JPH0979166A - Air compressor - Google Patents

Air compressor

Info

Publication number
JPH0979166A
JPH0979166A JP23645095A JP23645095A JPH0979166A JP H0979166 A JPH0979166 A JP H0979166A JP 23645095 A JP23645095 A JP 23645095A JP 23645095 A JP23645095 A JP 23645095A JP H0979166 A JPH0979166 A JP H0979166A
Authority
JP
Japan
Prior art keywords
pressure
air
valve
compressor
discharge
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP23645095A
Other languages
Japanese (ja)
Inventor
Hirochika Kametani
裕敬 亀谷
Riichi Uchida
利一 内田
Masakazu Aoki
優和 青木
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hitachi Ltd
Original Assignee
Hitachi Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hitachi Ltd filed Critical Hitachi Ltd
Priority to JP23645095A priority Critical patent/JPH0979166A/en
Publication of JPH0979166A publication Critical patent/JPH0979166A/en
Pending legal-status Critical Current

Links

Classifications

    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04CROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
    • F04C28/00Control of, monitoring of, or safety arrangements for, pumps or pumping installations specially adapted for elastic fluids
    • F04C28/24Control of, monitoring of, or safety arrangements for, pumps or pumping installations specially adapted for elastic fluids characterised by using valves controlling pressure or flow rate, e.g. discharge valves or unloading valves

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Applications Or Details Of Rotary Compressors (AREA)

Abstract

PROBLEM TO BE SOLVED: To reduce pressure adjusting parts and kinds of piping, simplify a capacity control system, reduce a load at starting time, control a delivery air quantity, and cope with many load conditions such as blowoff air unloading time. SOLUTION: In a suction throttle valve 5, a moving body 61 is fitted to an outer cylinder 71 arranged in a valve case 51, and a piston 58 is fitted to an inner cylinder 62, and a valve plate 55 is attached to it. The valve plate 55 reciprocatively operates, and comes into close contact with a valve seat 56, and blocks up an intake air passage 53, and stops intake air of an air compressor. Compression springs are provided in chambers on the valve plate 55 side of respective cylinders, and in the opposite side chambers, internal pressure of an air tank is communicated with an outside main chamber 72 through a solenoid valve 31, and the internal pressure is directly communicated with an inside main chamber 63. At starting time and blowoff air unloading time, the solenoid valve 31 is opened, and the valve plate 55 is closed by comparatively weak pressure applied to the outside main chamber 7, and at unloading time, the valve plate is opened and closed by comparatively strong pressure applied to the inside main chamber 63, and an intake air quantity is controlled.

Description

【発明の詳細な説明】Detailed Description of the Invention

【0001】[0001]

【産業上の利用分野】本発明は空気圧縮機に関する。FIELD OF THE INVENTION This invention relates to air compressors.

【0002】[0002]

【従来の技術】空気圧縮機は一般産業用を中心に広く普
及している。その基本動作は大気中から空気を吸い込
み、圧縮後に外部配管に送り出すものであり、送られた
圧縮空気は動力源や噴射媒体などとして使われる。空気
圧縮機は使用者が容易に使用可能でかつ安全確実な動作
が必要とされるため、圧縮機本体に加え幾つかの補機を
伴い、一体として実用に供されている。
2. Description of the Related Art Air compressors are widely used mainly for general industries. The basic operation is to take in air from the atmosphere and send it out to an external pipe after compression, and the sent compressed air is used as a power source or an injection medium. Since the air compressor is easy for the user to use and requires safe and reliable operation, the air compressor is put into practical use as an integral unit together with the compressor body and some auxiliary machines.

【0003】圧縮機の補機は多種多様あるが、空気清浄
器,吸入絞り弁,圧縮空気冷却器,空気槽、そして動力
源となる電動機あるいは内燃機関などが主要なものであ
る。空気清浄器は空気清浄手段として、吸い込む空気に
含まれる塵埃を除去する。吸入絞り弁は吸入量制限手段
として吸い込む空気の量を制限したり、あるいは吸入を
止める働きを持つ。圧縮空気冷却器は圧縮空気冷却手段
として、圧縮されて高温となった空気を冷却する。空気
槽は圧縮した空気を一旦溜めて、吐出圧の変動を抑制す
る。
There are various types of compressor accessories, but the main ones are an air purifier, a suction throttle valve, a compressed air cooler, an air tank, and an electric motor or an internal combustion engine as a power source. The air purifier removes dust contained in the sucked air as an air purifying means. The suction throttle valve has a function of limiting the amount of air to be sucked in, or stopping the suction as a suction amount limiting means. The compressed air cooler serves as compressed air cooling means and cools the compressed air that has become high temperature. The air tank temporarily stores compressed air and suppresses fluctuations in discharge pressure.

【0004】圧縮機本体が圧縮室に給油しながら圧縮を
行う油冷式圧縮機である場合には、圧縮機本体に給油機
能を持たせ、圧縮室に連続的な給油を可能とするほか、
いくつかの油関係の補機が必要となる。一例として空気
に混入した油を圧縮後に空気から分離する油分離手段と
しての油分離器や、圧縮により発熱した空気から熱を吸
収し温度上昇した油を冷却し再度の注油に備える油冷却
器などである。また、圧縮機本体の圧縮室,油分離器,
油冷却器を循環する油も圧縮機の性能や信頼性に係る重
要な要素である。
When the compressor main body is an oil-cooled compressor that compresses while supplying oil to the compression chamber, the compressor main body has an oil supply function to enable continuous oil supply to the compression chamber.
Some oil related accessories are needed. As an example, an oil separator as an oil separation means that separates the oil mixed in the air from the air after compression, an oil cooler that absorbs heat from the air generated by compression and cools the oil whose temperature has risen, and prepares for re-lubrication, etc. Is. In addition, the compression chamber of the compressor body, the oil separator,
The oil circulating in the oil cooler is also an important factor related to the performance and reliability of the compressor.

【0005】空気圧縮機に求められる重要な機能の一つ
が吐出圧力の制御である。使用者にとり、吐出圧力は一
定であることが望ましい。しかし、使用者の空気使用量
は一定しないことが多い。空気圧縮機を一定の能力で運
転したままで、空気使用量が減少すると、余剰となった
圧縮空気により吐出圧力は上昇し、逆に空気使用量が増
加すると吐出圧力は低下してしまう。そこで、空気圧縮
機には容量制御機能が備えられ、空気使用量に応じて吐
出量を制御し、吐出圧力を一定の範囲に維持するのが普
通である。
One of the important functions required of the air compressor is the control of the discharge pressure. For the user, it is desirable that the discharge pressure be constant. However, the amount of air used by the user is often not constant. If the amount of air used decreases while the air compressor is operating at a constant capacity, the discharge pressure rises due to the surplus compressed air, and conversely, if the amount of air used increases, the discharge pressure drops. Therefore, the air compressor is usually provided with a capacity control function to control the discharge amount according to the amount of air used and maintain the discharge pressure within a certain range.

【0006】空気圧縮機の容量制御の方法はいくつかの
種類が実用化されている。小型の圧縮機では、空気槽内
圧により電動機の起動,停止を繰り返すオン・オフ制御
が一般的である。中型以上の圧縮機では電動機の頻繁な
起動,停止が困難であり、再起動にも時間がかかるため
電動機の回転を持続させたまま、圧縮機本体の吸入量を
吸入絞り弁で抑制する吸入絞り式容量制御(別名:サク
ションアンロード)が広く使われている。また、圧縮機
本体をインバータにより可変速駆動し、容量制御する方
法も実用化されている。
Several types of air compressor capacity control methods have been put into practical use. In a small compressor, on / off control is generally performed by repeatedly starting and stopping the electric motor depending on the pressure in the air tank. Since it is difficult to start and stop the electric motor frequently with medium-sized or larger compressors, and it takes time to restart the electric motor, the suction throttle restricts the suction amount of the compressor body with the suction throttle valve while continuing the rotation of the electric motor. Expression capacity control (also known as suction unloading) is widely used. In addition, a method in which the compressor body is driven at a variable speed by an inverter to control the capacity has been put into practical use.

【0007】空気使用量が極めて少ない場合や他の圧縮
機と協調して運転する場合には、一定時間、圧縮空気を
吐出する必要がないことがある。その場合には、吸入を
ほぼ全閉にすると同時に空気槽内の圧縮空気を放気し、
吐出圧を下げる。すると、電動機の回転は持続しなが
ら、圧縮機本体を回転するのに必要なトルクが減少し消
費電力が節約される。この状態を放気アンロードと呼
び、中形以上の空気圧縮機で広く使われている。
When the amount of air used is extremely small or when the compressor is operated in cooperation with another compressor, it may not be necessary to discharge compressed air for a certain period of time. In that case, close the intake almost completely and at the same time release the compressed air in the air tank,
Lower the discharge pressure. Then, while the rotation of the electric motor continues, the torque required to rotate the compressor body is reduced, and the power consumption is saved. This state is called bleed unloading, and is widely used in medium-sized and larger air compressors.

【0008】中形以上の空気圧縮機で、容量制御ととも
に考慮すべきことは起動方法である。中形以上の電動機
は起動を容易にするため、電源投入直後は圧縮機の回転
に必要なトルクを通常の運転時よりも小さくしておく必
要がある。そのため、吸入絞り弁により吸入量を制限
し、圧縮機本体の吸入圧力と吐出圧である空気槽内圧を
低いままで維持する。これは先の放気アンロードに近い
状態であるが、空気槽の内圧が上昇する前に吸入を絞る
ため、空気槽圧力は放気アンロード時に比較し低く保た
れる。
In a medium-sized or larger air compressor, the starting method should be considered together with the capacity control. In order to easily start the electric motor of medium size or more, it is necessary to reduce the torque required for the rotation of the compressor to be smaller than that during normal operation immediately after the power is turned on. Therefore, the suction amount is limited by the suction throttle valve, and the suction pressure of the compressor body and the air tank internal pressure that is the discharge pressure are kept low. This is a state close to the previous unloading unloading, but since the suction is throttled before the internal pressure of the air tank rises, the air tank pressure is kept low compared to the unloading unloading.

【0009】複数の吸入圧力や吐出圧力の状態とそれを
実現するための吐出量を制御する構造は特開昭60−2565
91号公報に示されている。公知例では複数の電磁弁や圧
力調整のための弁が必要で、それらを繋ぐ配管系も複雑
となっている。
A structure for controlling a plurality of suction pressure and discharge pressure states and a discharge amount for realizing the states is disclosed in Japanese Patent Laid-Open No. 60-2565.
No. 91 publication. In the known example, a plurality of solenoid valves and valves for pressure adjustment are required, and the piping system connecting them is complicated.

【0010】従来用いられている容量制御装置の例を図
2と図3と図4を用いて説明する。図2は容量制御を実
施するための機構を備えた油冷式空気圧縮機の系統図で
ある。なお、本発明に直接関与しない部分については省
略した。図3は圧縮機の運転時の空気槽の内圧変化の一
例を時間を追って示したもので、縦軸は大気圧を1気圧
として絶対圧で示している。図4は本機構に用いられて
いる圧力調整弁の入出力圧力特性を示すグラフである。
An example of a conventional capacity control device will be described with reference to FIGS. 2, 3, and 4. FIG. 2 is a system diagram of an oil-cooled air compressor provided with a mechanism for carrying out capacity control. It should be noted that parts that are not directly involved in the present invention are omitted. FIG. 3 shows an example of changes in the internal pressure of the air tank during the operation of the compressor over time, and the vertical axis shows absolute pressure with the atmospheric pressure as 1 atm. FIG. 4 is a graph showing the input / output pressure characteristics of the pressure regulating valve used in this mechanism.

【0011】定常運転中、空気は大気から取り入れら
れ、空気清浄器14により塵埃を除去した後に、吸入絞
り弁2と吸入路19を通過する。続いて、空気は圧縮機
本体1に吸入口11から吸い込まれ圧縮後に吐出口12
から吐出される。圧縮過程では給油口13から連続的に
入れられた油が空気に混入され、油は潤滑,冷却,シー
ル材として働く。圧縮空気と油は混じった状態で油分離
器15に入り、分離後に圧縮空気は吐出弁16を経て外
部に導かれる。吐出弁16は直列に配置された逆止弁と
調圧弁より成り、逆流を防止すると同時に下流の圧力が
極端に低い場合には閉塞して空気槽内圧を一定圧以上に
維持する。一方、油分離器15から出た油は油冷却器1
7を経て、再び圧縮機本体に給油口13から注入され
る。油冷却器17はファン18によって送られる冷却風
が熱交換し、油温が下げられる。
During steady operation, air is taken in from the atmosphere and, after removing dust by the air purifier 14, passes through the suction throttle valve 2 and the suction passage 19. Subsequently, the air is sucked into the compressor body 1 through the suction port 11 and, after being compressed, the discharge port 12
Is discharged from. In the compression process, the oil continuously supplied from the oil supply port 13 is mixed into the air, and the oil functions as a lubricating, cooling and sealing material. The compressed air and the oil enter the oil separator 15 in a mixed state, and after the separation, the compressed air is guided to the outside through the discharge valve 16. The discharge valve 16 is composed of a check valve and a pressure regulating valve which are arranged in series, and prevents backflow and at the same time closes the pressure in the downstream when the pressure is extremely low to maintain the internal pressure of the air tank above a certain pressure. On the other hand, the oil discharged from the oil separator 15 is the oil cooler 1
After 7, the oil is again injected into the compressor body from the oil filler port 13. In the oil cooler 17, the cooling air sent by the fan 18 exchanges heat with the oil temperature.

【0012】油分離器15は内部に十分な容積を備えて
おり、下部には分離された油が溜り、残った上部の空間
は若干のオイルミストが浮遊するものの圧縮空気で満た
される。したがって、油分離器15は圧縮空気と油を分
離する機能の他に、空気槽と油溜めの機能を合わせ持
つ。そこで油分離器の上部を空気槽20として取扱う。
The oil separator 15 has a sufficient volume inside, and the separated oil collects in the lower part, and the remaining upper space is filled with compressed air although some oil mist floats. Therefore, the oil separator 15 has not only the function of separating compressed air and oil, but also the functions of an air tank and an oil sump. Therefore, the upper part of the oil separator is handled as the air tank 20.

【0013】吸入絞り弁2は弁ケース21に弁板22,
ピストン23、それらを繋ぐロッド24を内蔵する。弁
ケース21の一部はピストン23の往復するシリンダ2
5を形成し、ピストン23によって区切られた弁板22
側を副室27、その反対側を主室26と呼ぶことにす
る。副室26には圧縮ばね28が備えられる。
The intake throttle valve 2 includes a valve case 21, a valve plate 22,
A piston 23 and a rod 24 connecting them are built in. A part of the valve case 21 is a cylinder 2 in which a piston 23 reciprocates.
5 forming a valve plate 22 separated by a piston 23
The side will be called the sub chamber 27, and the opposite side will be called the main chamber 26. A compression spring 28 is provided in the sub chamber 26.

