电磁阀

电磁阀是阀门的一种，使用电磁线圈驱动。

电磁阀的工作原理 
 通过对电磁线圈通电／断电控制管路的开启／关闭或改变流体（一般是压缩空气或者液体）流向（电磁开关阀）。
 改变通过电磁线圈电压／电流（一般为电流譬如4-20mA的直流电流）等参数控制管路中流体流量或流体压力（电磁调节阀）。

常見的用途 
電磁閥用於流體動力氣動和液壓系統，控制氣缸，液壓傳動電機或較大的工業閥門。 自動灌溉噴頭系統還利用電磁閥與自動控制器。國內洗衣機和洗碗機用電磁閥來控制水進入機器。

電磁閥可用於工業應用的廣泛陣列，包括一般的通斷控制，校準和測試台，試驗工廠控制迴路，過程控制系統，和各種原始設備製造商的應用程序。

参考资料

外部連結
https://web.archive.org/web/20140407073548/http://www.mgacontrols.com/category/solenoid-valves/ illustrations of 2-way, 3-way, and pilot operated solenoid valves
https://web.archive.org/web/20140310224909/http://www.hnsa.org/doc/fleetsub/refrig/chap7.htm pp. 39–40. Solenoid valve illustration; breakaway pin / kick-off.
http://www.smc.eu/portal/WebContent/local/UK/Pneu_Book/Solenoid_Valves.jsp  Skinner valve, 1930s; magnetic path issues; wear; power; number of cycles
http://www.surmaq.com/html/cata/parker/contr/skinner.pdf pp. 128-131; tech details of design; different terminology; welded sleeve; valve sizing. Page 128: "Skinner Valve plunger assemblies, when appropriate, use floating top and bottom seals to enhance valve performance.  Floating seals permit the plunger to generate a larger actuation force to open against the pressure differential in the valve. This enables the valve to operate at higher pressure ratings." Material has implications for shading ring: copper is satisfactory for many materials, but it is unsatisfactory for coffee and urea; silver is satisfactory for those fluids. (pp 130–131.)

http://cr4.globalspec.com/thread/56783/Shading-Ring  discussion about shading coil
Design of Shading Coils for Minimizing the Contact Bouncing of AC Contactors, 
http://everything2.com/title/Shading+ring 
https://www.asconumatics.eu/images/site/upload/_en/pdf1/00022gb.pdf  More detailing information about solenoid and shading coil
http://relays.te.com/schrack/pdf/C0_v4bg_5.pdf  About relay design but includes relevant information

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