JP3940965B2

JP3940965B2 - Engine driven welding machine

Info

Publication number: JP3940965B2
Application number: JP11412597A
Authority: JP
Inventors: 宗潤高下; 忠司丸岡
Original assignee: 新ダイワ工業株式会社
Priority date: 1997-03-28
Filing date: 1997-03-28
Publication date: 2007-07-04
Anticipated expiration: 2017-03-28
Also published as: JPH10272564A

Description

【０００１】
【発明の属する技術分野】
この発明は、エンジンで駆動される発電体に複数の発電巻線を巻装し、各々の発電出力を直流溶接電源に変換して、エンジンの高速回転時にその直流溶接電源を複数の溶接棒に同時に供給可能なエンジン駆動溶接機であって、エンジンの高速回転時にその直流溶接電源を並列にして一つの溶接棒に供給して小電流から大電流域の溶接を行うことがき、また、エンジンの低速回転時で無負荷電圧の低下時に、その直流溶接電源を直列にして電圧を高めて一つの溶接棒に供給して、比較的に小電流域の溶接を良好に行うことができるようにしたエンジン駆動溶接機に関するものである。
また、他の発明は、エンジンで駆動される発電体に複数の発電巻線を巻装し、各々の発電出力を直流溶接電源に変換後、この直流溶接電源出力を一つにしたエンジン駆動溶接機であって、エンジンの高速回転時には前記複数の発電巻線からの各々の直流溶接電源を並列にして一つの溶接棒に供給して小電流から大電流域の溶接を行い、また、エンジンの低速回転時で無負荷電圧の低下時には前記複数の発電巻線からの各々の直流溶接電源を直列にして電圧を高めて一つの溶接棒に供給して小電流域の溶接を行うことができるようにしたエンジン駆動溶接機に関するものである。
【０００２】
【従来の技術】
従来、エンジンで交流発電機を駆動し、その交流発電機で発電された交流電力を整流して得た溶接用電力で溶接を行うエンジン駆動溶接機は、種々なものが開発されている。
例えば、前記のようなエンジン駆動溶接機を２台備え、前記溶接用電力を並列に接続して溶接棒に供給する大出力モードと、また、溶接用電力をそれぞれ独立に単独および／または平行的に溶接棒に供給する小出力モードとを選択する切替スイッチを備えたエンジン駆動溶接機が特公平６−４７１６９号公報、特開昭６３−３０２７６３号公報、特開昭６３−３０２７６４号公報、特開昭６３−３０２７６５号公報に開示されている。
【０００３】
【発明が解決しようとする課題】
従来のエンジン駆動溶接機においては、エンジンが作動して発電機が発電中に実作業すなわち溶接作業を行わない無負荷状態になることがしばしばあり、その溶接作業を行わない待機状態時には、低騒音と低燃費を目的としてエンジンの回転数を低速にしていた（スローダウン機能）。このエンジンの低速回転時の回転数は２０００ｒｐｍ程度であり、この時のエンジンの出力馬力は、高速回転時（３６００〜３７００ｒｐｍ程度）に比べると低下する。この溶接作業を行っていないエンジンの低速回転時には低燃費と言えども燃料を消費していた。
【０００４】
しかし、溶接の仕事内容、すなわち、小電流域で被溶接物が小さい溶接を行うときには、使用する溶接棒も小さく、エンジンの低速回転時の低馬力でよい場合もしばしばある。
また通常、溶接の直流溶接電源は３相交流発電機の発電出力を整流して得ているが、この３相交流発電機は、エンジンの高速回転時に合わせて設計されているため、エンジンの低速回転時には、無負荷電圧が、図６の（ハ）に示すように低下するという問題があった。このように、無負荷電圧が低下すると、溶接のアーク点弧性が悪化して良好な溶接作業を行うことができない実情があった。
この発明は、前記のような課題を解決したエンジン駆動溶接機を提供することを目的としたものである。
【０００５】
【課題を解決するための手段】
この発明は、前記目的を達成するために、エンジンで駆動される発電体に複数の発電巻線を巻装し、各々の発電出力を直流溶接電源に変換して複数の溶接棒を同時に使用可能なエンジン駆動溶接機において、エンジンの低速回転時で無負荷電圧の低下時においては、各直流溶接電源を直列にして電圧を高めて一つの溶接棒に供給されるような切換回路を備えたエンジン駆動溶接機としたものである。
【０００６】
また、エンジンで駆動される発電体に複数の発電巻線を巻装し、各々の発電出力を直流溶接電源に変換して複数の溶接棒を同時に使用可能なエンジン駆動溶接機において、エンジンの高速回転時に複数の溶接棒を同時に使用するときには各直流溶接電源が個別に各溶接棒に供給される小電流域の溶接を行い、エンジンの高速回転時に一つの溶接棒を使用して溶接を行うときには、その溶接棒に他の直流溶接電源が並列に供給されて小電流から大電流域の溶接を行い、エンジンの低速回転時で無負荷電圧の低下時には、各直流溶接電源を直列にして電圧を高めて一つの溶接棒に供給して小電流域の溶接を行うようにした切換回路を備え、この切換回路は、前記整流回路と、前記直流溶接電源の正電源端子および負電源端子との間に接続されているエンジン駆動溶接機としたものである。