【0014】油分離器15の下流の圧縮空気の吐出管3
3からは、電磁弁31と圧力調整弁32の二つの弁が並
列して分岐し両者共に放気路34に連通する。電磁弁3
1は通電すると閉塞し電圧をかけないと全開となる機能
を有する。放気路34の一端は吸入絞り弁2の主室26
に連通し、他端は放気絞り35を経て末端のサイレンサ
36に至り、大気に開放される。
A compressed air discharge pipe 3 downstream of the oil separator 15.
From 3, the two valves, the solenoid valve 31 and the pressure regulating valve 32, branch in parallel and both communicate with the discharge passage 34. Solenoid valve 3
1 has a function of being closed when energized and fully opened when no voltage is applied. One end of the discharge passage 34 is connected to the main chamber 26 of the intake throttle valve 2.
And the other end reaches the end silencer 36 through the discharge throttle 35 and is opened to the atmosphere.

【0015】圧力調整弁32にとり、上流側の空気槽2
0内圧が入力圧力,下流側の放気路34や主室26内圧
が出力圧力となる。図4に示すように、入力圧力が設定
圧力(図4では7気圧と仮定した。)を越えるまでは、圧
力調整弁32は閉塞したままである。設定圧力以上の入
力圧力に対しては設定圧力を越えた分の圧力、すなわち
入力圧力から設定圧力を引いた差圧を出力する機能を備
える。ただし、実際の圧力調整弁は図4に示す線から若
干逸脱した特性を示し、圧力上昇と減少の過程では入出
力特性の経路が異なるヒステリシスを持つこともある
が、本質にかかわる量ではない。また、設定圧力は圧力
調整弁32に付随した調整ハンドルにより変更すること
が可能である。
For the pressure regulating valve 32, the air tank 2 on the upstream side
The internal pressure of 0 is the input pressure, and the internal pressure of the discharge passage 34 and the main chamber 26 on the downstream side is the output pressure. As shown in FIG. 4, the pressure regulating valve 32 remains closed until the input pressure exceeds the set pressure (7 atmospheric pressure is assumed in FIG. 4). It has a function to output the pressure exceeding the set pressure, that is, the differential pressure obtained by subtracting the set pressure from the input pressure, for the input pressure higher than the set pressure. However, the actual pressure regulating valve exhibits a characteristic slightly deviating from the line shown in FIG. 4, and the path of the input / output characteristic may have different hysteresis in the process of pressure increase and decrease, but this is not an amount related to the essence. Further, the set pressure can be changed by an adjusting handle attached to the pressure adjusting valve 32.

【0016】吸入絞り弁2の副室27に連通する流路は
電磁三方弁37の共通口に至る。電磁三方弁37は通電
時は共通口を吸入路19側に連通させ、それ以外の時は
共通口を大気側に連通させる機能を有する。
A flow path communicating with the sub chamber 27 of the suction throttle valve 2 reaches a common port of the electromagnetic three-way valve 37. The electromagnetic three-way valve 37 has a function of connecting the common port to the suction passage 19 side when energized and connecting the common port to the atmosphere side at other times.

【0017】圧縮機本体1を駆動する電動機3は誘導電
動機であり、始動盤41を介して商用交流電力42が送
られて回転する。始動盤41は起動時にみられる過大電
流を抑制するために給電回路を切り換え、スターデルタ
起動を行う機能を有する。
The electric motor 3 that drives the compressor body 1 is an induction motor, and commercial AC power 42 is sent through a starter board 41 to rotate. The starter board 41 has a function of switching a power supply circuit and performing star delta start-up in order to suppress an excessive current that is seen at the time of start-up.

【0018】制御装置4はマイコンを中心とした電子回
路で構成され、電磁弁31と電磁三方弁39さらに、始
動盤41に対し指令を出す機能を有する。さらに、スイ
ッチ43と吐出弁16の下流に設けた圧力センサ44か
ら情報を受け取る機能を有する。
The control device 4 is composed of an electronic circuit centered on a microcomputer, and has a function of issuing a command to the electromagnetic valve 31, the electromagnetic three-way valve 39, and the starter board 41. Further, it has a function of receiving information from the pressure sensor 44 provided downstream of the switch 43 and the discharge valve 16.

【0019】空気圧縮機の一般的な動作の一例を図3の
時間軸に沿って示す。空気圧縮機の起動前には空気槽2
0内圧は大気圧である1気圧に等しい。時刻Aに使用者
がスイッチ43を入れる。制御装置4はそれを認識し、
始動盤41にスター回路での駆動を指令する。同時に電
磁弁31に開放を、電磁三方弁37に副室27と吸入路
19の連通を指令する。
An example of the general operation of the air compressor is shown along the time axis of FIG. Air tank 2 before starting the air compressor
The 0 internal pressure is equal to 1 atmospheric pressure, which is the atmospheric pressure. At time A, the user turns on the switch 43. The controller 4 recognizes it,
The starter board 41 is instructed to drive the star circuit. At the same time, the electromagnetic valve 31 is instructed to open, and the electromagnetic three-way valve 37 is instructed to communicate the sub chamber 27 with the suction passage 19.

【0020】電動機4は停止状態から次第に加速し、そ
れにつれて、圧縮機本体1も空気の圧縮を開始し、空気
槽20に空気が送られ内圧が次第に上昇する。この間、
空気槽20内圧は規定値に達しないため吐出弁16は開
かれていない。空気槽20に少しだけ溜った圧縮空気は
開かれた電磁弁31を経由して主室26に導かれる。空
気槽20内圧が設定圧に達しないため、圧力調整弁32
は閉じたままである。主室26に空気槽20内圧をかけ
た圧縮空気は放気絞り35を通過し、圧力を下げた後に
サイレンサ36から大気に放出される。したがって、主
室26の内圧は電磁弁31や途中の管路の流路抵抗と放
気絞り35の流路抵抗により定まり、空気槽20内圧と
大気圧の間となる。通常は放気絞り35の流路抵抗を大
きくするので、主室26内圧は空気槽20内圧に近い。
The electric motor 4 gradually accelerates from the stopped state, and the compressor body 1 also starts to compress the air, and the air is sent to the air tank 20 so that the internal pressure gradually rises. During this time,
Since the internal pressure of the air tank 20 does not reach the specified value, the discharge valve 16 is not opened. The compressed air slightly accumulated in the air tank 20 is guided to the main chamber 26 via the opened solenoid valve 31. Since the internal pressure of the air tank 20 does not reach the set pressure, the pressure adjusting valve 32
Remains closed. The compressed air in which the internal pressure of the air chamber 20 is applied to the main chamber 26 passes through the discharge throttle 35, and after the pressure is reduced, it is discharged from the silencer 36 to the atmosphere. Therefore, the internal pressure of the main chamber 26 is determined by the flow path resistance of the solenoid valve 31 and the conduit in the middle and the flow path resistance of the air discharge throttle 35, and is between the internal pressure of the air tank 20 and the atmospheric pressure. Normally, since the flow passage resistance of the discharge throttle 35 is increased, the internal pressure of the main chamber 26 is close to the internal pressure of the air tank 20.

【0021】副室27は吸入路19と連通するため、圧
縮機本体1に吸われて内圧が大気圧以下の負圧となる。
主室26と副室27の差圧からピストン23は図中左方
向へ移動し、遂には弁板22が流路を完全に塞ぐ。この
状態では圧縮機本体1へ空気が送られないので、空気槽
20内圧は大気圧より僅か0.5 気圧程度上昇するだけ
で、ほぼ一定のまま推移し、その間、圧縮機本体1の駆
動トルクは小さくなる。必要なトルクが小さいため、電
動機4は容易に加速し、起動電流も抑制される。
Since the sub chamber 27 communicates with the suction passage 19, the sub chamber 27 is sucked by the compressor body 1 and the internal pressure becomes a negative pressure below atmospheric pressure.
The piston 23 moves leftward in the figure due to the pressure difference between the main chamber 26 and the sub chamber 27, and finally the valve plate 22 completely closes the flow path. Since air is not sent to the compressor body 1 in this state, the internal pressure of the air tank 20 rises by about 0.5 atm from the atmospheric pressure and remains almost constant, during which the drive torque of the compressor body 1 is increased. Becomes smaller. Since the required torque is small, the electric motor 4 is easily accelerated and the starting current is suppressed.

【0022】時刻Bとなり電動機4ならびに圧縮機本体
1の回転速度が十分な値に達すると、制御回路4の指令
により始動盤41は回路をスター回路からデルタ回路に
よる駆動に切り換える。続いて、制御装置4は電磁弁3
1の閉塞ならびに電磁三方弁37を切り換えて副室27
と大気側38との連通を指令する。
When the rotation speeds of the electric motor 4 and the compressor body 1 reach a sufficient value at time B, the starter board 41 switches the circuit from the star circuit to the drive by the delta circuit according to a command from the control circuit 4. Subsequently, the control device 4 controls the solenoid valve 3
1 is closed and the electromagnetic three-way valve 37 is switched to switch the sub chamber 27.
To communicate with the atmosphere side 38.

【0023】空気槽20からの圧縮空気の供給が止まる
ので、主室26や放気路34内部の空気がサイレンサ3
6から出尽くし、内圧が大気圧まで降下する。一方、副
室27も電磁三方弁37を経て大気側38と連通するた
め内圧が大気圧となる。ピストン23へは両側圧力が等
しくなるので弁板22を閉じる方向のガス圧は働かず、
圧縮ばね28の反力と弁板22の両面の圧力差で弁板2
2は全開まで開かれる。
Since the supply of the compressed air from the air tank 20 is stopped, the air inside the main chamber 26 and the air discharge passage 34 is discharged from the silencer 3.
It runs out from 6, and the internal pressure drops to atmospheric pressure. On the other hand, since the sub chamber 27 also communicates with the atmosphere side 38 via the electromagnetic three-way valve 37, the internal pressure becomes atmospheric pressure. Since the pressure on both sides becomes equal to the piston 23, the gas pressure in the direction of closing the valve plate 22 does not work,
The valve plate 2 is caused by the reaction force of the compression spring 28 and the pressure difference between the two surfaces of the valve plate 22.
2 is open until it is fully opened.

【0024】吸入絞り弁2が全開となり、圧縮機本体1
も通常運転の回転速度なので、能力最大で圧縮空気を空
気槽20に送り込む。空気槽20内圧は次第に上昇し時
刻Cに7気圧に至る。吐出弁16も規定圧を越えてから
開放され圧縮空気を外部に送り出し、通常の運転状態と
なる。
The suction throttle valve 2 is fully opened, and the compressor body 1
Since the rotation speed is also in normal operation, the compressed air is sent into the air tank 20 at the maximum capacity. The internal pressure of the air tank 20 gradually increases and reaches 7 atm at time C. The discharge valve 16 is also opened after the specified pressure is exceeded, and compressed air is sent to the outside, and the normal operating state is achieved.

【0025】通常運転中には圧縮空気の使用量に応じて
空気槽20内圧が変化するが、吸入絞り制御を行い、吐
出圧を7気圧から8気圧の間に維持する。この機構の動
作を説明する。空気槽20内圧は常に圧力調整弁32の
入力側に作用するが、内圧が設定圧力である7気圧に達
するまで圧力調整弁32は開かれない。空気槽20内圧
が増加し、設定圧力に達すると、圧力調整弁32は自動
的に開かれ、圧縮空気が弁を通過し流れ出る。この時、
弁通過後の空気の圧力は入力である空気槽20内圧から
設定圧力を差し引いた値に圧力調整弁32によって自動
制御される。
During normal operation, the internal pressure of the air tank 20 changes according to the amount of compressed air used, but suction restriction control is performed to maintain the discharge pressure between 7 and 8 atmospheres. The operation of this mechanism will be described. The internal pressure of the air tank 20 always acts on the input side of the pressure adjusting valve 32, but the pressure adjusting valve 32 is not opened until the internal pressure reaches the set pressure of 7 atm. When the internal pressure of the air tank 20 increases and reaches the set pressure, the pressure regulating valve 32 is automatically opened, and the compressed air flows out through the valve. This time,
The pressure of the air after passing through the valve is automatically controlled by the pressure adjusting valve 32 to a value obtained by subtracting the set pressure from the internal pressure of the air tank 20 which is the input.

【0026】圧力調整弁32を通過した空気は吸込絞り
弁2の主室26に流れ込み、ピストンを押して、弁板2
2を閉じさせる。弁板22が閉じることにより、吸入空
気の圧損が増え吸入量が減少するため空気槽20内圧が
低下する。以上の働きにより吐出圧力が自動制御され、
過大な圧力となることはなく、最大で8気圧に抑制され
る。この時、設定圧力7気圧を差し引いた1気圧がピス
トンに作用し、吸入絞り弁を全閉にする。吸入絞り中に
は放気絞り35とサイレンサ36を経て若干の放気があ
る。
The air that has passed through the pressure regulating valve 32 flows into the main chamber 26 of the suction throttle valve 2, pushes the piston, and the valve plate 2
Close 2 When the valve plate 22 is closed, the pressure loss of the intake air increases and the intake amount decreases, so that the internal pressure of the air tank 20 decreases. With the above functions, the discharge pressure is automatically controlled,
The pressure does not become excessive and is suppressed to 8 atm at maximum. At this time, 1 atm obtained by subtracting the set pressure of 7 atm acts on the piston to fully close the suction throttle valve. During the suction throttle, some air is discharged through the discharge throttle 35 and the silencer 36.

【0027】ある時間、空気の消費がないため、吐出圧
が下がらないことを制御装置4が圧力センサ44により
感知すると、電力節約のため放気アンロード状態へ移行
することを判断する。放気アンロードへは以下に示す動
作により移行する。時刻Dで制御装置4は電磁弁31に
開放を指令する。空気槽20内の圧縮空気は電磁弁31
を通過し、主室26に入り、放気絞り35とサイレンサ
36を経て放気される。主室26内圧が上昇するため、
ピストン23はロッド24を押して弁板22を全閉にす
る。吸入がなくなると同時に放気が行われるので、空気
槽20内圧は次第に低下し約3気圧に漸近する。この圧
力より下回ると吸入絞り弁2が開かれ空気が流入し、こ
の圧力より上回ると吸入がないまま放気されるので、3
気圧で安定となる。安定圧がこれより高いと消費動力が
多くなり、電力節約の効果が小さくなり、また、安定圧
がこれより低いと、油に混入していた空気が膨張して泡
となるフォーミング現象を起こすことがある。
When the controller 4 senses with the pressure sensor 44 that the discharge pressure does not decrease because the air is not consumed for a certain period of time, it is determined that the discharge unloading state is entered to save power. The release operation is switched to the unloading unloading by the following operation. At time D, the control device 4 commands the solenoid valve 31 to open. The compressed air in the air tank 20 is a solenoid valve 31.
, Enters the main chamber 26, and is discharged through the discharge throttle 35 and the silencer 36. Since the internal pressure of the main chamber 26 rises,
The piston 23 pushes the rod 24 to fully close the valve plate 22. Since the air is discharged at the same time as the intake is stopped, the internal pressure of the air tank 20 gradually decreases and gradually approaches 3 atmospheric pressure. When the pressure is lower than this pressure, the intake throttle valve 2 is opened to allow air to flow in, and when the pressure is higher than this pressure, the air is discharged without being sucked.
It becomes stable at atmospheric pressure. If the stabilizing pressure is higher than this, the power consumption will be large and the effect of power saving will be small, and if the stabilizing pressure is lower than this, the air mixed in the oil will expand and cause a foaming phenomenon. There is.

