WO2004090929A1

WO2004090929A1 - Anode for magnetron in microwave oven, manufacturing method of the same and forming apparatus for thereof

Info

Publication number: WO2004090929A1
Application number: PCT/KR2004/000857
Authority: WO
Inventors: Bon-Su Ku; Kye-Young Lee
Original assignee: Bon-Su Ku; Kye-Young Lee
Priority date: 2003-04-14
Filing date: 2004-04-14
Publication date: 2004-10-21

Abstract

The present invention relates to the anode of a magnetron for microwave ovens, and manufacturing method and forming apparatus therefore. In particular, the present invention relates to the anode of a magnetron for microwave ovens, and manufacturing method and forming apparatus therefor, in which each casing and vanes are integrally formed rather than being separately formed, so that processes of separately forming casings and vanes, accurately arranging the vanes in the casings and attaching the vanes to the casings are not required, thus being efficient.

Description

ANODE FOR MAGNETRON IN MICROWAVE OVEN, MANUFACTURING METHOD OF THE SAME AND FORMING APPARATUS FOR THEREOF

Technical Field

The present invention relates, in general, to the anode of a magnetron for microwave ovens, and manufacturing method and forming apparatus therefor, and, more particularly, to the anode of a magnetron for microwave ovens, and manufacturing method and forming apparatus therefor, in which each casing and the vanes thereof are integrally formed rather than being separately formed, so that processes of separately forming casings and vanes, accurately arranging the vanes in the casings and attaching the vanes to the casings are not required, thus being efficient.

Background Art

A microwave oven is an appliance that cooks food using microwaves generated by the resonance (oscillation) of a magnetron. A technology of a magnetron is disclosed in Korean Unexamined Utility Model Publication No. 1999- 007640. Referring to the disclosed technology, a general magnetron is composed of an anode, a cathode part and a magnetic part. Known materials are referred to for the structures and operations of the cathode part and the magnetic part, and only a description of the anode is given below.

The anode, which will be described in detail later, is composed of cylindrical casings, a plurality of vanes radially attached to the inner walls of the casings, and dual straps. In this case, the casings and the vanes are brazed to each other in such a way that the vanes are radially arranged at the one ends thereof on the inner walls of the casings, annular silver rings are placed on the upper ends of the casings and the vanes where they come into contact with each other, the silver rings are melted at high temperature, and, therefore, liquid is allowed to flow along the contact surfaces of the casings and the vanes . Thereafter, the annular straps are assembled onto the vanes with silver being plated thereon, and are brazed to the vanes as the silver plated thereon melts at the time of the attachment of the vanes to the casings .

In the magnetron manufactured with the above- described elements, particularly in an anode, vanes must be radially arranged at regular intervals on the inner walls of the casings prior to the attachment of the vanes to the casings, so that there are problems in work efficiency and mass production because a lot of time and accurate work are required to accurately arrange the vanes at the same intervals . Furthermore, in the manufacture of the anode, the casings and the vanes are separately formed and, thereafter, the vanes are attached to the casings, so that forming and attaching processes are all necessary and, therefore, a problem arises in that work time and work costs are additionally required.

Furthermore, since vanes are radially brazed to casings and annular straps are arranged on and silver- welded to the vanes, accurate surface contact is not achieved between the vanes and the straps, so that a problem arises in that defects occur, thus deteriorating efficiency.

Disclosure of the Invention

An object of the present invention is to provide the anode of a magnetron for microwave ovens, and manufacturing method and forming apparatus therefor, in which each casing and the vanes thereof are integrally formed, so that there can be eliminated processes of separately forming casings and vanes, accurately arranging the vanes in the casings, and attaching the vanes to the casings.

Another object of the present invention is to provide the anode of a magnetron for microwave ovens, and manufacturing method and forming apparatus therefor, in which each casing and the vanes thereof are integrally formed with the strap notches formed in conformity with straps, so that accurate surface contact is achieved between the vanes and the straps, thus improving efficiency.

A further object of the present invention is to provide the anode of a magnetron for microwave ovens, and manufacturing method and forming apparatus therefor, in which each casing and vanes are integrally formed, so that work efficiency is increased and mass production can be implemented. The above objects are achieved by the anode of a magnetron for microwave ovens, including a cylindrical upper casing; a plurality of first vanes integrated with the upper casing, and radially arranged on an inner wall of the upper casing; a cylindrical lower casing attached to a bottom of the upper casing at a bottom thereof; a plurality of second vanes radially arranged to be integrated with an inner wall of the lower casing, and attached to bottoms of the first vanes; and dual straps attached to the first and second vanes, respectively. Meanwhile, the above objects are also achieved by the anode of a magnetron for microwave ovens, including a cylindrical upper casing; a plurality of first vanes radially integrated with an inner wall of a lower portion of the upper casing; a cylindrical center casing attached to a bottom of the upper casing; a plurality of second vanes radially integrated with an inner wall of the center casing, and attached to bottoms of the first vanes on tops thereof; a cylindrical lower casing attached to a bottom of the center casing on a bottom thereof; a plurality of third vanes radially integrated with an inner wall of a lower portion of the lower casing, and attached to bottoms of the second vanes on bottoms thereof; and dual straps interposed between the first and second vanes and between the second and third vanes, respectively.