【０００８】
【発明の実施の形態】
図１から図３はエンジンで駆動される発電体に複数の発電巻線を巻装し、各々の発電出力を直流溶接電源に変換して複数の溶接棒を同時に使用可能なこの発明のエンジン駆動溶接機の実施の形態を示すもので、図１はエンジンの高速回転時に二つの溶接棒を同時に使用する場合の切換回路の切換え状態を示し、図２はエンジンの高速回転時に一つの溶接棒を使用する場合の切換回路の切換え状態を示し、図３はエンジンの低速回転時で無負荷電圧の低下時に一つの溶接棒を使用する場合の切換回路の切換え状態を示す図である。
【０００９】
図において、１_１は一つのエンジン（図示しない）で駆動される発電体に複数巻装された第１の３相の発電巻線、１_２は同第２の３相の発電巻線、２_１は第１の発電巻線１_１で発電された３相交流を整流する第１の整流回路、２_２は第２の発電巻線１_２で発電された３相交流を整流する第２の整流回路、３_１は第１の整流回路２_１で整流された第１の直流溶接電源の（＋）電源端子、３_１′は同第１の直流溶接電源の（−）電源端子、３_２は第２の整流回路２_２で整流された第２の直流溶接電源の（＋）電源端子、３_２′は同第２の直流溶接電源の（−）電源端子、４_１は第１の直流溶接電源の（＋）電源端子３_１に接続された第１の溶接棒、４_２は第２の直流溶接電源の（＋）電源端子３_２に接続された第２の溶接棒、５_１は前記第１の直流溶接電源の（−）電源端子３_１′に接続された第１の被溶接物（ワーク）、５_２は前記第２の直流溶接電源の（−）電源端子３_２′に接続された第２の被溶接物（ワーク）、６_１は前記第１の整流回路２_１の両端に接続された溶接電流の環流用のダイオード、６_２は前記第２の整流回路２_２の両端に接続された溶接電流の環流用のダイオードである。
【００１０】
７はこの発明の主要部となる、エンジンの高速回転時に二つの溶接棒を同時に使用するときには、各直流溶接電源が個別に各溶接棒に加わり、エンジンの高速回転時に一つの溶接棒を使用するときには、その溶接棒に他の直流溶接電源が並列に加わり、エンジンの低速回転時で無負荷電圧の低下時には一つの溶接棒に各直流溶接電源が直列に加わるように切換・接続可能な切換回路であり、この切換回路７は、前記第１および第２の整流回路２_１，２_２と、第１および第２の直流溶接電源の（＋）電源端子３_１，３_２と、第１および第２の直流溶接電源の（−）電源端子３_１′，３_２′との間に接続されており、また、この切換回路７は、例えば図１（ｂ）、図２（ｂ）、図３（ｂ）で示すようなカムスイッチ８で構成され、後述するように、２人用の溶接、１人用の溶接、エンジンの低速回転時の溶接（スロー溶接）に回路が切換・接続されるようになっている。
【００１１】
以下、前記切換回路７の切換・接続を、２人用の溶接、１人用の溶接、エンジンの低速回転時の溶接に応じて詳細に説明する。
図１は切換回路７が２人用の溶接溶接作業に切換・接続された場合すなわちエンジンが高速回転時（３６００〜３７００ｒｐｍ）で二つの溶接棒４_１，４_２を同時に使用する場合の切換回路７の切換・接続された状態を示し、第１の整流回路２_１の（＋）側は第１の直流溶接電源の（＋）電源端子３_１に直接接続され、第１の整流回路２_１の（−）側に接続された接点１４と第１の直流溶接電源の（−）電源端子３_１′に接続された接点１３とが切換・接続され、第２の整流回路２_２の（＋）側に接続された接点７と第２の直流溶接電源の（＋）電源端子３_２に接続された接点８とが切換・接続され、第２の整流回路２_２の（−）側に接続された接点１と第２の直流溶接電源の（−）電源端子３_２′に接続された接点２とが接続され、第１および第２の直流溶接電源が個別に第１および第２の溶接棒４_１，４_２に供給され、二つの溶接棒４_１，４_２を同時に使用することができる。この溶接時の外部特性曲線を図６の（イ）に示す。また、この溶接時に一つの溶接棒を流れる溶接電流範囲は３０Ａ〜１６０Ａ程度である。なお、図６の（ホ）はアーク電圧ラインを示す。
【００１２】
図２はエンジンが高速回転時で一つの溶接棒を使用する場合の切換回路７の切換・接続状態を示し、第１の整流回路２_１の（−）側に接続された接点１４と第１の直流溶接電源の（−）電源端子３_１′に接続された接点１３とが切換・接続され、第２の整流回路２_２の（＋）側に接続された接点５と接点６と接点１０と第１の整流回路２_１の（＋）側に接続された接点９とが切換・接続されている。すなわち第２の整流回路２_２の（＋）側が第１の整流回路２_１の（＋）側に接続され、また、第２の整流回路２_２の（−）側が第１の整流回路２_１の（−）側に接続される。これによって、第１の直流溶接電源に第２の直流溶接電源が並列に加わった直流溶接電源で一つの溶接棒を使用することができる。この溶接時の外部特性曲線を図６の（ロ）に示す。この溶接時には一つの溶接棒を流れる溶接電流範囲は６０Ａ〜３００Ａ程度であり、この小電流から大電流域の溶接では、小さな被溶接物（ワーク）から大きな被溶接物まで溶接することができる。