【0028】放気アンロードによる空気槽内圧の安定圧
が起動時の安定圧よりも高い理由は起動時には負圧であ
った副室27の内圧が大気圧と高いため、その分だけ弁
板22を締め切るため主室26にかける圧力を高くする
必要があるためである。
The reason why the stable pressure of the internal pressure of the air tank due to the discharge unloading is higher than the stable pressure at the time of startup is that the internal pressure of the sub-chamber 27, which was a negative pressure at the time of startup, is as high as atmospheric pressure. This is because it is necessary to increase the pressure applied to the main chamber 26 in order to shut off.

【0029】放気アンロード中、空気槽20内圧は下流
側外部配管よりも低圧になるが、吐出弁16があるの
で、圧縮空気の逆流は防止される。
During the discharge unloading, the internal pressure of the air tank 20 becomes lower than that of the downstream side external pipe, but the discharge valve 16 prevents the backflow of the compressed air.

【0030】放気アンロード状態の時刻Eで、圧縮空気
の使用が再開されると、吐出圧が低下する。そのことを
圧力センサ44により制御装置4が感知すると、電磁弁
31への通電を止めて閉塞を指令する。圧縮空気の供給
が止まるため主室26内圧が大気圧まで低下し、空気の
吸込と圧縮が再開され、空気槽20内圧が上昇する。
When the use of compressed air is resumed at time E in the discharge unloading state, the discharge pressure drops. When the control device 4 detects this by the pressure sensor 44, the energization of the solenoid valve 31 is stopped and the closing is commanded. Since the supply of compressed air is stopped, the internal pressure of the main chamber 26 drops to atmospheric pressure, suction and compression of air are restarted, and the internal pressure of the air tank 20 rises.

【0031】時刻Fで使用者がスイッチ43を切ると、
制御装置4は始動盤41に電流の遮断と、電磁弁31に
開放を指令する。圧縮機本体1は停止し、空気槽20に
残留した圧縮空気は電磁弁31,放気絞り35,サイレ
ンサ36を通じて放気される。その過程で吸入絞り弁2
を全閉にするため、圧縮機本体1からの吸入路19を通
じての逆流を防止する。放気のため空気槽20の内圧は
大気圧となる時刻Gまで次第に下降する。また、停電時
でも、停止時と同様の動作により運転の停止ならびに放
気が行われる。
When the user turns off the switch 43 at time F,
The control device 4 commands the starter board 41 to shut off the current and the solenoid valve 31 to open. The compressor body 1 is stopped, and the compressed air remaining in the air tank 20 is discharged through the solenoid valve 31, the discharge throttle 35, and the silencer 36. In the process, suction throttle valve 2
Is fully closed to prevent backflow from the compressor body 1 through the suction passage 19. Due to the air release, the internal pressure of the air tank 20 gradually decreases until time G when the atmospheric pressure is reached. Further, even during a power failure, the operation is stopped and the air is discharged by the same operation as when stopped.

【0032】なお、本実施例で用いた圧力値は説明のた
めの仮の値であり、実際には圧縮機の使用条件や使用目
的により若干異なる。
The pressure value used in this embodiment is a tentative value for the purpose of explanation, and actually varies slightly depending on the usage conditions and purpose of use of the compressor.

【0033】[0033]

【発明が解決しようとする課題】従来例による容量制御
機構を備えた空気圧縮機は機能的には要求を満たし、広
く使われている。しかし、起動アンロード,放気アンロ
ード,吸入絞り式の容量制御に対応し、停止後の吸入流
路逆流防止や残留空気の放気まで行うため制御系が複雑
で必要な部品の数も多い。そのため、部品購入や製作,
組立,調整に多くの費用と手間,時間を要し、圧縮機全
体の費用が高くなってしまうという問題があった。ま
た、同じ理由により、圧縮機全体の信頼性確保のための
維持管理に手間がかかるという問題もあった。
The air compressor having the capacity control mechanism according to the conventional example functionally satisfies the requirements and is widely used. However, since it corresponds to capacity control of start-up unloading, discharge unloading, suction throttle type, and prevents backflow of suction flow path after stop and discharges residual air, the control system is complicated and many parts are required. . Therefore, parts purchase and production,
There is a problem in that much cost, labor and time are required for assembly and adjustment, and the cost of the compressor as a whole becomes high. Further, for the same reason, there is a problem that it takes time and effort to maintain and maintain the reliability of the entire compressor.

【0034】本発明の目的は、同じ機能を簡潔な構造で
少ない部品数により可能とする容量制御装置を実現した
空気圧縮機を提供することにある。
It is an object of the present invention to provide an air compressor which realizes a capacity control device which enables the same function with a simple structure and a small number of parts.

【0035】[0035]

【課題を解決するための手段】上記本発明の目的を達成
するため以下に示す第1の手段を用いる。
In order to achieve the above object of the present invention, the following first means is used.

【0036】吸入量制限手段である吸入絞り弁は空気清
浄機と圧縮機本体の吸入口を繋ぐ吸入流路ならびに外シ
リンダを内部に形成したケースを主体に他の部材を組み
合わせて構成する。吸入流路の途中に設けられる弁板は
可動支持され、弁板はその位置により吸入流路を部分的
に、あるいは完全に塞ぐ機能を有する。吸入絞り弁に
は、弁板と連結部材であるロッドにより結合したピスト
ン内が備えられ、ピストンは往復運動可能に内シリンダ
に嵌合する。内シリンダはピストンにより複数の室に区
切られる。内シリンダは移動部材である移動体の内部に
形成され、移動体はケースに設けた外シリンダに往復運
動可能に内蔵される。移動体により外シリンダは複数の
室に区切られる。また、ピストンの移動方向と移動体の
移動方向は一致し、各々必要に応じて移動範囲を制限す
る手段も設けることもできる。
The suction throttle valve, which is the suction amount limiting means, is mainly composed of a case in which the suction passage connecting the air purifier and the suction port of the compressor body and the outer cylinder are formed, and other members are combined. A valve plate provided in the middle of the suction passage is movably supported, and the valve plate has a function of partially or completely closing the suction passage depending on its position. The suction throttle valve is provided with an inside of a piston connected to a valve plate by a rod which is a connecting member, and the piston is fitted in an inner cylinder so as to be capable of reciprocating motion. The inner cylinder is divided into a plurality of chambers by a piston. The inner cylinder is formed inside a moving body that is a moving member, and the moving body is reciprocally incorporated in an outer cylinder provided in the case. The moving body divides the outer cylinder into a plurality of chambers. Further, the moving direction of the piston and the moving direction of the moving body coincide with each other, and means for limiting the moving range may be provided as needed.

【0037】上記本発明の目的をより効率的に達成する
ため、上記第1の手段に加えて、以下に示す第2の手段
を用いる。
In order to achieve the above object of the present invention more efficiently, the following second means is used in addition to the above first means.

【0038】ピストンにより内シリンダが区切られて形
成された室のうち弁板の反対側に位置する室(内主室と
呼ぶ)には圧縮機吐出口下流の空気槽から流路を連通さ
せる。移動体により外シリンダが区切られて形成された
室のうちの一方の室は空気槽から開閉手段を経て連通さ
せる。ここで、開閉手段とは電磁弁に代表される制御装
置の指令により電線を介した遠隔操作で開閉制御可能な
弁である。
Of the chamber formed by dividing the inner cylinder by the piston, the chamber located on the opposite side of the valve plate (referred to as the inner main chamber) is made to communicate with the flow path from the air tank downstream of the compressor discharge port. One of the chambers formed by dividing the outer cylinder by the moving body is communicated with the air tank through the opening / closing means. Here, the opening / closing means is a valve whose opening / closing can be controlled by remote control via an electric wire according to a command from a control device represented by a solenoid valve.

【0039】また、内副室内部に圧縮ばね、あるいは、
内主室に引張ばねを備え、そのばね定数の加減により、
圧縮機の吐出圧力設定値を選択することができる。
Further, a compression spring, or
Equipped with a tension spring in the inner main chamber, by adjusting the spring constant,
The discharge pressure set value of the compressor can be selected.

【0040】なお、第1,第2の手段共に、従来例で説
明した電磁三方弁を含む副室に連通する流路は必要とさ
れず、吸入絞り弁の内シリンダの弁板側の室は吸入路あ
るいは大気へ連通させておくのみでよい。従来例で述べ
た圧力調整弁とその前後の流路も不要となる。
Both the first and second means do not require a passage communicating with the sub chamber including the electromagnetic three-way valve described in the conventional example, and the chamber on the valve plate side of the inner cylinder of the suction throttle valve is not required. It only needs to be in communication with the inhalation passage or the atmosphere. The pressure regulating valve described in the conventional example and the flow passages before and after it are also unnecessary.

【0041】[0041]

【作用】上記課題解決の手段による吸入絞り弁と、それ
を用いて構成された空気圧縮機は以下に示すように作用
する。なお、開閉手段を経て空気槽内圧が連通する外シ
リンダ室は、移動体により区切られた弁板と反対側の室
として説明する。弁板側の室の場合は、開閉手段の開閉
を逆に考えれば同様の作用となる。
The suction throttle valve according to the means for solving the above-mentioned problems and the air compressor constructed using the suction throttle valve operate as follows. The outer cylinder chamber, through which the air tank internal pressure communicates via the opening / closing means, will be described as a chamber on the opposite side of the valve plate partitioned by the moving body. In the case of the chamber on the valve plate side, if the opening / closing of the opening / closing means is considered in reverse, the same operation is performed.

【0042】空気圧縮機の起動時は開閉手段が開かれ、
外主室に空気槽から圧縮空気が送られる。外シリンダの
断面積は比較的大きいので、空気槽内圧が吐出圧に満た
ない例えば2気圧程度でも外シリンダに嵌合したピスト
ンに相当する移動体を押すに十分な値となる。移動体が
弁板方向に移動すると、移動体内部のピストンも一体と
なって移動し弁板を閉じ、吸入路を塞ぐ。この時、内主
室圧力はピストンを動かすに十分な圧力に満たず、ピス
トンは内シリンダの内部で動かず一体となっている。吸
入路が塞がれるため吸入圧が大気圧よりも低くなり、吐
出圧も通常運転時に比較して十分に低いので、圧縮機本
体を動かす必要トルクは小さく、電動機にとり起動が容
易になる。
When the air compressor is started, the opening / closing means is opened,
Compressed air is sent from the air tank to the outer main chamber. Since the cross-sectional area of the outer cylinder is relatively large, even if the internal pressure of the air tank is less than the discharge pressure, for example, about 2 atm, the value is sufficient to push the moving body corresponding to the piston fitted in the outer cylinder. When the moving body moves toward the valve plate, the piston inside the moving body also moves integrally, closing the valve plate and closing the suction passage. At this time, the pressure in the inner main chamber does not reach a pressure sufficient to move the piston, and the piston does not move inside the inner cylinder and is integrated. Since the suction passage is blocked, the suction pressure becomes lower than the atmospheric pressure, and the discharge pressure is sufficiently lower than that during normal operation. Therefore, the torque required to move the compressor body is small, and the start-up becomes easy for the electric motor.

【0043】電動機ならびに圧縮機本体が通常運転の回
転速度まで加速されると制御装置の指令により起動回路
がデルタ回路となり、開閉手段が閉じられる。外主室は
作動室と切り離されるので、圧力の高い空気の供給が途
絶え内圧が低下し、移動体が外主室側に後退し弁板が開
かれる。この時、作動室内圧はまだ低いので、弁板とピ
ストンは移動体と一体となったままである。弁板が開か
れるので、空気が圧縮機本体に流入し、空気を圧縮し吐
出する通常の運転が開始される。
When the electric motor and the compressor body are accelerated to the rotational speed of normal operation, the start-up circuit becomes a delta circuit according to a command from the control device, and the opening / closing means is closed. Since the outer main chamber is separated from the working chamber, the supply of high-pressure air is interrupted, the internal pressure drops, the moving body retreats to the outer main chamber side, and the valve plate opens. At this time, since the pressure in the working chamber is still low, the valve plate and the piston remain integrated with the moving body. Since the valve plate is opened, the air flows into the compressor body, and the normal operation of compressing and discharging the air is started.

【0044】通常の運転状態で、以下に示すように吸入
絞り式の容量制御がなされる。圧縮空気使用量が圧縮機
能力よりも少ないと、空気槽内圧が上昇してくる。内主
室は空気槽に連通しているので、次第に内圧が上昇し、
遂には設定圧力を越える。すると、内主室内圧がピスト
ンを弁板方向に押す力が内シリンダに備えたばねの反力
を越え、ピストンが動きだす。内主室内圧が高いほど、
その力が大きく、ばねをより変形させ、弁板を閉じる。
ピストンの位置はピストン両側の差圧とばね定数と弁板
の両側の差圧と若干の摩擦力の釣合いによって決まり、
通常は空気槽内圧が設定圧力から約1気圧高い圧力まで
上昇すると弁板が完全に閉じられる。なお、この時、外
主室内圧はほぼ大気圧と低いので、移動体は外主室側に
停止したままで動かない。
In a normal operating condition, the suction throttle type capacity control is performed as shown below. If the amount of compressed air used is less than the compression function, the air tank internal pressure will rise. Since the inner main chamber communicates with the air tank, the internal pressure gradually rises,
Finally, the set pressure is exceeded. Then, the force of the inner main chamber pressure pushing the piston toward the valve plate exceeds the reaction force of the spring provided in the inner cylinder, and the piston starts to move. The higher the inner main chamber pressure,
The force is large, causing the spring to deform more and closing the valve plate.
The position of the piston is determined by the balance between the differential pressure on both sides of the piston, the spring constant, the differential pressure on both sides of the valve plate, and some frictional force.
Normally, when the internal pressure of the air tank rises from the set pressure to a pressure higher by about 1 atm, the valve plate is completely closed. At this time, since the pressure in the outer main chamber is as low as atmospheric pressure, the moving body remains stationary on the outer main chamber side and does not move.

【0045】圧縮空気使用量が皆無か極めて少ないなど
の条件により放気アンロード運転にすることが判断され
ると、制御装置は開閉手段に開放を支持する。空気槽内
圧が開閉手段を通過し外主室にかかるので、移動体は弁
板方向に動き始める。放気アンロードに移行する時点
で、ピストンが内副室側端にあり弁板が閉じられていて
も、弁板が閉じられたままで移動体のみが弁板方向に移
動するので、吸入路が開かれることはない。また、放気
により、空気槽内圧が低下し、内主室内圧がピストンを
押すに足りなくなっても、外主室内圧で移動体ごとピス
トンや弁板を押して、弁板の全閉を維持する。
When it is judged that the discharge unloading operation is to be carried out under the condition that the amount of compressed air used is none or extremely small, the control device supports the opening / closing means to open. Since the air tank internal pressure passes through the opening / closing means and is applied to the outer main chamber, the moving body starts to move toward the valve plate. Even when the piston is at the end of the inner sub-chamber and the valve plate is closed at the time of shifting to the discharge unloading, only the moving body moves in the valve plate direction with the valve plate being closed, so the suction passage is It will never be opened. Also, even if the air tank internal pressure decreases due to air release and the internal main chamber pressure becomes insufficient to push the piston, the piston and valve plate are pushed together with the moving body by the external main chamber pressure to maintain the valve plate fully closed. .

