CN1133405A - Slide-valve servo, plane bar linkage feedback type electric liquid step cylinder - Google Patents
Slide-valve servo, plane bar linkage feedback type electric liquid step cylinder Download PDFInfo
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- CN1133405A CN1133405A CN 95114820 CN95114820A CN1133405A CN 1133405 A CN1133405 A CN 1133405A CN 95114820 CN95114820 CN 95114820 CN 95114820 A CN95114820 A CN 95114820A CN 1133405 A CN1133405 A CN 1133405A
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Abstract
The slide valve servo plane link mechanism reaction-type electro-hydraulic stepping cylinder belongs to a numerical control element in electro-hydraulic control system. Because, a plane link mechanism is added in its structure, and has the conversion function for displacement, compared with existent electro-hydraulic cylinder, it has the advantages of quick starting and braking speed or high accuracy, low cost and easy manufacture. Said invention is applicable to electro-hydraulic position servo and speed servo control system.
Description
The present invention relates to a kind of digital controling element in electro-hydraulic position and the rate servo system---slide-valve servo, plane bar linkage feedback type electric liquid step cylinder.
The existing electric liquid step cylinder of using in electro-hydraulic position and the rate servo system is made up of stepper motor and hydraulic coupling amplifier.The hydraulic coupling amplifier is a direct position reaction type hydraulic servomechanism, can be divided into two kinds of forms by its structure: first kind of form is by control valve, piston cylinder and screw rod---and the feedback nut is formed, and belongs to slide-valve servo, screw rod---nut reaction type; Second kind of form is made up of screw thread spool and piston cylinder, on its piston control port arranged, and belongs to servo, piston (also the can be considered valve body) reaction type of screw thread.The LV series electric liquid step cylinder of Switzerland SIG company, the electric liquid step cylinder of Tokyo gauge company and the electric liquid step cylinder of Beijing Iron﹠Steel Design﹠Research Institute's development etc. all belong to first kind of form.The electric liquid step cylinder of Germany BOSCH-REXROTH company and Chinese patent " progressional electric-hydraulic converter " (patent No. ZL92220614.7) etc. belong to second kind of form.First kind of formal cause is subjected to that stepper motor opens, the restriction of braking frequency and screw rod helical pitch, and it opens, retro-speed is lower, is difficult to use under the occasion that opens fast, brakes requiring; Second kind of form then requires the machining accuracy height of screw thread spool, and manufacture cost is bigger.In addition, the feedback factor of the hydraulic servomechanism of existing electric liquid step cylinder is 1 (direct position feedback), and the restriction of controlled valve accuracy of manufacturing and static fuel consumption index request is difficult to obtain higher control accuracy.
Reference:
A. " oilhydraulic engineering handbook " Lei Tianjue edits
New bibliography: the 210-002 of China Machine Press's science and technology in April nineteen ninety
The 1308th page to 1311 pages of ISBN7-111-01724-2/TH.294;
B. " progressional electric-hydraulic converter " Chinese patent patent No. ZL92220614.7
Notice of authorization CN2150376Y
It is very fast or precision is higher, easy processing, electric liquid step cylinder---slide-valve servo, plane bar linkage feedback type electric liquid step cylinder with low cost to the purpose of this invention is to provide a kind of retro-speed that starts.
The present invention is made up of stepper motor, servo guiding valve and oil hydraulic cylinder, stepper motor is fixed on the cylinder body of oil hydraulic cylinder, oil hydraulic cylinder is controlled by servo guiding valve, it is characterized in that: be provided with planar linkage, planar linkage is connected with the piston of stepper motor, oil hydraulic cylinder and the spool of servo guiding valve, synthesize the command signal of importing by stepper motor with by the feedback signal that the piston of oil hydraulic cylinder is imported, and the signal after will synthesizing sends the spool of servo guiding valve to.
Planar linkage among the present invention has two kinds to constitute pattern: general expression and position are like formula.
The general expression planar linkage is made up of feedback linkage, rocking bar, frame, intermediate connecting rod, the synthetic connecting rod of signal and output connecting rod, and feedback linkage is connected with the piston of oil hydraulic cylinder, an end of rocking bar and an end of intermediate connecting rod; The other end of rocking bar connects with frame; Frame is fixed on the cylinder body of oil hydraulic cylinder; One end of the other end of intermediate connecting rod, output connecting rod and stepper motor connect with the synthetic connecting rod of signal; The other end of output connecting rod connects with the spool of servo guiding valve.