【００１３】
図３はエンジンの低速回転時で無負荷電圧の低下時に一つの溶接棒を使用する場合の切換回路７の切換・接続状態を示し、第１の整流回路２_１の（−）側に接続された接点１６と接点１５と接点１１と接点１２と接点６と第２の整流回路２_２の（＋）側に接続された接点５とが切換・接続される。すなわち、第２の整流回路２_２の（＋）側と第１の整流回路２_１の（−）側とが切換・接続される。また、第２の整流回路２_２の（−）側に接続された接点３と第１の直流溶接電源の（−）電源端子３_１′に接続され接点４とが切換・接続される。すなわち第１の直流溶接電源と第２の直流溶接電源とが直列になって電圧が高められて一つの溶接棒４_１に供給される。これによって、エンジンの低速回転時で無負荷電圧の低下時でも、電圧の低い無負荷電圧が約２倍に高められて一つの溶接棒４_１に供給されるので、エンジンの高速回転時と同様に溶接を良好に行うことができる。その溶接時の外部特性曲線を図６の（ニ）に示す。この溶接時に一つの溶接棒を流れる溶接電流範囲は５０Ａ〜１６０Ａ程度である。
【００１４】
図４および図５は、他の発明のエンジン駆動溶接機の実施の形態を示すものであり、エンジンで駆動される発電体に複数の発電巻線を巻装し、各々の発電出力を直流溶接電源に変換後、この直流溶接電源出力を一つにしたエンジン駆動溶接機であって、エンジンの高速回転時には前記複数の発電巻線からの各々の直流溶接電源を並列にして一つの溶接棒に供給して小電流から大電流域の溶接を行い、また、エンジンの低速回転時で無負荷電圧の低下時には前記複数の発電巻線からの各々の直流溶接電源を直列にして電圧を高めて一つの溶接棒に供給して小電流域の溶接を行うことができるようにしたものであり、前記図１から図３で示したものと同一部材には同一符号を付けてその詳細な説明を省略する。
【００１５】
この図４および図５に示す実施の形態が、前記図１から図３に示す実施の形態と相違する点を以下に説明する。
図４はエンジンの高速回転時に各々の直流溶接電源を並列にして一つの溶接棒に供給して小電流から大電流域の溶接を行う場合の切換回路７の切換・接続状態を示し、第１の整流回路２_１の（＋）側は直接に直流溶接電源の（＋）電源端子３に接続されており、第１の整流回路２_１の（−）側に接続された接点１４と直流溶接電源の（−）電源端子３′に接続された接点１３とが切換・接続され、第２の整流回路２_２の（＋）側に接続された接点１０と第１の整流回路２_１の（＋）側に接続された接点９とが切換・接続されている。
すなわち、第２の整流回路２_２の（＋）側が第１の整流回路２_１の（＋）側に接続され、また、第２の整流回路２_２の（−）側が第１の整流回路２_１の（−）側に接続される。これによって、第１の直流溶接電源に第２の直流溶接電源が並列に加わった直流溶接電源が一つの溶接棒に供給されて小電流から大電流域の溶接を行うことができる。
【００１６】
また、図５はエンジンの低速回転時で無負荷電圧の低下時に各々の直流溶接電源を直列にして電圧を高めて一つの溶接棒に供給して小電流域の溶接を行う場合の切換回路７の切換・接続状態を示し、第１の整流回路２_１の（＋）側は直接に直流溶接電源の（＋）電源端子３に接続されており、第１の整流回路２_１の（−）側に接続された接点１６と接点１５と接点１１と第２の整流回路２_２の（＋）側に接続された接点１２とが切換・接続され、第２の整流回路２_２の（−）側は直接に直流溶接電源の（−）電源端子３′に接続されている。すなわち、第２の整流回路２_２の（＋）側と第１の整流回路２_１の（−）側とが接続される。すなわち、第１の直流溶接電源と第２の直流溶接電源とが直列になって一つの溶接棒４に供給される。これによって、エンジンの低速回転時で無負荷電圧の低下時でも、電圧の低い無負荷電圧が約２倍に高められて一つの溶接棒４に供給されるので、エンジンの高速回転時と同様に溶接を良好に行うことができる。
【００１７】
【発明の効果】
この発明は請求項１に記載のように、すなわち、エンジンで駆動される発電体に複数の発電巻線を巻装し、各々の発電出力を直流溶接電源に変換して複数の溶接棒を同時に使用可能なエンジン駆動溶接機において、エンジンの低速回転時で無負荷電圧の低下時においては、各直流溶接電源を直列にして電圧を高めて一つの溶接棒に供給されるような切換回路を備えたエンジン駆動溶接機としたので、エンジンの低速回転時に第１および第２の直流溶接電源の無負荷電圧が低下しても、その低い第１および第２の直流溶接電源電圧を直列にして高くし、それを複数の溶接棒のうちの一つの溶接棒に供給することができるので、小電流域の溶接、例えば径が３．２ｍｍ程度の溶接棒で、５０Ａ〜１６０Ａ程度の電流を流して正常な溶接を行うことができる。
また、このエンジンの低速回転は、例えば２０００ｒｐｍ程度で、例えば回転数３６００〜３７００ｒｐｍ程度の高速回転時に比べて低燃費化と低騒音化が図れる利点がある。
【００１８】