【0046】放気アンロードから通常運転への復帰は開
閉手段が閉じられることにより、起動時と同様の動作が
なされ、空気槽内圧の上昇と、それに続く吐出再開が実
行される。
The return from the discharge unloading to the normal operation is performed by closing the opening / closing means, and the same operation as at the time of starting is performed, and the increase of the air tank internal pressure and the subsequent restart of discharge are executed.

【0047】圧縮機停止時では開閉手段が開放となり弁
板を閉じ、続いて、圧縮機本体の運転が停止する。弁板
が閉じることにより圧縮機本体からの空気や油冷式圧縮
機では作動室内部の油の逆流が防止される。また、空気
槽内圧が開閉手段を通じて放気され、圧縮機内部も大気
圧となる。よって、整備や分解調整時の安全を確保し、
あるいは油漏れ等の障害が防止される。
When the compressor is stopped, the opening / closing means is opened to close the valve plate, and subsequently the operation of the compressor main body is stopped. By closing the valve plate, air from the compressor body and backflow of oil in the working chamber of the oil-cooled compressor are prevented. Further, the air tank internal pressure is released through the opening / closing means, and the inside of the compressor also becomes atmospheric pressure. Therefore, ensure safety during maintenance and disassembly adjustment,
Alternatively, obstacles such as oil leakage are prevented.

【0048】[0048]

【実施例】以下、図1,図5,図6,図7を用いて、第
1の実施例である油冷式空気圧縮機の構成と動作を説明
する。図1は本実施例の空気圧縮機に用いる吸入絞り弁
の断面図であり、全負荷運転中における全開の様子を示
している。図5は本実施例の空気圧縮機の系統図であ
る。図6は本実施例の空気圧縮機に用いる吸入絞り弁が
起動時あるいは放気アンロード時で全閉となっている状
態の断面図である。図7は同じ放気絞り弁の圧縮空気使
用量が極めて少なく、ほぼ完全に吸入を絞った状態であ
る全閉アンロード時の断面図である。
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The construction and operation of the oil-cooled air compressor of the first embodiment will be described below with reference to FIGS. 1, 5, 6, and 7. FIG. 1 is a cross-sectional view of an intake throttle valve used in the air compressor of this embodiment, showing a state of full opening during full load operation. FIG. 5 is a system diagram of the air compressor of this embodiment. FIG. 6 is a cross-sectional view of a state in which the suction throttle valve used in the air compressor of this embodiment is fully closed at the time of starting or unloading air. FIG. 7 is a cross-sectional view at the time of fully closed unloading in which the amount of compressed air used by the same discharge throttle valve is extremely small and the suction is almost completely throttled.

【0049】本実施例の空気圧縮機に用いる吸入絞り弁
5の構造を図1を用いて説明する。吸入絞り弁5は弁ケ
ース51に吸入路53,54ならびに後述する各種部材
を内蔵し構成される。図中で左方向を正面側,右方向を
背面側として表現する。吸入路は弁板55が弁座56に
押し付けられ吸入路を塞ぐ面を境に、上流側を上吸入路
53,下流側を下吸入路54と分けて考える。上吸入路
53は空気清浄器14から連通し、下吸入路54は圧縮
機本体1の吸入口11へと連通する。
The structure of the suction throttle valve 5 used in the air compressor of this embodiment will be described with reference to FIG. The suction throttle valve 5 is configured by incorporating suction passages 53 and 54 and various members described later in a valve case 51. In the figure, the left direction is expressed as the front side and the right direction is expressed as the back side. The intake path is considered such that the upstream side is divided into the upper intake path 53 and the downstream side is divided into the lower intake path 54 with the surface of the valve plate 55 pressed against the valve seat 56 closing the intake path as a boundary. The upper suction passage 53 communicates with the air purifier 14, and the lower suction passage 54 communicates with the suction port 11 of the compressor body 1.

【0050】弁板55の弁座56に当たる部分である面
パッキン94は弾性材で密着密閉性のよいゴム等の材質
で構成する。弁板55の背面側にはロッド57が伸び、
その先にピストン58が固定される。弁板55とロッド
57とピストン58は一体となって往復運動する。ピス
トン58は移動体61の内部に形成された、内面の滑ら
かな円筒形孔である内シリンダ62に嵌合する。したが
って、往復運動ならびに自転は許されるが他の自由度は
拘束される。また、内シリンダ62の端部に形成した凸
部あるいは段差にピストン58が接触することにより、
往復運動も一定の範囲に限定される。ピストン58の外
周と内シリンダ62内面は接触せず、僅かなすきまを保
ち、ピストン58の外周に刻まれた溝に外周すきまを塞
ぐ環形状の内パッキン59が嵌められる。内パッキン5
9や他のパッキン類は弾性を持ちすきまの両面に密着す
る一方、摩擦力の小さい材質や断面形状や表面処理を選
定する。内シリンダ62はピストン58により、二つの
部屋に区切られ、そのうち背面側の部屋を内主室63,
正面側の部屋を内副室64と呼ぶ。
The surface packing 94, which is the portion of the valve plate 55 that abuts on the valve seat 56, is made of an elastic material such as rubber having a close contact and airtightness. A rod 57 extends on the back side of the valve plate 55,
The piston 58 is fixed at the tip thereof. The valve plate 55, the rod 57, and the piston 58 integrally reciprocate. The piston 58 fits into an inner cylinder 62 that is a smooth cylindrical hole formed on the inner surface of the moving body 61. Therefore, reciprocating motion and rotation are allowed, but other degrees of freedom are restricted. Further, since the piston 58 comes into contact with a convex portion or a step formed on the end portion of the inner cylinder 62,
The reciprocating motion is also limited to a certain range. The outer periphery of the piston 58 and the inner surface of the inner cylinder 62 are not in contact with each other, a slight clearance is maintained, and a ring-shaped inner packing 59 that closes the outer clearance is fitted in a groove formed on the outer periphery of the piston 58. Inner packing 5
While 9 and other packings have elasticity and adhere to both sides of the clearance, a material having a small frictional force, a sectional shape and a surface treatment are selected. The inner cylinder 62 is divided into two chambers by a piston 58, of which the rear chamber is the inner main chamber 63,
The room on the front side is called an inner sub-chamber 64.

【0051】内副室64には圧縮ばね65が備えられ、
内副室64の正面側端面である移動体61の内壁とピス
トン58の間を引き離す方向に力を与える。ばねの自由
長は両者間が最も離れた時よりも長く、したがって、両
者間が最も離れた時でも、ある値の初期力を働かせる。
この力の大きさにより圧縮機の吐出の設定圧が決まる。
A compression spring 65 is provided in the inner sub chamber 64,
A force is applied in a direction in which the piston 58 is separated from the inner wall of the moving body 61, which is the front end surface of the inner sub chamber 64. The free length of the spring is longer than when the two are farthest apart, and therefore even when the two are farthest apart, a certain amount of initial force is exerted.
The magnitude of this force determines the set pressure for the compressor discharge.

【0052】移動体61はそれ自身がピストンとして、
弁ケース51に内蔵した外シリンダ71に嵌合し、ピス
トン58と同一の方向に往復運動可能である。およそ円
筒形状をした移動体61は軸方向に長く、その両端近く
に設けられた各々の外周溝には外周すきまを塞ぐ環形状
の外パッキン60が嵌められる。外シリンダ71は移動
体61の二つの外パッキン60を境にして三つの部屋に
区切られる。そのうち背面側の部屋を外主室72,正面
側の部屋を外副室73,二つの外パッキン60にはさま
れる移動体61外周と取り巻く薄い円環状空間を外側室
74とする。
The moving body 61 itself serves as a piston,
It fits into an outer cylinder 71 built in the valve case 51 and can reciprocate in the same direction as the piston 58. The moving body 61 having a substantially cylindrical shape is long in the axial direction, and ring-shaped outer packing 60 that closes the outer peripheral clearance is fitted in each outer peripheral groove provided near both ends thereof. The outer cylinder 71 is divided into three chambers with the two outer packings 60 of the moving body 61 as boundaries. The room on the back side is the outer main room 72, the room on the front side is the outer sub-chamber 73, and the outer circumference of the movable body 61 sandwiched between the two outer packings 60 is the outer room 74.

【0053】外副室73には圧縮ばね75が備えられ、
外副室73の正面側端面と移動体61の間を引き離す方
向に力を与える。ばねの自由長は両者間が最も離れた時
よりも長い。したがって、両者が最も離れた時でも、あ
る値の初期力を働かせる。圧縮ばね75は内副室64内
の圧縮ばね65よりもばね定数が小さく、初期力も小さ
く設定する。
A compression spring 75 is provided in the outer auxiliary chamber 73,
A force is applied in a direction in which the front end surface of the outer auxiliary chamber 73 and the moving body 61 are separated from each other. The free length of the spring is longer than when the two are farthest apart. Therefore, even when the two are farthest apart, a certain amount of initial force is exerted. The compression spring 75 has a smaller spring constant than the compression spring 65 in the inner sub chamber 64, and is set to have a small initial force.

【0054】移動体61の正面側端面には内副室64と
外副室73を結ぶ連通孔66を貫通させる。また、弁ケ
ース51には外副室73と下吸入路54を結ぶ連通孔7
6が設けられる。したがって、連通する内副室64と外
副室73の内圧は下吸入路54の内圧に追従する。ロッ
ド57が通る弁ケース51や移動体61に明けた孔に
は、両側の室がほぼ同圧となるため、軸シールは不要で
ある。但し、滑らかな動きを確保するための摺動性は必
要となる。移動体61にはまた、側面に内主室63と外
側室74を結ぶ連通路67も設けられる。
A communication hole 66 connecting the inner sub-chamber 64 and the outer sub-chamber 73 is made to penetrate through the front end surface of the moving body 61. Further, the valve case 51 has a communication hole 7 connecting the outer sub chamber 73 and the lower suction passage 54.
6 are provided. Therefore, the internal pressures of the inner sub-chamber 64 and the outer sub-chamber 73 communicating with each other follow the inner pressure of the lower suction passage 54. Since the chambers on both sides have almost the same pressure in the hole formed in the valve case 51 and the moving body 61 through which the rod 57 passes, a shaft seal is not required. However, slidability is required to ensure smooth movement. The moving body 61 is also provided with a communication passage 67 connecting the inner main chamber 63 and the outer chamber 74 on the side surface.

【0055】移動体61の背面側端面中央に内主室63
と外主室72を繋ぐ過大圧放気弁68を備える、過大圧
放気弁68は移動体61端面に開けた、径を途中で変え
た貫通孔に弁玉69と弁ばね70を組み構成する。外主
室72内圧が内主室63内圧より高い時は弁玉69が差
圧で押されて孔を塞ぎ、過大圧放気弁68は閉じられ
る。逆に、内主室63内圧が外主室72内圧より高い時
は、ある値の差圧までは弁ばね70の力で弁玉69が押
され孔が塞がれたままで、その差圧以上では弁玉69が
背面方向に動かされ、すきまが生じ、過大圧放気弁68
は開く。外主室72内圧が大気圧の時の過大圧放気弁6
8が開く時の内主室63内圧を過大圧と呼ぶことにし、
吐出圧の設定値よりも通常は1気圧程度高くしておく。
なお、本実施例では過大圧放気弁68は移動体61の背
面側端部に設けたが、入力が吐出圧管77,出力が制御
圧管78と連通する関係を維持し、また同じ機能を持て
ば位置や構造を選ばない。
An inner main chamber 63 is provided at the center of the rear end surface of the moving body 61.
And the outer main chamber 72 are connected to each other. An overpressure air release valve 68 is provided. The overpressure air release valve 68 is formed by assembling a valve ball 69 and a valve spring 70 in a through hole opened on the end face of the moving body 61 and having a diameter changed in the middle. To do. When the internal pressure of the outer main chamber 72 is higher than the internal pressure of the inner main chamber 63, the valve ball 69 is pushed by the differential pressure to close the hole, and the overpressure relief valve 68 is closed. On the contrary, when the inner pressure of the inner main chamber 63 is higher than the inner pressure of the outer main chamber 72, the valve ball 69 is pushed by the force of the valve spring 70 until the pressure difference reaches a certain value, and the hole is blocked, and the pressure difference is not less than the pressure difference. In this case, the valve ball 69 is moved to the back side, a clearance is generated, and the overpressure release valve 68 is released.
Opens. Overpressure release valve 6 when the internal pressure of the outer main chamber 72 is atmospheric pressure
The internal pressure of the inner main chamber 63 when 8 is opened will be called overpressure,
Usually, it is set higher than the set value of the discharge pressure by about 1 atm.
Although the overpressure relief valve 68 is provided at the rear end of the moving body 61 in this embodiment, it maintains the relationship that the input communicates with the discharge pressure pipe 77 and the output communicates with the control pressure pipe 78, and has the same function. Position and structure.

【0056】上吸入路53と下吸入路54の他に、本吸
入絞り弁5へ外部から制御用の2本の配管が接続され
る。1本は吐出流路33から分岐した吐出圧管77で、
外側室74に弁ケース51を貫通して連通する。その貫
通位置は移動体61が動作範囲のいかなる位置にあって
も、外側室74と連通する位置とする。もう1本は吐出
圧管77から電磁弁31を経由して外主室72に連通す
る制御圧管78である。制御圧管78から分岐した放気
路34は放気絞り35とサイレンサ36を経て外気に連
通する。
In addition to the upper suction passage 53 and the lower suction passage 54, two pipes for control are connected to the main suction throttle valve 5 from the outside. One is a discharge pressure pipe 77 branched from the discharge passage 33,
The outer chamber 74 penetrates the valve case 51 and communicates therewith. The penetration position is a position that communicates with the outer chamber 74 regardless of the position of the moving body 61 in the operating range. The other is a control pressure pipe 78 that communicates with the outer main chamber 72 from the discharge pressure pipe 77 via the solenoid valve 31. The air discharge passage 34 branched from the control pressure pipe 78 communicates with the outside air via an air discharge throttle 35 and a silencer 36.

【0057】吸入絞り弁5の弁ケース51,弁板55,
ロッド57,ピストン58や移動体61などの構造体は
一個の部材である必要はなく、複数の部材を組み立てた
ものであってもよい。その場合の構造体の分割位置や、
密閉のためのパッキンやシールの配置に関しては本発明
の本質にかかわらない。
The valve case 51 of the intake throttle valve 5, the valve plate 55,
The structures such as the rod 57, the piston 58, and the moving body 61 do not have to be a single member, and may be an assembly of a plurality of members. In that case, the division position of the structure,
The arrangement of packings and seals for sealing does not matter to the essence of the present invention.

【0058】本吸入絞り弁5を備えた空気圧縮機の構成
を図5を用い、従来例である図2と比較して説明する。
The structure of the air compressor having the intake throttle valve 5 will be described with reference to FIG. 5 in comparison with FIG. 2 which is a conventional example.

