CN100590324C - Guide proportion directional throttle valve - Google Patents

Guide proportion directional throttle valve Download PDF

Info

Publication number
CN100590324C
CN100590324C CN200610102032A CN200610102032A CN100590324C CN 100590324 C CN100590324 C CN 100590324C CN 200610102032 A CN200610102032 A CN 200610102032A CN 200610102032 A CN200610102032 A CN 200610102032A CN 100590324 C CN100590324 C CN 100590324C
Authority
CN
China
Prior art keywords
main valve
valve
oil
oil duct
main
Prior art date
Application number
CN200610102032A
Other languages
Chinese (zh)
Other versions
CN1936343A (en
Inventor
权龙�
秦太龙
李敏
Original Assignee
太原理工大学
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 太原理工大学 filed Critical 太原理工大学
Priority to CN200610102032A priority Critical patent/CN100590324C/en
Publication of CN1936343A publication Critical patent/CN1936343A/en
Application granted granted Critical
Publication of CN100590324C publication Critical patent/CN100590324C/en

Links

Abstract

This invention discloses a pilot proportion direction throttle characterizing in setting an electronic switch controlled by a shift sensor between an adjuster and a feedback signal adjuster, an adjusting ring for adjusting area of the main valve core is set in the main valve, an open-cycle controller is set between set signal Uxs received by the controller and a proportion amplifying valve, the main valve core and its area adjusting ring are distributed in the main valve coaxially and an oil intake P is set between the core and the valve to induce pressure oil, outlets A and B are connected with two cavities of an executor and a release port T is connected with the oil tank.

