JP3754552B2

JP3754552B2 - Compressor control circuit

Info

Publication number: JP3754552B2
Application number: JP06760098A
Authority: JP
Inventors: 潤一金井
Original assignee: HOKUETSU INDUSTRIES CO., LTD.
Current assignee: HOKUETSU INDUSTRIES CO., LTD.
Priority date: 1998-02-10
Filing date: 1998-02-10
Publication date: 2006-03-15
Anticipated expiration: 2018-02-10
Also published as: JPH11230053A

Description

【０００１】
【発明の属する技術分野】
本発明は、回転形空気圧縮機の制御回路に関する。
【０００２】
【従来技術】
従来技術の一例を、図３を用いて説明する。
図３において、圧縮機本体１で圧縮された圧縮空気は、一旦レシーバタンク２内に蓄えられ、その後吐出配管３７を通り消費側へ供給される。
この時、消費側で圧縮空気の消費が無いか、若しくは圧縮機本体１から吐出される圧縮空気の量よりも消費側で消費される圧縮空気の量が少なければ、レシーバタンク２内の圧力が上昇する。レシーバタンク２内の圧力が上昇し、吐出配管３７内の圧力が無負荷運転開始圧力に達すると、圧力スイッチＰＳ１が作動して電磁弁３，５，６に信号を送り、制御配管２２と２３，２１と２８，３０と２７の間を開通する。
まず、電磁弁３のＮＣ−ＣＯＭ間を開き、レシーバタンク２内の圧縮空気を容量調整弁５１の受圧室５１ｃへ導入し、バルブ５１ｅで吸入口５２を閉塞する。
しかしこの状態では、圧縮機本体１の吸入室１ａ内が負圧になって、圧縮機本体１からバキューム音が出たり、振動が起きたりする不具合が生じる。そのため、電磁弁５を開き、レシーバタンク２内の圧縮空気を吸入室１ａ内に導入することにより負圧を緩和してバキューム音や振動の発生を防止している。
さらに、電磁弁６を開き、レシーバタンク２内の圧縮空気を大気に開放する、所謂パージを開始する。そして、レシーバタンク２内の圧力がパージ停止圧力まで低下すると、圧力スイッチＰＳ２が作動して電磁弁６に信号を送り、制御配管３０を遮断してレシーバタンク２内の圧縮空気の大気開放を停止する。以上の動作により、無負荷運転時の動力を大幅に下げ、省エネ効果を得ている。
【０００３】
また、消費側で圧縮空気の消費が始まり、吐出配管３７内の圧力が負荷運転復帰圧力まで低下すると、圧力スイッチＰＳ１が作動して、電磁弁３，５，６への信号を停止し、制御配管２２と２３，２１と２８，３０と２７間を閉鎖し、制御配管２３と２４間を開通する。
まず、電磁弁３のＮＯ−ＣＯＭ間を開き、容量調整弁５１の受圧室５１ｃの圧縮空気を圧縮機本体１の吸入室１ａに導入し、バルブ５１ｅを下げ吸入口５２を開口する。また、レシーバタンク２内の圧縮空気を圧縮機本体１に戻しているため、圧縮機の負荷運転時における吸入空気量が減り効率が低下する。そこで、電磁弁５を閉じ制御配管２１と２８を閉鎖して圧縮空気の吸入室１ａへの流入を遮断する。
さらに、電磁弁６に信号を送り、制御配管３０を遮断してレシーバタンク２内の圧縮空気の大気開放を停止する。
【０００４】
また、圧縮機を停止させると、電磁弁４を開き、レシーバタンク２内の圧縮空気を大気に開放し、圧縮機本体１の再始動時におけるバックプレッシャによる始動渋滞を回避すると共に、圧縮機停止時にレシーバタンク２内に圧縮空気を残すこともない。
【０００５】
【考案が解決しようとする課題】
以上のように構成された従来技術の制御回路では、次に示すような問題点がある。
図３の制御回路では、複数個の電磁弁や圧力スイッチが必要であり、制御回路の信頼性がそれらの信頼性ならびに電磁弁を動作するための電気回路の信頼性にも大きく影響されてしまう。何よりも、多くの電磁弁を使用するため圧縮機パッケージ内の電磁弁設置スペースが多く必要になることと、部品コストおよびパッケージの製作コストが高くなることおよび電磁弁動作中に多くの電力を消費することが問題となる。
【０００６】
そこで本発明は、上記の課題を解決し、圧縮機の制御回路の信頼性を向上させること、および、部品点数を減らすことによる組立工数の低減、部品コストの低減を図り、無負荷運転時の消費動力を最小限に抑えた画期的な圧縮機の制御回路を提供することを目的とする。
【０００７】
【課題を解決するための手段】