【0059】吐出路33と放気路34を結ぶ2本の経路
のうち、圧力調整弁32を経由する管路が圧力調整弁3
2とともに不要となる。新たに吐出圧管77を必要とす
るが、電磁弁31を吸入絞り弁5上に一体化し配管類を
弁ケース51に開けた孔に代えることにより、部品数が
増えることはない。また、以上のような構成とすること
により機器類をコンパクトにまとめられる。
Of the two paths connecting the discharge path 33 and the discharge path 34, the line passing through the pressure adjusting valve 32 is the pressure adjusting valve 3.
It becomes unnecessary with 2. Although a new discharge pressure pipe 77 is required, the number of parts does not increase by integrating the solenoid valve 31 on the suction throttle valve 5 and replacing the piping with the hole formed in the valve case 51. In addition, the devices described above can be compactly configured.

【0060】従来例で設けられていた電磁三方弁37な
らびに電磁三方弁37から伸びる3本の配管が不要とな
る。また、制御装置4の電磁三方弁37への出力機能も
不要となる。
The electromagnetic three-way valve 37 and the three pipes extending from the electromagnetic three-way valve 37, which are provided in the conventional example, are unnecessary. Further, the output function of the control device 4 to the electromagnetic three-way valve 37 is also unnecessary.

【0061】本実施例による空気圧縮機は以下のように
作用する。
The air compressor according to this embodiment operates as follows.

【0062】圧縮機の起動前には、空気槽20をはじめ
機器や配管の内圧はすべて大気圧である。吸入絞り弁5
は内部の各室間に差圧がなく、ばね力により弁板55は
背面側位置にあり、全開状態となっている。
Before starting the compressor, the internal pressure of the air tank 20 and other equipment and pipes are all atmospheric pressure. Suction throttle valve 5
There is no pressure difference between the inner chambers, and the valve plate 55 is at the back side position due to the spring force and is in the fully open state.

【0063】スイッチ43により使用者の運転開始の指
示が感知されると、制御装置4は開閉手段31を開放の
まま、始動盤41にスター回路による起動を指令する。
始動盤41から電動機3に電力が送られ、圧縮機本体1
が駆動されて運転開始する。空気が全開の吸入絞り弁5
を通過し吸入口11から圧縮機本体1に吸い込まれ、圧
縮されて空気槽20に送られる。この時まで吸入絞り弁
5の内外各シリンダ室の内圧はほぼ大気圧であり、圧縮
ばね65,75の反力で弁板55は全開となっている。
したがって、空気の圧縮は障害なく実行される。また、
空気槽20内圧も低いため駆動トルクも小さく、起動が
スムーズに行われる。
When the user's instruction to start driving is sensed by the switch 43, the controller 4 instructs the starter board 41 to start by the star circuit while keeping the opening / closing means 31 open.
Electric power is sent from the starter board 41 to the electric motor 3, and the compressor body 1
Is driven to start operation. Intake throttle valve 5 with air fully open
Is sucked into the compressor body 1 through the suction port 11, compressed, and sent to the air tank 20. Until this time, the internal pressure of each of the inner and outer cylinder chambers of the intake throttle valve 5 is substantially atmospheric pressure, and the valve plate 55 is fully opened by the reaction force of the compression springs 65 and 75.
Therefore, the compression of the air is carried out without hindrance. Also,
Since the internal pressure of the air tank 20 is also low, the driving torque is also small, and the startup is smoothly performed.

【0064】以上の起動直後の短時間の運転により、空
気槽20内圧が若干上昇してくると、圧縮空気は電磁弁
31と制御圧管78を経て外主室72に作用する。外シ
リンダ71の圧縮ばね75は比較的軟らかく、移動体6
1の正面面積が比較的広いので、大気圧から若干上昇し
た程度の圧力で押された移動体61が正面方向に動きだ
す。外副室73内圧は圧縮機本体1の吸入により大気圧
より低い負圧となっているため、移動体61の動きを助
ける。
When the internal pressure of the air tank 20 slightly rises due to the short-time operation immediately after the start-up as described above, the compressed air acts on the outer main chamber 72 through the electromagnetic valve 31 and the control pressure pipe 78. The compression spring 75 of the outer cylinder 71 is relatively soft, and the moving body 6
Since the front area of No. 1 is relatively large, the moving body 61 pushed by a pressure slightly higher than the atmospheric pressure starts to move in the front direction. Since the internal pressure of the outer sub chamber 73 is a negative pressure lower than the atmospheric pressure due to the suction of the compressor body 1, the movement of the moving body 61 is assisted.

【0065】この起動過程で、内主室63内圧も外主室
72と同じ圧力が作用するが、圧縮ばね65の反力が大
きく、さらにピストン58断面積が移動体61断面積に
比較して小さいため、ばねの反力に勝るガス力は生じな
い。したがって、ピストン58は内シリンダ62の背面
側端部に圧縮ばね65で押し付けられたままである。そ
のため、ピストン58はロッド57や弁板55も含め
て、移動体61と一体となっており、移動体61の正面
方向への移動は弁板55の移動となる。
In this starting process, the internal pressure of the inner main chamber 63 is also the same as that of the outer main chamber 72, but the reaction force of the compression spring 65 is large, and the cross-sectional area of the piston 58 is larger than that of the moving body 61. Since it is small, no gas force is generated that exceeds the reaction force of the spring. Therefore, the piston 58 remains pressed against the rear end of the inner cylinder 62 by the compression spring 65. Therefore, the piston 58 including the rod 57 and the valve plate 55 is integrated with the moving body 61, and the movement of the moving body 61 in the front direction is the movement of the valve plate 55.

【0066】期間が経過し空気槽20内圧がさらに上昇
すると、遂には弁板55が弁座56に密着し、吸入路が
閉塞し、吸入が停止される。この状態を図6に示す。こ
の時の空気槽29内圧は高々1.5 から2気圧程度であ
り、通常運転の吐出圧に比較すれば十分に低い。吸入が
閉塞されたために、吸入圧も負圧と低く、圧縮機本体1
を起動ならびに加速するトルクが抑制され、起動や回転
速度の加速が容易となる。
When the period elapses and the internal pressure of the air tank 20 further rises, the valve plate 55 finally comes into close contact with the valve seat 56, the suction passage is closed, and suction is stopped. This state is shown in FIG. At this time, the internal pressure of the air tank 29 is at most about 1.5 to 2 atmospheres, which is sufficiently lower than the discharge pressure in normal operation. Since the suction is blocked, the suction pressure is also low at negative pressure, and the compressor body 1
The torque for starting and accelerating the engine is suppressed, and starting and acceleration of the rotation speed are facilitated.

【0067】以上の起動状態では、空気槽20内の圧縮
空気は放気路34から放気絞り35とサイレンサ36を
経て、大気へ放出され続ける。放気は放気絞り35に制
限され量的には少ないが継続するので、空気槽20内圧
に連動して外主室72内圧も次第に不足する。外主室7
2内圧の低下により移動体61が圧縮ばね75に押し戻
され背面方向へ後退する。移動体61に連動した弁板5
5も僅かに後退し、弁板55と弁座56の間にすきまが
生じる。そのすきまから空気が吸い込まれ、空気槽20
内圧は再び上昇する。この一連の働きにより起動時の空
気槽20内圧はほぼ一定に自動制御される。また、弁板
55と弁座56の間に形成するすきまに代えて、吸入絞
り弁5の吸入路と並行に、弁板55で閉塞しない意図的
な漏れ流路(パージ流路)を備えておくことも可能であ
る。その場合には、漏れ流路に逆止弁を備え、圧縮機停
止直後の逆流を防止する必要がある。
In the above-mentioned start-up state, the compressed air in the air tank 20 is continuously discharged from the discharge passage 34 to the atmosphere through the discharge throttle 35 and the silencer 36. Since the discharge is limited by the discharge throttle 35 and is small in quantity but continues, the internal pressure of the outer main chamber 72 gradually becomes insufficient in conjunction with the internal pressure of the air tank 20. Outside main room 7
2 Due to the decrease in the internal pressure, the moving body 61 is pushed back by the compression spring 75 and retracts in the rearward direction. The valve plate 5 that is interlocked with the moving body 61
5 also retracts slightly, and a gap is created between the valve plate 55 and the valve seat 56. Air is sucked in through the gap, and the air tank 20
The internal pressure rises again. With this series of operations, the internal pressure of the air tank 20 at the time of startup is automatically controlled to be substantially constant. Further, instead of the clearance formed between the valve plate 55 and the valve seat 56, an intentional leak flow path (purge flow path) that is not blocked by the valve plate 55 is provided in parallel with the suction path of the suction throttle valve 5. It is also possible to set it. In that case, it is necessary to provide a check valve in the leak passage to prevent backflow immediately after the compressor is stopped.

【0068】電動機3と圧縮機本体1の回転速度が通常
の運転回転速度に達すると、制御装置4の判断により、
始動盤41がデルタ回路に切り換えられ、続いて、電磁
弁31が閉じられる。電磁弁31下流の放気路34や外
主室72内への圧縮空気は供給を絶たれるため、サイレ
ンサ36から出尽くしてしまい、外主室72内圧は低下
し大気圧となる。弁板55両側の差圧と圧縮ばね75の
反力による移動体61に働く背面方向の力が、大気圧の
外主室72と負圧の外副室73の差圧による正面方向の
力を上回る。移動体61は弁板55とともに背面方向に
移動限度まで移動し、吸入絞り弁5は図1に示す全開状
態となる。
When the rotational speeds of the electric motor 3 and the compressor main body 1 reach the normal operating rotational speed, the control device 4 judges that
The starter board 41 is switched to the delta circuit, and subsequently the solenoid valve 31 is closed. The supply of compressed air to the air discharge passage 34 downstream of the solenoid valve 31 and the inside of the outer main chamber 72 is cut off, so the silencer 36 is exhausted and the inner pressure of the outer main chamber 72 decreases to atmospheric pressure. The rearward force acting on the moving body 61 due to the differential pressure on both sides of the valve plate 55 and the reaction force of the compression spring 75 causes the frontward force due to the differential pressure between the outer main chamber 72 at atmospheric pressure and the outer subchamber 73 at negative pressure. Surpass. The moving body 61 moves in the rearward direction to the movement limit together with the valve plate 55, and the suction throttle valve 5 is in the fully open state shown in FIG.

【0069】電動機が通常運転のデルタ回路で給電さ
れ、吸入絞り弁5が全開となったので、圧縮機は全負荷
運転となり、空気の圧縮,吐出量は最大となる。空気槽
20内圧は上昇し、規定圧力を越えた圧縮空気は吐出弁
16を経て外部に送られ、使用される。
Since the electric motor is fed by the delta circuit in normal operation and the intake throttle valve 5 is fully opened, the compressor is in full load operation, and the compression and discharge amounts of air are maximized. The internal pressure of the air tank 20 rises, and the compressed air exceeding the specified pressure is sent to the outside through the discharge valve 16 and used.

【0070】通常運転中に圧縮機の吐出能力よりも圧縮
空気の使用量が少ない場合には、圧縮空気が余剰となる
ので、空気槽20内圧が次第に上昇し設定値を越える。
空気槽20内圧は常に吐出圧管77,外側室74,連通
路67を経由して内主室63に作用している。そのた
め、空気槽20内圧が設定値を越えると、ピストン58
両側の差圧による正面方向の力が圧縮ばね65の初期力
を越え、ピストン58を正面方向に動かす。圧縮ばね6
5の反力はピストン58の移動量に比例して増加するの
で、差圧が大きくなるほど、移動量も大きくなる。ピス
トン58の移動は一体である弁板55の移動となり、吸
入路を次第に閉塞し吸入量を制限する。吸入量の制限は
圧縮空気の吐出量の制限であり、空気槽20内圧を低減
する作用がある。したがって、圧縮空気の使用量と吐出
量がつりあう位置にピストン58は安定し、吐出圧が設
定値かそれより僅かに高い値に維持される。以上の制御
を吸入絞り制御と呼び、その状態をアンロードと呼ぶ。
When the amount of compressed air used is smaller than the discharge capacity of the compressor during normal operation, the compressed air becomes excessive, so the internal pressure of the air tank 20 gradually rises and exceeds the set value.
The inner pressure of the air tank 20 always acts on the inner main chamber 63 via the discharge pressure pipe 77, the outer chamber 74, and the communication passage 67. Therefore, if the internal pressure of the air tank 20 exceeds the set value, the piston 58
The force in the front direction due to the pressure difference on both sides exceeds the initial force of the compression spring 65, and moves the piston 58 in the front direction. Compression spring 6
Since the reaction force of 5 increases in proportion to the moving amount of the piston 58, the moving amount increases as the differential pressure increases. The movement of the piston 58 results in the movement of the valve plate 55 which is integrated, and gradually closes the suction passage to limit the suction amount. The limitation of the suction amount is the limitation of the discharge amount of the compressed air, and has the action of reducing the internal pressure of the air tank 20. Therefore, the piston 58 stabilizes at a position where the amount of compressed air used and the amount of discharge are balanced, and the discharge pressure is maintained at a set value or a value slightly higher than that. The above control is called intake throttle control, and that state is called unloading.

【0071】圧縮空気使用量が極端に少なく空気槽20
内圧がある値(通常は吐出圧設定値より約1気圧程度高
い値)まで上昇すると、弁板55が弁座56に接触する
まで移動し、吸入絞り弁5は全閉となり、圧縮空気の吐
出は中断される。図7に示すこの状態を全閉アンロード
と呼ぶ。
Air tank 20 with extremely small amount of compressed air used
When the internal pressure rises to a certain value (usually about 1 atmosphere higher than the discharge pressure set value), the valve plate 55 moves until it comes into contact with the valve seat 56, the suction throttle valve 5 is fully closed, and the compressed air is discharged. Is interrupted. This state shown in FIG. 7 is called full-closed unload.

【0072】アンロードや全閉アンロード状態で、外主
室72内圧は大気圧、外副室73は負圧であり、差圧は
正面方向の力を生じるが、圧縮ばね75の背面方向の初
期力が勝り、移動体61は内シリンダ71の背面側端に
押し付けられたままである。したがって、移動体61は
弁ケース51と一体となったまま動かない。
In the unloading or fully-closed unloading state, the internal pressure of the outer main chamber 72 is atmospheric pressure, and the outer sub-chamber 73 is a negative pressure. The differential pressure produces a force in the front direction, but the pressure in the rear direction of the compression spring 75. The initial force prevails, and the moving body 61 remains pressed against the rear end of the inner cylinder 71. Therefore, the moving body 61 does not move while being integrated with the valve case 51.

【0073】経年変化や組立誤差による面パッキン94
の劣化で発生する弁板55と弁座56の間の僅かなすき
まからの漏れや、意図的な僅かな吸入空気であるパージ
などにより、全閉アンロード時にも僅かながら空気が吸
入絞り弁5を通過することがある。その空気は圧縮され
空気槽20に送られる。圧縮空気の使用がなく、行き先
がないため、空気槽20内圧は通常の吐出圧を越えたま
ま上昇を続ける。過大な圧力は危険であるので、次に述
べる過大圧放気の機能が動作し、安全が確保される。
Face packing 94 due to secular change and assembly error
Due to the leakage from the slight gap between the valve plate 55 and the valve seat 56 caused by the deterioration of the intake air, and the intentional purging of the intake air, a small amount of air is sucked even during the fully closed unloading. May pass through. The air is compressed and sent to the air tank 20. Since the compressed air is not used and there is no destination, the internal pressure of the air tank 20 continues to rise while exceeding the normal discharge pressure. Since excessive pressure is dangerous, the function of excessive pressure release described below operates to ensure safety.