Description

Guide proportion directional throttle valve
Technical field
The invention belongs to the electro-hydraulic control valve technical field, especially fluid flow direction and flow carry out the guide proportion directional throttle valve of continuous ratio control.
Background technique
Pilot-operated electrical liquid proportional directional throttle valve is one of most important element in the electrohydraulic control technology, is mainly used in the occasion of big flow.Its effect is that the direction of fluid flow and the size of flow are carried out continuous control.In the prior art, guide proportion directional throttle valve has valve internal components feedback-type and electrical equipment closed loop control type two big classes, and the former control accuracy is lower, be mainly used in open system, the latter has high dynamic response and control accuracy, can have the function of servovalve, mainly is used in the closed loop control.For the internal feedback valve, at present the principle that adopts mainly contains displacement-force feedback, displacement-pressure balance, guide's decompression, guide's overflow and five kinds of forms of displacement servo-actuated, and most widely used be guide's decompression type valve that German Rexroth company produces.Replace traditional switching mode electro-hydraulic reversing valve though use such proportioning element, can simplify the loop, improve systematic function,, can not large-scale popularization use because manufacture difficulty causes the cost of these elements too high greatly.
For the guide proportion directional throttle valve of electric closed loop,, mainly contain the two closed loop controls of main valve plug and guide's spool, two kinds of forms of pilot valve employing high response servovalve in order to improve its dynamic response.In case maximum deficiency is that main valve plug position-detection sensor and relative device break down, valve is with regard to function out of hand, even causes big production accident.Electricity closed loop valve is structurally also incompatible with the valve of internal components feedback, and such element cost is very high, only requires the occasion of closed loop control just to be used in minority.
Summary of the invention
The present invention improves the structure of existing electrical feedback proportional directional throttle valve, when solution main valve plug position-detection sensor and relative device break down, valve is with regard to function out of hand, even cause the problem of big production accident, and provide a kind of and structurally internal feedback valve and electric closed loop valve can be united, and simple in structure, be easy to make and the guide proportion directional throttle valve that under main valve position-detection sensor fault state, still can work on.
The present invention is based on the problems referred to above and purpose, the first kind of technological scheme that proposes comprises solenoid-operated proportional pilot valve, proportional amplifier, open-cycle controller, main valve plug, main valve body and main valve plug retaining spring, its improvement is to set up the two-position three way solenoid directional control valve between main valve body and solenoid-operated proportional pilot valve, cavity volume I in the main valve body is communicated with the filler opening I of two-position three way solenoid directional control valve through first flow, and the cavity volume II in the main valve body is communicated with the filler opening II of two-position three way solenoid directional control valve through second runner; The oil outlet of two-position three way solenoid directional control valve is communicated with control port I in the solenoid-operated proportional pilot valve, and the drain tap in the solenoid-operated proportional pilot valve is communicated with main return opening on the main valve body through the 3rd runner; Main valve plug area regulating ring and main valve plug, main valve plug retaining spring coaxial arrangement are in main valve body.
Second kind of technological scheme of guide proportion directional throttle valve of the present invention is to have additional electronic switch, closed loop controller, adder I, adder II, feedback signal amplifier, displacement transducer on the basis of first kind of technological scheme; The input end of electronic switch is connected with the output terminal of closed loop controller, and the output terminal of electronic switch and the output terminal of open-cycle controller are connected to the input end of adder I, and the output terminal of adder I is connected to the input end of proportional amplifier; The output signal of displacement transducer is connected to the feedback signal amplifier input terminal, the output signal of feedback signal amplifier is connected with the control end of electronic switch, the output signal of feedback signal amplifier is connected to the input end of adder II, setting signal Uxs is connected to the input end of adder II and open-cycle controller simultaneously, and the output terminal of adder II is connected to the input end of closed loop controller; Displacement transducer and main valve plug area regulating ring, main valve plug, main valve plug retaining spring coaxial arrangement detect the displacement of main valve plug in main valve body.
The third technological scheme of guide proportion directional throttle valve of the present invention is on the basis of first kind of technological scheme, remove the two-position three way solenoid directional control valve, cavity volume I in the main valve body is communicated with the control port I of solenoid-operated proportional pilot valve through first flow, cavity volume II in the main valve body is communicated with the control port II of solenoid-operated proportional pilot valve through second runner, and the drain tap of solenoid-operated proportional pilot valve is communicated with main oil return inlet T on the main valve body through the 3rd runner.
The 4th kind of technological scheme of guide proportion directional throttle valve of the present invention is on the basis of first kind of technological scheme, change the solenoid-operated proportional pilot valve into manual proportional pilot valve, remove proportional amplifier, open-cycle controller, promptly constitute the manually type pilot proportion directional throttle valve of control.
