JP4154064B2

JP4154064B2 - Magnetron parts manufacturing method

Info

Publication number: JP4154064B2
Application number: JP07027299A
Authority: JP
Inventors: 利行松崎
Original assignee: Toshiba Corp
Current assignee: Toshiba Corp
Priority date: 1999-03-16
Filing date: 1999-03-16
Publication date: 2008-09-24
Anticipated expiration: 2019-03-16
Also published as: JP2000263239A

Description

【０００１】
【発明の属する技術分野】
本発明はマグネトロン部品の製造方法に係り、特に溶接部の接合強度を高く安定化させることができ、品質および信頼性が高いマグネトロン部品を高い製造歩留りで製造することが可能なマグネトロン部品の製造方法に関する。
【０００２】
【従来の技術】
２極真空管の一種でマイクロ波を発生させるための電子管としてマグネトロンがマイクロ波通信装置や家庭電化製品に広く利用されている。このマグネトロンは円筒形状の陰極（カソード）とこれを取り囲む陽極（アノード）との間に数キロボルトの直流高電圧を印加し、マイクロ波を発生させるものである。現在では周波数が２４５０ＭＨｚ，出力７００〜１５００Ｗ程度のマイクロ波を食品に照射して誘導加熱方式によって食品を加熱調理する電子レンジの主要部品として広く利用されている。
【０００３】
従来、上記電子レンジ用のマグネトロン本体内に装備されるマグネトロン部品１としてのカソード（陰極）部品は、例えば図４および図５に示す方法で製造されている。すなわち、マグネトロン部品本体２としてのエンドハットに、端面を平坦に形成した被接合部材３としてのリード棒を数１０ｋｇの押圧力を印加して突き合せた状態で、抵抗溶接によって一体に接合して製造されている。上記エンドハットおよびリード棒は共にモリブデン（Ｍｏ）などの高融点金属材から形成されている。
【０００４】
しかしながら、上記のように端面を平坦に形成したリード棒３をエンドハット２の側面に一体に接合した従来のマグネトロン部品１においては、図５に示すように、突き合せ溶接部に溶着金属が盛り上った突出部（ダレ）４が形成され易い難点があり、この突出部４がエンドハット２の外周面から僅かに突出しても不良品となるため、マグネトロン部品１の製造歩留りが大幅に低下してしまう問題点があった。
【０００５】
また、リード棒３およびエンドハット２は共にモリブデンなどの高融点金属材で形成されているため、それらの溶接接合に際しては、溶接の各段階におけるリード棒３への押圧力や溶接電流を厳格に制御するなど高度な溶接技術が必要とされていた。しかし、上記のように厳格に溶接条件を制御した場合においてもリード棒３の溶接強度のばらつきは大きく、マグネトロン部品１としての特性安定性や信頼性が低下する問題点があった。
【０００６】
上記問題点を解決するために、例えば図６に示すように、被接合部品３としてのリード棒素材をバレル加工法やタンブリング加工法によって処理して、その両端部に球面加工部（Ｒ加工部）５を形成したリード棒３ａを用いることも試行されている。この製造方法によれば、部品本体２と球面加工部５との間の空間に接合金属が収容される構造となるため、図５に示すような溶接金属の盛り上りによる突出部４の形成がやや減少し、不良率も若干改善される効果も得られている。
【発明が解決しようとする課題】
しかしながら、突き合せ部を球面加工したリード棒を用いる上記従来の製造方法によれば、リード棒を突き合せた時点で、エンドハットとリード棒とが点接触となるため、接触部にアークが発生して溶接電流が一定にならない欠点がある。また点接触していた部位がエンドハット母材側に急速にくい込み、エンドハットとの通電接触面積が急変するために、初期溶接条件の設定が極めて不安定になり、溶接部の仕上り精度にも大きなばらつきを生じる問題点があった。
【０００７】
また、バレル加工またはタンブリング加工によって多数のリード棒素材の端面を同時に球面化加工をした場合においても、球面形状のばらつきが大きくなり、各リード棒毎に初期溶接条件が大きく変化してしまい、いずれにしても最終的に製造されたマグネトロン部品の溶接接合強度や仕上り形状が一定とならず、特性および信頼性のばらつきが大きくなる問題点があった。
【０００８】
本発明は上記問題点を解決するためになされたものであり、特に溶接部の接合部の接合強度を高く安定化させることができ、品質および信頼性が高いマグネトロン部品を高い製造歩留りで製造することが可能なマグネトロン部品の製造方法を提供することを目的とする。
【０００９】
【課題を解決するための手段】
上記目的を達成するために本願発明者は被接合部材としてのリード棒の端面形状を種々に変えて、それらの端面形状が溶接強度，溶接操作の安定性，最終部品の信頼性および製造歩留りに及ぼす影響を比較調査した。
【００１０】
その結果、リード棒の端面に所定の平坦部を残すとともに突き合せ方向に縮径する傾斜面を形成したリード棒を用いたときに、リード棒の溶接強度が安定して高くなり、溶接操作も安定するとともに、溶接部の突出等による不良がなく、信頼性が高いマグネトロン部品を高い製造歩留りで簡単に量産できるという知見を得た。本発明は上記知見に基づいて完成されたものである。