【0074】過大圧放気弁68の両側の圧力は内主室6
3は空気槽20内圧、外主室72は大気圧であり、差圧
は空気槽20内圧によって定まる。空気槽20内圧があ
る値に設定された過大圧力に達すると、過大圧放気弁6
8が開く。空気槽20内に溜った圧縮空気を吐出圧管7
7から連通路67を経由し、過大圧放気弁68を通り、
制御圧管78やサイレンサ36を経て大気へ放出され
る。放気により空気槽20内圧が過大圧力を下回ると、
過大圧放気弁68は閉じて、無意味な圧力低下は防止さ
れる。以上の動作により無制限な圧力上昇や圧力低下は
起こらない。なお、本機構の故障や他の予期せぬ事態に
より空気層20内圧が過大圧力を越える場合に備え、空
気槽20には安全弁が備えられ、万一の際には強制的に
放気し内圧を下げることができる。
The pressure on both sides of the overpressure relief valve 68 is set to the inner main chamber 6
3 is the internal pressure of the air tank 20, the external main chamber 72 is the atmospheric pressure, and the differential pressure is determined by the internal pressure of the air tank 20. When the internal pressure of the air tank 20 reaches an overpressure set to a certain value, the overpressure release valve 6
8 opens. The compressed air accumulated in the air tank 20 is discharged into the discharge pressure pipe 7
7 through the communication passage 67, the excessive pressure release valve 68,
It is discharged to the atmosphere through the control pressure pipe 78 and the silencer 36. When the internal pressure of the air tank 20 falls below the excessive pressure due to the release of air,
The overpressure relief valve 68 is closed to prevent a meaningless pressure drop. The above operation does not cause unlimited pressure increase or pressure decrease. In addition, in case the internal pressure of the air layer 20 exceeds the excessive pressure due to a failure of this mechanism or other unexpected situations, the air tank 20 is equipped with a safety valve. Can be lowered.

【0075】圧縮空気の使用がないか、あるいは複数の
空気圧縮機の協調運転がなされている場合に圧縮空気使
用量が少なく1台分以上の休止が可能である場合があ
る。これらの状況は全閉アンロード状態が長く続くなど
の条件から感知され、放気アンロードに移行すべきと、
制御装置4が判断する。制御装置4の指示で電磁弁31
が開放され放気アンロードへの移行が開始される。
In some cases, when compressed air is not used or when a plurality of air compressors are operated in concert, the amount of compressed air used is small and one or more units can be stopped. These situations are detected from conditions such as a fully closed unloading state that lasts for a long time, and it is necessary to shift to air release unloading.
The control device 4 determines. The solenoid valve 31 is instructed by the control device 4.
Is released and the transition to the air release unloading begins.

【0076】開かれた電磁弁31から空気槽20内の圧
縮空気が制御圧管78を経て外主室72に導かれる。外
主室72内圧が十分に高くなり、ガス力が移動体61を
正面方向に移動させる。この時、弁板55は弁座56に
密着したままであり、弁板55やピストン58の弁ケー
ス51との相対位置はそのままで、移動体61のみが正
面方向に動く。移動体61の移動開始とともに電磁弁3
1が開かれるため、放気路34から放気絞り35,サイ
レンサ36を経て、空気槽20内部の圧縮空気が次第に
放気される。
The compressed air in the air tank 20 is introduced from the opened solenoid valve 31 into the outer main chamber 72 via the control pressure pipe 78. The internal pressure of the outer main chamber 72 becomes sufficiently high, and the gas force moves the moving body 61 in the front direction. At this time, the valve plate 55 remains in close contact with the valve seat 56, the relative positions of the valve plate 55 and the piston 58 with the valve case 51 remain unchanged, and only the moving body 61 moves in the front direction. When the moving body 61 starts moving, the solenoid valve 3
1, the compressed air in the air tank 20 is gradually discharged from the discharge passage 34 through the discharge throttle 35 and the silencer 36.

【0077】放気が進行し、空気槽20内圧が低下して
くると、内主室63内圧によりピストン58を正面方向
に押している力が不足してくる。しかし、ピストン58
が内シリンダ62の背面側端に接触し、その接触力でピ
ストン58を正面方向に押し、移動体61ごと外主室6
3の圧力で弁板55を弁座56に押し付ける状態にな
る。したがって、吸入絞り弁5の閉塞は放気アンロード
への移行過程の間や移行完了後も維持される。放気完了
時の吸入絞り弁5は図6に示す起動アンロード時と同じ
状態となる。
When the air release progresses and the internal pressure of the air tank 20 decreases, the internal pressure of the inner main chamber 63 causes the force for pushing the piston 58 in the front direction to become insufficient. However, the piston 58
Comes into contact with the rear end of the inner cylinder 62, and the contact force pushes the piston 58 in the front direction to move the moving body 61 together with the outer main chamber 6
With the pressure of 3, the valve plate 55 is pressed against the valve seat 56. Therefore, the closing of the suction throttle valve 5 is maintained during the transition process to the discharge unloading and after the transition is completed. The suction throttle valve 5 at the time of completion of the discharge is in the same state as that at the time of starting unloading shown in FIG.

【0078】放気が完了し、空気槽20内圧が放気アン
ロード状態の定常値まで低下すると、起動アンロード状
態と同様の安定状態になる。この時の空気槽20内圧を
起動アンロード時よりも高くする必要のある場合には次
に示すような手段を用いる。一例として、電磁弁31の
開度に起動アンロードと放気アンロードで差を付ける。
あるいは、電磁弁31か制御圧管78に起動アンロード
と放気アンロードで流路抵抗を変える部材を挿入する。
または放気絞り35の絞りの大きさを起動アンロードと
放気アンロードで変える。
When the discharge of air is completed and the internal pressure of the air tank 20 drops to the steady value in the discharge unloading state, the same stable state as the starting unloading state is reached. When it is necessary to make the internal pressure of the air tank 20 higher than that at the time of starting unloading, the following means are used. As an example, the opening degree of the solenoid valve 31 is made different between the start unload and the discharge unload.
Alternatively, the solenoid valve 31 or the control pressure pipe 78 is inserted with a member that changes the flow path resistance by starting unloading and air release unloading.
Alternatively, the size of the throttle of the air discharge throttle 35 is changed by starting unloading and air discharge unloading.

【0079】放気アンロード状態にある時に、圧縮空気
の使用再開などによる下流圧力の低下を圧力センサ44
により制御装置4が感知すると、通常運転への復帰を判
断し、電磁弁31の閉塞を指示する。電磁弁31の閉塞
により外主室72にかかる圧力が大気圧まで低下し、起
動アンロードから通常運転への移行と同様に動作し、吸
入絞り弁5が開かれる。放気アンロード中も電動機3の
回転は維持されたままであるので、通常運転への復帰も
瞬時に可能である。
When the discharge air is unloaded, the pressure sensor 44 detects the decrease in the downstream pressure due to the restart of use of the compressed air.
When the control device 4 senses, the control device 4 determines to return to the normal operation, and gives an instruction to close the solenoid valve 31. Due to the closing of the solenoid valve 31, the pressure applied to the outer main chamber 72 is reduced to the atmospheric pressure, the same operation as the transition from the starting unload to the normal operation is performed, and the suction throttle valve 5 is opened. Since the rotation of the electric motor 3 is maintained even during the air discharge and unloading, it is possible to instantly return to the normal operation.

【0080】圧縮機の運転を停止する時にはスイッチ4
3を使用者が押し、それを感知した制御装置4が電磁弁
31の開放と始動盤41による電動機3への電流遮断を
指示する。電磁弁31を通過した圧縮空気は制御圧管7
8から外主室72に至り、移動体61を正面方向に押し
て弁板55を弁座56に押し付ける。この時、圧縮機が
通常運転中で弁板55が開いていても、全閉アンロード
や放気アンロード状態で弁板55が既に閉じられていて
も、同様に動作する。吸入路が閉じられたため、圧縮機
本体1が停止しても吸入口11からの空気や油の逆流が
防止できる。また、逆流しようとする下吸気路54内圧
の一時的上昇で、弁板55の両側差圧は大きくなり、弁
板55を閉じる力は増大する。
The switch 4 is used to stop the operation of the compressor.
The user presses 3, and the control device 4 that senses it instructs opening of the solenoid valve 31 and interruption of current to the electric motor 3 by the starter board 41. The compressed air that has passed through the solenoid valve 31 is controlled by the control pressure pipe 7.
From 8 to the outer main chamber 72, the moving body 61 is pushed in the front direction to push the valve plate 55 against the valve seat 56. At this time, the same operation is performed even if the compressor is in normal operation and the valve plate 55 is open, or if the valve plate 55 is already closed in the fully-closed unloading state or the discharge unloading state. Since the suction passage is closed, backflow of air and oil from the suction port 11 can be prevented even if the compressor body 1 stops. Further, due to the temporary rise in the internal pressure of the lower intake passage 54 that is about to flow backward, the pressure difference between the two sides of the valve plate 55 increases, and the force for closing the valve plate 55 increases.

【0081】以上の吸入路閉塞動作と同時に放気路34
から放気絞り35とサイレンサ36を経て空気槽20内
部に残留した圧縮空気が放気される。放気は油分離機1
5を通過した空気なので油の混入は極めて少なく、大気
への放出も問題ない。圧縮機内部に高圧の空気が残留し
ないため、運転停止完了後には圧縮機の点検や油の補給
などのメインテナンスを安全に行うことができる。ま
た、再度の起動でも、残留圧力がないため、先に述べた
起動動作が確実に実行できる。
Simultaneously with the above-described suction passage closing operation, the discharge passage 34
The compressed air remaining inside the air tank 20 is discharged through the discharge throttle 35 and the silencer 36. Degassing is an oil separator 1
Since it is air that has passed through 5, there is very little mixing of oil, and there is no problem in releasing it to the atmosphere. Since high-pressure air does not remain inside the compressor, maintenance such as inspection of the compressor and replenishment of oil can be safely performed after the operation stop is completed. In addition, since there is no residual pressure even when restarting, the above-described starting operation can be reliably executed.

【0082】本実施例では、従来の油冷式空気圧縮機に
対して、大きな設計変更を加えることなく、本発明を実
施することができる。本実施例の吸入絞り弁5は従来の
吸入絞り弁に比較して若干の部材の追加はあるものの、
単純な構造であり安価かつ高信頼性を実現することがで
きる。
In the present embodiment, the present invention can be implemented without making major design changes to the conventional oil-cooled air compressor. Although the intake throttle valve 5 of the present embodiment has some additional members as compared with the conventional intake throttle valve,
It has a simple structure and can be inexpensive and highly reliable.

【0083】以下、図8,図9と図5を用いて、第2の
実施例である空気圧縮機の構成と動作を説明する。図8
は本実施例に用いられる吸入絞り弁の断面図である。図
9は本実施例の吸入絞り弁の非常停止時における動作中
の断面図である。本実施例における空気圧縮機は吸入絞
り弁の構成のみ第1の実施例と異なり、配管の系統は図
5に示した第1の実施例と共通するので新たな系統図の
図示は省略し図5を用いて説明する。
The construction and operation of the air compressor of the second embodiment will be described below with reference to FIGS. 8, 9 and 5. FIG.
FIG. 4 is a sectional view of an intake throttle valve used in this embodiment. FIG. 9 is a sectional view of the intake throttle valve of the present embodiment during operation during an emergency stop. The air compressor in this embodiment is different from the first embodiment only in the structure of the suction throttle valve, and the piping system is common to the first embodiment shown in FIG. 5, so a new system diagram is not shown. This will be described using 5.

【0084】吸入絞り弁6は第1の実施例における吸入
絞り弁5に近いと基本構造を持つが以降で述べる幾つか
の点が異なる。
The intake throttle valve 6 has a basic structure when it is close to the intake throttle valve 5 in the first embodiment, but there are some differences described below.

【0085】弁ケース51に外副室73と下吸入路54
を繋ぐ連通路は設けず、ロッド57の周囲はパッキン8
1でシールし、空気の漏れを防止する。移動体61にも
内副室64と外副室73を繋ぐ連通路は設けず、ロッド
57の周囲はパッキン81でシールする。外シリンダ7
1内に設ける圧縮ばね79は外副室73ではなく外主室
72に設ける。圧縮ばね79の自由長は移動体61が最
も正面側にある時の圧縮ばね79長さよりも長く、ある
程度の初期力を及ぼすよう設定する。
The valve chamber 51 has an outer auxiliary chamber 73 and a lower suction passage 54.
No communication passage is provided to connect the
Seal with 1 to prevent air leakage. The movable body 61 is also not provided with a communication passage connecting the inner sub chamber 64 and the outer sub chamber 73, and the periphery of the rod 57 is sealed with a packing 81. Outer cylinder 7
The compression spring 79 provided inside 1 is provided not in the outer sub chamber 73 but in the outer main chamber 72. The free length of the compression spring 79 is set longer than the length of the compression spring 79 when the moving body 61 is located on the most front side, and is set so as to exert some initial force.

【0086】吐出管33から分岐した空気槽20と連通
する管路83は、ケース51の背面側に接続する。管路
83の先は弁ケース51内部で分岐し、一方は吐出圧管
84として外副室73に至リ、他方は電磁弁31を経て
制御圧管85と放気路86に繋ぐ。制御圧管85は外主
室72に連通し、放気路86は放気絞り87とサイレン
サ36を経て大気へ開放される。吐出圧管84や制御圧
管85や放気路86は弁ケース51に形成した孔であ
り、管材や配管接続部品を必要としないので、構造が簡
素となる。放気絞り87も専用の部品ではなく、孔径を
他の部分に比較して細くして実現する。
The conduit 83, which branches from the discharge pipe 33 and communicates with the air tank 20, is connected to the back side of the case 51. The end of the pipe 83 is branched inside the valve case 51, one of which is connected to the outer sub chamber 73 as a discharge pressure pipe 84, and the other is connected to the control pressure pipe 85 and the discharge passage 86 via the electromagnetic valve 31. The control pressure pipe 85 communicates with the outer main chamber 72, and the discharge passage 86 is opened to the atmosphere via the discharge throttle 87 and the silencer 36. The discharge pressure pipe 84, the control pressure pipe 85, and the air discharge passage 86 are holes formed in the valve case 51 and do not require a pipe material or a pipe connection component, so that the structure is simple. The exhaust throttle 87 is also not a dedicated part, and is realized by making the hole diameter smaller than other parts.

【0087】移動体61には内主室63から外副室73
に繋がる連通路88を設ける。本実施例では連通路88
を移動体61側壁の内部に軸方向に長く設定したが、吐
出圧管84から外副室73を経由せず、第1の実施例の
ように吐出圧管84から外側室74を経由し、連通して
もよい。
The movable body 61 includes an inner main chamber 63 to an outer sub chamber 73.
A communication passage 88 that is connected to In this embodiment, the communication passage 88
Is set to be long inside the side wall of the movable body 61 in the axial direction, but the discharge pressure pipe 84 does not pass through the outer sub chamber 73 but the discharge pressure pipe 84 passes through the outer chamber 74 as in the first embodiment, and is communicated. May be.