The connecting mode of general expression planar linkage and stepper motor can be the bolt and nut pair, also can be the cam bawl pair.Adopt bolt and nut pair (sliding-type or roll type) generally speaking, screw rod is connected on the axle of stepper motor, and the nut hinge joint is on the synthetic connecting rod of the signal of this planar linkage; In particular cases, as being when obtaining the input-output characteristic of specific curves, to adopt the cam bawl pair, cam connects firmly on the axle of stepper motor, and the signal that the roller sky is enclosed within this planar linkage synthesizes on the corresponding axis of connecting rod.
When adopting the general expression planar linkage, signal transmission way of the present invention is:
Command signal: step-by-step impulse → stepper motor rotates and drives screw rod (or cam) rotations → nut (or roller) and produces displacement → signal to synthesize connecting rod be that fulcrum shakes with the rotary pair center of it and intermediate connecting rod, and drive output connecting rod generation displacement → servo valve core of the spool valve moves the piston generation displacement of control oil hydraulic cylinder.
Feedback signal: hydraulic cylinder piston displacement → feedback linkage, rocker assembly with the rotary pair center of itself and frame be fulcrum shake → to produce the synthetic connecting rod of displacement → signal be that fulcrum shakes with it and nut hinge joint place (or Roller Shaft) to intermediate connecting rod, and driving the output connecting rod, to produce displacement → servo valve core of the spool valve mobile on the recovery direction.
The position is made up of feedback linkage, rocking bar, frame, the synthetic connecting rod of signal and auxiliary connecting rod like formula planar linkage machine, and feedback linkage connects with the piston of oil hydraulic cylinder; The synthetic connecting rod of signal connects with the spool of stepper motor and servo guiding valve; Frame is fixed on the cylinder body of oil hydraulic cylinder; To be center of similarity with the rotary pair of frame connect like relation by how much positions of scaling ruler for synthetic connecting rod of feedback linkage, rocking bar, frame, signal and auxiliary connecting rod, and the straight-line displacement of hydraulic cylinder piston is transformed to the synthetic connecting rod of signal connects rotary pair with stepper motor and servo valve core of the spool valve straight-line displacement pro rata.
The position adopts bolt and nut pair (sliding-type or roll type) to connect like the formula planar linkage with the spool of stepper motor and servo guiding valve; Screw rod connects with the axle of stepper motor through gear or axially-displaceable formula coupling, and connects firmly into the integral body of coaxial line with the spool of servo guiding valve; The nut hinge joint is on the synthetic connecting rod of the signal of this planar linkage.
When adopting the position like the formula planar linkage, signal transmission way of the present invention is:
Command signal: step-by-step impulse → stepper motor rotates and drives screw rod and rotate → because nut is not moving, causes screw rod to produce the spool that moves axially and drive servo guiding valve and move, and the piston of control oil hydraulic cylinder produces displacement.
Feedback signal: hydraulic cylinder piston displacement → make nut produce corresponding moving →, cause screw rod to produce and the spool that drives servo guiding valve moves on the direction recovering like the formula planar linkage because stepper motor and screw rod do not rotate by the position.
Servo guiding valve among the present invention generally adopts three-port structure, in particular cases, as for improving the ouput force of electric liquid step cylinder, then can adopt four-way or five-way structure.
Oil hydraulic cylinder among the present invention generally adopts the double piston-rod differential hydro cylinder, in particular cases, also can adopt the oil hydraulic cylinder of existing other types: as adopting the double piston-rod double acting cylinder for improving ouput force; Adopt the single-piston rod double acting cylinder for reducing axial dimension; Adopt single-acting cylinder or the like for simplifying oil channel structures.
Adopt the servo mode of direct position feedback (feedback factor is 1) to compare with existing electric liquid step cylinder, the present invention adopts planar linkage to realize the transmission of command signal and feedback signal, its velocity ratio needn't be defined as 1, when hydraulic cylinder piston to the velocity ratio (feedback factor) of servo valve core of the spool valve greater than 1 the time, can obtain high control precision; When the ratio of the required displacement of the stroke of hydraulic cylinder piston and corresponding command signal input point (being the rotary pair that planar linkage and stepper motor link) greater than 1 the time, then can control the oil hydraulic cylinder of big displacement output with the displacement of less command signal input point, thereby the electric liquid step cylinder that obtains than existing first kind of form is high startup retro-speed.All constituent elementss among the present invention all are easy to processing, so lower than the electric liquid step cylinder cost of existing second kind of form.In addition, the present invention can also realize the input-output characteristic of required curved line relation, can be formed in product special-purpose under some occasion, in the hope of simplifying the structure of The whole control system.
