CN2234005Y - Slide valve servo, plane bar linkage feedback type electric solution step cylinder - Google Patents

Abstract

The utility model relates to a feedback type electric solution step cylinder for a slide valve servo and plane bar linkage mechanism, which belongs to a digital control element in the electric solution control system. Under the transformation function of a plane bar linkage mechanism additionally arranged structurally for the displacement, the utility model has the advantages of easy production, low cost, and high starting and braking speed or high precision compared with the existing electric solution step cylinder. The utility model is suitable for electric solution position servo and speed servo control systems, and has obvious functions for improving the dynamic performance or the precision of the whole system, reducing manufacturing cost, etc.

Description

Slide-valve servo, plane bar linkage feedback type electric liquid step cylinder

The utility model 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 the first sharp 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

The new bibliography of China Machine Press's science and technology in April nineteen ninety: 210-002

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 that the purpose of this utility model provides a kind of retro-speed that starts.

The utility model 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 of the present utility model 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 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.

Signal transmission way of the present utility model 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 connecting rod of the utility model midplane linkage mechanism, also can by scaling ruler or other existing patterns how much positions connect like relation, make it to the transmission of command signal and the ratio that is transmitted into, to realize required linearity requirement to feedback signal.

All rotary pairs in the utility model should be taked the gap measure that disappears.

Servo guiding valve in the utility model 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 in the utility model 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 utility model 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 in the utility model all are easy to processing, so lower than the electric liquid step cylinder cost of existing second kind of form.In addition, the utility model can also be realized 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.

Fig. 1 is a theory diagram of the present utility model;

Fig. 2 is a structure diagram of the present utility model;

Fig. 1 shows principle square frame of the present utility model, and it is by stepper motor [1], hydraulic cylinder [3] and servo guiding valve [4] form, hydraulic cylinder [3] be is characterized in that by servo guiding valve [4] control: Be provided 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 utility model is that the direct position in the existing electric liquid step cylinder is anti-Feedback formula hydraulic servomechanism is replaced by indirect position reaction type hydraulic servomechanism and is realized.

Embodiment:

Fig. 2 shows the utility model embodiment's structure diagram.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.

As can be seen from the above embodiments, its constituent elements all is easy workpiece, and is so the utility model is easy to manufacture, with low cost.

Claims (3)

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.

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