Brief Description of the Drawings

The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is an exploded perspective view showing the anode of a magnetron in accordance with an embodiment of the present invention;

FIG. 2 is a sectional view showing the anode of a magnetron in accordance with an embodiment of the present invention; FIG. 3 is a sectional view showing the step of forming upper or lower casings with a first punch;

FIG. 4 is a perspective view showing an upper or lower casing formed by the first punch;

FIG. 5 is a sectional view showing the step of forming vanes on the bottom of an upper or lower casing with a second punch;

FIG. 6 is a perspective view showing the second punch turned upside down; FIG. 7 is a perspective view showing an upper or lower casing and vanes formed by the second punch;

FIG. 8 is a sectional view showing the step of forming strap notches and antenna notches by pressing vanes with a third punch; FIG. 9 is a perspective view showing the third punch turned upside down;

FIG. 10 is a perspective view showing an upper or lower casing and vanes formed by the third punch;

FIG. 11 is a sectional view showing the step of cutting out the bottom of the upper or lower casing having undergone the step of FIG. 10;

FIG. 12 is a sectional view showing the step of attaching the upper casing and the vanes thereof to the lower casing and the vanes thereof, respectively; FIG. 13 is a sectional view showing the step of attaching dual straps to the vanes attached to each other;

FIG. 14 is a flowchart illustrating a process of manufacturing the anode of a magnetron for microwave ovens in accordance with the embodiment of the present invention; FIGS. 15a and 15b are exploded perspective views showing the anodes of a magnetron fro microwave ovens in accordance with other embodiments of the present invention;

FIG. 16 is an exploded perspective view showing the anode of a magnetron for microwave ovens in accordance with another embodiment of the present invention; FIG. 17 is a sectional view showing the anode of a magnetron for microwave ovens in accordance with the embodiment of the present invention;

FIG. 18 is a sectional view showing the step of forming an upper or lower casing with a first punch; FIG. 19 is a perspective view showing an upper or lower casing formed by the first punch;

FIG. 20 is a sectional view showing the step of forming first or third vanes to be integrated with an upper or lower casing using a second punch; FIG. 21 is a perspective view showing the second punch turned upside down;

FIG. 22 is a perspective view showing an upper or lower casing and first or third vanes formed by the second punch; FIG. 23 is a sectional view showing the step of cutting out the bottom of an upper or lower casing;

FIG. 24 is a sectional view showing the step of forming first strap notches on the bottom of first or third vanes using a third punch; FIG. 25 is a perspective view showing the third punch turned upside down; FIG. 26 is a sectional view showing the upper or lower casing on which first strap notches are formed with the third punch;

FIG. 27 is a sectional view showing the step of integrally forming a center casing and second vanes with the third punch;

FIG. 28 is a perspective view showing the center casing and the second vanes formed by the third punch;

FIG. 29 is a sectional view showing the step of cutting out the bottom of the center casing;

FIG. 30 is a sectional view showing the step of forming the second strap notches on the bottoms of the second vanes with the third punch;

FIG. 31 is a sectional view showing the center casing and the second vanes finally formed;

FIG. 32 is a sectional view showing the step of mounting dual straps on the tops and bottoms of the second vanes finally formed;

FIG. 33 is a sectional view showing the step of attaching the upper casing, the center casing and the lower casing to each other; and

FIG. 34 is an exploded perspective view showing the anode of a magnetron for microwave ovens in accordance with another embodiment of the present invention.

Best Mode for Carrying Out the Invention Referring to FIGS. 1 and 2, a magnetron for microwave ovens in accordance with an embodiment of the present invention includes a cylindrical upper casing 10, a plurality of first vanes 20 radially formed on the inner wall of the lower portion of the upper casing 10 to be integrated with the upper casing 10, a cylindrical lower casing 30 attached to the lower surface of the upper casing 10 at the upper surface thereof, a plurality of second vanes 40 radially formed on the inner wall of the lower portion of the lower casing 30 to be integrated with the lower casing 30, and dual straps 50 and 60 attached to the first and second vanes 20 and 40 to electrically connect the first and second vanes 20, respectively.