【００１１】
すなわち、本発明に係るマグネトロン部品の製造方法は、マグネトロン部品本体に高融点金属から成る被接合部品を突き合せて抵抗溶接により一体に接合するマグネトロン部品の製造方法において、上記被接合部品の突き合せ端面に平坦部を残して突き合せ方向に縮径する傾斜面を予め形成し、上記被接合部品の軸直角方向の断面積に対する上記平坦部の面積率を２〜２５％とし、上記傾斜面の開き角度を９０〜１５０度の範囲とし、しかる後に上記平坦部をマグネトロン部品本体に突き合せて抵抗溶接を実施することを特徴とする。
【００１２】
また、上記被接合部品の軸直角方向の断面積に対する上記平坦部の面積率は、さらに３〜２０％であることが望ましい。
【００１３】
さらに、上記傾斜面の開き角度は、１００〜１４０度の範囲であることがより望ましい。
【００１４】
上記製造方法は、特にマグネトロン部品本体および被接合部品が高融点金属であるモリブデン（Ｍｏ）から成る場合に、溶接強度の安定化，溶接操作の安定化等に優れた効果を発揮する。
【００１５】
本発明方法において、被接合部品の端面に残す平坦部は、突き合せ直後における溶接作業で初期接触面積を一定量確保して初期通電密度を一定にし、溶接操作を安定化させるために重要な構成となる。
【００１６】
図１に示すように、上記被接合部品３ｂの軸直角方向の断面積（πＤ^２／４）に対する上記平坦部６の面積率（（ｄ^２／Ｄ^２）×１００（％））は２〜２５％であることが望ましい。この平坦部の面積率が２％未満と過少な場合には、溶接初期の通電密度が高くなり、溶接部にアークが発生して被接合部品の先端が局部的に溶解したり、溶接条件が不安定になるとともに溶接性（溶接強度）が低下する。一方、面積率が２５％を超えるように過大になると、部品本体と被接合部品との間の空間が過少になり、溶接金属が収容できないため、突出部などの不良が生じ易い上に溶接強度も低下する。したがって、面積率は２〜２５％の範囲とされるが、３〜２０％の範囲がより好ましい。
【００１７】
また、上記平坦部６の外周に形成され、突き合せ方向に縮径するように形成される傾斜面７は、被接合部材３ｂをマグネトロン部品本体２に突き合せたときに、部品本体２と傾斜面７との間に空間を形成し、この空間に溶接金属を収容して突出することを防止するために形成される。
【００１８】
上記傾斜面７の開き角度θは９０〜１５０度の範囲であることが望ましい。この開き角度θも部品の溶接性（溶接強度）の安定性および不良率に大きな影響を与える。開き角度θが９０度未満と過少な場合には、被接合部品の端面が鋭角になり、抵抗溶接初期にアークが発生し易くなり、溶接条件が不安定になる。一方、開き角度θが１５０度を超えるように過大になると、部品本体と傾斜面との間の空間が小さくなり、溶接金属を収容しにくくなり、突出不良が生じ易くなる。したがって、上記傾斜面７の開き角度は９０〜１５０度の範囲とされるが、１００〜１４０度の範囲がより好ましく、１１０〜１３０度の範囲がさらに好ましい。
【００１９】
上記構成に係るマグネトロン部品の製造方法によれば、被接合部品の突き合せ端面に平坦部を残して突き合せ方向に縮径する傾斜面を予め形成し、しかる後に上記平坦部をマグネトロン部品本体に突き合せて抵抗溶接を実施しているため、溶接初期において平坦部により一定の接触面積が確保できる。したがって、初期通電密度が過大にならず、またアークも発生しないため、溶接初期条件が一定となる。そのため、溶接操作が安定して接合部の接合強度も高くなり、接合部の仕上り状態のばらつきも減少して高い信頼性を有するマグネトロン部品を量産することができる。
【００２０】
また、平坦部の外周に傾斜面を形成し、部品本体と傾斜面との間の空間に溶接金属を収容することができ、溶接金属の突出による不良を解消することが可能であり、高品質のマグネトロン部品を高い製造歩留りで量産することができる。
【００２１】
【発明の実施の形態】
次に本発明の実施形態について添付図面を参照して以下の実施例に基づいて具体的に説明する。
【００２２】
図１は本実施例で使用する被接合部品としてのリード棒３ｂの端面形状を示す部分断面図であり、図２は本実施例の製造方法によって製造したマグネトロン部品１ａとしてのカソード部品の形状を示す断面図である。
【００２３】
上記マグネトロン部品としてのカソード部品は以下のような手順で製造した。まず、直径Ｄが１．３ｍｍのＭｏ棒を多数用意し、各Ｍｏ棒の端面を、図１に示すように旋盤加工によって切削して開き角度θが１２０度となる傾斜面７をそれぞれ形成した。このとき、平坦部６の直径ｄが０．１５〜０．６９ｍｍで面積率が１．２〜２８％の範囲で変化するように加工してそれぞれリード棒３ｂを形成した。
【００２４】
一方、図２に示す形状を有し、モリブデンから成り、外径８ｍｍで厚さが２．４ｍｍである、マグネトロン部品本体としてのエンドハット２を多数用意した。そして、前記のように調製した各リード棒３ｂの平坦部６をエンドハット２の側面に７５ｋｇの押圧力を付加して突き合せ、抵抗溶接を実施することにより、各実施例に係るマグネトロン部品としてのカソード部品をそれぞれ製造した。なお抵抗溶接時の押圧力や電流等の溶接条件は全ての実施例について同一とした。
【００２５】
こうして調製した各カソード部品のリード棒３ｂと部品本体２との溶接強度を評価するために、各リード棒３ｂの破断トルクを測定して図３に示す結果を得た。