上記課題を解決するため、まず第１に圧縮機本体１と、圧縮機本体１で圧縮された空気を貯留するレシーバタンク２と、無負荷運転時にレシーバタンク２の圧縮空気を大気に開放する手段と、無負荷運転時に圧縮機本体１の吸入室１ａとレシーバタンク２とを連通する手段と、停止時にレシーバタンク２の圧縮空気を大気開放する手段とを備えた圧縮機において、
圧縮機の無負荷運転時に、レシーバタンク２内の圧縮空気を大気に開放すると共に、前記圧縮空気の一部を圧縮機本体１の吸入室１ａに導入し、且つ、圧縮機停止時にもレシーバタンク２内の圧縮空気を大気に開放する切換弁８を設け、切換弁８は導入口８ｂと排出口８ｃと受圧室８ａとを備え、該受圧室８ａ内の圧力によって導入口８ｂと排出口８ｃとを開通又は閉鎖し、前記受圧室８ａを電磁弁３を介して前記レシーバタンク２と接続し、前記導入口８ｂをレシーバタンク２と接続し、前記排出口８ｃを吸入室１ａと接続すると共に大気と連通し、圧縮機の無負荷運転時には、該受圧室８ａを加圧することにより、切換弁８の導入口８ｂと排出口８ｃとを連通し、また、圧縮機の負荷運転時には、該受圧室８ａを減圧することにより切換弁８の導入口８ｂと排出口８ｃとの連通を遮断し、また、圧縮機の停止時には、該受圧室８ａを加圧することにより、切換弁８の導入口８ｂと排出口８ｃとを連通する制御回路とした。
【０００８】
第２に、切換弁８は導入口８ｂと排出口８ｃと受圧室８ａとを備え、該受圧室８ａ内の圧力によって導入口８ｂと排出口８ｃとを開通又は閉鎖するパイロット式の切換弁であって、前記受圧室８ａを電磁弁３を介して前記レシーバタンク２と接続すると共に、前記圧縮機本体１の吸入室１ａと接続し、前記導入口８ｂをレシーバタンク２と接続し、前記排出口８ｃを吸入室１ａと接続すると共に大気と連通し、圧縮機の無負荷運転時には、該受圧室８ａを加圧することにより、切換弁８の導入口８ｂと排出口８ｃとを連通し、また、圧縮機の負荷運転時には、該受圧室８ａを減圧することにより切換弁８の導入口８ｂと排出口８ｃとの連通を遮断し、また、圧縮機の停止時には、該受圧室８ａを加圧することにより、切換弁８の導入口８ｂと排出口８ｃとを連通する制御回路とした。
【０００９】
第３に、切換弁８の排出口８ｃからサイレンサ８ａへの回路途中に、オリフィス１９ａを設けた。
第４に、切換弁８の排出口８ｃからサイレンサ８ａへの回路途中に、流量調整弁１７およびオリフィス１９ａを設けた。
第５に、圧縮機の吸入通路１ｂと吸入室１ａを繋ぐバイパス通路２９を設け、前記通路の途中に吸入通路１ｂ側から吸入室１ａ側へ流れる向きに逆止弁１５を設けた。
【００１０】
【発明の実施の形態】
以下、図面に沿って、本発明の好ましい実施形態の例について説明する。
【００１１】
【実施例】
第１の実施例を図１に示す。
図１において、圧縮機本体１で圧縮された圧縮空気は、一旦レシーバタンク２に蓄えられ、その後吐出配管３７を通り、消費側へ供給される。
この時、消費側で圧縮空気の消費が無いか、若しくは圧縮機本体１から吐出される圧縮空気の量よりも消費側で消費される圧縮空気の量が少なければ、レシーバタンク２内の圧力が上昇する。レシーバタンク２内の圧力が上昇し、吐出配管３７内の圧力が無負荷運転開始圧力に達すると、圧力スイッチＰＳ１が作動して電磁弁３に信号を送り、制御配管２２と２３，２５間を開通する。
【００１２】
動作を詳しく説明すると、まず、レシーバタンク２内の圧力が上昇し、吐出配管３７内の圧力が無負荷運転開始圧力に達すると、圧力スイッチＰＳ１が作動し、電磁弁３への通電を行い、前記電磁弁３のＮＣ−ＣＯＭ間を開き、レシーバタンク２内の圧縮空気を容量調整弁５１の受圧室５１ｃへ導入し、容量調整弁５１のバルブ５１ｅで吸入口５２を閉塞する。
しかしこの状態では、圧縮機本体１の吸入室１ａ内が負圧になって、圧縮機本体１からバキューム音が出たり、振動が起きたりする不具合が生じる。そのため、電磁弁３の作動と同時に、レシーバタンク２内の圧縮空気を切換弁８の受圧室８ａに導入し、ピストン８ｄを押し上げることで、導入口８ｂと排出口８ｃを開通させレシーバタンク２内の圧縮空気を圧縮機本体１の吸入室１ａに導入する。これにより、前記吸入室１ａの負圧が緩和されるため、圧縮機本体１から出るバキューム音や振動の発生を防止できる。
【００１３】
さらに、切換弁８の排出口８ｃと圧縮機本体１の吸入室１ａをつなぐ配管２８を分岐し、これに流量調整弁１７とオリフィス１９ａ、サイレンサ１８ａを設けパージ回路を構成することで、無負荷運転に切り換わった時レシーバタンク２内の圧縮空気を大気に開放する。
オリフィス１９ａは、無負荷運転中のレシーバタンク２内の最低圧力を保持するために設けるものであり、例えば、レシーバタンク２内の圧力を１．２ｋｇ／ｃｍ^２以下にならないように設定している。
また、流量調整弁１７は、大気開放する圧縮空気の量を調整することで、吸入室１ａに導入される圧縮空気の量を増減して、圧縮機の無負荷運転時に発生するバキューム音や振動を防止し、且つ、消費動力が低くなるように設定するため、およびレシーバタンク２内の圧力を調整するために設けている。