For reference, reference numerals 10 and 30 denote the upper and lower casings, respectively, but both of them are identical with each other in essence. That is, the anode is formed by combining the two identical casings, with each of which the vanes are integrated and which are reversed with respect to each other. Accordingly, even though for ease of description, the casing, with which the first vanes 20 are integrated, is denoted by the upper casing 10 and the casing, with which the second vanes 40 are integrated, is denoted by the lower casing 30, those items are identical in essence. It can be expected that this feature is effective in mass production. The upper casing 10 and the plurality of first vanes 20 are integrally formed by sequentially pressing a copper disk 100 with punches of specific shapes (first, second and third punches), that is, by forging. The lower casing 30 and the plurality of second vanes 40, which are identical with the upper casing 10 and the first vanes 20, are integrally formed in the same manner as the upper casing 10 and the first vanes 20.

The upper casing 10, with which the first vanes 20 are integrated by forging, and the lower casing 30, with which the second vanes 40 are integrated by forging, are attached to each other by brazing, with the lower surfaces of the first and second vanes 20 and 40 being in contact with each other. The numbers of the first vanes 20 and the second vanes 40 are even each, and the first vanes 20 and the second vanes 40 are radially arranged on the inner walls of the lower portions of the upper and lower casings 10 and 30 at regular intervals, respectively. Strap notches 20a, 20a^f , 40a and 40a' , in which the dual straps 50 and 60 are placed, and antenna notches 20b and 40b, onto which antennas are mounted, are formed on the tops of the vanes 20 and 40.

Since the vanes 20 and 40 are integrated with the upper and lower casings 10 and 30, respectively, by forging as described below, the strap notches 20a and 20a' , and 40a and 40a' formed in the vanes 20 and 40, respectively, do not form rectilinear shapes, but form arcuate shapes that correspond to those of the straps 50 and 60. Accordingly, accurate surface contact can be achieved between the vanes 20 and the dual strap 50 and between the vanes 40 and the dual straps 60, so that the efficiency thereof can be improved.

For reference, the inside straps 50 of the dual straps 50 and 60 do not connect all the vanes, but alternately connect the vanes, thus electrically connecting halves of the vanes, respectively. The outside straps 60 thereof electrically connect the remaining halves of the vanes, respectively.

First and second protrusions 21 and 22, or 41 and 42, on which the inside and outside straps 50 and 60 are fixedly mounted, respectively, are projected from the strap notches 20a and 20a' , or 40a and 40a' , respectively. The first protrusions 21 and 41 are projected from the inner walls of the strap notches 20a and 40a with which the inside straps 50 and 60 come into contact, respectively, and the second protrusions 22 and 42 are projected from the outer walls of the strap notches 20a and 40a with which the outside straps 60 come into contact, respectively.

The outside inner walls of the strap notches 20a and 40a, in which the first protrusions 21 and 41 are formed, respectively, are located outside the outside inner walls of the neighboring strap notches 20a' and 40a' , respectively, whereas the inside inner walls of the strap notches 20a' and 40a' , in which the second protrusions 22 and 42 are formed, are located inside the inside inner walls of the neighboring strap notches 20a and 40a. Accordingly, the outside straps 60 do not come into contact with the vanes on which the inside straps 50 are fixedly mounted, whereas the inside straps 50 do not come into contact with the vanes on which the outside straps 60 are fixedly mounted.

The antenna notches 20b and 40b are formed on the tops of the vanes, on which the inside straps 50 are mounted, respectively, outside the strip notches 20a and 40a, respectively, and accommodate the lower ends of antennas, respectively.

In the meantime, the inside and outside straps 50 and 60 and the antennas are inserted into the strap notches 20a and 40a, and 20a' and 40a' and the antenna notches 20b and 40b with the surfaces thereof plated with silver, respectively, and are heated at high temperature, so that the inside and outside straps 50 and 60 and the antennas are brazed to the vanes as the silver plated on the surfaces melts .

A process of manufacturing the anode of a magnetron for microwave ovens according to an embodiment of the present invention, which is constructed as described above, is described below with reference to FIGS. 3 to 14.

After copper has been formed into a copper disk 100 of a specific thickness, the copper disk 100 is inserted into the forming depressing 101a of a die 101, and the top of the copper disk 100 is pressed with a circular rod- shaped first punch 102, as shown in FIG. 3. Then, the copper disk 100, as shown in FIG. 4, is formed into an upper or lower casing 10 or 30 with the top thereof opened at step S10. Although for ease of description, it has been described as being the upper or lower casing 10 or 30 herein, both of them are identical items as described above .