【００２６】
図３に示す結果から明らかなように、リード棒３ｂの軸直角方向の断面積（πＤ^２／４）に対する上記平坦部６の面積率（（ｄ^２／Ｄ^２）×１００）が２〜５．５％の範囲（Ａ−Ａ′間）においてリード棒３ｂの溶接強度が最大値をとり、面積率が５．５〜２５％の範囲（Ａ′−Ｂ間）で徐々に溶接強度が低下する傾向があり、さらに面積率が２８％を超える範囲（Ｃ点以降）で溶接強度が急激に低下することが判明した。
【００２７】
なお、リード棒３ｂ端面の平坦部６の直径ｄが０．１５ｍｍ以下である試料（Ｓ点）については、溶接初期にスパークが発生してリード棒３ｂの先端部が急激に溶融したため、接合操作が不能であった。
【００２８】
したがって、高い溶接強度が安定して得られる面積率の範囲は２〜２５％である。特に上記面積率を３〜５．５％の範囲とすることにより、溶接強度値をより高められることが判明した。
【００２９】
このように本実施例に係るマグネトロン部品としてのカソード部品の製造方法によれば、リード棒の端面に所定量の平坦部６が形成されているため、突き合せ抵抗溶接時の初期から溶接電流密度が一定になる。そのため、接合部における金属の溶融状態が安定するため、信頼性が高い溶接部品が得られた。また、リード棒３ｂの端面の平坦部６の直径ｄを所定範囲に高精度に加工することにより、溶接強度が高く、特性安定性に優れたカソード部品を製造することが可能になった。
【００３０】
また上記各実施例に係るマグネトロン部品１ａとしてのカソード部品のうち、平坦部の面積率が２〜２５％の範囲のものは、いずれも図２に示すように、リード棒３ｂがエンドハット２の側面に強固に接合されており、かつ図５の従来例で示すような溶接金属の盛り上りによる突出不良は一切発生せず、高い製造歩留りでカソード部品を量産できることも実証された。
【００３１】
【発明の効果】
以上説明の通り、本発明に係るマグネトロン部品の製造方法によれば、被接合部品の突き合せ端面に平坦部を残して突き合せ方向に縮径する傾斜面を予め形成し、しかる後に上記平坦部をマグネトロン部品本体に突き合せて抵抗溶接を実施しているため、溶接初期において平坦部により一定の接触面積が確保できる。したがって、初期通電密度が過大にならず、またアークも発生しないため、溶接初期条件が一定となる。そのため、溶接操作が安定して接合部の接合強度も高くなり、接合部の仕上り状態のばらつきも減少して高い信頼性を有するマグネトロン部品を量産することができる。
【００３２】
また、平坦部の外周に傾斜面を形成し、部品本体と傾斜面との間の空間に溶接金属を収容することができ、溶接金属の突出による不良を解消することが可能であり、高品質のマグネトロン部品を高い製造歩留りで量産することができる。
【図面の簡単な説明】
【図１】本発明方法で使用する被接合部品の端面形状を示す部分断面図。
【図２】本発明方法で製造したマグネトロン部品の形状を示す断面図。
【図３】本発明方法における平坦部面積率と溶接強度との関係を示すグラフ。
【図４】従来のマグネトロン部品の製造方法を示す断面図。
【図５】図４に示すマグネトロン部品の仕上り状態を示す断面図。
【図６】従来の他のマグネトロン部品の製造方法を示す断面図。
【符号の説明】
１，１ａマグネトロン部品（カソード部品）
２マグネトロン部品本体（エンドハット）
３，３ａ，３ｂ被接合部材（リード棒）
４突出部（ダレ）
５球面加工部（Ｒ加工部）
６平坦部
７傾斜面[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method of manufacturing a magnetron component, and more particularly, a method of manufacturing a magnetron component that can stabilize the joint strength of a welded portion and can manufacture a magnetron component with high quality and reliability at a high manufacturing yield. About.
[0002]
[Prior art]
Magnetrons are widely used in microwave communication devices and household appliances as electron tubes for generating microwaves as a kind of bipolar tube. This magnetron generates a microwave by applying a high DC voltage of several kilovolts between a cylindrical cathode (cathode) and an anode (anode) surrounding the cathode. At present, it is widely used as a main part of a microwave oven that irradiates food with microwaves having a frequency of 2450 MHz and an output of about 700 to 1500 W and heats the food by induction heating.