さらに、吸入通路５１ｂと吸入室１ａとを逆止弁１５を介して繋ぐバイパス回路２９は、パージ回路から大気開放される圧縮空気を補う量の空気を吸入して、レシーバタンク２内の圧力が最低圧力を保持できるように設けられている。
ここで、このまま無負荷運転を続けながらレシーバタンク２内の圧力が大気開放により低下していくと、受圧室５１ｃの圧力も低下し、容量調整弁を閉塞の状態にしておくことが困難になる。それを防止するため、レシーバタンク２と電磁弁３を繋ぐ配管２２の途中に逆止弁１２を設け、レシーバタンク２内の圧力が低下しても、容量調整弁５１の受圧室５１ｃ内および切換弁８の受圧室８ａ内の圧力を保持し、容量調整弁５１の閉塞を維持し続けるようにする。
【００１４】
また、消費側で圧縮空気の消費が始まり、吐出配管３７内の圧力が負荷運転復帰圧力まで低下すると、圧力スイッチＰＳ１が作動して、電磁弁３への信号を停止し、制御配管２２と２３，２５間を閉鎖し、制御配管２３，２５と２４の間を開通する。
まず、電磁弁３のＮＯ−ＣＯＭ間を開き、容量調整弁５１の受圧室５１ｃの圧縮空気を圧縮機本体１の吸入室１ａに導入し、バルブ５１ｅを下げ吸入口５２を開口する。次に制御配管２５が吸入室１ａと連通するため、受圧室８ａ内が減圧されピストン８ｄが下がるため、導入口８ｂと排出口８ｃ間が遮断され、レシーバタンク２内の圧縮空気の吸入室１ａへの導入および大気開放を停止する。
【００１５】
また、圧縮機を停止すると、容量調整弁５１内の逆流防止用スプリング５１ｆにより、バルブ５１ｅが吸入口５２を閉塞すると共に、レシーバタンク２内の圧縮空気が圧縮機本体１に逆流し、吸入室１ａを加圧する。その圧力を、制御配管２６を介して切換弁８の受圧室８ａに導入，加圧し、ピストン８ｄを押し上げることで、導入口８ｂと排出口８ｃを開通させ、レシーバタンク２内の圧縮空気を流量調整弁１７、オリフィス１９ａ、サイレンサ１８ａを通して大気に放出するので、レシーバタンク２内の圧力を大気圧まで低下することができる。
これにより、圧縮機本体１の再始動時におけるバックプレッシャによる始動渋滞を回避すると共に、圧縮機停止時にレシーバタンク２内に圧縮空気を残すこともなくなる。
【００１６】
次に第２の実施例を図２に示す。
図２において、圧縮機本体１で圧縮された圧縮空気は、一旦レシーバタンク２に蓄えられ、その後吐出配管３７を通り、消費側へ供給される。
この時、消費側で圧縮空気の消費が無いか、若しくは圧縮機本体１から吐出される圧縮空気の量よりも消費側で消費される圧縮空気の量が少なければ、レシーバタンク２内の圧力が上昇する。レシーバタンク２内の圧力が上昇し、吐出配管３７内の圧力が無負荷運転開始圧力に達すると、圧力スイッチＰＳ１が作動して電磁弁３に信号を送り、制御配管２２と２３，２５間を開通する。
まず、レシーバタンク２内の圧力が上昇し、吐出配管３７内の圧力が無負荷運転開始圧力に達すると、圧力スイッチＰＳ１が作動し、前記電磁弁３を開き、レシーバタンク２内の圧縮空気を容量調整弁５１の受圧室５１ｃへ導入し、容量調整弁５１のバルブ５１ｅで吸入口５２を閉塞する。
しかしこの状態では、圧縮機本体１の吸入室１ａ内が負圧になって、圧縮機本体１からバキューム音が出たり、振動が起きたりする不具合が生じる。そのため、電磁弁３の作動と同時に、レシーバタンク２内の圧縮空気を切換弁８の受圧室８ａに導入，加圧し、ピストン８ｄを押し上げることで、導入口８ｂと排出口８ｃを開通させレシーバタンク２内の圧縮空気を圧縮機本体１の吸入室１ａに導入する。これにより、前記吸入室１ａの負圧が緩和されるため、圧縮機本体１から出るバキューム音や振動の発生を防止できる。
【００１７】
さらに、切換弁８の排出口８ｃと圧縮機本体１の吸入室１ａをつなぐ配管２８を分岐し、これにオリフィス１９ａとサイレンサ１８ａを設けパージ回路を構成することで、無負荷運転に切り換わった時、レシーバタンク２内の圧縮空気を大気に開放することができる。
オリフィス１９ａは、無負荷運転中のレシーバタンク２内の最低圧力を保持し、大気開放する圧縮空気の量を調整するために設けるものであり、例えば、レシーバタンク２内の圧力を１．２ｋｇ／ｃｍ^２以下にならないようにしている。
【００１８】
また、消費側で圧縮空気の消費が始まり、吐出配管３７内の圧力が負荷運転復帰圧力まで低下すると、圧力スイッチＰＳ１が作動して、電磁弁３への信号を停止し、制御配管２２と２３，２５間を閉鎖する。
まず、電磁弁３を閉じ、容量調整弁５１の受圧室５１ｃの圧縮空気を制御配管２９，オリフィス１９ｂを通して容量調整弁５１の吸入通路５１ｂに導入し、バルブ５１ｅを下げ吸入口５２を開口する。次に制御配管２５が吸入通路５１ｂと連通するため、受圧室８ａ内の圧力が下がりピストン８ｄが下がるため、導入口８ｂと排出口８ｃ間が遮断され、レシーバタンク２内の圧縮空気の吸入室１ａへの導入および大気開放を停止する。