In four kinds of above-mentioned technological schemes, described main valve plug is provided with oil duct I, oil duct II and oil duct III, and be interconnected, oil duct I is communicated with the main filler opening of oil duct II, valve, oil duct II along spool axial arranged and with cavity volume I, cavity volume II is communicated with, and oil duct III is symmetricly set on the main valve plug two ends, and is connected with oil duct II in the main valve plug; Described main valve plug area regulating ring is provided with oil through I and oil through II, and oil through I and the coaxial installation of main valve plug, oil through II are incorporated into cavity volume I and cavity volume II with the oil in the main valve plug internal oil channel II; Main valve plug area regulating ring is provided with oil duct IV and oil duct V, and oil duct IV and oil duct III are communicated with, and pressure oil is incorporated into oil duct V, and the end face h of oil duct V and main valve body forms the throttling limit; Proportional valve or high-speed switch valve that described solenoid-operated proportional pilot valve is continuous control.
The hydrovalve of continuous control flow direction of the present invention and flow, major advantage be embodied in one be simple in structure, cost is low, be easy to apply.The 2nd, internal feedback valve and electric closed loop valve are structurally united, and at the main valve plug displacement transducer with under the situation that the feedback signal regulator breaks down accordingly, be automatically converted to the internal feedback state of a control, system can be worked on, guaranteed the safety reliability of system.The present invention can replace existing switching mode electro-hydraulic reversing valve, is widely used in hydraulic control system.
Description of drawings
Fig. 1 is the structural principle schematic representation of embodiment of the present invention 1
Fig. 2 is embodiment of the present invention 2 structural principle schematic representation
Fig. 3 is embodiment of the present invention 3 structural principle schematic representation
Fig. 4 is embodiment of the present invention 4 structural principle schematic representation
Fig. 5 is a main valve plug structural representation of the present invention
Fig. 6 is a main valve plug area regulating ring structural representation of the present invention
Among the figure: 1: solenoid-operated proportional pilot valve, 2: proportional amplifier, 3: closed loop controller, 4: feedback signal amplifier, 5: displacement transducer, 6: main valve plug, 7: main valve body, 8: main valve plug retaining spring, 9: electronic switch, 10: main valve plug area regulating ring, 11: open-cycle controller, 12: two-position three way solenoid directional control valve, 13: adder I, 14: manual proportional pilot valve, 15: adder II.
Among the figure: P 1: oil duct I, P 2: oil duct II, P 3: oil duct III,
Oil duct I P 1With oil duct IIIP 3With the axis normal of main valve plug, oil duct II P 2By the axis and the perforation spool two limit end faces of main valve plug,
P 4: oil duct IV, P 5: oil duct V, K 1: oil through I, K 2: oil through II, e: cavity volume I, f: cavity volume II, L1: first flow, L2: second runner, L3: the 3rd runner, P: main filler opening, A: main oil outlet I, B: main oil outlet II, T: main return opening, q: oil outlet, t: drain tap, c: control port I, d: control port II, n: filler opening I, m: filler opening II.
Embodiment
Can make and further describing the principle and the structure of invention with mode of execution in conjunction with the accompanying drawings, present embodiment be a detailed description of the invention, the present invention is not made any restriction.
Mode of execution 1
The guide proportion directional throttle valve of continuous control flow direction of the present invention and flow comprises solenoid-operated proportional pilot valve 1, proportional amplifier 2, open-cycle controller 11, main valve plug 6, main valve body 7 and main valve plug retaining spring 8.In Fig. 1, structure characteristic of the present invention is that two-position three way solenoid directional control valve 12 is installed between main valve body 7 and the solenoid-operated proportional pilot valve 1, cavity volume I e in the main valve body 7 is communicated with the filler opening I n of two-position three way solenoid directional control valve 12 through first flow L1, and the cavity volume II f in the main valve body 7 is communicated with the filler opening II m of two-position three way solenoid directional control valve 12 through the second runner L2; The oil outlet q of two-position three way solenoid directional control valve 12 is communicated with control port I c in the solenoid-operated proportional pilot valve 1, and the drain tap t in the solenoid-operated proportional pilot valve 1 is communicated with main oil return inlet T on the main valve body 7 through the 3rd runner L3.Main valve plug area regulating ring 10 and main valve plug 6, main valve plug retaining spring 8 coaxial arrangement are in main valve body 7.
Among Fig. 1, main valve plug 6 forms 4 hydraulic fluid port P that are connected with the external world, A with main valve body 7, B, T, wherein, the P mouth is main filler opening, introduces pressure oil, A, B is oil outlet I and II, be communicated with two chambeies of final controlling element, the T mouth is main return opening, is communicated with fuel tank, oil outlet I A, the open amount size of oil outlet II B and main oil return inlet T is directly proportional with the displacement amount of main valve plug 6.
The structure of main valve plug 6 has 3 steps as shown in Figure 5, and 4 steps also can be arranged, and has oil duct I P on the main valve plug 6 1, oil duct II P 2With oil duct IIIP 3In spool, be communicated with oil duct I P 1Be communicated with oil duct II P with the main oil inlet P of valve 2With cavity volume I e, cavity volume II f is communicated with, oil duct IIIP 3Be arranged symmetrically in main valve plug 6 two ends, at main valve plug 6 inner and oil duct II P 2Be communicated with.