Generally speaking, the planar linkage among the present invention adopts general expression; When strict, then adopting the position like formula to the linearity of input-output characteristic.All rotary pairs among the present invention should be taked the gap measure that disappears.
Fig. 1 is a theory diagram of the present invention;
Fig. 2 is a structure diagram of the present invention when adopting the general expression planar linkage;
Fig. 3 is a structure diagram of the present invention when adopting the position like the formula planar linkage.
Fig. 1 shows principle square frame of the present invention, and it is by stepper motor [1], hydraulic cylinder [3] Form with servo guiding valve [4], hydraulic cylinder [3] be is characterized in that: establish by servo guiding valve [4] control Be equipped with planar linkage mechanism [2]; Planar linkage mechanism [2] and stepper motor [1], hydraulic cylinder The spool of piston [3] and servo guiding valve [4] connects, the finger by stepper motor [1] input Make signal and the feedback signal of being imported by the piston of hydraulic cylinder [3] synthesize, and will synthesize After signal pass to the spool of servo guiding valve [4].
In Fig. 1, X represents the electric pulse of Driving Stepping Motor [1], and Y represents that hydraulic cylinder is defeated The mechanical displacement that goes out, P and O represent respectively the input of hydraulic pressure and the end that refluxes; The command signal arrow "-" of "+" of head top number and feedback signal arrow top number represents the utmost point of this two signal Property is opposite.
As seen from Figure 1, the present invention is with the direct position reaction type in the existing electric liquid step cylinder Hydraulic servomechanism is replaced by indirect position reaction type hydraulic servomechanism and is realized.
Embodiment:
Fig. 2 shows first embodiment's of the present invention structure diagram, structure diagram of the present invention when promptly adopting the general expression planar linkage.Among the figure, [1] is stepper motor, [5] be the cylinder body of oil hydraulic cylinder, [6] be the piston of oil hydraulic cylinder, [13] be the spool of servo guiding valve, [14] be nut, [15] be screw rod, [16] are the gap spring that disappears, and [17] are spring cup, stepper motor [1] is fixed on the upper end of the cylinder body [5] of oil hydraulic cylinder [3], it is characterized in that: be provided with planar linkage, this planar linkage is by feedback linkage [9], rocking bar [8], frame [7], intermediate connecting rod [10], the synthetic connecting rod [11] of output connecting rod [12] and signal is formed, the left end of feedback linkage [9] and piston 6 hinge joints, the upper end hinge of right-hand member and rocking bar [8], the lower end hinge joint of somewhere, stage casing and intermediate connecting rod [10]; The lower end of rocking bar [8] and frame [7] hinge joint; Frame [7] is fixed on the cylinder body [5]; The right-hand member hinge joint of the synthetic connecting rod [11] of the upper end of intermediate connecting rod [10] and signal; Signal synthesizes the upper end hinge of left end with the output connecting rod [12] of connecting rod [11]; The lower end of output connecting rod [12] and the hinge joint of the spool [13] of servo guiding valve; Stepper motor [1] connects by screw rod [15] and nut [14] with the synthetic connecting rod [11] of signal, and screw rod [15] connects firmly on the axle of stepper motor [1], and nut [14] hinge joint is at the middle part of the synthetic connecting rod [11] of signal.
In this embodiment, servo guiding valve adopts Three way type, and oil hydraulic cylinder adopts the double piston-rod differential type; Spring cup [17] compresses spring [16], makes spool [13] be subjected to a downward active force, to eliminate the drive gap of linkage mechanism.
This embodiment's working procedure is as follows:
When the lower shoulder of servo valve core of the spool valve [13] is closed control window A, hydraulic cylinder piston [6] transfixion, this moment, servo guiding valve then remained on closed condition, thereby electric liquid step cylinder is remained static if stepper motor [1] is not moving.