[0003]
Conventionally, a cathode (cathode) component as the magnetron component 1 provided in the magnetron main body for the microwave oven is manufactured by the method shown in FIGS. 4 and 5, for example. That is, the lead bar as the member 3 to be joined having a flat end surface is joined to the end hat as the magnetron component main body 2 by applying a pressing force of several tens of kg and joined together by resistance welding. It is manufactured. Both the end hat and the lead rod are made of a refractory metal material such as molybdenum (Mo).
[0004]
However, in the conventional magnetron component 1 in which the lead rod 3 having a flat end face as described above is integrally joined to the side face of the end hat 2, as shown in FIG. There is a difficulty that the raised protrusion (sag) 4 is easily formed, and even if the protrusion 4 slightly protrudes from the outer peripheral surface of the end hat 2, it becomes a defective product, so that the production yield of the magnetron component 1 is greatly reduced. There was a problem that would do.
[0005]
In addition, since both the lead bar 3 and the end hat 2 are formed of a refractory metal material such as molybdenum, the pressing force and welding current to the lead bar 3 at each stage of welding are strictly limited in welding them. Advanced welding technology such as control was required. However, even when the welding conditions are strictly controlled as described above, the variation in the welding strength of the lead rod 3 is large, and there is a problem that the characteristic stability and reliability as the magnetron part 1 are lowered.
[0006]
In order to solve the above problems, for example, as shown in FIG. 6, a lead rod material as the part to be joined 3 is processed by a barrel processing method or a tumbling processing method, and spherical processing portions (R processing portions) are formed at both ends thereof. Attempts have also been made to use the lead bar 3a formed with 5). According to this manufacturing method, since the joining metal is accommodated in the space between the component main body 2 and the spherical processed portion 5, the protruding portion 4 is formed by the rising of the weld metal as shown in FIG. 5. There is an effect that it is slightly reduced and the defect rate is slightly improved.