【００１９】
また、圧縮機を停止すると、容量調整弁５１内の逆流防止用スプリング５１ｆにより、バルブ５１ｅが吸入口５２を閉塞すると共に、レシーバタンク２内の圧縮空気が圧縮機本体１に逆流し、吸入室１ａを加圧する。その圧力を、切換弁８の受圧室８ａに導入すると、受圧室８ａ内の圧力が上昇するため、ピストン８ｄを押し上げ、導入口８ｂと排出口８ｃを開通させる。すると、レシーバタンク２内の圧縮空気が流量調整弁１７、オリフィス１９ａ、サイレンサ１８ａを通り大気に放出され、レシーバタンク２内の圧力が大気圧まで低下する。
これにより、圧縮機本体１の再始動時におけるバックプレッシャによる始動渋滞を回避すると共に、圧縮機停止時にレシーバタンク２内に圧縮空気を残すこともなくなる。
【００２０】
【発明の効果】
以上のように構成された本発明の圧縮機の制御回路によれば、従来の制御回路に比べ同等以上の機能、性能を持ちながら、少ない部品で構成されているため信頼性も向上し、また、部品コストも低く抑え、且つ、消費動力も低く抑えることができるという、従来にない画期的な圧縮機の制御回路を提供することができる。
【図面の簡単な説明】
【図１】本発明の第１実施例の圧縮機の制御回路系統図
【図２】本発明の第２実施例の圧縮機の制御回路系統図
【図３】従来技術の圧縮機の制御回路
【符号の説明】
１圧縮機本体
１ａ吸入室
２レシーバタンク
３〜７電磁弁
８切換弁
８ａ受圧室
８ｂ導入口
８ｃ排出口
８ｄピストン
９オートレリーフ弁
９ａ受圧室
９ｂ導入口
９ｃ排出口
９ｄピストン
１０レギュレータ
１０ｂ導入口
１０ｃ排出口
１２逆止弁
１７流量調整弁
１８ａ，１８ｂサイレンサ
１９ａ，１９ｂオリフィス
２１〜３６制御配管
３７吐出配管
ＰＳ１，ＰＳ２圧力スイッチ
５１容量調整弁
５１ｂ吸入通路
５１ｃ受圧室
５１ｄピストン
５１ｅバルブ
５１ｆスプリング[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a control circuit for a rotary air compressor.
[0002]
[Prior art]
An example of the prior art will be described with reference to FIG.
In FIG. 3, the compressed air compressed by the compressor main body 1 is temporarily stored in the receiver tank 2 and then supplied to the consumer side through the discharge pipe 37.
At this time, if there is no consumption of compressed air on the consuming side or the amount of compressed air consumed on the consuming side is less than the amount of compressed air discharged from the compressor body 1, the pressure in the receiver tank 2 is increased. To rise. When the pressure in the receiver tank 2 rises and the pressure in the discharge pipe 37 reaches the no-load operation start pressure, the pressure switch PS1 is activated to send a signal to the solenoid valves 3, 5 and 6, and the control pipes 22 and 23 , 21 and 28, and 30 and 27 are opened.
First, the NC-COM of the electromagnetic valve 3 is opened, the compressed air in the receiver tank 2 is introduced into the pressure receiving chamber 51c of the capacity adjustment valve 51, and the suction port 52 is closed with the valve 51e.
