JPH0414801U - - Google Patents

Description

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

第１図は本考案に係る負荷保持機構付切換弁の
断面図、第２図は要部の拡大断面図、第３図は油
圧回路図である。 １……切換弁本体、２……主スプール、１６…
…供給通路、１７……弁座、１８……第一のバネ
、１９……ポペツト弁、２０……第二のバネ、２
１……バネ室、２２……補助スプール、２２ｂ…
…連通孔、２３……スリーブ、２４……バネ室、
２５……シートリング、２８……ピストン、２９
，３０……排出通路、３１……絞り、３２，３４
……シリンダポート。 FIG. 1 is a sectional view of a switching valve with a load holding mechanism according to the present invention, FIG. 2 is an enlarged sectional view of the main parts, and FIG. 3 is a hydraulic circuit diagram. 1...Switching valve body, 2...Main spool, 16...
... Supply passage, 17 ... Valve seat, 18 ... First spring, 19 ... Poppet valve, 20 ... Second spring, 2
1...Spring chamber, 22...Auxiliary spool, 22b...
...Communication hole, 23...Sleeve, 24...Spring chamber,
25... Seat ring, 28... Piston, 29
, 30...Discharge passage, 31...Aperture, 32, 34
...Cylinder port.

Claims (1)

【実用新案登録請求の範囲】[Scope of utility model registration request] 油圧シリンダ等のアクチユエータ３３を作動す
る切換弁本体１の主スプール２を介して圧油を供
給する通路１６ａに弁座１７を設け、該弁座に向
かつて第一のバネ１８によつて付勢され着座可能
なポペツト弁１９と、該ポペツト弁内に第二のバ
ネ２０を有するバネ室２１を設け、該バネ室２１
に一端が挿入され上記第二のバネ２０により付勢
され、かつ、一端をバネ室２１に他端を排出通路
２９，３０に開口する連通孔２２ｂを有する補助
スプール２２を、前記切換弁本体１に設けたスリ
ーブ２３の内周面にパイロツト圧Ｐ_２により摺動
可能に嵌合させると共に、ポペツト弁１９にシリ
ンダポート３２から第一のバネ１８を有するバネ
室２４に通ずる絞り３１を設け、パイロツト圧Ｐ
_２の作動時は、前記第一のバネ１８を有するバネ
室２４が第二のバネ２０を有するバネ室２１に連
通してバネ室２４の油がバネ室２１および補助ス
プール２２の連通孔２２ｂを経て排出通路２９，
３０に排出され、パイロツト圧Ｐ_２の遮断時は、
第一のバネ１８を有するバネ室２４と第二のバネ
２０を有するバネ室２１との連通が遮断すること
を特徴とする負荷保持機構付切換弁。 A valve seat 17 is provided in a passage 16a that supplies pressure oil through the main spool 2 of the switching valve body 1 that operates an actuator 33 such as a hydraulic cylinder, and is biased by a first spring 18 toward the valve seat. A poppet valve 19 that can be seated and a spring chamber 21 having a second spring 20 inside the poppet valve is provided.
The auxiliary spool 22 is inserted into the switching valve main body 1 and has a communication hole 22b which is biased by the second spring 20 and has one end opened to the spring chamber 21 and the other end opened to the discharge passages 29 and 30. The poppet valve 19 is provided with a throttle 31 that communicates from the cylinder port 32 to the spring chamber 24 having the first spring 18, and is slidably fitted to the inner peripheral surface of the sleeve 23 provided in the pilot pressure _P2 . Pressure P
₂ , the spring chamber 24 having the first spring 18 communicates with the spring chamber 21 having the second spring 20, and the oil in the spring chamber 24 flows through the spring chamber 21 and the communication hole 22b of the auxiliary spool 22. through the discharge passage 29,
30, and when the pilot pressure _P2 is cut off,
A switching valve with a load holding mechanism characterized in that communication between a spring chamber 24 having a first spring 18 and a spring chamber 21 having a second spring 20 is cut off.