また、この発明は、エンジンで駆動される発電体に複数の発電巻線を巻装し、各々の発電出力を直流溶接電源に変換して複数の溶接棒を同時に使用可能なエンジン駆動溶接機において、エンジンの高速回転時に複数の溶接棒を同時に使用するときには各直流溶接電源が個別に各溶接棒に供給される小電流域の溶接を行い、エンジンの高速回転時に一つの溶接棒を使用して溶接を行うときには、その溶接棒に他の直流溶接電源が並列に供給されて小電流から大電流域の溶接を行い、エンジンの低速回転時で無負荷電圧の低下時には、各直流溶接電源を直列にして電圧を高めて一つの溶接棒に供給して小電流域の溶接を行うようにした切換回路を備えたエンジン駆動溶接機としたので、前記切換回路を２人用に切換・接続すると、エンジンの高速回転時に個別になった各直流溶接電源が各溶接棒に供給されて小電流域の溶接を行うことができる。
また、前記切換回路を１人用に切換・接続すると、エンジンの高速回転時に各直流溶接電源が並列になって一つの溶接棒に供給されるので、小電流から大電流域の溶接、すなわち、一つの溶接棒に流れる電流をさらに多くすることができ、例えば６０Ａ〜３００Ａ程度にして、大きな被溶接物を溶接することができる。
また、前記切換回路を、エンジンの低速回転時の溶接（スロー溶接）に切換・接続すると、第１および第２の直流溶接電源の低い無負荷電圧が直列になって高められ、それが一つの溶接棒に供給されるので、小電流域の溶接、すなわち、比較的に小さな被溶接物を良好に溶接することができ、このように、切換回路の切換・接続によって三つの溶接モードにして良好な溶接を行うことができる。
【図面の簡単な説明】
【図１】この発明の二つの溶接棒を同時に使用可能なエンジン駆動溶接機において、エンジンの高速回転時に二つの溶接棒を同時に使用する場合の切換回路の切換・接続状態を示した図である。
【図２】この発明の二つの溶接棒を同時に使用可能なエンジン駆動溶接機において、エンジンの高速回転時に一つの溶接棒を使用する場合の切換回路の切換・接続状態を示した図である。
【図３】この発明の二つの溶接棒を同時に使用可能なエンジン駆動溶接機において、エンジンの低速回転時で無負荷電圧の低下時に一つの溶接棒を使用する場合の切換回路を切換・接続状態を示す図である。
【図４】この発明の一つの溶接棒を使用するエンジン駆動溶接機において、エンジンの高速回転時に一つの溶接棒を使用する場合の切換回路の切換・接続状態を示した図である。
【図５】この発明の一つの溶接棒を使用するエンジン駆動溶接機において、エンジンの低速回転時で無負荷電圧の低下時に一つの溶接棒を使用する場合の切換回路を切換・接続状態を示す図である。
【図６】それぞれの溶接状態における外部特性曲線を示す図である。
【符号の説明】
１_１第１の溶接用の発電巻線
１_２第２の溶接用の発電巻線
２_１第１の整流回路
２_２第２の整流回路
３_１第１の直流溶接電源の（＋）電源端子
３_１′ 第１の直流溶接電源の（−）電源端子
３_２第２の直流溶接電源の（＋）電源端子
３_２′ 第２の直流溶接電源の（−）電源端子
４_１第１の溶接棒
４_２第２の溶接棒
５_１第１の被溶接物（ワーク）
５_２第２の被溶接物（ワーク）
６_１溶接電流の環流用のダイオード
６_２溶接電流の環流用のダイオード
７切換回路
８カムスイッチ[0001]
BACKGROUND OF THE INVENTION
In the present invention, a plurality of power generation windings are wound around a power generator driven by an engine, each power generation output is converted into a DC welding power source, and the DC welding power source is converted into a plurality of welding rods during high-speed rotation of the engine. This is an engine-driven welding machine that can be supplied at the same time. When the engine rotates at a high speed, the DC welding power can be supplied in parallel and supplied to a single welding rod to perform welding from a small current to a large current range. When the no-load voltage drops at low speed, the DC welding power source is connected in series to increase the voltage and supply it to one welding rod, so that welding in a relatively small current range can be performed satisfactorily. The present invention relates to an engine driven welding machine.