When the inner bottom of the upper or lower casing 10 or 30, as shown in FIG. 5, is pressed with a second punch 103, the plurality of first or second vanes 20 or 40 are formed to be integrated with the inner bottom of the upper or lower casing 10 or 30, as shown in FIG. 7, at step S20.

In that case, the second punch 103, as shown in FIG. 6, is formed in a circular rod shape. A plurality of vane forming slits 103a are radially formed at regular intervals in the bottom of the second punch 103 to press the bottom of the upper or lower casing 10 or 30 and, thus, form the plurality of first or second vanes 20 or 40.

When the first or second vanes 20 or 40 are pressed with a third punch 104 after the plurality of first and second vanes 20 or 40 have been formed with the second punch 103, the strap notches 20a and 20a', or 40a and 40a', on which the dual strap 50 and 60 is mounted, and the antenna notches 20b and 40b, on which the antennas are mounted, are formed on the tops of the first or second vanes 20 or 40, and the first or second protrusions 21 and 22, or 41 and 42, on which the inside and outside straps 50 and 60 are fixedly mounted, are projected from the strap notches 20a and 20a', or 40a and 40a' at step S30.

In that case, the third punch 104, as shown in FIG. 9, is formed in a circular rod shape. A plurality of vane receiving slits 104a, into which the first or second vanes 20 or 40 are inserted, are radially formed in the bottom of the third punch 104, and a plurality of pressing protrusions 105, 106 and 107, which are used to press the tops of the first or second vanes 20 or 40 and, thus, form the strap notches 20a and 20a', or 40a and 40a', the antenna notches 20b or 40b, and the first or second protrusions 21 and 22, or 41 and 42, are projected from the bottoms of the vane receiving slits 104a. As described above, when the forming of the upper or lower casing 10 or 30 and the first or second vanes 20 or 40 is completed by the punches 102, 103 and 104, the cylindrical upper or lower casing 10 or 30 are drawn out of the fastening cavity of the first die 101, and thereafter the bottom of the upper or lower casing 10 or 30 is cut out with a cutting tool, as shown in FIG. 11, as step S40. After the bottoms of the upper and lower casings 10 and 30 are cut out as described above, the upper and lower casings 10 and 30 are brazed to each other with the bottoms of the first and second vanes 20 and 40 brought into contact with each other. In this case, the first vanes with the first protrusions 21 being projected from the strap notches 20a are attached to the second vanes with the second protrusions 42 being projected from the strap notches 40a' , whereas the first vanes with the second protrusions 22 being projected from the strap notches 20a' are attached to the second vanes with the first protrusions 41 being projected from the strap notches 40a, at step S50.

When the attachment of the upper and lower casings 10 and 30 and the first and second vanes 20 and 40 is completed as described above, the dual straps 50 and 60 are brazed to the strap notches 20a and 20a', and 40a and 40a', as shown in FIG. 13, at step S60, which completes the process of manufacturing the anode of the magnetron for microwave ovens in accordance with an embodiment of the present invention.

As a result, in the above-described embodiment, integrated items are manufactured with vanes being integrated with cylindrical casings so as to facilitate mass production, and the items, in which one is referred to as the upper casing 10 integrated with the first vanes 20 and the other is referred to as the lower casing 30 integrated with the second vanes 40, are brazed to each other with the bottoms thereof facing each other.

Accordingly, there can be eliminated conventional processes of separately forming casings and vanes, accurately arranging the vanes in the casings, and attaching the vanes to the casings.

Furthermore, the casings and the vanes are integrally formed and the strap notches of the vanes are formed in conformity with the arcuate shapes of the straps, so that tight surface contact can be achieved between the vanes and the straps, thus increasing the efficiency thereof. Furthermore, since the casing and the vanes are integrally formed as described above, work efficiency is increased and mass production is possible. Meanwhile, when the upper casing 10 integrated with the first vanes 20 and the lower casing 30 integrated with the second vanes 40 are brazed to each other with the bottoms thereof facing each other, the relative arrangement of the first and second vanes 20 and 40 as well as the arrangement of the upper and lower casings 10 and 30 are important. That is, the upper and lower casings 10 and 30 must be brazed to each other, with the upper and lower casings 10 and 30 being properly matched with each other, and with the first and second vanes 20 and 40 being properly matched with each other.

However, the above-described processes may not be performed easily. Therefore, another embodiment of the present invention presents an example in which the above- described operations can be easily performed.

Referring to FIG. 15a, fastening protrusions 10a and fastening depressions 30a are formed at the one ends of the upper and lower casings 10 and 30 while being alternately arranged.