The structure of the area regulating ring 10 of main valve plug 6 has two as shown in Figure 6, is processed with oil through I K thereon 1With oil through II K 2, oil through I K wherein 1Cooperate coaxial installation with main valve plug 6, oil through II K 2With main valve plug 6 internal oil channel II P 2Interior oil is incorporated into cavity volume I e, and cavity volume II f also is processed with oil duct IVP on it 4With oil duct V P 5, oil duct IVP 4With oil duct V P 5Symmetric arrangement, oil duct IVP 4With oil duct IIIP 3Be communicated with, pressure oil is incorporated into oil duct V P 5, oil duct V P 5Form the throttling limit with the end face h of main valve body 7.
The said structure feature constitutes the type pilot proportion directional throttle valve of first kind of technological scheme.
Mode of execution 2
Among Fig. 2, as the structure and the working principle of the guide proportion directional throttle valve of mode of execution 1 described continuous control flow direction of the present invention and flow, mode of execution 2 is to have additional electronic switch 9, closed loop controller 3, adder I 13, adder II 15, feedback signal amplifier 4, displacement transducer 5 on the basis of mode of execution 1.The input end of electronic switch 9 is connected with the output terminal of closed loop controller 3, and the output terminal of the output terminal of electronic switch 9 and open-cycle controller 11 is connected to the input end of adder I 13, and the output terminal of adder I 13 is connected to the input end of proportional amplifier 2; The output signal of displacement transducer 5 is connected to the input end of feedback signal amplifier 4, the output signal of feedback signal amplifier 4 is connected with the control end of electronic switch 9, the output signal of feedback signal amplifier 4 is connected to the input end of adder II15, setting signal Uxs is connected to the input end of adder II 15 and open-cycle controller 11 simultaneously, and the output terminal of adder II 15 is connected to the input end of closed loop controller 3; Displacement transducer 5 and main valve plug area regulating ring 10, main valve plug 6, main valve plug retaining spring (8) coaxial arrangement detect the displacement of main valve plug 6 in main valve body (7).
In Fig. 2, electronic switch 9 is controlled by the working state of displacement transducer 5, under the situation that displacement transducer 5 and feedback signal amplifier 4 break down, electronic switch 9 is with regard to automatic disconnection, at this moment the working state of closed loop valve in whole valve is under the control of open-cycle controller 11, the displacement amount of control main valve plug 6 that still can continuous ratio.Open-cycle controller 11 is accepted setting signal Uxs, and this signal carried out after the conversion being input to proportional amplifier 2 behind the signal plus with PID closed loop controller 3, main valve plug 6, form cavity volume I e and cavity volume II f between main valve plug area regulating ring 10 and the main valve body 7, cavity volume I e is communicated with the control port I c of solenoid-operated proportional pilot valve 1 through first flow L1, cavity volume II f is communicated with the control port II d of solenoid-operated proportional pilot valve 1 through the second runner L2, but solenoid-operated proportional pilot valve 1 is the Proportional valve of move left and right, control port I c is arranged on it, control port II d and drain tap t, the size of these 3 hydraulic fluid port opening amounts and given signal are proportional, control port I c and control port II d are in closed condition when no signal, when the spool of solenoid-operated proportional pilot valve 1 is moved to the left, control port I c opens greatly, be communicated with cavity volume I e and drain tap t, when the electromagnetic pilot spool moves right, control port II d opens greatly, is communicated with cavity volume II f and drain tap t.
The structure of main valve plug 6 has 3 steps as shown in Figure 5, and 4 steps also can be arranged, and has oil duct I P on the main valve plug 6 1, oil duct II P 2With oil duct IIIP 3In spool, be communicated with oil duct I P 1Be communicated with oil duct II P with the main oil inlet P of valve 2With cavity volume I e, cavity volume II f is communicated with, oil duct IIIP 3Be arranged symmetrically in main valve plug 6 two ends, at main valve plug 6 inner and oil duct II P 2Be communicated with.
The structure of the area regulating ring 10 of main valve plug 6 has two as shown in Figure 6, is processed with oil through I K thereon 1With oil through II K 2, oil through I K wherein 1Cooperate coaxial installation with main valve plug 6, oil through II K 2With main valve plug 6 internal oil channel II P 2Interior oil is incorporated into cavity volume I e, and cavity volume II f also is processed with oil duct IVP on it 4With oil duct VP 5, oil duct IVP 4With oil duct VP 5Symmetric arrangement, oil duct IVP 4With oil duct IIIP 3Be communicated with, pressure oil is incorporated into oil duct VP 5, oil duct VP 5Form the throttling limit with the end face h of main valve body 7.
The said structure feature constitutes the type pilot proportion directional throttle valve of second kind of technological scheme.
Mode of execution 3
Formation and working principle as the guide proportion directional throttle valve of continuous control flow direction of the present invention described in mode of execution 1 and 2 and flow, mode of execution 3 is on the basis of mode of execution 2, remove two-position three way solenoid directional control valve 12, cavity volume I e is communicated with the control port I c of solenoid-operated proportional pilot valve 1 through first flow L1, cavity volume II f is communicated with the control port II d of solenoid-operated proportional pilot valve 1 through the second runner L2, and the drain tap t of solenoid-operated proportional pilot valve 1 is communicated with main oil return inlet T on the main valve body 7 through the 3rd runner L3.This structure characteristic constitutes the third type pilot proportion directional throttle valve.
Mode of execution 4
Formation and working principle as the guide proportion directional throttle valve of continuous control flow direction of the present invention described in mode of execution 1 and 2 and flow, mode of execution 4 is on the basis of mode of execution 1, change solenoid-operated proportional pilot valve 1 into manual proportional pilot valve 14, remove proportional amplifier 2, open-cycle controller 11, this structure characteristic constitutes the 4th kind of manually type pilot proportion directional throttle valve of control.

