CN1003466B - Digital hydraulic servo rotating valve - Google Patents

Abstract

The present invention relates to a control element, namely a digital hydraulic servo rotary valve used in a hydraulic servo system. The valve is composed of a valve body [1], a valve sleeve [2] and a valve core [3], wherein the valve sleeve [2] and the valve core [3] correspondingly rotate in the valve body [1] without axial slide, and are respectively directly driven by a step motor or are driven in a speed reduction mode. The valve digitally controls the hydraulic servo system by controlling the opening and closing of a valve port according to a step working principle. The present invention has the advantages of simple manufacture, low cost, good buffering effect, high positioning accuracy, no zero drift, simple control, etc., is suitable for position servo systems with high accuracy, and can be used as feeding devices of various numerically controlled machine tools and joints of various industrial robots.

Description

A kind of digital hydraulic servo rotating valve

The invention relates to a kind of control unit-digital hydraulic servo rotating valve in the Hydrauservo System.

The most nozzle-flapper type servo valves that adopt of employed control unit in the existing Hydrauservo System, the control unit of this valve is to adopt the guiding valve form; Also have direct-acting type two-stage sliding valve style servovalve, the said goods complex structure, make difficulty, cost is very high, and has shortcoming such as zero shift.U. S. Patent: " rotary servo valve " US 03254674 " ROTARY SERVOVALVE " (on June 7th, 1966) is the servovalve that oil is joined in a kind of rotation, and its structure is quite complicated.

The purpose of this invention is to provide a kind of simple in structure, easy to manufacture, cheap, can directly carry out numerically controlled simple type servovalve-digital hydraulic servo rotating valve.

The present invention is made up of valve body (1), valve pocket (2) and spool (3) as shown in the figure.Valve pocket (2) is directly driven or deceleration by stepper motor (4), and spool (3) is directly driven or deceleration by stepper motor (5).Relatively rotate in valve body (1) by valve pocket (2) and spool (3), do not endwisely slip, to realize that system is carried out servocontrol and do not produce.The stepper motor (4) that drives valve pocket (2) preferably adopts the identical stepper motor of step angle with the stepper motor (5) that drives spool (3).

The present invention is designed to the form of three-position four-way valve, and four logical oil pockets are set in the valve at least, i.e. O chamber-oil back chamber, P chamber-pressure oil cavity, A chamber and B chamber-control oil pocket.

Four annulars logical oil groove, i.e. O chamber groove, P chamber groove, A chamber groove and B chamber groove are set in the valve body (1) at least.Leave accordingly four on the junction plane of valve body (1) at least and lead to the tangent logical oily interface of oil groove with annular.

Spool (3) is gone up corresponding to O chamber and place, P chamber and is had two annular grooves, i.e. oil-return groove (6) and pressure oill tank (7).Having 2n(n respectively corresponding to A chamber and B chamber place is positive integer) oil groove of individual identical shaped or area, leave the convex shoulder of certain width between the oil groove, with convex shoulder oil groove is separated the pass symmetry and be divided into two groups, one group is pressure oil distributing groove (8), and another group is oil return distributing groove (9).

At least bore two axial oilholes in the end of spool (3), one of them oilhole is communicated with pressure oil distributing groove (8) and pressure oill tank (7), and another oilhole communicates with oil return distributing groove (9) and oil-return groove (6).The oilhole end is blocked with plug in the spool end then.

Valve pocket (2) is gone up corresponding to O chamber and place, P chamber symmetry and is had radial direction oil hole.Make that oil-return groove (6) on the spool (2) communicates with the O chamber, pressure oill tank (7) communicates with the P chamber.In that to make 2n(n separately corresponding to A chamber and B chamber place be positive integer) individual control window, and make A chamber place's window and place, B chamber window be mutually (360/2n) ° (n is a positive integer), the size of its control window should just cover its formation less than the convex shoulder width on the pairing spool (3).

The stepper motor (5) that drives spool (3) is main motor, and the stepper motor (4) that drives valve pocket (2) is the feedback motor.Stepper motor has latching characteristics when energising is static, it makes the present invention not produce zero shift when zero-bit.Spool (3) and valve pocket (2) all carry out work with the synchronised elongation.When main motor was worked under the effect of some pulse signals, because the hysteresis of system feedback motor still is in self-locking state, at this moment valve port was opened big gradually by zero.System starts working under the effect of pressure oil, produces displacement, and at this moment detection system is measured displacement amount and sent pulse signal drive feedback driven by motor valve pocket (2) and rotate in the same way to spool (3).Because the autoregulation valve port of system keeps certain aperture to proceed work.When main motor stopped, spool (3) was closed because the hysteresis valve port of system is descending gradually by locked, just quits work up to the complete closed-system of valve port.The condition of valve port closure is that the step number that main motor (5) is walked must equate with the step number that feedback motor (4) is walked.Entire work process is undertaken by the stepping principle.According to this stepping working principle, the present invention has performances such as good buffering, location.Easy from control angle controlling method, only need number by the control figure pulse and frequency to remove to drive main motor (5) and can carry out work.

