch (2) is located in the alloy sleeve (5) and abuts against the green embryo (4) together with the upper die (1), and the inner diameter of the magnetic ring (6) is the same as the outer diameter of the alloy sleeve (5) and is coaxial.

2. A forming die for increasing the magnetic deflection angle of a magnetic ring for a microwave oven magnetron according to claim 1, characterized in that: The height of the magnetic conductive ring (6) is lower than the height of the green body.

3. A forming die for increasing the magnetic deflection angle of a magnetic ring for a microwave oven magnetron according to claim 1, characterized in that: The magnetic ring (6) is made of magnetic material or a permanent magnet.

4. A forming die for increasing the magnetic deflection angle of a magnetic ring for a microwave oven magnetron according to claim 1, characterized in that: The magnetic material is 45 steel, hard alloy or copper.

5. A forming die for increasing the magnetic deflection angle of a magnetic ring for a microwave oven magnetron according to claim 1, characterized in that: The permanent magnet is a radially magnetized AlNiCo permanent magnet.

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