However, in this state, the suction chamber 1a of the compressor body 1 has a negative pressure, which causes a problem that a vacuum sound is generated from the compressor body 1 or vibrations occur. For this reason, the electromagnetic valve 5 is opened and the compressed air in the receiver tank 2 is introduced into the suction chamber 1a to relieve the negative pressure and prevent the generation of vacuum noise and vibration.
Further, the solenoid valve 6 is opened, and so-called purge is started to release the compressed air in the receiver tank 2 to the atmosphere. When the pressure in the receiver tank 2 drops to the purge stop pressure, the pressure switch PS2 is activated to send a signal to the solenoid valve 6, shut off the control pipe 30 and stop the release of compressed air in the receiver tank 2 to the atmosphere. To do. Through the above operation, the power during no-load operation is greatly reduced, and an energy saving effect is obtained.
[0003]
When consumption of compressed air starts on the consumption side and the pressure in the discharge pipe 37 decreases to the load operation return pressure, the pressure switch PS1 is activated to stop the signals to the solenoid valves 3, 5 and 6 and control The pipes 22 and 23, 21 and 28, 30 and 27 are closed, and the control pipes 23 and 24 are opened.
First, between NO and COM of the solenoid valve 3 is opened, compressed air in the pressure receiving chamber 51c of the capacity adjustment valve 51 is introduced into the suction chamber 1a of the compressor body 1, the valve 51e is lowered, and the suction port 52 is opened. Moreover, since the compressed air in the receiver tank 2 is returned to the compressor body 1, the amount of intake air during load operation of the compressor is reduced and efficiency is lowered. Therefore, the solenoid valve 5 is closed and the control pipes 21 and 28 are closed to block the flow of compressed air into the suction chamber 1a.
Further, a signal is sent to the electromagnetic valve 6 to shut off the control piping 30 and stop the compressed air in the receiver tank 2 from being released into the atmosphere.
[0004]
When the compressor is stopped, the electromagnetic valve 4 is opened, the compressed air in the receiver tank 2 is opened to the atmosphere, and the start-up congestion due to back pressure when the compressor body 1 is restarted is avoided and the compressor is stopped. Sometimes no compressed air is left in the receiver tank 2.
[0005]
[Problems to be solved by the invention]
The conventional control circuit configured as described above has the following problems.
The control circuit shown in FIG. 3 requires a plurality of solenoid valves and pressure switches, and the reliability of the control circuit is greatly influenced by the reliability of these and the reliability of the electric circuit for operating the solenoid valve. . Above all, the use of a large number of solenoid valves requires a large amount of installation space for the solenoid valve in the compressor package, increases the cost of parts and packages, and consumes a lot of power during solenoid valve operation. It becomes a problem to do.
[0006]
Therefore, the present invention solves the above-mentioned problems, improves the reliability of the control circuit of the compressor, reduces the number of assembly steps by reducing the number of parts, and reduces the parts cost, and at the time of no-load operation. It is an object of the present invention to provide a revolutionary compressor control circuit that minimizes power consumption.
[0007]
[Means for Solving the Problems]
In order to solve the above problems, first, the compressor body 1, the receiver tank 2 for storing the air compressed by the compressor body 1, and means for opening the compressed air in the receiver tank 2 to the atmosphere during no-load operation And a compressor having a means for communicating the suction chamber 1a of the compressor body 1 and the receiver tank 2 during no-load operation, and a means for releasing the compressed air of the receiver tank 2 to the atmosphere when stopped.
During the no-load operation of the compressor, the compressed air in the receiver tank 2 is released to the atmosphere, a part of the compressed air is introduced into the suction chamber 1a of the compressor body 1, and the receiver tank is also in a stopped state. 2 is provided . The switching valve 8 is provided with an inlet 8b, a discharge port 8c, and a pressure receiving chamber 8a, and the introduction port 8b and the discharge port 8c are controlled by the pressure in the pressure receiving chamber 8a. Are opened or closed, the pressure receiving chamber 8a is connected to the receiver tank 2 through the electromagnetic valve 3, the inlet 8b is connected to the receiver tank 2, and the outlet 8c is connected to the suction chamber 1a. The pressure receiving chamber 8a is pressurized to communicate with the atmosphere and pressurize the pressure receiving chamber 8a so that the inlet 8b and the discharge port 8c of the switching valve 8 communicate with each other. Switching by depressurizing chamber 8a 8, the communication between the inlet 8b and the outlet 8c of the switching valve 8 is controlled by blocking the communication between the inlet 8b and the outlet 8c, and pressurizing the pressure receiving chamber 8a when the compressor is stopped. A circuit was used.