Claims (6)

1. guide proportion directional throttle valve, it contains solenoid-operated proportional pilot valve (1), proportional amplifier (2), open-cycle controller (11), main valve plug (6), main valve body (7) and main valve plug retaining spring (8), it is characterized in that two-position three way solenoid directional control valve (12) is installed between main valve body (7) and the solenoid-operated proportional pilot valve (1), cavity volume I (e) in the main valve body (7) is communicated with the filler opening I (n) of two-position three way solenoid directional control valve (12) through first flow (L1), and the cavity volume II (f) in the main valve body (7) is communicated with the filler opening II (m) of two-position three way solenoid directional control valve (12) through second runner (L2); The oil outlet (q) of two-position three way solenoid directional control valve (12) is communicated with control port I (c) in the solenoid-operated proportional pilot valve (1), and the drain tap (t) in the solenoid-operated proportional pilot valve (1) is communicated with main return opening (T) on the main valve body (7) through the 3rd runner (L3); Main valve plug area regulating ring (10) and main valve plug (6), main valve plug retaining spring (8) coaxial arrangement are in main valve body (7).
2. guide proportion directional throttle valve as claimed in claim 1 is characterized in that having additional electronic switch (9), closed loop controller (3), adder I (13), adder II (15), feedback signal amplifier (4), displacement transducer (5); The input end of electronic switch (9) is connected with the output terminal of closed loop controller (3), the output terminal of the output terminal of electronic switch (9) and open-cycle controller (11) is connected to the input end of adder I (13), and the output terminal of adder I (13) is connected to the input end of proportional amplifier (2); The output signal of displacement transducer (5) is connected to the input end of feedback signal amplifier (4), the output signal of feedback signal amplifier (4) is connected with the control end of electronic switch (9), the output signal of feedback signal amplifier (4) is connected to the input end of adder II (15), setting signal Uxs is connected to the input end of adder II (15) and open-cycle controller (11) simultaneously, and the output terminal of adder II (15) is connected to the input end of closed loop controller (3); Displacement transducer (5) and main valve plug area regulating ring (10), main valve plug (6), main valve plug retaining spring (8) coaxial arrangement detect the displacement of main valve plug (6) in main valve body (7).
3. guide proportion directional throttle valve as claimed in claim 1 or 2, it is characterized in that removing two-position three way solenoid directional control valve (12), cavity volume I (e) in the main valve body (7) is communicated with the control port I (c) of solenoid-operated proportional pilot valve (1) through first flow (L1), cavity volume II (f) in the main valve body (7) is communicated with control port II (d) in the solenoid-operated proportional pilot valve (1) through second runner (L2), and the drain tap (t) of solenoid-operated proportional pilot valve (1) is communicated with main return opening (T) on the main valve body (7) through the 3rd runner (L3).
4. as each described guide proportion directional throttle valve in the claim 1~3, it is characterized in that main valve plug (6) is provided with oil duct I (P 1), oil duct II (P 2) and oil duct III (P 3), and be interconnected oil duct I (P 1) and oil duct II (P 2), the main oil inlet P of valve is communicated with oil duct II (P 2) axial arranged and be communicated with oil duct III (P with cavity volume I (e), cavity volume II (f) along spool 3) be symmetricly set on the two ends of main valve plug (6), and with main valve plug (6) in oil duct II (P 2) be connected;
5. as each described guide proportion directional throttle valve in the claim 1~3, it is characterized in that main valve plug area regulating ring (10) is provided with oil through I (K 1) and oil through II (K 2), oil through I (K 1) with the coaxial installation of main valve plug (6), oil through II (K 2) with main valve plug (6) internal oil channel II (P 2) in oil be incorporated into cavity volume I (e) and cavity volume II (f); Main valve plug area regulating ring (10) is provided with oil duct IV (P 4) and oil duct V (P 5), oil duct IV (P 4) and oil duct III (P 3) be communicated with, pressure oil is incorporated into oil duct V (P 5), oil duct V (P 5) form the throttling limit with the end face h of main valve body (7).
6. guide proportion directional throttle valve as claimed in claim 1 is characterized in that solenoid-operated proportional pilot valve (1) is the Proportional valve or the high-speed switch valve of continuous control.
CN200610102032A 2006-10-16 2006-10-16 Guide proportion directional throttle valve CN100590324C (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN200610102032A CN100590324C (en) 2006-10-16 2006-10-16 Guide proportion directional throttle valve