Therefore, the fastening protrusions 10a are engaged with the fastening depressions 30a while the upper and lower casings 10 and 30 faces each other, so that the arrangement of the upper and lower casings 10 and 30 and the arrangement of the first and second vanes 20 and 40 can be achieved accurately and the upper and lower casings 10 and 30 can be easily brazed to each other. Even in the case of FIG. 15a, since a single type of casings are formed are used as the upper and lower casings, it is certain that mass production can be implemented.

However, as shown in FIG. 15b, the upper and lower casing 10 and 30 may have triangular teeth-shaped fastening structures 10b and 30b. In the case of the triangular teeth-shaped fastening structures 10b and 30b, it is preferable to locate the triangular teeth-shaped fastening structures 10b and 30b inside the circumferences of the one ends of the casings 10 and 30. Meanwhile, FIGS. 1 to 15b have illustrated the anode of a magnetron that can be applied to a domestic microwave oven. However, when a magnetron is applied to an industrial field, the structure of this magnetron becomes different from that of the above-described magnetron, which is illustrated by FIGS. 16 and 34. The anode of the magnetron, which has been illustrated is shown in FIGS. 1 to 15b and applied to the domestic microwave oven, is composed of the upper casing 10 integrated with the first vanes 20 and the lower casing 30 integrated with the second vanes 40, whereas the anode of a magnetron, which is shown in FIGS. 16 to 34 and applied to an industrial microwave oven, is composed of a total of three parts because a center casing further exists.

In the meantime, in the following drawings and description, regardless of the above-described references, upper, central and lower casings are denoted by 10, 30 and 50, respectively, corresponding first, second and third vanes are denoted by 20, 40 and 60, respectively, and inside and outside straps are denoted by 70 and 80, respectively. Referring to FIGS. 16 and 17, the anode of the magnetron for microwave ovens in accordance with another embodiment of the present invention includes the cylindrical upper casing 10, a plurality of first vanes 20 radially integrated with the inner wall of the lower portion of the upper casing 10, the cylindrical center casing 30 attached to the bottom of the upper casing 10, a plurality of second vanes 40 radially integrated with the inner wall of the center casing 30, the cylindrical lower casing 50 the bottom of which is attached to the bottom of the center casing 30, a plurality of third vanes radially integrated with the inner wall of the lower portion of the lower casing 50, and two dual straps 70 and 80 placed between the first and second vanes 20 and 40 and between the second and third vanes 40 and 60 to electrically connect the vanes, respectively. In that case, the upper and lower casings 10 and 50 except for the center casing 30 with a different size are merely identical items in reversed positions . Accordingly, this anode is effective in mass production.

The upper casing 10 and the plurality of first vanes 20 are integrally formed by sequentially pressing a copper disk 100 of a specific thickness with forming tools of specific shapes (a first punch, a second punch and a third punch), that is, by forging. The lower casing 50 and the plurality of third vanes 60 are also integrally formed in the same process as the upper casing 10 and the first vane 20.

The numbers of the first and third vanes 20 and 60 each are even, and the first and third vanes 20 and 60 are radially arranged on the inner walls of the upper and lower casings 10 and 50, respectively. Antenna notches 61 are formed on the tops of the upper and lower casings 10 and 50, respectively, and first strap notches 22 and 22', and 62 and 62' are formed on the bottoms of the upper and lower casings 10 and 50, respectively.

In this case, the antenna notches 21 and 61 are not formed on all the first and third vanes 20 and 60, respectively, but are formed on the tops of the halves of the first and third vanes 20 and 60, respectively.

The center casing 30 and the plurality of second vanes 40 are integrally formed by pressing a material with a third punch of a specific shape, that is, by forging. The number of the second vanes 40 is the same as that of the first and third vanes 20 and 60.

The center casing 30 integrated with the plurality of second vanes 40 by forging is brazed to the upper and lower casings 10 and 50 while being interposed between the upper and lower casings 10 and 50, that is, while being in contact with the bottoms of the upper and lower casings 10 and 50 at the top and bottom thereof.

In this case, second strap notches 41 and 41', in which dual straps 70 and 80 are placed, respectively, are formed on the top and bottom of the second vanes 40, respectively. The inside straps of the dual straps 70 and 80, which are placed in the second straps 41 and 41', do not connect all the second vanes 40, but alternately connect the second vanes 40, thus electrically connecting halves of the second vanes 40, respectively. The outside straps 80 thereof electrically connect the remaining halves of the second vanes 40, respectively.

First and second protrusions 42 and 43, on which the inside and outside straps 70 and 80 are mounted, are projected from the second strap notches 41 and 41' . The first protrusions 42 are projected from the inside inner walls of the second straps 41 with which the inside straps 70 come into contact, and the second protrusions 43 are projected from the outside inner walls of the second strap notches 41' with which the outside straps 80 come into contact.