[0008]
Secondly, the switching valve 8 is a pilot-type switching valve that includes an introduction port 8b, a discharge port 8c, and a pressure receiving chamber 8a, and opens or closes the introduction port 8b and the discharge port 8c by the pressure in the pressure receiving chamber 8a. The pressure receiving chamber 8a is connected to the receiver tank 2 through the electromagnetic valve 3, and is connected to the suction chamber 1a of the compressor body 1, the inlet 8b is connected to the receiver tank 2, and the exhaust The outlet 8c is connected to the suction chamber 1a and communicates with the atmosphere. When the compressor is not loaded, the pressure receiving chamber 8a is pressurized so that the inlet 8b and the outlet 8c of the switching valve 8 communicate with each other. During the load operation of the compressor, the pressure receiving chamber 8a is depressurized to block communication between the inlet 8b and the outlet 8c of the switching valve 8, and when the compressor is stopped, the pressure receiving chamber 8a is pressurized. Thus, the inlet 8b of the switching valve 8 and And a control circuit for communicating the outlet 8c.
[0009]
Third, an orifice 19a is provided in the circuit from the discharge port 8c of the switching valve 8 to the silencer 8a.
Fourth, a flow rate adjusting valve 17 and an orifice 19a are provided in the circuit from the discharge port 8c of the switching valve 8 to the silencer 8a.
Fifth, a bypass passage 29 connecting the suction passage 1b of the compressor and the suction chamber 1a is provided, and a check valve 15 is provided in the middle of the passage so as to flow from the suction passage 1b side to the suction chamber 1a side.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, examples of preferred embodiments of the present invention will be described with reference to the drawings.
[0011]
【Example】
A first embodiment is shown in FIG.
In FIG. 1, the compressed air compressed by the compressor body 1 is temporarily stored in the receiver tank 2 and then supplied to the consumer side through the discharge pipe 37.
At this time, if there is no consumption of compressed air on the consuming side or the amount of compressed air consumed on the consuming side is less than the amount of compressed air discharged from the compressor body 1, the pressure in the receiver tank 2 is increased. To rise. When the pressure in the receiver tank 2 rises and the pressure in the discharge pipe 37 reaches the no-load operation start pressure, the pressure switch PS1 is actuated to send a signal to the solenoid valve 3, and between the control pipes 22, 23, and 25 Open.
[0012]
The operation will be described in detail. First, when the pressure in the receiver tank 2 rises and the pressure in the discharge pipe 37 reaches the no-load operation start pressure, the pressure switch PS1 is activated to energize the solenoid valve 3, The NC-COM of the electromagnetic valve 3 is opened, the compressed air in the receiver tank 2 is introduced into the pressure receiving chamber 51c of the capacity adjustment valve 51, and the suction port 52 is closed by the valve 51e of the capacity adjustment valve 51.
However, in this state, the suction chamber 1a of the compressor body 1 has a negative pressure, which causes a problem that a vacuum sound is generated from the compressor body 1 or vibrations occur. Therefore, simultaneously with the operation of the electromagnetic valve 3, the compressed air in the receiver tank 2 is introduced into the pressure receiving chamber 8a of the switching valve 8, and the piston 8d is pushed up to open the inlet port 8b and the outlet port 8c. The compressed air is introduced into the suction chamber 1 a of the compressor body 1. Thereby, since the negative pressure in the suction chamber 1a is relieved, it is possible to prevent the generation of vacuum noise and vibrations from the compressor body 1.
[0013]
Furthermore, a pipe 28 connecting the discharge port 8c of the switching valve 8 and the suction chamber 1a of the compressor body 1 is branched, and a flow rate adjusting valve 17, an orifice 19a, and a silencer 18a are provided to form a purge circuit so that no load is applied. When switching to operation, the compressed air in the receiver tank 2 is released to the atmosphere.
The orifice 19a is provided to maintain the minimum pressure in the receiver tank 2 during no-load operation, and is set so that the pressure in the receiver tank 2 does not become 1.2 kg / cm ² or less, for example. .
Further, the flow rate adjusting valve 17 increases or decreases the amount of compressed air introduced into the suction chamber 1a by adjusting the amount of compressed air that is released to the atmosphere, so that the vacuum noise and vibration generated during no-load operation of the compressor. Is provided to prevent power consumption and to reduce the power consumption, and to adjust the pressure in the receiver tank 2.
Further, the bypass circuit 29 that connects the suction passage 51b and the suction chamber 1a via the check valve 15 sucks in an amount of compressed air that is released from the purge circuit to the atmosphere, and the pressure in the receiver tank 2 is increased. It is provided so that the minimum pressure can be maintained.
Here, if the pressure in the receiver tank 2 decreases due to release to the atmosphere while continuing the no-load operation as it is, the pressure in the pressure receiving chamber 51c also decreases, making it difficult to keep the capacity adjustment valve closed. . In order to prevent this, a check valve 12 is provided in the middle of the pipe 22 connecting the receiver tank 2 and the electromagnetic valve 3, so that even if the pressure in the receiver tank 2 drops, the capacity adjusting valve 51 can be switched between the pressure receiving chamber 51 c and the switching. The pressure in the pressure receiving chamber 8a of the valve 8 is maintained, and the capacity adjustment valve 51 is kept closed.
