SU603777A1 - Hydraulic stepping servomotor - Google Patents

Description

(54) HYDRAULIC STEP SERVO DRIVE

one

The invention relates to control devices for hydraulic actuators, for example, lifting transport machines, namely, to a hydraulic step-by-step servo drive for controlling a reversible variable pump.

Hydraulic stepper servo drives are known, comprising an actuating hydraulic cylinder, a hydraulic switch, a discrete valve consisting of a plunger with annular grooves associated with a movable element of the hydraulic cylinder, and a fixed stationary housing with input and output windows communicated respectively to the hydraulic switch windows and controllable hydraulic cylinder cavities, as well as devices for setting the servo drive to the neutral position.

Known servo drives and have limited speed and complex design, as they contain throttles and spring devices to set the servo in neutral position.

The purpose of the invention is to simplify the design of the servo and increase its speed.

This is achieved by teM that the device for setting the servo actuator to the neutral position is made in the form of three-way spool valves - one for each controllable hydraulic cylinder cavity, and each of the three-line distributors and. A two-way plunger connected by the e plunger of the discrete distributor, the distance between the bridges of which is equal to the full travel of the movable element of the hydraulic cylinder, and the sleeve with three windows, of which the outermost are connected, respectively, with the pressure and drain lines of the servo drive, and the average is Kno

through a hydraulic switch, it communicates with the corresponding controlled cavity of the hydraulic cylinder, with the distance between the outermost windows equal to the distance between the plunger sections.

The drawing shows the described servo with differential Executive

hydraulic cylinder m. With this design, the hydraulic cylinder also has one controlled cavity with a larger working area of the piston, which corresponds to one three-way distributor in the device for setting the movable element of the hydraulic cylinder to the neutral (middle) position.

Claims (1)

The hydraulic cylinder contains a movable cylinder 1, interacting with the finger 2 of the regulating body of the controlled pump. In cylinder 1 there are accommodated. Fixed piston 3 with rods 4 is small (1 ×) diameter and 5 6ojibujcro diameter. Po-usst ts.linlra. in which the displacement of the rod 5, a constant cooduiae Tcn with pressure line G of the source of the working fluid (not shown). The cavity 7 of the cylinder, in which the rod 4 is placed, is connected by line 8 to the output window 9 in the housing 10 of the discrete distributor. In the bore of the housing, there is a plunger 1 in which a number of equally spaced bays are placed. There are 8 grooves 12, and a groove 13. In the housing 10, four outer windows 14–17 and three annular grooves 18–20 are also made. The control windows 14-17 are connected by lines 2b - 24 to the windows of a hydro-mummutato) 27, which is designed as two six-line three-inlet distributors 28 and 29, having pressure ports 30 and drain windows 31 connected in parallel, respectively, to the pressure line 6 by a line 32 and with a drain line 33. The distributor 28 has a window 34 connected to the keel 19 in the discrete distributor body 10 by a line 35, and a window 36 connected to the distributor window 37 by the line 38. The distributor 29 window 39 is connected by a line 40 to the line 8 , lead into the cavity of the 7 cylinder. The groove 18 in the housing 10 of the discrete distributor is connected by line 41 to the pressure line 6, and the groove 20 is connected to the drain line 42. The distributor 28 of the hydro-switch is equipped with control electromagnets 43 and the distributor 29 is electromagnet 45 and 46. The plunger 11 of the discrete distributor is rigidly connected element 47 with cylinder 1; grooves 18-20 and groove 13 in a discrete distributor; windows 34 and 36, 37 and 39 in distributors 28, 29, as well as lines 41, 35, 42, 38, 40 form a device for installing cylinder 1 in zero (average) faction. As can be seen from the diagram, when the distributors 28 and 29 are installed in the neutral position, the cavity 7 of the hydraulic cylinder communicates with the middle groove 19, which, when the valve is shifted to the right; 11, is connected with the drain, line 42, and when the adapter plunger is left, it communicates with the nano line 6 In any case, the installation of valves 28, 29 in the neutral position causes the cylinder 1 and the plunger P to move to the middle position, as a result of communication of the cavity 7 in the first case with the drain, in the second - with the pressure line 6. The accuracy of the installation in the zero position sieve from overlapping windows 18, 20 by edges 13. To prevent cylinder 1 from zero 1 ° and), for example, to the right, include electromagnet 43 of distributor 28, and as a result, hydraulic cylinder 7 7 is communicated through line 8, window 9, the groove in the plunger 11, window 14, line 21, windows 25 and 30 of the distributor 28, line 32 with pressure line 6. The cylinder and 1, together with it plunger 1: Leremeshpps one step to block the window 14 of the skirt of the plunger 11. For Further, in the future, the magnets 46, 44 and 45 must be switched on in sequence. After a four-stroke stroke on The power up sequence is repeated. In order not to move cylinder i from the zero position to the left, it is necessary to connect base 7 to drain line 33. To do this, turn on electromagnets 44, 45, 43, 46, and then repeat the four-stroke cycle. At the same time, the valves 28, 29 should not simultaneously be in a neutral position. In the last case, the transfer of the cylinder to the initial zero position occurs, as described above. The combination of the device installation cylinder in the zero position with di. , retn1) 1M distributor and the proposed form of its implementation provide simplicity, accuracy, reliability, and high speed servo drive with precise setting to zero. This is especially important for variable reversing pumps. When using symmetr. A double acting hydraulic cylinder should be provided with a second, like, zero positioning device. The invention can be used not only in the four-stroke stepping system, but, for example, in the three-stroke one. Claims of the Invention Hydraulic stepping servo, for example, for controlling the hydraulic drive of a hoisting machine, comprising an actuating hydraulic cylinder, a hydraulic switch, a discrete distributor consisting of a plunger with annular sockets connected to the movable element of the hydraulic cylinder, and a housing fixed body with inlets and outlets. Windows connected, respectively, with the windows of the hydraulic switch and with the right cavities of the hydraulic cylinder, and also the device for installing the servo-drive neutral position, characterized in that, in order to harden the construction, to increase its speed, the servo actuator assembly in a neutral position is made in the form of a three-line spool valve - but one seemingly controlled cavity of the hydraulic cylinder, and each of the three-line distributors has a discrete valve associated with the plunger The distributor is a double track plunger, the distance between which is equal to the full travel of the hydraulic cylinder moving element, and a vtula with three windows, from which the edges are communicated respectively, with porn and drain ini .mi servo, and the average window through idrokommutator communicates with sootvetstvuyuey controllable cylinder cavity, receiving the distance between the outermost windows equal DRA NIJ plunger between at bench. 2t / I IS 13 th / / /