In that case, the outside inner walls of the second strap notches 41, on which the first protrusions 42 are formed, are located outside the outside inner walls of the neighboring second strap notches 41' , and the inside inner walls of the second strap notches 41, on which the second protrusions 43 are formed, are located inside the inside inner walls of the neighboring second strap notches 41. Accordingly, the outside straps 80 do not come into contact with the second vanes on which the inside straps 70 are fixedly mounted, and the inside straps do not come into contact with the second vanes on which the outside straps 80 are fixedly mounted.

In the meantime, the inside and outside straps 70 and 80 and antennas are inserted into the second strap notches 41 and 41' and the antenna notches 21 and 61 with the surfaces thereof plated with silver, respectively, and are heated at high temperature, so that the inside and outside straps 70 and 80 and the antennas are brazed to the vanes as the silver plated on the surfaces melts . A process of manufacturing the anode of a magnetron for microwave ovens according to an embodiment of the present invention, which is constructed as described above, is described below with reference to FIGS. 18 to 34.

After copper has been formed into a copper disk 100 of a specific thickness, the copper disk 100 is inserted into the forming depressing 101a of a first die 101 having a flat bottom, and the top of the copper disk 100 is pressed with a circular rod-shaped first punch 102, as shown in FIG. 18. Then, the copper disk 100, as shown in FIG. 19, is formed into an upper or lower casing 10 or 50 with the top thereof opened.

When the inner bottom of the upper or lower casing 10 or 50, as shown in FIG. 20, is pressed with a second punch 103, the plurality of first or third vanes 20 or 60 are formed to be integrated with the inner bottom of the upper or lower casing 10 or 50, and the antenna notch 21 or 61 is formed on the first or third vanes 20 or 60, as shown in FIG. 22.

In that case, the second punch 103, as shown in FIG. 21, is formed in a circular rod shape. A plurality of vane forming slits 103a are radially formed in the inner bottom of the second punch 103 at regular intervals to press the bottom of the upper or lower casing 10 or 30 and, thus, form the plurality of first or second vanes 20 or 60.

When the plurality of first or third vane 20 and 60 is formed, the upper or lower casing 10 or 50 is drawn out of the fastening cavity 101a of the first die 101 and the bottom of the upper or lower casing 10 or 50 is cut out. Thereafter, the upper or lower casing 10 or 50 turned upside down is put into the fastening cavity 104b of a second die 104 from which a circular rod-shaped protrusion 104a is projected, and the bottoms of the first or third vanes 20 and 60 are pressed with a third punch 105, thus forming the first strap notches 22 and 22', or 62 and 62' in which the dual strap 70 and 80 is placed. In that case, the third punch 104, as shown in FIG.

25, is formed in a circular rod shape. A plurality of vane receiving slits 105a, into which the first or third vanes 20 or 60 are inserted, are radially formed in the bottom of the third punch 104, and a plurality of second pressing protrusions 105b and 105c, which is used to press the bottoms of the first or third vanes 20 or 60 and, thus, form the first strap notches 22 and 22', or 62 and 62' in which the dual strap 70 and 80 is placed, are projected from the bottoms of the vane receiving slits 105a. As described above, when the forming of the upper and lower casings 10 and 50 and the first and second vanes 20 and 60 is completed, a copper disk 100' of a specific thickness, as shown in FIG. 27, is put into the fastening cavity 101a of the first die 101 and the copper disk 100' is pressed with the third punch 105, thus integrally forming the cylindrical central casing 30 and the plurality of second vanes 40. In this case, the second strap notches 41 or 41' , in which the dual strap 70 and 80 is placed, are formed on the tops of the second vanes 40.

As described above, when the center casing 30 is integrated with the plurality of second vanes 40 and the second strap notches 41 and 41' are formed on the tops of the second vanes 40, the center casing 30 is drawn out of the fastening cavity 101a of the first dice 101 and the bottom of the center casing 30, as shown in FIG. 29, is cut out with a cutting tool. The center casing 30 turned upside down is put into the fastening cavity 101a of the first dice 101 and the second vanes 40, as shown in FIG. 30, are pressed with the third punch 105, thus forming the second strap notches 41 or 41' on the bottoms of the second vanes 40.

When the forming of the center casing 30 and the second vanes 40 is completed, the center casing 30 is drawn out of the fastening cavity 101a of the first die 101 and the dual straps 70 and 80, as shown in FIG. 32, are attached to the second strap notches 41 and 41' .

Thereafter, the center casing 30 is interposed between the upper and lower casings 10 and 50, the upper, center and lower casing 10, 30 and 50 are attached to each other, and the first, second and third vanes 20, 40 and 60 are attached to each other, thus completing the process of manufacturing the anode of a magnetron for microwave ovens according to the embodiment of the present invention.