[Problems to be solved by the invention]
However, according to the above-described conventional manufacturing method using a lead bar whose butt portion is spherically processed, an arc occurs at the contact portion because the end hat and the lead rod are in point contact when the lead rod is butted. As a result, the welding current is not constant. In addition, the point contact part is difficult to quickly move to the end hat base metal side, and the current contact area with the end hat changes suddenly, so the initial welding conditions are extremely unstable and the finish accuracy of the weld is also reduced. There was a problem that caused large variations.
[0007]
Also, even when end faces of many lead rod materials are simultaneously spheronized by barrel processing or tumbling processing, the variation in spherical shape becomes large, and the initial welding conditions change greatly for each lead rod. However, there is a problem in that the weld joint strength and finished shape of the finally produced magnetron part are not constant, and variations in characteristics and reliability are increased.
[0008]
The present invention has been made to solve the above-described problems, and in particular, can produce a high-quality and reliable magnetron part with a high production yield, which can stabilize the joint strength of the welded part at a high level. It is an object of the present invention to provide a method for manufacturing a magnetron component that can be used.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, the inventor of the present application changes the end face shape of the lead rod as the member to be joined in various ways, and the end face shape contributes to the welding strength, the stability of the welding operation, the reliability of the final part, and the production yield. The effects were compared and investigated.
[0010]
As a result, when using a lead rod that leaves a predetermined flat portion on the end face of the lead rod and has an inclined surface that is reduced in diameter in the butting direction, the welding strength of the lead rod is stably increased and the welding operation is also improved. We have gained the knowledge that magnetron parts that are stable and free from defects due to protrusions of the welded parts and that are highly reliable can be easily mass-produced with a high production yield. The present invention has been completed based on the above findings.
[0011]
That is, the method for manufacturing a magnetron component according to the present invention is a method for manufacturing a magnetron component in which a bonded component made of a refractory metal is butted against a magnetron component main body and bonded together by resistance welding. An inclined surface that is reduced in diameter in the butting direction leaving a flat portion on the end surface is formed in advance, and the area ratio of the flat portion with respect to the cross-sectional area in the direction perpendicular to the axis of the bonded parts is 2 to 25% . The opening angle is in the range of 90 to 150 degrees, and then the flat portion is abutted against the magnetron component main body and resistance welding is performed.
[0012]
The area ratio of the flat portion with respect to the cross-sectional area in the direction perpendicular to the axis of the parts to be joined is preferably 3 to 20%.
[0013]
Furthermore, the opening angle of the inclined surface is more preferably in the range of 100 to 140 degrees.
[0014]
The above manufacturing method exhibits an excellent effect in stabilizing welding strength, stabilizing welding operation, and the like particularly when the magnetron component main body and the component to be joined are made of molybdenum (Mo) which is a refractory metal.
[0015]
In the method of the present invention, the flat portion remaining on the end face of the parts to be joined is an important configuration for stabilizing the welding operation by securing a certain amount of initial contact area and a constant initial current density in the welding operation immediately after the butting. It becomes.
[0016]
As shown in FIG. 1, the area ratio of the flat portion 6 with respect to the direction perpendicular to the axis of the cross-sectional area of the object to be bonded part ^{^{3b (πD 2/4) (}} (d 2 / D 2) × 100 (%)) is 2 25% is desirable. When the area ratio of the flat part is too small, such as less than 2%, the current density at the initial stage of welding becomes high, an arc is generated in the welded part, the tip of the part to be joined is locally melted, or the welding conditions are It becomes unstable and weldability (welding strength) decreases. On the other hand, if the area ratio exceeds 25%, the space between the component main body and the part to be joined becomes too small, and the weld metal cannot be accommodated. Also decreases. Therefore, the area ratio is in the range of 2 to 25%, but the range of 3 to 20% is more preferable.
[0017]
Further, the inclined surface 7 formed on the outer periphery of the flat portion 6 and having a diameter reduced in the abutting direction is inclined with the component main body 2 when the member 3b is abutted against the magnetron component main body 2. A space is formed between the surface 7 and the weld metal is accommodated in the space and is prevented from protruding.