Characteristics of the present invention are: control that easy, simple in structure, shock-absorbing capacity is good, accurate positioning, inferred-zero drift, can realize the location, arbitrfary point.

The present invention has avoided the shortcoming of machine feedback owing to adopt stepper motor to feed back, and has overcome valve and the disadvantage that actuator must carry out organic combination the-" hard connection ", brings great convenience for use, installation and control.

The present invention can do high-precision positioning servo system usefulness, particularly does each joint and other automatic mechanisms of the work feeder of various numerical control machine tools, various industrial robots and uses.

Most preferred embodiment of the present invention:

As shown in the figure: (1) is that valve body, (2) are that pressure oill tank, (8) for pressure oil distributing groove, (9) for oil return distributing groove, (10) for oil leakaging port, (11) be end cap for stepper motor, (6) for oil-return groove, (7) for spool, (4) and (5) for valve pocket, (3).

Have four the equidistant annular grooves that wait width, i.e. O chamber groove, P chamber groove, A chamber groove and B chamber grooves on the valve body (1).Valve body (1) carries out facing-up with valve pocket (2), valve pocket (2) with spool (3), and its facing-up gap is 0.005mm.

Spool (3) is respectively opened the logical oil groove of an annular corresponding to O chamber and place, P chamber, is called oil-return groove (6) and pressure oill tank (7).In oil-return groove (6), be drilled with the radial direction oil hole of four symmetries.Having four rectangular oil grooves separately and leaving the convex shoulder that four width equate separately corresponding to A chamber and B chamber place, four oil grooves are separated making its two oil return distributing grooves (9) that form two groups of symmetries and two pressure oil distributing grooves (8).Bore an oilhole between the oil return distributing groove (9), two oil return distributing grooves of symmetry (9) are communicated.Bore an oil through vertically in the center, end of spool (3), it is communicated with four radial direction oil hole in the oil-return groove (6) and communicate, the oilhole end is blocked with plug in the end then with oilhole between the oil return distributing groove (9).

The end of spool (3) corresponding to two side positions of pressure oil distributing groove (8) vertically symmetry bore three little oil throughs separately, it is communicated with pressure distributing groove (8) and pressure oill tank (7), in the end six little oilholes are blocked then.

Valve pocket (2) is gone up and to be located separately corresponding to O chamber and P chamber that symmetry is drilled with four radially oil throughs, and oil return and pressure oil can be circulated between valve body (1) and valve pocket (3).Have two rhombuses control windows in A chamber place symmetry, make and go up corresponding convex shoulder with spool (3) and just form and cover, locate also symmetry in the B chamber and have two rhombuses and control windows, make also just to form to cover with the upward corresponding convex shoulder of spool (3).Two two control windows controlling window and place, B chamber at place, A chamber are mutually 90 °.

Suitable place in the valve body (1) has leaks hydraulic fluid port (10).End cap (11) is stamped at the two ends of valve body (1), seals with seal ring at the stop portion of end cap (11).The end cap center is connected with draws axle and seals with seal ring.

It is 1.5 ° that stepper motor is selected step angle for use, and the employing speed ratio is 5 the gap gear transmission that disappears during as deceleration.

Claims (3)

1, a kind of digital hydraulic servo rotating valve, by valve body (1), valve pocket (2) and spool (3) are formed, have four logical oil pockets in the valve body (1): O chamber-oil back chamber, P chamber-pressure oil cavity, A chamber and B chamber-control oil pocket, the form of forming three-position four-way valve, it is characterized in that valve pocket (2) is directly driven or deceleration by stepper motor (4), spool (3) is directly driven or deceleration by stepper motor (5), by valve pocket (2), spool (3) relatively rotates in valve body (1), to realize the servocontrol of system, go up corresponding to the A chamber at spool (3), it is positive integer that B chamber place has 2n(n respectively) oil groove of individual identical shaped or area, and symmetry is divided into two groups, one group is pressure oil distributing groove (8), another group is for leaving the convex shoulder of certain width between each adjacent oil groove of oil return distributing groove (9), go up corresponding to the A chamber at valve pocket (2), it is positive integer that place, B chamber has 2n(n respectively separately) individual control window, the size of window should go up pairing convex shoulder width less than spool (3), make it just to form with corresponding convex shoulder and cover, control window on the A chamber and the control window on the B chamber are mutually (360/2n) ° (n is a positive integer).

2, by the described digital hydraulic servo rotating valve of claim 1, the end that it is characterized in that spool (3) is drilled with two axial oilholes at least, one of them oilhole is communicated with pressure oil distributing groove (8) and pressure oill tank (7), and another oilhole communicates with oil return distributing groove (9) and oil-return groove (6).

3, by the described digital hydraulic servo rotating valve of claim 1, the stepper motor (4) that it is characterized in that driving valve pocket (2) adopts the identical stepper motor of step angle with the stepper motor (5) that drives spool (3).

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