摘要:
According to the parent patent on inadequate power of the delivery pump the flow rate set at the directional control valves for the consumers is reduced in equal proportions in that electrical signals proportional to the flow rates are supplied to a summation stage and the sum voltage is compared in a comparison stage with a limit value corresponding to the maximum pump delivery flow. When the limit value is exceeded a control signal is generated with which the stroke of all the driven directional control valves can be jointly reduced. According to the application of addition the signal voltage supplied to the summation stages and corresponding to the respective flow rate can be obtained in a displacement pickup associated with each directional control valve or in a pressure pickup measuring the pilot pressure if the directional control valves are not controlled electrically but hydraulically. Furthermore, the pilot pressure can also be generated by a valve arrangement which switches in pulsating manner and to the regulator of which the control signal is supplied when the limit value is exceeded.
摘要:
A pump supplies via in each case a directional valve a plurality of consumers with fluid, a pressure balance for load-independent division of the pump displacement being provided between each branch line branching off the pump delivery line and the directional valve. In a pressure regulating valve common to all pressure balances a control pressure is generated from the pressure difference between the pump pressure and the respective highest consumer pressure and is applied to all the pressure balances so that when the pump power is inadequate a proportional quantity reduction at all consumers is achieved.
摘要:
A pump supplies a plurality of consumers each via a directional control valve with pressure balance. When the pump delivery is not adequate, manifesting itself in a dropping of the pump pressure, the pressure balance of the consumer with the highest load pressure is displaced out of the end position of its regulating position into a further control position in which a control pressure line is connected via a throttle point to a discharge so that by means of the throttle point a control pressure is generated which is used for equiproportional reduction of the supply flow to the consumers. This is done either by reducing the stroke of the directional control valves or by acting on the pressure balances in the closure direction.
摘要:
Into the housing of a multiway valve a pressure balance is incorporated, the end of the control piston subjected to the load report pressure facing a housing recess in which the load report pressure obtains while the opposite end of the control piston is subjected to the supply pressure and in the opposite sense to the supply pressure to the force of a spring. The valve has a simple structure.
摘要:
Supporting device for a plastic profile (2), in particular for a plastic pipe, in a calibration device which has a supporting region (1), in which it supports the plastic profile (2), wherein the contour (3) in the supporting region (1) is adapted to the contour of the plastic profile (2). According to the invention, provision is made in that the contour (3) in the supporting region (1), in particular the radius (4), can be changed.Furthermore, the invention relates to a process for changing a supporting region of a supporting device, in which the position of one or more series-arranged supporting devices with continuously changeable supporting region are changed as a function of a predetermined theoretical diameter such that the predetermined diameter is produced.
摘要:
In a priority control device the supply flow to the lower-ranking consumer is set by a flow control valve (pressure balance) whose control chamber subjected to the control pressure of the lower-ranking consumer can be relieved of pressure via a proportional valve. The proportional valve is adjusted in dependence upon the load pressure of the priority consumer so that the flow of fluid to the lower-ranking consumer is throttled by the pressure balance when the pressure difference at the priority consumer drops on increased volume flow requirement. The priority control device thus consists of two simply constructed power valves and a small-dimensioned pilot valve.
摘要:
Supporting device for a plastic profile (2), in particular for a plastic pipe, in a calibration device which has a supporting region (1), in which it supports the plastic profile (2), wherein the contour (3) in the supporting region (1) is adapted to the contour of the plastic profile (2). According to the invention, provision is made in that the contour (3) in the supporting region (1), in particular the radius (4), can be changed. Furthermore, the invention relates to a process for changing a supporting region of a supporting device, in which the position of one or more series-arranged supporting devices with continuously changeable supporting region are changed as a function of a predetermined theoretical diameter such that the predetermined diameter is produced.
摘要:
A method of manufacturing of continuous, at least two-layer products having an upper layer formed of a lacquer material, the method having the steps of providing an apparatus including a co-extrusion tool having first and second conduits, respectively, with the first and second inlets, with the second conduit circumscribing the first conduit, and a merging section in which flows exiting the first and second conduits merge, and first and second extruders connected with the first and second inlets, respectively, and simultaneously injecting melts of base and lacquer materials with the first and second extruders, respectively, through the first and second conduits, respectively, so that on at least two-layer product exiting the merging section of the co-extrusion tool and having an upper lacquer layer, is produced in a single step.
摘要:
A pump supplies via in each case a directional valve with associated pressure balance fluid or pressure medium to a plurality of loads. When the pump power is not sufficient a proportional quantity reduction is achieved at all loads in that the control voltages of the control members for electrical actuation of the directional valves are supplied to a summation stage and the sum voltage is compared in a comparison stage with a limit value corresponding to the maximum pump displacement, whereupon when the limit value is exceeded a control signal is generated with which the stroke of the driven directional valves is reduced.
摘要:
The invention relates to a priority control means with which the actuation sequence of two servo motors can be automated. For this purpose a priority control valve is provided which on actuation of the higher priority control valve immediately blocks the lower priority servo motor. If the priority servo motor has reached a certain position the associated control valve is automatically switched back so that the actuation of the lower priority servo motor then follows automatically. Via a changeover valve the working pressure of the respective servo motor is furthermore automatically switched to the pump control of an adjustment pump or, with a constant pump, to the load-pressure-dependent pressure control so that a load-dependent regulation takes place.