In the meantime, the upper, center and lower casings 10, 30 and 50 are brazed to each other after being brought into accurate contact with each other. To this end, the upper, center and lower casings 10, 30 and 50 are engaged with each other to allow them to be combined with each other.

However, in view of the fact that the upper and lower casings 10 and 50 are identical items as described above, fastening protrusions 10a and 50a are formed on the upper and lower casings 10 and 50, and fastening depressions 30a are formed on the top and bottom of the center casing 30.

The brazing position of the upper, center and lower casings 10, 30 and 50 can be adjusted by the simple engagement of the fastening protrusions 10a and 50a and the fastening depressions 30a, and brazing is performed in position, thus considerably improving work efficiency.

Although the present invention has been described in detail with reference to the drawings, the present invention is not limited to this.

In addition to the above-described embodiments, it is possible to form the upper and lower casings 10 and 30 and first and second vanes 20 and 40 of the present invention only with a third punch. In this case, the vane receiving slits of the third punch function as vane forming slits . Although in the above-described FIG. 34, the fastening protrusions 10a and 50a are formed on the upper and lower casings 10 and 50 and the fastening depressions 30a are formed on the center casing 30, fastening depressions may be formed on the upper and lower casings 10 and 50 and fastening depressions may be formed on both surfaces of the center casing 30. In this case, the shape of the fastening protrusions may be triangular.

Industrial Applicability

As described above, in accordance with the present invention, each casing and the vanes thereof are integrally formed, so that there can be eliminated processes of separately forming the casing and the vanes, accurately arranging the vanes in the casing, and attaching the vanes to the casing. Furthermore, the casing and the vanes are integrally formed with the strap notches of the vanes formed in conformity with straps, so accurate surface contact is achieved between the vanes and the straps, thus increasing the efficiency thereof. Additionally, since the casing and the vanes are integrally formed, work efficiency is increased and mass production can be performed.

Claims

1. An anode of a magnetron for microwave ovens, comprising: a cylindrical upper casing; a plurality of first vanes integrated with the upper casing, and radially arranged on an inner wall of the upper casing; a cylindrical lower casing attached to a bottom of the upper casing at a bottom thereof; a plurality of second vanes radially arranged to be integrated with an inner wall of the lower casing, and attached to bottoms of the first vanes; and dual straps attached to the first and second vanes, respectively.

2. The anode as set forth in claim 1, wherein the upper casing and the first vanes are integrally formed and the lower casing and the second vanes are integrally formed by forging, and the upper casing integrated with the first vanes and the lower casing integrated with the second vanes are identical items.

3. The anode as set forth in claim 1 or 2, wherein a bottom of one of the upper and lower casings is provided with at least one fastening protrusion and a bottom of a remaining one of the upper and lower casings is provided with at least one fastening depression.

4. The anode as set forth in claim 1 or 2, wherein the upper and lower casings are provided with prominences and depressions in which fastening protrusions and fastening recesses are alternated arranged.

5. An anode of a magnetron for microwave ovens, comprising: a cylindrical upper casing; a plurality of first vanes radially integrated with an inner wall of a lower portion of the upper casing; a cylindrical center casing attached to a bottom of the upper casing; a plurality of second vanes radially integrated with an inner wall of the center casing, and attached to bottoms of the first vanes on tops thereof; a cylindrical lower casing attached to a bottom of the center casing on a bottom thereof; a plurality of third vanes radially integrated with an inner wall of a lower portion of the lower casing, and attached to bottoms of the second vanes on bottoms thereof; and dual straps interposed between the first and second vanes and between the second and third vanes, respectively.

6. The anode as set forth in claim 5, wherein the upper casing and the first vanes are integrally formed, the center casing and the second vanes are integrally formed, the lower casing and the third vanes are integrally formed by forging, and the upper casing integrated with the first vanes and the lower casing integrated with the third vanes are identical items .

7. The anode as set forth in claim 5 or 6, wherein the upper, lower and center casings are engaged with each other in a prominence and depression manner.

8. A method of manufacturing an anode of a magnetron for microwave ovens, comprising:

(1) forming cylindrical upper and lower casings, which are open at tops thereof, by pressing a disk of a predetermined thickness with a first punch;

(2) forming a plurality of vanes, which are integrated with the upper and lower casings, respectively, by pressing tops of inner bottoms of the upper and lower casings; (3) forming strap notches, in which dual straps are placed, and antenna notches, onto which antennas are mounted, by pressing tops of the vanes with a third punch;

(4) cutting out bottoms of the upper and lower casings;

(5) attaching the upper casing and vanes thereof to the lower casing and vanes thereof with bottoms thereof being in contact with each other; and (6) attaching the dual straps to the strap notches of the vanes that have been attached to each other.