In another invention, a plurality of power generation windings are wound around a power generator driven by an engine, and each power generation output is converted into a DC welding power source. When the engine rotates at high speed, each DC welding power source from the plurality of power generation windings is supplied in parallel to one welding rod to perform welding from a small current to a large current region. It is possible to perform welding in a small current region by increasing the voltage by connecting each DC welding power source from the plurality of power generation windings in series and supplying it to one welding rod when the no-load voltage is lowered at low speed. The present invention relates to an engine driven welding machine.
[0002]
[Prior art]
2. Description of the Related Art Various types of engine-driven welding machines have been developed in which an AC generator is driven by an engine and welding is performed using welding power obtained by rectifying AC power generated by the AC generator.
For example, two engine-driven welding machines as described above are provided, a high output mode in which the welding power is connected in parallel and supplied to the welding rod, and the welding power is independently and / or parallel. Japanese Patent Publication No. 6-47169, Japanese Patent Publication No. Sho 63-302763, Japanese Patent Publication No. Sho 63-302764, Japanese Patent Publication No. Sho 63-302764, This is disclosed in Japanese Utility Model Publication No. 63-302765.
[0003]
[Problems to be solved by the invention]
In a conventional engine-driven welder, the engine is operated and the generator is often in an unloaded state during which no actual work, that is, welding work is performed during power generation. In order to reduce fuel consumption, the engine speed was reduced (slow down function). The rotational speed of the engine at low speed is about 2000 rpm, and the output horsepower of the engine at this time is lower than that at high speed (about 3600-3700 rpm). Even when fuel consumption is low, fuel is consumed when the engine that does not perform the welding operation rotates at low speed.
[0004]
However, when welding work is performed, that is, when welding is performed on a small workpiece in a small current range, the welding rod used is small, and a low horsepower at the time of low-speed rotation of the engine is often sufficient.
Usually, a welding DC welding power source is obtained by rectifying the power generation output of a three-phase AC generator. This three-phase AC generator is designed for high-speed rotation of the engine. During rotation, there is a problem that the no-load voltage decreases as shown in FIG. As described above, when the no-load voltage is lowered, there is a situation in which the arc ignition performance of welding is deteriorated and a good welding operation cannot be performed.
An object of the present invention is to provide an engine-driven welding machine that solves the above-described problems.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, the present invention allows a plurality of power generation windings to be wound around a power generator driven by an engine, and converts each power generation output to a DC welding power source to simultaneously use a plurality of welding rods. In an engine driven welding machine, an engine equipped with a switching circuit that increases the voltage in series with each DC welding power source and supplies it to a single welding rod when the no-load voltage decreases at low engine speed. It is a drive welder.
[0006]
In an engine-driven welding machine in which a plurality of power generation windings are wound around a power generator driven by an engine, and each power generation output is converted into a DC welding power source and a plurality of welding rods can be used simultaneously, When using multiple welding rods simultaneously at the time of rotation, perform welding in a small current range where each DC welding power source is individually supplied to each welding rod, and when using one welding rod during high-speed rotation of the engine When the welding rod is supplied with another DC welding power source in parallel to perform welding from a small current to a large current region, and when the no-load voltage drops at a low speed of the engine, the DC welding power source is connected in series. A switching circuit which is supplied to one welding rod and performs welding in a small current region , and this switching circuit is provided between the rectifier circuit and the positive power source terminal and the negative power source terminal of the DC welding power source. Connected to It is obtained by the engine driven welding machine.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
1 to 3 show an engine drive according to the present invention in which a plurality of power generation windings are wound around a power generator driven by an engine, and each power generation output is converted into a DC welding power source so that a plurality of welding rods can be used simultaneously. FIG. 1 shows an embodiment of a welding machine. FIG. 1 shows a switching state of a switching circuit when two welding rods are used simultaneously at the time of high-speed rotation of the engine, and FIG. 2 shows one welding rod at the time of high-speed rotation of the engine. FIG. 3 is a diagram showing the switching state of the switching circuit when one welding rod is used when the no-load voltage is lowered during low-speed rotation of the engine.