When step-by-step impulse makes stepper motor [1] when just changeing, screw rod [15] just changes thereupon, nut [14] moves down, driving the synthetic connecting rod [11] of signal is fulcrum with the rotary pair center of it and intermediate connecting rod [10], towards swing counterclockwise, the left end that signal synthesize connecting rod [11] moves down, and drives servo valve core of the spool valve [13] and move down by exporting connecting rod [12], the epicoele that pressure oil promptly enters oil hydraulic cylinder by the P mouth through the pressure chamber and the window A of servovalve is opened in the upper edge of control window A; Because the last cavity area of oil hydraulic cylinder is bigger than following cavity area, the effect that piston [6] will be subjected to making a concerted effort downwards and moving down, and drive feedback linkage [9] counter-clockwise swing, feedback linkage [9] drives intermediate connecting rod [10] and moves down, making signal synthesize connecting rod [11] is that fulcrum is swung clockwise with the rotary pair center of it and nut [14], and spool [13] is upwards recovered, thereby the open amount of control window A is reduced by output connecting rod [12].If stepping machine [1] stops after just changeing several angle, then hydraulic cylinder piston [6] makes control window A cut out after moving down corresponding displacement, thereby makes the piston [6] of electric liquid step cylinder stablize motionless on new position.
The working procedure that makes stepper motor [1] when counter-rotating present embodiment when step-by-step impulse to make the working procedure of stepper motor [1] when just changeing similar, brief description it:
Stepper motor [1] counter-rotating → spool [13] moves up, open the lower edge of window A, the oil of controlling on the oil hydraulic cylinder is discharged through the oil extraction control and the oil drain out O of window A, servo guiding valve, piston [6] moves up under the pressure oil effect of oil hydraulic cylinder cavity of resorption → spool [13] recovery downwards, and the open amount of window A is reduced.If stepper motor [1] stops behind the counter-rotating several angle, then hydraulic cylinder piston [6] cuts out window A after the corresponding displacement that moves up, thereby makes the piston [6] of electric liquid step cylinder stablize motionless on new position.
In the stroke range of present embodiment, if stepper motor [1] rotates with certain rotating speed, then hydraulic cylinder piston [6] moves as straight line with the speed of correspondence.Possess position servo and speed servo function so present embodiment is the same with existing electric liquid step cylinder.
In the present embodiment, to transmitting the change action of displacement, make the nut [14] can be by planar linkage, thereby obtain higher startup, retro-speed with the big displacement of the corresponding piston of less displacement [6].Equally,, can make displacement velocity ratio that piston [6] feeds back to spool [13] greater than 1, thereby obtain high control precision transmitting the change action of displacement by planar linkage.
Fig. 3 shows second embodiment's of the present invention structure diagram, structure diagram of the present invention when promptly adopting the position like the formula planar linkage.[19] are gear pair among the figure, and stepper motor is fixed on the upper end of hydraulic cylinder body [5].It is characterized in that: be provided with planar linkage, this planar linkage is made up of feedback linkage [9], rocking bar [8], frame [7], the synthetic connecting rod [11] of signal and auxiliary connecting rod [18], and feedback linkage [9] links with the piston [6] of oil hydraulic cylinder; Signal synthesizes connecting rod [11] and connects with stepper motor [1] and servo valve core of the spool valve [13]; Frame [7] is fixed on the cylinder body [5] of oil hydraulic cylinder; Feedback linkage [9], rocking bar [8], frame [7], the synthetic connecting rod [11] of signal and auxiliary connecting rod [18] are the how much positions seemingly relation hinge joint of center of similarity by scaling ruler with the rotary pair of frame [7], and the straight-line displacement of hydraulic cylinder piston [6] is transformed to the synthetic connecting rod [11] of signal connects rotary pair with stepper motor [1] and servo valve core of the spool valve [13] straight-line displacement pro rata; Signal synthesizes connecting rod [11] and adopts screw rod [15], nut [14] and gear pair [19] to connect with stepper motor [1] and servo valve core of the spool valve [13]; Screw rod [15] connects through the axle of gear pair [19] and stepper motor [1], and connects firmly into the integral body of coaxial line with servo valve core of the spool valve [13]; Nut [14] hinge joint is on the synthetic connecting rod [11] of signal.
This embodiment's servo guiding valve adopts Three way type, and oil hydraulic cylinder adopts the double piston-rod differential type.Spring cup [17] compresses spring [16], makes spool [13] be subjected to a downward active force, to eliminate the drive gap of linkage mechanism.