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN200610102032A CN100590324C (en) 2006-10-16 2006-10-16 Guide proportion directional throttle valve

Publications (2)

Publication Number Publication Date
CN1936343A CN1936343A (en) 2007-03-28
CN100590324C true CN100590324C (en) 2010-02-17

Family

ID=37954008

Family Applications (1)

Application Number Title Priority Date Filing Date
CN200610102032A CN100590324C (en) 2006-10-16 2006-10-16 Guide proportion directional throttle valve

Country Status (1)

Country Link
CN (1) CN100590324C (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2014047874A1 (en) * 2012-09-28 2014-04-03 中联重科股份有限公司 Proportional steering valve, proportional steering hydraulic circuit, proportional steering system and vehicle

Families Citing this family (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102954057B (en) * 2012-11-22 2015-08-19 太原理工大学 The threeway proportional pressure-reducing valve of electricity closed loop control
CN103335834B (en) * 2013-07-02 2015-08-19 南京工业大学 A kind of throttle valve port performance test device
CN104675804A (en) * 2014-03-17 2015-06-03 南通爱慕希机械有限公司 Comprehensive hydraulic cylinder performance testing system
CN105003477B (en) * 2015-06-19 2017-03-15 太原理工大学 The type pilot electro hydraulic valve of motor Collaborative Control
JP5876185B1 (en) * 2015-08-27 2016-03-02 憲平 山路 Electromagnetic proportional control valve system
CN105545852B (en) * 2015-12-30 2017-05-17 浙江大学 High-speed switch pilot proportioning valve
CN105822624B (en) * 2016-05-18 2017-07-11 浙江大学 A kind of valve element dynamic test system of pilot-operated type load control valve
CN106555785B (en) * 2016-10-11 2018-01-05 太原理工大学 Type pilot proportion directional flow rate continuous control valve
CN106246629B (en) * 2016-10-11 2017-10-13 太原理工大学 External control type guide proportion directional valve