[0009]
In the figure, ₁₁ is a first three-phase power generation winding wound around a power generator driven by one engine (not shown), ₁₂ is the second three-phase power generation winding, 2 ₁ a first rectifier circuit for rectifying the three-phase AC power generated at the first power generating winding 1 _1, 2 ₂ and the second for rectifying the three-phase AC power generated at the second power generating winding 1 ₂ rectifier circuit, 3 ₁ a first DC welding power supply (+) power supply terminal, which is rectified by the first rectifier circuit 2 _1, 3 1 _'of the same first direct current welding power supply (-) power supply terminal, 3 ₂ the second DC welding power supply (+) power supply terminal, which is rectified by the second rectifier circuit 2 _2, 3 2 _'of the same second direct current welding power supply (-) power supply terminal, 4 ₁ a first DC first welding rod connected to the welding power supply (+) to the power supply terminal 3 _1, 4 ₂ and the second welding rod that is connected to (+) power supply terminal 3 of the _second DC welding power supply, 5 ₁ Said first direct current welding power supply (-) power supply terminal 3 _{1 'first} welded object that is connected to a (work), 5 ₂ of the second DC welding power source - the power supply terminal 3 _{2 ()'} to the second object to be welded, which is connected (work), 6 ₁ of the first rectifier circuit 2 ₁ of the connected welding current to both ends of the ring diverted diode, 6 ₂ of the second rectifier circuit 2 ₂ It is a diode for circulating current of welding current connected to both ends.
[0010]
7 is a main part of the present invention. When two welding rods are used simultaneously at the time of high-speed rotation of the engine, each DC welding power source is individually added to each welding rod, and one welding rod is used at the time of high-speed rotation of the engine. Sometimes, a switching circuit that can be switched and connected so that another DC welding power source is added in parallel to the welding rod, and each DC welding power source is added in series to one welding rod when the no-load voltage is reduced at low engine speeds. The switching circuit 7 includes the first and second rectifier circuits 2 ₁ and 2 ₂ , (+) power terminals 3 ₁ and 3 ₂ of the first and _second DC welding power supplies, The switching circuit 7 is connected between the (−) power supply terminals 3 ₁ ′ and 3 ₂ ′ of the second DC welding power source, and the switching circuit 7 is, for example, shown in FIG. 1 (b), FIG. 2 (b), FIG. It is composed of a cam switch 8 as shown in FIG. As described above, the circuit is switched and connected to welding for two persons, welding for one person, and welding during slow rotation of the engine (slow welding).
[0011]
Hereinafter, switching / connection of the switching circuit 7 will be described in detail according to welding for two persons, welding for one person, and welding during low-speed rotation of the engine.
FIG. 1 shows a switching circuit when the switching circuit 7 is switched and connected to welding welding work for two persons, that is, when two welding rods 4 ₁ and 4 ₂ are used simultaneously when the engine rotates at high speed (3600 to 3700 rpm). the seven switching-connected state of the first rectifier circuit 2 ₁ (+) side is connected to a first direct current welding power supply (+) power supply terminal 3 ₁ directly to the first rectifier circuit 2 ₁ The contact 14 connected to the (−) side and the contact 13 connected to the (−) power supply terminal 3 ₁ ′ of the first DC welding power source are switched and connected, and the (+) of the _second rectifier circuit 22 ) and the contact 7 connected to the side and a second DC welding power supply (+) contacts 8 connected to the power supply terminal 3 ₂ is switched-connection, the second rectifier circuit 2 ₂ (-) side to the connection by contacts 1 and the second DC welding power supply (-) connected to the contacts 2 are connected to the power supply terminal 3 _{2 '} The first and second DC welding power sources are separately supplied to the first and second welding rods 4 ₁ and 4 ₂ , and the two welding rods 4 ₁ and 4 ₂ can be used simultaneously. The external characteristic curve at the time of welding is shown in FIG. Moreover, the welding current range which flows through one welding rod at the time of this welding is about 30A-160A. In addition, (e) of FIG. 6 shows an arc voltage line.
[0012]
Figure 2 shows a switched-connection state of the switching circuit 7 when the engine is to use a single welding rod at the time of high speed rotation, the first rectifier circuit 2 ₁ (-) side connected to contact 14 and the first of DC welding power supply (-) power supply terminal 3 ₁ and the contact 13 connected to _'is switched-connected, the second rectifier circuit 2 ₂ (+) contact 5 and the contact point 6 connected to the side and the contact 10 When the first rectifier circuit 2 ₁ (+) connected to the side to contacts 9 are switched-connection. That second rectifier circuit _{2 2} (+) side is connected to the first rectifier circuit _{2 1} (+) side and, in the second rectifier circuit _{2 2} (-) side first rectifier circuit _{2 1} Connected to the (-) side. Thereby, one welding rod can be used with the DC welding power source in which the second DC welding power source is added in parallel to the first DC welding power source. The external characteristic curve at the time of welding is shown in FIG. In this welding, the range of the welding current flowing through one welding rod is about 60 A to 300 A, and welding from a small work piece (work) to a large work piece can be performed in this small current to large current range welding.