[0014]
When consumption of compressed air starts on the consumption side and the pressure in the discharge pipe 37 decreases to the load operation return pressure, the pressure switch PS1 is activated to stop the signal to the solenoid valve 3, and the control pipes 22 and 23 , 25 is closed, and the control pipes 23, 25 and 24 are opened.
First, between NO and COM of the solenoid valve 3 is opened, compressed air in the pressure receiving chamber 51c of the capacity adjustment valve 51 is introduced into the suction chamber 1a of the compressor body 1, the valve 51e is lowered, and the suction port 52 is opened. Next, since the control pipe 25 communicates with the suction chamber 1a, the inside of the pressure receiving chamber 8a is depressurized and the piston 8d is lowered, so that the space between the inlet 8b and the outlet 8c is shut off, and the compressed air suction chamber 1a in the receiver tank 2 is closed. Stop the introduction and release to the atmosphere.
[0015]
When the compressor is stopped, the valve 51e closes the suction port 52 by the backflow prevention spring 51f in the capacity adjustment valve 51, and the compressed air in the receiver tank 2 flows back to the compressor main body 1, and the suction chamber Pressurize 1a. The pressure is introduced and pressurized into the pressure receiving chamber 8a of the switching valve 8 via the control pipe 26, and the piston 8d is pushed up to open the inlet 8b and the outlet 8c, and the compressed air in the receiver tank 2 is flowed. Since it discharge | releases to air | atmosphere through the regulating valve 17, the orifice 19a, and the silencer 18a, the pressure in the receiver tank 2 can be reduced to atmospheric pressure.
This avoids start-up congestion due to back pressure when the compressor body 1 is restarted, and does not leave compressed air in the receiver tank 2 when the compressor is stopped.
[0016]
Next, a second embodiment is shown in FIG.
In FIG. 2, the compressed air compressed by the compressor body 1 is temporarily stored in the receiver tank 2 and then supplied to the consumer side through the discharge pipe 37.
At this time, if there is no consumption of compressed air on the consuming side or the amount of compressed air consumed on the consuming side is less than the amount of compressed air discharged from the compressor body 1, the pressure in the receiver tank 2 is increased. To rise. When the pressure in the receiver tank 2 rises and the pressure in the discharge pipe 37 reaches the no-load operation start pressure, the pressure switch PS1 is actuated to send a signal to the solenoid valve 3, and between the control pipes 22, 23, and 25 Open.
First, when the pressure in the receiver tank 2 rises and the pressure in the discharge pipe 37 reaches the no-load operation start pressure, the pressure switch PS1 is activated, the electromagnetic valve 3 is opened, and the compressed air in the receiver tank 2 is discharged. The pressure adjusting chamber 51 is introduced into the pressure receiving chamber 51 c, and the inlet 52 is closed by the valve 51 e of the capacity adjusting valve 51.
However, in this state, the suction chamber 1a of the compressor body 1 has a negative pressure, which causes a problem that a vacuum sound is generated from the compressor body 1 or vibrations occur. Therefore, simultaneously with the operation of the electromagnetic valve 3, the compressed air in the receiver tank 2 is introduced and pressurized into the pressure receiving chamber 8a of the switching valve 8, and the piston 8d is pushed up to open the inlet port 8b and the outlet port 8c. The compressed air in 2 is introduced into the suction chamber 1 a of the compressor body 1. Thereby, since the negative pressure in the suction chamber 1a is relieved, it is possible to prevent the generation of vacuum noise and vibrations from the compressor body 1.
[0017]
Furthermore, the piping 28 connecting the discharge port 8c of the switching valve 8 and the suction chamber 1a of the compressor body 1 is branched, and an orifice 19a and a silencer 18a are provided to form a purge circuit, thereby switching to no-load operation. At times, the compressed air in the receiver tank 2 can be opened to the atmosphere.
The orifice 19a is provided to maintain the minimum pressure in the receiver tank 2 during no-load operation and adjust the amount of compressed air released to the atmosphere. For example, the pressure in the receiver tank 2 is 1.2 kg / so that not to cm ² or less.
[0018]
When consumption of compressed air starts on the consumption side and the pressure in the discharge pipe 37 decreases to the load operation return pressure, the pressure switch PS1 is activated to stop the signal to the solenoid valve 3, and the control pipes 22 and 23 , 25 is closed.
First, the electromagnetic valve 3 is closed, the compressed air in the pressure receiving chamber 51c of the capacity adjustment valve 51 is introduced into the suction passage 51b of the capacity adjustment valve 51 through the control pipe 29 and the orifice 19b, the valve 51e is lowered, and the suction port 52 is opened. Next, since the control pipe 25 communicates with the suction passage 51b, the pressure in the pressure receiving chamber 8a is lowered and the piston 8d is lowered, so that the space between the inlet 8b and the outlet 8c is cut off, and the compressed air suction chamber in the receiver tank 2 is closed. Stop introduction to 1a and release to atmosphere.