This embodiment's working procedure is as follows:
When the upper shoulder of servo valve core of the spool valve [13] is closed control window A, hydraulic cylinder piston [6] transfixion, this moment, servo guiding valve then remained on closed condition, thereby electric liquid step cylinder is remained static if stepper motor [1] is not moving.
When step-by-step impulse rotates stepper motor [1] clockwise direction,, screw rod [15] is rotated counterclockwise by the engagement of gear pair [19]; If the screw thread of screw rod [15] is dextrorotation, because nut [14] is not moving, so screw rod [15] moves up when rotating counterclockwise; The spool [13] that joins together with screw rod [15] also rotate thereupon and on move, the epicoele that pressure oil promptly enters oil hydraulic cylinder by the P mouth through the pressure chamber and the window A of servo guiding valve is opened in lower edge that will control window A; Because the last cavity area of oil hydraulic cylinder is bigger than following cavity area, piston [6] will be subjected to making a concerted effort downward effect and move down, and nut [14] be moved down pro rata like the formula planar linkage by the position; Nut [14] drives screw rod [15] and spool [13] recovers downwards, and the open amount of window A is reduced.If stop after stepper motor turns an angle in the clockwise direction, then hydraulic cylinder piston [6] makes window A cut out after moving down corresponding displacement, thereby makes the piston [6] of electric liquid step cylinder stablize motionless on new position.
The working procedure that makes stepper motor [1] present embodiment when rotating counterclockwise when step-by-step impulse to make the working procedure of stepper motor [1] when clockwise rotating similar, brief description it:
Stepper motor [1] rotates counterclockwise → and spool [13] moves down, open the upper edge of window A, the oil of controlling on the oil hydraulic cylinder is discharged through the oil-discharging cavity and the oil drain out O of window A, servo guiding valve, piston [6] moves up under the pressure oil effect of oil hydraulic cylinder cavity of resorption → upwards recovery of spool [13], and the open amount of window A is reduced.If stepper motor [1] stops after turning an angle in the counterclockwise direction, then hydraulic cylinder piston [6] moves up and window A is closed after the corresponding displacement, thereby makes the piston [6] of electric liquid step cylinder stablize motionless on new position.
In the stroke range of present embodiment, if stepper motor [1] rotates with certain rotating speed, then hydraulic cylinder piston [6] is with the speed moving linearly of correspondence.Possess position servo and speed servo function so present embodiment is also the same with existing electric liquid step cylinder.
In the present embodiment, by the position like the formula planar linkage to transmitting the proportional change action of displacement, not only can make the nut [14] can be with the big displacement of the corresponding piston of less displacement [6], thereby obtain higher startup retro-speed, and the corresponding relation that can guarantee this two displacement is proportional, thereby guarantees that the present invention can possess the linear performance the same with existing electric liquid step cylinder.
Can take adequate measures to improve the control accuracy of present embodiment.For example, it can be exchanged like the connection of point like two positions in the formula planar linkage, the feedback factor that makes servomechanism is greater than 1; Also can increase by a linkage mechanism, drive spool [13] or the like again after the displacement of screw rod [15] is amplified.
By above two embodiments as can be seen, its constituent elements all is easy workpiece, and is so the present invention is easy to manufacture, with low cost.
Claims (5)
1. a slide-valve servo, plane bar linkage feedback type electric liquid step cylinder, form by stepper motor [1], oil hydraulic cylinder [3] and servo guiding valve [4], stepper motor [1] is fixed on the cylinder body [5] of oil hydraulic cylinder [3], oil hydraulic cylinder [3] be is characterized in that: be provided with planar linkage [2] by servo guiding valve [4] control; Planar linkage [2] connects with the piston [6] of stepper motor [1], oil hydraulic cylinder [3] and the spool [13] of servo guiding valve [4], command signal of being imported by stepper motor [1] and the feedback signal of being imported by the piston [6] of oil hydraulic cylinder [3] are synthesized, and the signal after will synthesizing sends the spool [13] of servo guiding valve [4] to.