[0013]
Figure 3 shows a switching-connection state of the switching circuit 7 when using a single welding rod during lowering of the load voltage at the time of low-speed rotation of the engine, the first rectifier circuit 2 ₁ (-) is connected to the side and the contact 5 contacts 16 and the contact 15 and the contact 11 and the contact 12 and the contact 6 and which is connected to the second rectifier circuit 2 ₂ (+) side is switched-connection. That is, the second rectifier circuit 2 ₂ (+) side and the first rectifier circuit 2 ₁ (-) and side are switched-connection. Further, the second rectifier circuit 2 ₂ (-) connected to the contact 3 of the first direct-current welding power supply side (-) and the contacts 4 are connected to the power supply terminal 3 _{1 'is} switched-connection. That first DC welding power source and the second direct-current welding power supply is supplied to one of the welding rod 4 ₁ a voltage is elevated in series. Thus, even when lowering of the no-load voltage at the time of low-speed rotation of the engine, due to the low no-load voltage of the voltage supplied is increased to about twice the one of the welding rod 4 _1, similarly to the high-speed rotation of the engine It is possible to perform welding well. The external characteristic curve at the time of welding is shown in FIG. The welding current range that flows through one welding rod during welding is about 50A to 160A.
[0014]
4 and 5 show an embodiment of an engine-driven welding machine according to another invention, in which a plurality of power generation windings are wound around a power generation body driven by an engine, and each power generation output is DC-welded. An engine-driven welding machine that combines this DC welding power source output after conversion to a power source, and at the time of high-speed rotation of the engine, each DC welding power source from the plurality of power generation windings is paralleled into one welding rod. The welding is performed from a small current to a large current region, and when the no-load voltage is reduced during low-speed rotation of the engine, each DC welding power source from the plurality of power generation windings is connected in series to increase the voltage. The same members as those shown in FIGS. 1 to 3 are designated by the same reference numerals and detailed description thereof is omitted. To do.
[0015]
The points of the embodiment shown in FIGS. 4 and 5 different from the embodiment shown in FIGS. 1 to 3 will be described below.
FIG. 4 shows the switching / connection state of the switching circuit 7 when each DC welding power source is supplied in parallel to one welding rod during welding at a high speed of the engine to perform welding from a small current to a large current region. the rectifying circuit 2 ₁ (+) side are directly connected to the (+) power supply terminal 3 of the DC welding power supply, the first rectifier circuit 2 ₁ (-) connected to the contacts 14 and the side DC welding power (-) power supply terminal 3 'to the connected contact 13 is switched-connection, the second rectifier circuit 2 ₂ (+) connected to the contact 10 first to side rectifier circuit 2 ₁ ( The contact 9 connected to the (+) side is switched and connected.
That is, the second rectifier circuit 2 ₂ (+) side is connected to the first rectifier circuit 2 ₁ (+) side and, in the second rectifier circuit 2 ₂ (-) side first rectifier circuit 2 ₁ is connected to the (−) side. Accordingly, a DC welding power source in which a second DC welding power source is added in parallel to the first DC welding power source is supplied to one welding rod, and welding from a small current to a large current region can be performed.
[0016]
Further, FIG. 5 shows a switching circuit 7 in the case of performing welding in a small current region by increasing the voltage by connecting each DC welding power source in series when the no-load voltage is lowered at the time of low-speed rotation of the engine and supplying it to one welding rod. It indicates the switching-connected state, the first rectifier circuit 2 ₁ (+) side directly to the direct current welding power supply (+) is connected to the power supply terminal 3, the first rectifier circuit 2 ₁ (-) and the contact 16 connected to the side contact 15 and the contact 11 and the second rectifier circuit 2 ₂ (+) connected to the side the contact 12 is switched-connected, a second rectifier circuit 2 ₂ (-) The side is directly connected to the (-) power terminal 3 'of the DC welding power source. That is, the second rectifier circuit 2 ₂ (+) side and the first rectifier circuit 2 ₁ (-) and side connected. That is, the first DC welding power source and the second DC welding power source are supplied to one welding rod 4 in series. As a result, even when the no-load voltage is lowered at the time of low-speed engine rotation, the low-voltage no-load voltage is approximately doubled and supplied to one welding rod 4. Welding can be performed well.
[0017]
【The invention's effect】
According to the first aspect of the present invention, that is, a plurality of power generation windings are wound around a power generator driven by an engine, and each power generation output is converted into a DC welding power source so that a plurality of welding rods are simultaneously attached. In a usable engine-driven welding machine, when the engine is running at low speed and the no-load voltage drops, a switching circuit is provided to increase the voltage in series with each DC welding power source and supply it to one welding rod. Therefore, even if the no-load voltage of the first and second DC welding power supplies decreases during low-speed rotation of the engine, the lower first and second DC welding power supply voltages are increased in series. Since it can be supplied to one welding rod among a plurality of welding rods, a current of about 50 A to 160 A is applied by welding in a small current region, for example, a welding rod having a diameter of about 3.2 mm. Perform normal welding It can be.