9. An apparatus for forming an anode of a magnetron for microwave ovens, comprising: a first punch formed in a circular rod-shape, and adapted to form cylindrical upper and lower casings, which are open at tops thereof, by pressing disks of a predetermined thickness within a die; a second punch formed in a cylindrical shape, radially provided with a plurality of vane forming slits on a bottom of thereof, and adapted to form a plurality of vanes by pressing inner bottoms of the upper and lower casings; and a third punch formed in a cylindrical shape, radially provided with a plurality of vane receiving slits on a bottom thereof, and provided with pressing protrusions that form strap notches, in which dual straps are placed, and antenna notches, onto which antennas are mounted, by pressing tops of the vanes against bottoms of the vane receiving slits.

10. An apparatus for forming an anode of a magnetron for microwave ovens, comprising a punch, the punch forming cylindrical upper and lower casings by pressing disks of a predetermined thickness within a die, a bottom of the punch being radially provided with a plurality of vane forming slits that radially form a plurality of vanes on inner walls of lower portions of the upper and lower casings when pressing the disks, bottoms of the vane forming slits being provided with pressing protrusions that form strap notches, in which dual straps are placed, and antenna notches, onto which antennas are mounted, by pressing tops of the vanes .

11. A method of manufacturing an anode of a magnetron for microwave ovens, comprising:

(1) inserting disks of a predetermined thickness into a forming cavity of a first die having a flat bottom, and forming cylindrical upper and lower casings, which are open at tops thereof, by pressing the disks with a first punch;

(2) forming a plurality of vanes and antenna notches, onto which antennas are mounted, on tops of the vanes by pressing inner bottoms of the upper and lower casings with a second punch;

(3) drawing the upper and lower casings out of the forming cavity of the first die, and cutting out bottoms of the upper and lower casings; (4) inserting the upper and lower casings turned upside down into a forming cavity of a second die, and forming first strap notches, in which dual strap is placed, on bottoms of the vanes with a third punch;

(5) inserting a disk of a predetermined thickness into the forming cavity of the first die, integrally forming a cylindrical center casing and a plurality of vanes, which are integrated with an inner wall of the center casing, by pressing the disk with the third punch, and forming second strap notches on tops of the vanes in which a dual strap is placed;

(6) drawing the center casing integrated with the vanes out of the forming cavity of the die, and cutting out a bottom of the center casing;

(7) inserting the center casing, whose bottom has been cut out and turned upside down, into the forming cavity of the first die, and forming second strap notches on bottoms of the vanes by pressing the center casing with the third punch;

(8) drawing the center casing out of the first die, and attaching a dual strap to the strap notches; and

(9) attaching a top of the center casing to a bottom of the upper casing, and a bottom of the lower casing to a bottom of the center casing.

12. An apparatus for forming an anode of a magnetron for microwave ovens, comprising: a first punch formed in a circular rod-shape, and adapted to form cylindrical upper and lower casings, which are open at tops thereof, by pressing disks of a predetermined thickness; and a second punch formed in a cylindrical shape, radially provided with a plurality of vane forming slits on a bottom of thereof, and adapted to form a plurality of vanes by pressing inner bottoms of the upper and lower casings; and a third punch formed in a cylindrical shape, radially provided with a plurality of vane receiving slits, into which the vanes are inserted, on a bottom thereof, and provided with first pressing protrusions that form strap notches, in which dual straps are placed, by pressing bottoms of the vanes against bottoms of the vane receiving slits.

13. The method as set forth in claim 12, wherein bottoms of the vane forming slits are provided with second pressing protrusions that form antenna notches, onto which antennas are mounted, on tops of the vanes when pressing the vanes.

14. An apparatus for forming an anode of a magnetron for microwave ovens, comprising: a first punch formed in a circular rod-shape, radially provided with a plurality of vane forming slits on a bottom of thereof, and adapted to form cylindrical upper and lower casings and radially form a plurality of vanes on inner walls of lower portions of the upper and lower casings by pressing disks of a predetermined thickness; and a second punch formed in a cylindrical shape, and radially provided with a plurality of vane receiving slits, into which the vanes are inserted, on a bottom thereof, and provided with first pressing protrusions that form strap notches, in which dual straps are placed, by pressing bottoms of the vanes against bottoms of the vane receiving slits.

15. The apparatus as set forth in claim 14, wherein bottoms of the vane forming slits are provided with second pressing protrusions that form antenna notches, onto which antennas are mounted, on tops of the vanes when pressing the vanes .