2. by the described slide-valve servo of claim 1, plane bar linkage feedback type electric liquid step cylinder, it is characterized in that: planar linkage [2] is made up of the synthetic connecting rod [11] of feedback linkage [9], rocking bar [8], frame [7], intermediate connecting rod [10], output connecting rod [12] and signal, and feedback linkage [9] connects with the piston [6] of oil hydraulic cylinder [3], an end of rocking bar [8] and an end of intermediate connecting rod [10]; The other end of rocking bar [8] connects with frame [7]; Frame [7] is fixed on the cylinder body [5] of oil hydraulic cylinder [3]; One end of the other end of intermediate connecting rod [10], output connecting rod [12] and stepper motor [1] connect with the synthetic connecting rod [11] of signal; The other end of output connecting rod [12] connects with the spool [13] of servo guiding valve [4].
3. by the described slide-valve servo of claim 2, plane bar linkage feedback type electric liquid step cylinder, it is characterized in that: stepper motor [1] adopts screw rod [15] and nut [14] to connect with the synthetic connecting rod [11] of signal, screw rod [15] connects firmly on the axle of stepper motor [1], and nut [14] hinge joint is at the middle part of the synthetic connecting rod [11] of signal.
4. by the described slide-valve servo of claim 1, plane bar linkage feedback type electric liquid step cylinder, it is characterized in that: planar linkage [2] is made up of feedback linkage [9], rocking bar [8], frame [7], the synthetic connecting rod [11] of signal and auxiliary connecting rod [18], and feedback linkage [9] connects with the piston [6] of oil hydraulic cylinder [3]; Signal synthesizes connecting rod [11] and connects with the spool [13] of stepper motor [1] and servo guiding valve [4]; Frame [7] is fixed on the cylinder body [5] of oil hydraulic cylinder [3]; To be center of similarity with the rotary pair of frame [7] connect like relation by how much positions of scaling ruler for synthetic connecting rod [11] of feedback linkage [9], rocking bar [8], frame [7], signal and auxiliary connecting rod [18], the straight-line displacement of hydraulic cylinder piston [6] is transformed to signal pro rata synthesizes connecting rod [11] connects rotary pair with stepper motor [1] and servo valve core of the spool valve [13] straight-line displacement.
5. by the described slide-valve servo of claim 4, plane bar linkage feedback type electric liquid step cylinder, it is characterized in that: signal synthesizes connecting rod [11] and adopts screw rod [15], nut [14] and gear pair [19] to connect with stepper motor [1] and servo valve core of the spool valve [13]; Screw rod [15] connects through the axle of gear pair [19] and stepper motor [1], and connects firmly into the integral body of coaxial line with servo valve core of the spool valve [13]; Nut [14] hinge joint is on the synthetic connecting rod [11] of signal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN95114820A CN1062340C (en) | 1995-03-26 | 1995-03-26 | Slide-valve servo, plane bar linkage feedback type electric liquid step cylinder |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN95114820A CN1062340C (en) | 1995-03-26 | 1995-03-26 | Slide-valve servo, plane bar linkage feedback type electric liquid step cylinder |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1133405A true CN1133405A (en) | 1996-10-16 |
| CN1062340C CN1062340C (en) | 2001-02-21 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN95114820A Expired - Fee Related CN1062340C (en) | 1995-03-26 | 1995-03-26 | Slide-valve servo, plane bar linkage feedback type electric liquid step cylinder |
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| Country | Link |
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| CN (1) | CN1062340C (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1092298C (en) * | 1997-12-09 | 2002-10-09 | 雷践仁 | Driving power amplified electrohydraulic converter |
| CN105298970A (en) * | 2015-12-09 | 2016-02-03 | 山东科技大学 | Electro-hydraulic valve control displacement module and using method thereof |
| CN106812761A (en) * | 2017-02-10 | 2017-06-09 | 武汉科技大学 | Crank block type feedback digital hydraulic cylinder |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1030099C (en) * | 1992-04-12 | 1995-10-18 | 雷践仁 | Multifunctional step-by-step electrohydraulic servo valve |
-
1995
- 1995-03-26 CN CN95114820A patent/CN1062340C/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1092298C (en) * | 1997-12-09 | 2002-10-09 | 雷践仁 | Driving power amplified electrohydraulic converter |
| CN105298970A (en) * | 2015-12-09 | 2016-02-03 | 山东科技大学 | Electro-hydraulic valve control displacement module and using method thereof |
| CN106812761A (en) * | 2017-02-10 | 2017-06-09 | 武汉科技大学 | Crank block type feedback digital hydraulic cylinder |
Also Published As
| Publication number | Publication date |
|---|---|
| CN1062340C (en) | 2001-02-21 |
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