[0018]
The opening angle θ of the inclined surface 7 is desirably in the range of 90 to 150 degrees. This opening angle θ also greatly affects the stability of the weldability (welding strength) of the part and the defect rate. If the opening angle θ is less than 90 degrees, the end face of the parts to be joined becomes an acute angle, an arc is likely to occur at the initial stage of resistance welding, and the welding conditions become unstable. On the other hand, when the opening angle θ is excessively larger than 150 degrees, the space between the component main body and the inclined surface becomes small, it becomes difficult to accommodate the weld metal, and a protrusion failure is likely to occur. Therefore, the opening angle of the inclined surface 7 is in the range of 90 to 150 degrees, more preferably in the range of 100 to 140 degrees, and still more preferably in the range of 110 to 130 degrees.
[0019]
According to the method of manufacturing a magnetron component according to the above configuration, an inclined surface that is reduced in diameter in the butting direction is formed in advance, leaving a flat portion on the butted end surface of the joined component, and then the flat portion is formed on the magnetron component body. Since resistance welding is performed by abutting, a constant contact area can be secured by the flat portion in the initial stage of welding. Therefore, the initial energization density does not become excessive and no arc is generated, so that the initial welding conditions are constant. Therefore, the welding operation is stabilized, the joint strength of the joint portion is increased, the variation in the finished state of the joint portion is reduced, and magnetron parts having high reliability can be mass-produced.
[0020]
In addition, an inclined surface is formed on the outer periphery of the flat part, and the weld metal can be accommodated in the space between the component main body and the inclined surface. Can be mass-produced with a high production yield.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be specifically described based on the following examples with reference to the accompanying drawings.
[0022]
FIG. 1 is a partial sectional view showing the end face shape of a lead bar 3b as a part to be joined used in this embodiment, and FIG. 2 shows the shape of a cathode part as a magnetron part 1a manufactured by the manufacturing method of this embodiment. It is sectional drawing shown.
[0023]
The cathode part as the magnetron part was manufactured by the following procedure. First, a large number of Mo rods having a diameter D of 1.3 mm were prepared, and the end surfaces of the respective Mo rods were cut by a lathe as shown in FIG. 1 to form inclined surfaces 7 having an opening angle θ of 120 degrees. . At this time, processing was performed so that the diameter d of the flat portion 6 was 0.15 to 0.69 mm and the area ratio was changed in the range of 1.2 to 28%, thereby forming the lead rods 3b.
[0024]
On the other hand, many end hats 2 having a shape shown in FIG. 2 and made of molybdenum, having an outer diameter of 8 mm and a thickness of 2.4 mm as a magnetron component main body were prepared. Then, the flat portion 6 of each lead bar 3b prepared as described above is butted against the side surface of the end hat 2 with a pressing force of 75 kg, and resistance welding is performed, so that the magnetron component according to each embodiment is obtained. Each cathode part was manufactured. The welding conditions such as pressing force and current during resistance welding were the same for all the examples.
[0025]
In order to evaluate the welding strength between the lead bar 3b and the component body 2 of each cathode component thus prepared, the breaking torque of each lead rod 3b was measured and the results shown in FIG. 3 were obtained.
[0026]
As apparent from the results shown in FIG. 3, the area ratio of the flat portion 6 with respect to the direction perpendicular to the axis of the cross-sectional area of the lead rod ^{^{3b (πD 2/4) (}} (d 2 / D 2) × 100) is 2 to 5 In the range of 0.5% (between A and A '), the welding strength of the lead bar 3b takes the maximum value, and the welding strength gradually decreases in the range of 5.5 to 25% (between A' and B). Further, it has been found that the welding strength sharply decreases in the range where the area ratio exceeds 28% (after the C point).
[0027]
For the sample (S point) in which the diameter d of the flat portion 6 on the end face of the lead rod 3b is 0.15 mm or less, sparking occurred at the initial stage of welding and the tip of the lead rod 3b was rapidly melted. Was impossible.
[0028]
Accordingly, the range of the area ratio at which high welding strength can be stably obtained is 2 to 25%. In particular, it has been found that the welding strength value can be further increased by setting the area ratio in the range of 3 to 5.5%.
[0029]
As described above, according to the manufacturing method of the cathode component as the magnetron component according to the present embodiment, the predetermined amount of the flat portion 6 is formed on the end face of the lead rod, so that the welding current density from the initial stage at the time of butt resistance welding. Becomes constant. Therefore, since the molten state of the metal at the joint is stable, a highly reliable welded part is obtained. Further, by processing the diameter d of the flat portion 6 of the end surface of the lead bar 3b within a predetermined range with high accuracy, it becomes possible to manufacture a cathode component having high welding strength and excellent characteristic stability.