【0088】内シリンダ62内面の正面寄りには軸方向
に長さを持つ過大圧放気溝93を設ける。移動体61が
最も背面側にあり、弁板55が弁座56に接触した時の
内パッキン59の位置を過大圧放気溝93の背面側端と
する。過大圧放気溝93の軸方向長さはパッキン59の
軸方向幅よりも余分に長くする。
An overpressure discharge groove 93 having a length in the axial direction is provided near the front of the inner surface of the inner cylinder 62. The position of the inner packing 59 when the movable body 61 is on the rearmost side and the valve plate 55 contacts the valve seat 56 is the rear side end of the overpressure discharge groove 93. The axial length of the excessive pressure air discharge groove 93 is made longer than the axial width of the packing 59.

【0089】弁板55の正面側中央からロッド57内部
中心を通り、ロッド57の背面側端部近くで側面に開口
し、内副室64に連通する大気連通路89を設ける。ま
た、弁板55とロッド57は一体の部材であるが、ピス
トン58は別部材とする。ロッド57の背面側端部がピ
ストン58の正面側中央に設けた凹部に嵌合させ、通常
はロッド57とピストン58を一体化する。ピストン5
8の凹部の底には緊急放気路90が内主室63と内副室
64を繋ぐように開けられるが、通常はロッド64の背
面側端面が内副室64側の口を塞いでいる。
An atmosphere communication passage 89 is provided which passes from the center of the front side of the valve plate 55 to the center of the inside of the rod 57, opens to the side surface near the rear end of the rod 57 and communicates with the inner sub chamber 64. The valve plate 55 and the rod 57 are integral members, but the piston 58 is a separate member. The rear end of the rod 57 is fitted into a recess provided in the center of the front side of the piston 58, and usually the rod 57 and the piston 58 are integrated. Piston 5
An emergency air discharge passage 90 is opened at the bottom of the recess of 8 so as to connect the inner main chamber 63 and the inner sub chamber 64, but normally the rear end face of the rod 64 closes the mouth on the inner sub chamber 64 side. .

【0090】弁ケース51には上吸入路53から下吸入
路54に至るパージ流路91を設ける。パージ流路91
は弁板55により塞がれないが、流路断面積が小さく抵
抗が大きいため僅かな流量しか流れない。また、途中に
は逆止弁92が設けられ、圧縮機本体1へ向かう順方向
のみ流れ得る。吸入絞り弁6の吸入流路の主たる経路
で、パージ流路91によらず弁板55と弁座56の密着
で塞がれる部分を主弁と呼ぶことにする。
The valve case 51 is provided with a purge flow passage 91 extending from the upper suction passage 53 to the lower suction passage 54. Purge channel 91
Is not blocked by the valve plate 55, but has a small flow passage cross-sectional area and a large resistance, so only a small flow rate flows. Further, a check valve 92 is provided on the way, so that the check valve 92 can flow only in the forward direction toward the compressor body 1. A portion of the main passage of the intake passage of the intake throttle valve 6 that is closed by the close contact between the valve plate 55 and the valve seat 56 regardless of the purge passage 91 is referred to as a main valve.

【0091】本実施例は以下のように作用する。The present embodiment operates as follows.

【0092】圧縮機の起動前には、吸入絞り弁6内部の
各室内圧はすべて大気圧であり圧縮ばね65,79の初
期力のみ作用している。そのため、ピストン88は内シ
リンダ62の背面側端にあり、移動体61は外シリンダ
71の正面方向に押し、弁板55を弁座56に押し付け
ている。したがって、吸入絞り弁6の主弁は閉じてい
る。
Before the compressor is activated, the internal pressures of the suction throttle valve 6 are all atmospheric pressure, and only the initial force of the compression springs 65 and 79 is applied. Therefore, the piston 88 is located at the rear end of the inner cylinder 62, and the moving body 61 pushes in the front direction of the outer cylinder 71 to push the valve plate 55 against the valve seat 56. Therefore, the main valve of the suction throttle valve 6 is closed.

【0093】使用者がスイッチ43を押したことを制御
装置4が感知し、起動動作が開始する。制御装置4は電
磁弁31を閉じ、同時に始動盤41により電動機3に電
力を送り圧縮機本体1が起動,加速する。圧縮機本体1
の運転で下吸入路54内が負圧となり、パージ流路91
経由で吸入された少量の空気が圧縮される。圧縮が少量
ずつであるので空気槽20内圧の上昇は遅く、圧縮機本
体1の駆動トルクが増加する以前に回転速度の加速が完
了する。
The controller 4 senses that the user has pressed the switch 43, and the starting operation is started. The control device 4 closes the solenoid valve 31, and at the same time, the starter board 41 sends electric power to the electric motor 3 to start and accelerate the compressor body 1. Compressor body 1
During operation, the inside of the lower suction passage 54 becomes negative pressure, and the purge passage 91
A small amount of air drawn in via is compressed. Since the compression is performed little by little, the increase in the internal pressure of the air tank 20 is slow, and the acceleration of the rotation speed is completed before the driving torque of the compressor body 1 increases.

【0094】空気槽20内圧は吐出圧管84を通じて常
に外副室73に作用しており、加速が完了した後に、徐
々に上昇した圧力によって移動体61は背面側へ動かさ
れる。電磁弁31は閉じており、外主室72に連通する
放気路86が放気絞り87とサイレンサ36を経て大気
に連通しているため、外主室72内圧は大気圧のままで
あり、移動体61の動きを妨げない。移動体61の動き
により主弁が若干開かれると、空気の吸込量がさらに増
し、それにより空気槽20内圧の上昇が加速され、さら
に移動体61が動く。この一連の作用により主弁は一気
に開かれ通常の運転状態に移行する。
The inner pressure of the air tank 20 is constantly acting on the outer sub chamber 73 through the discharge pressure pipe 84, and after the acceleration is completed, the moving body 61 is moved to the back side by the gradually rising pressure. Since the solenoid valve 31 is closed and the air discharge passage 86 communicating with the outer main chamber 72 communicates with the atmosphere via the discharge throttle 87 and the silencer 36, the inner pressure of the outer main chamber 72 remains the atmospheric pressure. It does not hinder the movement of the moving body 61. When the main valve is slightly opened by the movement of the moving body 61, the intake amount of air further increases, whereby the increase in the internal pressure of the air tank 20 is accelerated, and the moving body 61 further moves. By this series of actions, the main valve is opened at a stroke and the normal operating state is entered.

【0095】なお、内主室63にも常に空気槽20内圧
が作用しているが、内シリンダ62断面積が比較的小さ
く、圧縮ばね65の反力が強いため、ピストン58は内
シリンダ62の背面側端面に押し付けられたままであ
る。したがって、起動時には弁板55はピストン58や
移動体61と一体となったままである。
Although the internal pressure of the air tank 20 is constantly applied to the inner main chamber 63, the cross-sectional area of the inner cylinder 62 is relatively small and the reaction force of the compression spring 65 is strong. It remains pressed against the rear end face. Therefore, at the time of start-up, the valve plate 55 remains integrated with the piston 58 and the moving body 61.

【0096】通常の運転状態で、圧縮空気の使用量が本
圧縮機の吐出能力よりも少ないと、余剰となった圧縮空
気が空気槽20に溜り、内圧が次第に上昇する。その圧
力は連通する内主室63に及び、吐出の設定圧力を越え
た時点で、ピストン58を動かし始める。内副室64内
圧は大気連通路89の働きでほぼ大気圧に維持される。
ピストン58は両側の差圧によるガス力が圧縮ばね65
の初期力に等しい時の内主室63内圧が設定圧となる。
When the amount of compressed air used is less than the discharge capacity of the present compressor under normal operating conditions, the surplus compressed air is accumulated in the air tank 20 and the internal pressure gradually rises. The pressure reaches the communicating inner main chamber 63, and when it exceeds the discharge set pressure, the piston 58 starts to move. The inner pressure of the inner sub-chamber 64 is maintained at almost atmospheric pressure by the action of the atmosphere communication passage 89.
The gas force due to the differential pressure on both sides of the piston 58 causes the compression spring 65
The internal pressure of the inner main chamber 63 when the initial pressure is equal to is the set pressure.

【0097】ピストン58が正面方向に動かされるため
連動した弁板55が閉じる方向に動き、吸入量を制限す
るアンロード状態となる。吸入量の制限により圧縮空気
の吐出量は減少し、空気槽20の内圧を下げる方向に作
用する。以上の吐出空気量を制御する働きにより、圧縮
空気使用量と等しい吐出量となる位置で弁板55は安定
し、吐出圧は設定圧かそれより僅か高い程度に維持され
る。
Since the piston 58 is moved in the front direction, the interlocking valve plate 55 moves in the closing direction, and the unloading state that restricts the intake amount is established. Due to the limitation of the suction amount, the discharge amount of the compressed air is reduced, which acts to lower the internal pressure of the air tank 20. With the above-described function of controlling the discharge air amount, the valve plate 55 is stabilized at the position where the discharge amount is equal to the compressed air usage amount, and the discharge pressure is maintained at the set pressure or slightly higher than it.

【0098】アンロード時の吐出圧は起動時の空気槽2
0内圧に比較して十分に高いため、外副室73の圧力は
移動体61を背面側端部に押し付けたままであり、移動
体61は弁ケース51と一体として考えることができ
る。
The discharge pressure at the time of unloading is the air tank 2 at the time of startup.
Since the pressure in the outer sub-chamber 73 is still pressed against the rear side end portion because it is sufficiently higher than the zero internal pressure, the movable body 61 can be considered to be integral with the valve case 51.

【0099】圧縮空気の使用量が皆無の時などでは、弁
板55は弁座56に密着し、全閉アンロードとなる。全
閉アンロード時にもパージ路91を通る僅かな吸入はあ
り、圧縮されて空気槽20に送られる。圧縮空気の使用
もなく、圧縮空気の行き先がなくなり、空気槽20内圧
は通常の吐出圧を越えたまま上昇を続ける。過大な圧力
は危険であるので、次に述べる過大圧放気が動作し安全
が確保される。
When the amount of compressed air used is zero, the valve plate 55 is in close contact with the valve seat 56 and is fully closed. Even during the fully-closed unload, there is a slight suction through the purge passage 91, and the compressed air is sent to the air tank 20. No compressed air is used, the destination of the compressed air is lost, and the internal pressure of the air tank 20 continues to rise while exceeding the normal discharge pressure. Since excessive pressure is dangerous, the overpressure release described below operates to ensure safety.

【0100】空気槽20内圧が過大圧力に達すると、内
主室63にかかるガス力がピストン58を押し、弁板5
5を強く弁座56に押し付ける。面パッキン94は弾性
変形し、ピストン58が全閉アンロードとなった時より
も正面方向に移動し、パッキン59が過大圧放気溝93
を跨ぐ位置に来る。すると、内主室63から過大圧放気
溝93を通り内副室64への連通路ができる。過大圧の
圧縮空気はその経路を通り、さらに大気連通路89から
大気に連通する上吸入路53に放気される。この放気に
より空気槽20内圧が危険なほど上昇することは防止さ
れる。
When the internal pressure of the air tank 20 reaches an excessive pressure, the gas force applied to the inner main chamber 63 pushes the piston 58 and the valve plate 5
5 is strongly pressed against the valve seat 56. The face packing 94 is elastically deformed, and the piston 58 moves in the front direction more than when the piston 58 is fully closed and unloaded, and the packing 59 causes the overpressure discharge groove 93.
Come to the position where you cross. Then, a communication passage is formed from the inner main chamber 63 to the inner sub chamber 64 through the overpressure air release groove 93. The compressed air of excessive pressure passes through that path, and is further discharged from the atmosphere communication path 89 to the upper suction path 53 that communicates with the atmosphere. This air release prevents the internal pressure of the air tank 20 from dangerously increasing.

【0101】圧縮空気の使用がないなど全閉アンロード
状態が長く続くことが感知されると、放気アンロードに
移行すべきと、制御装置4は判断する。制御装置4の指
示で電磁弁31が開放され放気アンロードへの移行が開
始される。
When it is sensed that the fully-closed unload state continues for a long time such as no use of compressed air, the control device 4 judges that the discharge unload should be started. The solenoid valve 31 is opened according to an instruction from the control device 4, and the shift to the discharge unloading is started.

【0102】圧縮空気は電磁弁31から外主室63に流
れ込むと同時に、放気路86から放気絞り87,サイレ
ンサ36を経て大気に放気される。移動室61は両側の
圧力が等しくなるため圧縮ばね79の力で正面方向に移
動するが、主弁の閉塞は放気アンロードへの移行過程の
間や移行完了後も維持される。放気完了時の吸入絞り弁
6内部の各部材の位置関係は起動開始直後とほぼ同じ状
態となるが、移動体61両側の圧力が大気圧レベルより
も高くなる。
At the same time as the compressed air flows into the outer main chamber 63 from the solenoid valve 31, it is discharged from the discharge passage 86 to the atmosphere through the discharge throttle 87 and the silencer 36. The moving chamber 61 moves in the front direction by the force of the compression spring 79 because the pressures on both sides become equal, but the closure of the main valve is maintained during the transition process to the discharge unloading and after the transition is completed. The positional relationship of each member inside the intake throttle valve 6 at the time of completion of the air release is almost the same as that immediately after the start of activation, but the pressure on both sides of the moving body 61 becomes higher than the atmospheric pressure level.

【0103】放気アンロード中もパージ流路91からの
流入があるが、放気量とバランスし、圧縮機本体1の吸
入圧,吐出圧は低く保たれる。また、その時の各部の圧
力はパージ流路91の流路抵抗と放気絞り87などによ
る放気系の流路抵抗に依存し、ある程度の範囲で選択す
ることができる。
Although there is an inflow from the purge passage 91 even during the discharge unloading, it is balanced with the discharge amount, and the suction pressure and the discharge pressure of the compressor body 1 are kept low. Further, the pressure of each part at that time depends on the flow passage resistance of the purge flow passage 91 and the flow passage resistance of the discharge system by the discharge throttle 87, and can be selected within a certain range.

【0104】放気アンロードから通常運転への復帰が判
断されると、制御装置4が電磁弁31を閉塞する。外主
室72内圧は大気圧まで低下し、起動アンロードと同様
の作用により吐出が再開される。起動時に比較し、外主
室72内圧の低下と外副室73内圧の上昇の両者による
ため、吐出再開に至る移動室61の移動速度は速く、通
常運転への復帰が速い。
When it is judged that the discharge unloading is returned to the normal operation, the controller 4 closes the solenoid valve 31. The internal pressure of the outer main chamber 72 is reduced to the atmospheric pressure, and the discharge is restarted by the same action as the startup unload. Since the internal pressure of the outer main chamber 72 is decreased and the internal pressure of the outer sub chamber 73 is increased, the moving speed of the moving chamber 61 until the discharge is restarted is faster than that at the time of startup, and the return to the normal operation is quick.

