DE2240188A1 - DEVICE FOR THE SUPPRESSION OF IMPACT SIZES IN THE LONG CONTROL LINES OF SLOW RUNNING HYDRO MOTORS WITH 4/3 WAY VALVES - Google Patents

Description

Device for suppression of disturbance variables in the long control lines of low-speed hydraulic motors with / 0 directional control valves-The invention relates to a Device for suppression of obstructions in the long control lines from lengthways on the running rydromotor with 4/3-way valves.

Hydraulic control systems sometimes need to be included of hydraulic signal and energy transmitters and of hydraulic actuators a very fine and precise positioning of machine parts, weapons and target acquisition devices and allow extremely little movement of these devices to be positioned0 Since the tax routes, dth. the aforementioned devices and systems to be positioned, usually not changed and with reference to the control behavior cannot be optimized, the control system must be designed accordingly. In many cases there is no possibility of suppressing disturbance variables in the control system to be carried out with the help of a closed control loop. In all such cases comes So it depends on the conpoents belonging to the control system and the control system to be designed in such a way that the control properties are influenced by Disturbance is reduced to a minimum.

In known rotary hydraulic drives with 4/3-way valves, where there is a very large speed range and extremely low Rotational speeds in the lower range are commercially available hydraulic motors used with downstream gear. Since hydraulic motors have a minimum speed limit and this cannot be undercut, are used for the purpose of a further Reduction gear with gear ratios used in slow speed. The control of the Motor takes place with the help of a 4/3-way valve, the flow characteristic of which is a has a parabolic course in order to enable the very large speed range.

As a rule it is necessary, between the control valve and the actuator, i.e. to switch on various shut-off safety switching valves on the hydraulic motor.

Furthermore, technical installation reasons force motors and valves through to connect long pipelines together. Due to elasticities in the Storage or at the coupling point between the part to be positive and the Actuator, i.e. on the hydraulic motor, is due to the compressibility of the oil in the long pipelines to vibrations. The swing leads to an unacceptable sequence of movements at extremely low engine speeds ten. Another cause of the oscillation is the relatively high response threshold of the oil motor due to the friction of the moving parts.

The invention is based on the object with the simplest possible Means to eliminate such vibrations and the causes for them.

This object is achieved according to the invention in that flow-determining throttles are installed in the control line in the vicinity of the llydromotors for the purpose of vibration damping and, in parallel, pressure-controlled valves for the purpose of achieving higher hydraulic motor rotation speeds, with a coordination of the throttle cross-sections with the control cross-sections in 4/3 Directional valve takes place and / or that in the Lcckölleitung the hydraulic motor with the aid of pressure relief valves and / or with the help of control pressure dependencies in pressure relief valves for the purpose of damping within the hydraulic motor and above all to reduce the starting friction, a pressure is built up.

By means of these devices and system-technical measures, such a Satisfactory degree of uniformity of the motor rotation despite the effect of disturbance variables the control path and despite oil compressibility and long pipeline achieved that thus the technical Requirements for the drive with regard to the finest Positioning and the slowest movement sequence are ensured.

The following are three application examples, including the drawing explained and described in more detail.

According to Figure 1, the vibration damping is done by installing a Throttle 1 in control line 2 between hydraulic motor 6 and valve block 7 and in parallel to do this through two check valves 3 and 4, the opposite flow direction to have.

The non-return valves only open and allow for larger flows thus high rotational speeds. In the fine control area this flows from the 4/3 Directional valve 5 controlled Ö1 only through the throttle because the differential pressures This throttle is very low because of the throttling that has already taken place in the 4/3 way valve 5 are. The aforementioned measure is only used to dampen the vibration, is sufficient but in many cases it is already enough to achieve a flawless surface when machining Processing, or e.g. in order to achieve perfect target acquisition with straightening systems to enable.

Figure 2 shows a measure which can be used to eliminate one of the possible Causes of the vibration excitation is used. A reduction in the response threshold by reducing the start-up friction, a preload pressure in the leakage oil line of Oil engine 6 reached. The pressure relief valve 8 is at a certain opening pressure set.

The pressure relief valve 9 is in the normal position and with flow closed in the flow direction 10, while the pressure relief valve 11 at the same The direction of flow opens because the control line 12 via the 4/3 way valve 5 with is connected to the return and therefore has a lower pressure than the control line 2. In this way, at higher engine speeds, the engine case pressure is achieved to lower values compared to the opening pressure of the Druckbegrenzungsven tiles 8 bring to. On the other hand, however, the pressure difference between the pressures in the control lines 2 and 2 low, the pressure relief valves e 9 and remain 11 closed and the leakage oil flows against the opening pressure of the pressure relief valve 8 from.

FIG. 3 once again shows a simplified measure for generating the motor housing pressure and also a way of reducing the vibrations by throttling in the respective to attenuate the outflow-side control lines.

The pressure relief valve 8 is set to a certain opening pressure set. At very low rotational speeds, i.e. with very little deflection of the control spool of the 4/3 directional valve 5, flows on the inlet side, e.g. corresponding to the Flow direction 19 the control oil through the throttle 18 and also by the check valve 15 to the oil motor 6. From there it only passes through the throttle 17 via valve 5 into the return.

At higher turning speeds, the increased flow leads to the control line 12 to build up pressure and thereby allows the valve 14 to open. Inlet side the oil can flow through the valve 15 without any significant pressure drop. With the reverse The direction of flow is the same as in the pre-standardized case.

Claims (1)

Claim Device for suppression of disturbance variables in the long control lines of low-speed hydraulic motors with 4/3 way valves, characterized by that in the control line (2 and 12) in the vicinity of the hydraulic motor (6) flow-determining end Throttles (1,17,18) for the purpose of vibration damping and parallel pressure-controlled Valves (3, 4, 13, 14) for the purpose of achieving higher ZiyBi6 engine speeds are installed, whereby a coordination of the throttle cross-sections with the control cross-sections takes place in the 4/3 way valve (5), and / or that in the leakage oil line (20) of the Llydromotors (6) with the help of pressure relief valves (8) and / or with the help of control pressure dependencies in pressure relief valves (9 and 11) for the purpose of damping within the hydraulic motor and above all, a pressure is built up to reduce the start-up friction. Blank page