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3854382A (en) * 1973-06-20 1974-12-17 Sperry Rand Ltd Hydraulic actuator controls
US3874269A (en) * 1972-11-08 1975-04-01 Sperry Rand Ltd Hydraulic actuator controls
US3878765A (en) * 1971-01-05 1975-04-22 Sperry Rand Ltd Hydraulic actuator controls
US4031813A (en) * 1973-10-10 1977-06-28 Sperry Rand Limited Hydraulic actuator controls
DE4112065A1 (en) * 1991-04-12 1992-10-22 Rexroth Mannesmann Gmbh Pilot valve with adjustable switch pressure differential - has connection between pressure valve and servo control space
CN2197500Y (en) * 1994-07-13 1995-05-17 中外合资绍兴春晖冷冻器材有限公司 Four way electromagnetic chargeover valve

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3878765A (en) * 1971-01-05 1975-04-22 Sperry Rand Ltd Hydraulic actuator controls
US3874269A (en) * 1972-11-08 1975-04-01 Sperry Rand Ltd Hydraulic actuator controls
US3854382A (en) * 1973-06-20 1974-12-17 Sperry Rand Ltd Hydraulic actuator controls
US4031813A (en) * 1973-10-10 1977-06-28 Sperry Rand Limited Hydraulic actuator controls
DE4112065A1 (en) * 1991-04-12 1992-10-22 Rexroth Mannesmann Gmbh Pilot valve with adjustable switch pressure differential - has connection between pressure valve and servo control space
CN2197500Y (en) * 1994-07-13 1995-05-17 中外合资绍兴春晖冷冻器材有限公司 Four way electromagnetic chargeover valve

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2014047874A1 (en) * 2012-09-28 2014-04-03 中联重科股份有限公司 Proportional steering valve, proportional steering hydraulic circuit, proportional steering system and vehicle

Also Published As

Publication number Publication date
CN1936343A (en) 2007-03-28

Similar Documents

Publication Publication Date Title
CN102777434B (en) Hydraulic driving apparatus for working machine
CN100514241C (en) Valve
EP0079870B1 (en) Hydraulic valve means
CA2793440C (en) Hydraulic valve with pressure limiter
KR100234605B1 (en) Hydraulic control system having poppet and spool type valves
CN107324215B (en) Crane and its hydraulic control system
CN2682235Y (en) Load sensing pressure compensation multi-port valve
CN103016438B (en) A kind of electrohydraulic proportional control valve group
CN103807231B (en) Hydraulic drive apparatus for work machine
CN202251199U (en) Electro-hydraulic proportional combined maneuvering valve
CN103047208B (en) Load-sensitive electro-hydraulic proportional multi-way valve
JP2014173614A (en) Joining circuit for hydraulic device
CN105221506B (en) A kind of load-sensitive valve and load-sensitive hydraulic system
CN101571155A (en) Digital electric-hydraulic synchronous control system
CN201255257Y (en) Power constant control valve
CN205190903U (en) Electromagnetism proportinal flow valve
CN202673874U (en) Constant-pressure variable control system of load sensitive hydraulic pump
CN102734247B (en) Flow control system and method of multi-way directional valve and engineering machinery
CN102042273B (en) Hydraulic control loop and method
CN103895698B (en) Fluid pressure type agricultural machinery automatic steering control device and control method
CN102251996A (en) Engineering mechanical load sensing hydraulic system
CN102720711A (en) Automatic-switch type load sensing hydraulic system
CN2892805Y (en) Motor rotational speed memory hoisting braker control device
CN204284032U (en) Single actuator automatic switchover rapid movement oil hydraulic circuit
CN201581382U (en) Electro-hydraulic proportional control piston type two-lifting-point hydraulic hoist

Legal Events

Date Code Title Description
PB01 Publication
C06 Publication
SE01 Entry into force of request for substantive examination
C10 Entry into substantive examination
GR01 Patent grant
C14 Grant of patent or utility model
CF01 Termination of patent right due to non-payment of annual fee

Granted publication date: 20100217

Termination date: 20171016

CF01 Termination of patent right due to non-payment of annual fee