【0105】圧縮機停止時は電磁弁31が閉じられ、放
気アンロードへの移行と同様に作用し、主弁が閉じられ
同時に空気槽20の放気がなされる。パージ流路91も
逆止弁92があるため、停止直後の逆流が防止される。
When the compressor is stopped, the solenoid valve 31 is closed, and the same operation as the transition to the discharge unloading is performed. The main valve is closed and the air tank 20 is discharged at the same time. Since the purge passage 91 also has the check valve 92, the backflow immediately after the stop is prevented.

【0106】電動機3から圧縮機本体1に回転を伝達す
る機械要素はベルトが用いられることが多いが、寿命な
どにより破断することがある。ベルト破断により、電動
機3は空転を続け、圧縮機本体1は停止してしまう。こ
の場合、緊急に吸入絞り弁6を閉塞し、空気槽20内圧
を放気しないと、停止直後と同様の作用で吸入口11か
ら圧縮空気に混入した油が逆流するなど障害が発生す
る。ベルト破断を電動機3の消費電流の変化で検出し制
御装置4にて電磁弁31を開き、通常の停止と同じ状態
にする方法もあるが、応答が遅くコストなどの問題があ
る。そこで、吸入絞り弁6自身にベルト破断時の主弁か
らの逆流防止機能と、空気槽20に残留した圧縮空気を
放気する機能があると望ましい。
A belt is often used as a mechanical element for transmitting the rotation from the electric motor 3 to the compressor main body 1, but it may be broken due to its life or the like. Due to the belt breakage, the electric motor 3 continues to idle, and the compressor body 1 stops. In this case, unless the suction throttle valve 6 is urgently closed and the internal pressure of the air tank 20 is not released, a trouble occurs such that oil mixed in the compressed air flows backward from the suction port 11 by the same action as immediately after the stop. There is also a method in which a belt break is detected by a change in the current consumption of the electric motor 3 and the control device 4 opens the solenoid valve 31 to bring it into the same state as a normal stop, but there is a problem such as a slow response and cost. Therefore, it is desirable that the suction throttle valve 6 itself has a function of preventing backflow from the main valve when the belt is broken and a function of discharging the compressed air remaining in the air tank 20.

【0107】圧縮機本体1が急停止すると吐出側に溜っ
た油を含む圧縮空気が圧力の低い吸入側に逆流する。下
吸入路54内圧が上吸入路53内圧に比較して高くなる
ため、弁板55は正面方向の力を受ける。弁板55と一
体であるロッド57はピストン58の凹部から引き抜か
れ、弁板55が閉じて逆流が防止される。ロッド57の
端部によって塞がれていた緊急放気路90が開かれ、内
主室63と内副室64が連通する。この状態を図9に示
す。空気槽20に残留する圧縮空気は吐出圧管84,外
副室73,連通路88,内主室63,内副室64,大気
連通路89を経由して上放気路53から大気に放気され
る。この経路による放気は油分離器15を通過した空気
なので、放気中に含まれる油は極めて少なく問題となら
ない。
When the compressor body 1 suddenly stops, the compressed air containing oil that has accumulated on the discharge side flows backward to the suction side where the pressure is low. Since the internal pressure of the lower suction passage 54 becomes higher than the internal pressure of the upper suction passage 53, the valve plate 55 receives a force in the front direction. The rod 57, which is integral with the valve plate 55, is withdrawn from the recess of the piston 58, closing the valve plate 55 and preventing backflow. The emergency air discharge passage 90 closed by the end portion of the rod 57 is opened, and the inner main chamber 63 and the inner sub chamber 64 communicate with each other. This state is shown in FIG. The compressed air remaining in the air tank 20 is discharged to the atmosphere from the upper discharge passage 53 through the discharge pressure pipe 84, the outer auxiliary chamber 73, the communication passage 88, the inner main chamber 63, the inner auxiliary chamber 64, and the atmosphere communication passage 89. To be done. Since the air released through this path is the air that has passed through the oil separator 15, the oil contained in the air released is extremely small and does not pose a problem.

【0108】放気が完了し、内部各室が大気圧になる
と、ピストン88を内蔵した移動体61は圧縮ばね71
に正面方向に押されて端まで移動する。ピストン88の
凹部にロッド87の端部が再び嵌まり込み、ベルト交換
後の次の運転開始時には通常と同様に起動可能となる。
When the discharge of air is completed and the internal pressure of each chamber reaches the atmospheric pressure, the moving body 61 having the piston 88 built therein is compressed by the compression spring 71.
It is pushed in the front direction and moves to the end. The end of the rod 87 is re-fitted into the recess of the piston 88, and can be started as usual at the start of the next operation after the belt replacement.

【0109】本実施例によれば、各流路抵抗の設定によ
り、起動アンロードと放気アンロード時の空気槽20内
圧を別々に設定することができる。また、放気アンロー
ドから通常の吐出運転への復帰が迅速で応答性のよい空
気圧縮機を実現することができる。さらには動力伝達部
材であるベルト破断による圧縮機本体停止時にも逆流防
止と放気を同時に対応可能である。
According to this embodiment, the internal pressure of the air tank 20 at the time of starting unloading and the air unloading can be set separately by setting each flow path resistance. In addition, it is possible to realize an air compressor that quickly returns from the discharge unload to the normal discharge operation and has good responsiveness. Further, it is possible to simultaneously prevent backflow and release air even when the compressor main body is stopped due to breakage of the belt which is a power transmission member.

【0110】[0110]

【発明の効果】本発明による吸入絞り弁を空気圧縮機に
適用することにより、付属する圧力調整弁や電磁三方弁
などの部材やそれらを繋ぐ配管類を不要とし、簡潔な構
成で吸入絞り式容量制御系を実現することができる。制
御系を単純化したため安価に高信頼性を実現できる。こ
の制御系は圧縮空気使用量に応じた吐出圧制御はもちろ
んのこと、起動時のトルク低減や放気アンロード時の吸
気閉塞ならびに放気動作も行い、停止時にも対応するた
め、空気圧縮機のすべての運転状況を満足できる。
By applying the suction throttle valve according to the present invention to an air compressor, a member such as an attached pressure control valve or electromagnetic three-way valve or piping for connecting them is unnecessary, and the suction throttle valve has a simple structure. A capacity control system can be realized. Since the control system is simplified, high reliability can be realized at low cost. This control system not only controls the discharge pressure according to the amount of compressed air used, but also performs torque reduction at start-up, intake blockage and air release operation at the time of air discharge and unloading, and even when stopped, the air compressor Satisfy all driving situations.

【図面の簡単な説明】[Brief description of drawings]

【図1】第1の実施例で用いる吸入絞り弁のフルロード
による全開時の断面図。
FIG. 1 is a sectional view of a suction throttle valve used in the first embodiment when it is fully opened by full load.

【図2】従来例の油冷式空気圧縮機の系統図。FIG. 2 is a system diagram of a conventional oil-cooled air compressor.

【図3】空気圧縮機の吐出圧力の時間変化の一例を示す
説明図。
FIG. 3 is an explanatory diagram showing an example of a temporal change in discharge pressure of the air compressor.

【図4】従来例で用いられる圧力調整弁の入出力圧力特
性図。
FIG. 4 is an input / output pressure characteristic diagram of a pressure control valve used in a conventional example.

【図5】第1の実施例による空気圧縮機の系統図。FIG. 5 is a system diagram of the air compressor according to the first embodiment.

【図6】第1の実施例で用いる吸入絞り弁の起動時ある
いは放気アンロード時の断面図。
FIG. 6 is a cross-sectional view of the intake throttle valve used in the first embodiment when the intake throttle valve is started or when air is discharged.

【図7】第1の実施例で用いる吸入絞り弁の全閉アンロ
ード時の断面図。
FIG. 7 is a cross-sectional view of the suction throttle valve used in the first embodiment when it is fully closed and unloaded.

【図8】第2の実施例で用いる吸入絞り弁の断面図。FIG. 8 is a sectional view of an intake throttle valve used in the second embodiment.

【図9】第2の実施例で用いる吸入絞り弁の緊急動作時
の断面図。
FIG. 9 is a sectional view of the suction throttle valve used in the second embodiment during an emergency operation.

【符号の説明】[Explanation of symbols]

5…吸入絞り弁、51…弁ケース、53…上吸入路、5
5…弁板、56…弁座、57…ロッド、58…ピスト
ン、59…内パッキン、60…外パッキン、61…移動
体、62…内シリンダ、63…内主室、64…内副室、
65,75,79…圧縮ばね、66,67,76…連通
路、68…過大圧放気弁、69…弁玉、70…弁ばね、
71…外シリンダ、72…外主室、73…外副室、74
…外側室、77…吐出圧管、78…制御圧管。
5 ... suction throttle valve, 51 ... valve case, 53 ... upper suction passage, 5
5 ... Valve plate, 56 ... Valve seat, 57 ... Rod, 58 ... Piston, 59 ... Inner packing, 60 ... Outer packing, 61 ... Moving body, 62 ... Inner cylinder, 63 ... Inner main chamber, 64 ... Inner auxiliary chamber,
65,75,79 ... Compression spring, 66,67,76 ... Communication passage, 68 ... Excessive pressure air release valve, 69 ... Valve ball, 70 ... Valve spring,
71 ... Outer cylinder, 72 ... Outer main chamber, 73 ... Outer auxiliary chamber, 74
Outer chamber, 77 ... Discharge pressure tube, 78 ... Control pressure tube.

Claims (2)

【特許請求の範囲】[Claims] 【請求項1】スクリュー式あるいはスクロール式などの
回転式容積形の圧縮機と、前記圧縮機本体の吸入口の上
流側に連なる吸入量制限手段と、前記圧縮機の吐出口の
下流側に連なる空気槽と、前記圧縮機の運転を管理する
制御装置と、前記圧縮機の駆動手段である電動機を備え
た空気圧縮機において、 前記吸入量制限手段は吸入流路ならびに外シリンダを内
部に形成した弁ケースと、前記吸入流路を閉塞する機能
を有する弁板と、前記弁板と連結部材により結合したピ
ストンと、前記ピストンを往復運動可能に嵌合しつつ前
記ピストンにより複数の室に区切られる内シリンダを内
部に形成した移動部材を備え、前記移動部材は前記外シ
リンダに往復運動可能に内蔵されつつ前記外シリンダを
複数の室に区切り、前記ピストンの往復運動の方向と前
記移動部材の往復運動の方向を一致させたことを特徴と
する空気圧縮機。
1. A rotary positive displacement compressor such as a screw type or scroll type, a suction amount limiting means connected to an upstream side of an intake port of the compressor body, and a downstream side of a discharge port of the compressor. In an air compressor including an air tank, a control device that manages the operation of the compressor, and an electric motor that is a driving unit of the compressor, the suction amount limiting unit has an intake passage and an outer cylinder formed therein. A valve case, a valve plate having a function of closing the suction passage, a piston coupled to the valve plate by a connecting member, and a piston that is reciprocally fitted while being divided into a plurality of chambers by the piston. A moving member having an inner cylinder formed therein, wherein the moving member is built in the outer cylinder so as to be reciprocally movable, and divides the outer cylinder into a plurality of chambers to reciprocate the piston. An air compressor in which the direction and the direction of the reciprocating motion of the moving member are matched.
【請求項2】請求項1において、前記内シリンダが区切
られ形成された室のうち前記弁板と反対側に位置する室
へ前記空気槽から流路が連通し、前記外シリンダが区切
られ形成された室のうちの一方の室へ前記空気槽から開
閉手段を経て連通する流路を形成し、前記開閉手段は電
磁弁に代表される前記制御装置の指令により開閉操作可
能である機能を有する空気圧縮機。
2. The flow passage from the air tank to the chamber located on the side opposite to the valve plate among the chambers formed by dividing the inner cylinder, and the outer cylinder being divided. A flow path that communicates with one of the stored chambers from the air tank through the opening / closing means, and the opening / closing means has a function capable of opening / closing operation according to a command from the control device represented by a solenoid valve. air compressor.
JP23645095A 1995-09-14 1995-09-14 Air compressor Pending JPH0979166A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP23645095A JPH0979166A (en) 1995-09-14 1995-09-14 Air compressor

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP23645095A JPH0979166A (en) 1995-09-14 1995-09-14 Air compressor

Publications (1)

Publication Number Publication Date
JPH0979166A true JPH0979166A (en) 1997-03-25

Family

ID=17000935

Family Applications (1)

Application Number Title Priority Date Filing Date
JP23645095A Pending JPH0979166A (en) 1995-09-14 1995-09-14 Air compressor

Country Status (1)

Country Link
JP (1) JPH0979166A (en)

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EP1160455A2 (en) * 2000-06-01 2001-12-05 Westinghouse Air Brake Technologies Corporation Scroll compressor
US6517325B2 (en) * 2000-06-30 2003-02-11 Hitachi, Ltd. Air compressor and method of operating the same
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Cited By (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1160455A2 (en) * 2000-06-01 2001-12-05 Westinghouse Air Brake Technologies Corporation Scroll compressor
EP1160455A3 (en) * 2000-06-01 2003-04-02 Westinghouse Air Brake Technologies Corporation Scroll compressor
US6517325B2 (en) * 2000-06-30 2003-02-11 Hitachi, Ltd. Air compressor and method of operating the same
WO2006091200A1 (en) * 2005-02-24 2006-08-31 Carrier Corporation Compressor unloading valve
US7874820B2 (en) * 2005-02-24 2011-01-25 Carrier Corporation Compressor unloading valve
JP2008175152A (en) * 2007-01-19 2008-07-31 Hitachi Industrial Equipment Systems Co Ltd Air compressor
EP2096315A3 (en) * 2008-02-28 2015-01-14 Calsonic Kansei Corporation Gas compressor
JP2011099348A (en) * 2009-11-04 2011-05-19 Hitachi Industrial Equipment Systems Co Ltd Air compressor
KR101257829B1 (en) * 2010-12-02 2013-04-29 웬-산 초우 Air compressor
KR20140147704A (en) 2013-06-19 2014-12-30 가부시키가이샤 고베 세이코쇼 Compressor
TWI585301B (en) * 2015-03-16 2017-06-01 復盛股份有限公司 Intake valve for compressor
CN108397368A (en) * 2017-02-06 2018-08-14 北越工业株式会社 The control method and engine driving type compressor of engine driving type compressor
WO2019093007A1 (en) * 2017-11-09 2019-05-16 株式会社神戸製鋼所 Air compressor and air compressor control method
JP2019085974A (en) * 2017-11-09 2019-06-06 株式会社神戸製鋼所 Air compressor and control method of air compressor
CN111279078A (en) * 2017-11-09 2020-06-12 株式会社神户制钢所 Air compressor and control method thereof
WO2020095503A1 (en) * 2018-11-08 2020-05-14 照男 小林 Concentrated oxygen pressure boosting device and concentrated oxygen pressure boosting method
JPWO2020095503A1 (en) * 2018-11-08 2021-09-02 照男 小林 Concentrated oxygen pressure booster and concentrated oxygen pressure boosting method
CN114729639A (en) * 2019-11-26 2022-07-08 三菱电机株式会社 Screw compressor
DE102020121963A1 (en) 2020-08-21 2022-02-24 Bürkert Werke GmbH & Co. KG compressor system
CN112065691A (en) * 2020-09-30 2020-12-11 台州吉克汽车零部件有限公司 Automobile air compressor with uninstallation gas storage oil mist separation chamber

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