[0019]
When the compressor is stopped, the valve 51e closes the suction port 52 by the backflow prevention spring 51f in the capacity adjustment valve 51, and the compressed air in the receiver tank 2 flows back to the compressor main body 1, and the suction chamber Pressurize 1a. When this pressure is introduced into the pressure receiving chamber 8a of the switching valve 8, the pressure in the pressure receiving chamber 8a rises, so that the piston 8d is pushed up, and the introduction port 8b and the discharge port 8c are opened. Then, the compressed air in the receiver tank 2 is released to the atmosphere through the flow rate adjustment valve 17, the orifice 19a, and the silencer 18a, and the pressure in the receiver tank 2 is reduced to atmospheric pressure.
This avoids start-up congestion due to back pressure when the compressor body 1 is restarted, and does not leave compressed air in the receiver tank 2 when the compressor is stopped.
[0020]
【The invention's effect】
According to the compressor control circuit of the present invention configured as described above, reliability is improved because it is configured with fewer parts while having the same or higher function and performance than the conventional control circuit. Further, it is possible to provide an unprecedented innovative control circuit for a compressor that can reduce the component cost and power consumption.
[Brief description of the drawings]
FIG. 1 is a control circuit diagram of a compressor according to a first embodiment of the present invention. FIG. 2 is a control circuit diagram of a compressor according to a second embodiment of the present invention. [Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Compressor main body 1a Suction chamber 2 Receiver tank 3-7 Solenoid valve 8 Switching valve 8a Pressure receiving chamber 8b Inlet 8c Outlet 8d Piston 9 Auto relief valve 9a Pressure receiving chamber 9b Inlet 9c Outlet 9d Piston 10 Regulator 10b Inlet 10c Discharge port 12 Check valve 17 Flow rate adjusting valve 18a, 18b Silencer 19a, 19b Orifice 21-36 Control piping 37 Discharge piping PS1, PS2 Pressure switch 51 Capacity adjustment valve 51b Suction passage 51c Pressure receiving chamber 51d Piston 51e Valve 51f Spring

Claims

A compressor main body, a receiver tank for storing air compressed by the compressor main body, means for releasing compressed air in the receiver tank to the atmosphere during no-load operation, and a suction chamber of the compressor main body during no-load operation In the compressor comprising: means for communicating with the receiver tank; and means for releasing the compressed air of the receiver tank to the atmosphere when stopped.
During no-load operation of the compressor, the compressed air in the receiver tank is released to the atmosphere, a part of the compressed air is introduced into the suction chamber of the compressor body, and the receiver is also stopped when the compressor is stopped. A switching valve is provided to release the compressed air in the tank to the atmosphere .
The switching valve includes an introduction port, a discharge port, and a pressure receiving chamber, communicates or blocks the introduction port and the discharge port by pressure in the pressure receiving chamber, and connects the pressure receiving chamber to the receiver tank via a solenoid valve; The inlet is connected to the receiver tank, the outlet is connected to the suction chamber and communicates with the atmosphere, and the pressure receiving chamber is pressurized during no-load operation of the compressor, thereby introducing the inlet and outlet of the switching valve. When the compressor is in a load operation, the pressure receiving chamber is depressurized to cut off the communication between the introduction port and the discharge port of the switching valve, and when the compressor is stopped, the pressure receiving chamber is A control circuit for a compressor , wherein pressurizing causes the inlet and outlet of the switching valve to communicate with each other .

The switching valve is a pilot-type switching valve that includes an introduction port, a discharge port, and a pressure receiving chamber, and that communicates or blocks the introduction port and the discharge port by the pressure in the pressure receiving chamber. Connected to the receiver tank and connected to the suction chamber of the compressor body, the inlet is connected to the receiver tank, the discharge port is connected to the suction chamber and communicates with the atmosphere, and the compressor is unloaded. During operation, the pressure receiving chamber is pressurized to connect the inlet and outlet of the switching valve, and during load operation of the compressor, the pressure receiving chamber is reduced to reduce the pressure from the inlet and outlet of the switching valve. 2. The compressor according to claim 1, wherein communication with the outlet is cut off, and when the compressor is stopped, the pressure receiving chamber is pressurized to connect the inlet and the outlet of the switching valve. Control circuit.

3. The compressor control circuit according to claim 1, wherein an orifice is provided in the middle of the circuit from the switching valve discharge port to the atmosphere opening port.

3. The compressor control circuit according to claim 1, wherein a flow rate adjusting valve and an orifice are provided in the middle of the circuit from the switching valve discharge port to the atmosphere opening port.

5. The bypass passage connecting the suction passage and the suction chamber of the compressor is provided, and a check valve is provided in the direction of flow from the suction passage side to the suction chamber side in the middle of the passage. Compressor control circuit.