[0030]
In addition, among the cathode parts as the magnetron parts 1a according to the above-described embodiments, those having a flat area ratio in the range of 2 to 25% are shown in FIG. It was also proved that the cathode parts can be mass-produced with a high production yield without being caused by any protrusion failure due to the rise of the weld metal as shown in the conventional example of FIG.
[0031]
【The invention's effect】
As described above, according to the method of manufacturing a magnetron component according to the present invention, an inclined surface that is reduced in diameter in the butting direction is formed in advance so as to leave a flat portion on the butted end surface of the parts to be joined, and then the flat portion. Since the resistance welding is performed by butting the magnetron component main body, a constant contact area can be secured by the flat portion in the initial stage of welding. Therefore, the initial energization density does not become excessive and no arc is generated, so that the initial welding conditions are constant. Therefore, the welding operation is stabilized, the joint strength of the joint portion is increased, the variation in the finished state of the joint portion is reduced, and magnetron parts having high reliability can be mass-produced.
[0032]
In addition, an inclined surface is formed on the outer periphery of the flat part, and the weld metal can be accommodated in the space between the component main body and the inclined surface. Can be mass-produced with a high production yield.
[Brief description of the drawings]
FIG. 1 is a partial sectional view showing an end face shape of a part to be joined used in the method of the present invention.
FIG. 2 is a sectional view showing the shape of a magnetron part manufactured by the method of the present invention.
FIG. 3 is a graph showing the relationship between the flat area ratio and the welding strength in the method of the present invention.
FIG. 4 is a cross-sectional view showing a conventional method of manufacturing a magnetron part.
FIG. 5 is a cross-sectional view showing a finished state of the magnetron part shown in FIG. 4;
FIG. 6 is a cross-sectional view showing another conventional method of manufacturing a magnetron part.
[Explanation of symbols]
1,1a Magnetron parts (cathode parts)
2 Magnetron parts body (end hat)
3, 3a, 3b Joined member (lead bar)
4 Protrusion (sag)
5 Spherical surface processing part (R processing part)
6 Flat part 7 Inclined surface

Claims

マグネトロン部品本体に高融点金属から成る被接合部品を突き合せて抵抗溶接により一体に接合するマグネトロン部品の製造方法において、上記被接合部品の突き合せ端面に平坦部を残して突き合せ方向に縮径する傾斜面を予め形成し、上記被接合部品の軸直角方向の断面積に対する上記平坦部の面積率を２〜２５％とし、上記傾斜面の開き角度を９０〜１５０度の範囲とし、しかる後に上記平坦部をマグネトロン部品本体に突き合せて抵抗溶接を実施することを特徴とするマグネトロン部品の製造方法。In a method of manufacturing a magnetron part in which a part to be joined made of a refractory metal is abutted against a magnetron part body and joined together by resistance welding, the diameter of the part to be joined is reduced in the abutting direction while leaving a flat portion on the abutting end face. An inclined surface to be formed in advance, an area ratio of the flat portion with respect to a cross-sectional area in a direction perpendicular to the axis of the parts to be joined is set to 2 to 25%, and an opening angle of the inclined surface is set to a range of 90 to 150 degrees. A magnetron component manufacturing method, wherein the flat portion is butted against a magnetron component main body and resistance welding is performed.

被接合部品の軸直角方向の断面積に対する上記平坦部の面積率が３〜２０％であることを特徴とする請求項１記載のマグネトロン部品の製造方法。 2. The method of manufacturing a magnetron part according to claim 1, wherein an area ratio of the flat portion with respect to a cross-sectional area in a direction perpendicular to the axis of the parts to be joined is 3 to 20%.

傾斜面の開き角度が１００〜１４０度の範囲であることを特徴とする請求項１記載のマグネトロン部品の製造方法。 2. The method of manufacturing a magnetron part according to claim 1, wherein an opening angle of the inclined surface is in a range of 100 to 140 degrees.

マグネトロン部品本体および被接合部品がモリブデン（Ｍｏ）から成ることを特徴とする請求項１記載のマグネトロン部品の製造方法。 2. The method of manufacturing a magnetron part according to claim 1, wherein the magnetron part main body and the part to be joined are made of molybdenum (Mo).