Further, the low-speed rotation of the engine is, for example, about 2000 rpm, and there is an advantage that fuel consumption and noise can be reduced as compared with a high-speed rotation of, for example, about 3600-3700 rpm.
[0018]
Further, the present invention is wound around a plurality of generator winding to a power generating body driven by the engine, in the same time the available engine driven welding machine multiple welding rod by converting each power output of the DC welding power supply When using multiple welding rods simultaneously during high-speed engine rotation, each DC welding power source is individually supplied to each welding rod, and welding is performed in a small current range, and one welding rod is used during high-speed engine rotation. When welding is performed, another DC welding power source is supplied in parallel to the welding rod to perform welding from a small current to a large current region, and when the no-load voltage decreases at low engine speed, each DC welding power source is connected in series. Since the engine-driven welding machine is equipped with a switching circuit that increases the voltage and supplies it to one welding rod to perform welding in a small current region, when the switching circuit is switched and connected for two persons, Engine high speed It is possible to perform welding of the small-current region and the DC welding power supply which has become individually supplied to each of the welding rod during the rolling.
Further, when the switching circuit is switched and connected for one person, each DC welding power source is supplied in parallel to one welding rod during high-speed rotation of the engine, so that welding from a small current to a large current region, that is, The current flowing through one welding rod can be further increased. For example, a large workpiece can be welded at about 60A to 300A.
Further, when the switching circuit is switched and connected to welding (slow welding) at the time of low-speed rotation of the engine, the low no-load voltage of the first and second DC welding power sources is increased in series. Since it is supplied to the welding rod, welding in a small current range, that is, relatively small workpieces can be welded well. Thus, three welding modes can be achieved by switching and connecting the switching circuit. Welding can be performed.
[Brief description of the drawings]
FIG. 1 is a diagram showing a switching / connecting state of a switching circuit when two welding rods are used simultaneously at the time of high-speed rotation of an engine in an engine-driven welding machine capable of simultaneously using two welding rods of the present invention. .
FIG. 2 is a diagram showing a switching / connecting state of a switching circuit when one welding rod is used during high-speed rotation of the engine in an engine-driven welding machine capable of simultaneously using two welding rods of the present invention.
FIG. 3 shows an engine-driven welding machine capable of using two welding rods of the present invention at the same time, in which the switching circuit is switched and connected when one welding rod is used when the no-load voltage is lowered at a low engine speed. FIG.
FIG. 4 is a diagram showing a switching / connecting state of a switching circuit when one welding rod is used during high-speed rotation of the engine in an engine-driven welding machine using one welding rod according to the present invention.
FIG. 5 shows the switching / connecting state of the switching circuit in the case of using one welding rod when the no-load voltage is lowered in the engine-driven welding machine using one welding rod according to the present invention at low speed rotation of the engine. FIG.
FIG. 6 is a diagram showing external characteristic curves in respective welding states.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ₁ Power generation winding 1 for 1st welding ₂ 2 Power generation winding 2 for 2 welding ₁ 1st rectification circuit 2 ₂ 2nd rectification circuit 3 ₁ (+) power supply terminal of 1st DC welding power supply 3 ₁ 'of the first DC welding power supply (-) power supply terminal ₃ of the _second DC welding power supply (+) power supply terminal ₃ 2' of the second DC welding power supply (-) power supply terminal _{4 1} first welding Rod 4 ₂ Second welding rod 5 ₁ First workpiece (work)
5 ₂ Second work piece (workpiece)
6 ₁ diode for circulating current of welding current 6 ₂ diode for circulating current of welding current 7 switching circuit 8 cam switch

Claims

A plurality of power generation windings are wound around a power generator driven by an engine, and each power generation output is converted into a DC welding power source by a plurality of rectifier circuits corresponding to the plurality of power generation windings, thereby simultaneously connecting a plurality of welding rods. In available engine-driven welders,
A plurality of persons mode cormorants line welding small-current region to the DC welding power is supplied to each welding rods individually when using a plurality of welding rod during high-speed rotation of the engine at the same time,
When performing welding using a welding rod during high-speed rotation of the engine, a one-person mode intends line welding of a large current region from another DC welding power is supplied to the parallel small current to the welding rods,
When the no-load voltage drops during low-speed engine rotation, the DC welding power source is connected in series to increase the voltage and supply it to one welding rod to switch to the slow welding mode in which welding is performed in a small current range. With a switching circuit,
The switching circuit is connected between the rectifier circuit and a positive power source terminal and a negative power source terminal of the DC welding power source .