DE102013016030A1 - Conveyor - Google Patents

Abstract

A conveying device, with a conveying piston (27) which can be moved in a pumping space (31) by means of an actuating device (3) and removes fluid from a fluid line (35) in a conveying direction in a pressure-reducing manner and fluid in another, preferably counter-rotating conveying direction to another Fluid line (37) discharges in a pressure-increasing manner, is characterized in that in the respective fluid line (35, 37) a valve means (39, 41) is introduced with opposite action, that the pressure-reducing removal operation, the respective valve means (39, 41) in the one fluid line (35) opens and in the other fluid line (37) blocks, and in the reverse case, the respective valve means (39, 41) in the one fluid line (35) blocks in the further fluid line (37) in the pressure-increasing dispensing operation.

Description

The invention relates to a conveyor, with a movable in a pump chamber by means of an actuator delivery piston which removes fluid from a fluid line in a pressure-reducing manner in a conveying direction and delivers in a further, preferably opposite conveying direction fluid to another fluid line in a pressure-increasing manner.

Conveyors of this type are state of the art and are used in the most diverse fields for the hydrostatic conveyance of liquids. As piston feed pumps which are actuated by means of lifting magnets, such conveyors are often used in electrically controlled operating systems. In such applications, high demands must be placed on the operating behavior, in particular with regard to the tolerances of the delivery pressure, the fast response with high repeat accuracy and without hysteresis during periodic operation.

In view of this problem, the invention has the object to provide a conveyor of said genus available, which is characterized by a particularly favorable performance.

This object is achieved by a conveyor according to the invention, having the features of claim 1 in its entirety.

Accordingly, a significant feature of the invention resides in the fact that a valve device is introduced into the respective fluid lines associated with the pump chamber, which opens in the one conveying direction during the pressure-reducing removal operation and blocks in the further conveying direction and in the reverse case blocks in one conveying direction and in the other Conveying direction opens. Without hysteresis a high response precision and repeat accuracy can be achieved.

In preferred exemplary embodiments, the respective valve device is formed by check valves whose opening directions point together into a provided fluid delivery device in the associated fluid line.

In a particularly advantageous manner, the arrangement is such that the respective fluid lines, calculated from the pump chamber to the respective assignable check valve, one and the same line section having the same flow cross-section. As a result, a particularly high repeat accuracy can be achieved without hysteresis.

Advantageously, in this case the free cross section of the pump chamber is equal to or smaller than the free cross section of each connected line section, based on this connection area. Such an approximation of the cross-sectional sizes is particularly advantageous at low flow rates and high delivery pressure in terms of repeatability.

In a particularly advantageous manner, the arrangement may be such that the respective fluid line is part of a common fluid conveyor line, in which the pump chamber is connected with its integrated delivery piston.

For high repeatability during periodic operation and small flow rates, the delivery piston has a needle-like extension, wherein the needle-like extension engages as a displacement element in the pump chamber into which open at their free end, the respective fluid lines.

In a particularly advantageous manner, the actuating device is formed from an energizable actuating magnet which spends the delivery piston in its pressure-reducing or pressure-increasing travel position in its one currentless or other energized operating state.

In particularly advantageous embodiments of the invention, the at least from the delivery piston and the pump chamber existing piston delivery pump is provided with a pressure limiting device that is limited at an unintentional pressure increase in the fluid delivery line, the pressure within the pump chamber to a predetermined maximum pressure value. By integrated into the piston pump pressure relief device eliminates the need to provide other pressure relief devices, such as pressure relief valves. Furthermore, the disadvantages are avoided when trying to make the pressure limitation by utilizing the stroke-force characteristic of the magnetic actuator. Because of the possible deviations of the intended electrical power supply, this results in disadvantages in terms of response, hysteresis and repeatability.

In a particularly advantageous manner, to form the pressure limiting device, the delivery piston, with the assistance of an energy store, in particular in the form of a compression spring, can be moved into a return area which increases the receiving volume of the pump chamber, in accordance with the fluid pressure in the fluid delivery line.

In particularly advantageous embodiments, the arrangement is in this case made such that on the delivery piston, a further energy storage, in particular in the form of a further compression spring, permanently acting, which seeks to move the delivery piston in a reducing the volume of the pump chamber delivery area. As a result, the pressure limitation is independent of the power supply of the actuating magnet, but determined by the characteristics of the two pressure springs acting on the delivery piston.

The invention with reference to an embodiment shown in the drawing is explained in detail. Show it:

1 in a highly schematically simplified representation in the manner of a longitudinal section of an embodiment of the conveyor according to the invention;

2 a longitudinal section of the embodiment, wherein the magnetic housing of the electromagnetic actuator omitted and the operating state of the de-energized actuating magnet is shown;

3 one of the 2 corresponding longitudinal section, wherein the operating state of the energized actuating magnet is shown, and

4 a the 2 and 3 corresponding longitudinal section, wherein the operating state of the energized actuating magnet is shown with active pressure limitation.

In 1 are a pump housing with 1 and provided as an electrical actuator actuating magnet with 3 designated. The pump housing 1 has a hole 5 on, in whose in 1 right-hand end an internal thread 7 is trained. The actuating magnet 3 is by screwing an extension 9 his pole core 11 with the internal thread 7 the bore 5 on the pump housing 1 appropriate. The actuating magnet 3 points inside its magnet housing 13 a coil winding 15 on, in the case of such actuation magnets 3 usual way parts of the pole core 11 and a pole tube 17 surrounds in which a magnet armature 19 is axially movable, at the one to the longitudinal axis of the bore 5 coaxial actuating tappet 21 firmly attached.

The actuating tappet 21 lies with its free end to a pressure body 23 on, which is a compression spring 25 supported with one end, the other end to an actuating part 26 of the pump delivery piston 27 rests with his operating part 26 in the hole 5 is guided axially movable. The delivery piston 27 indicates at its from the operating part 26 opposite end of a needle-like extension 29 on, as the actual displacer part of the delivery piston 27 in a pump room 31 engages in the housing 1 as a diameter greatly reduced continuation of the bore 5 is formed. Another pressure spring 33 that the delivery piston 27 between the actuating part 26 and in the hole 5 at the transition to the pump room 31 formed stage 28 surrounds, is between this stage 28 and the operating part 26 clamped.

As only in the 1 symbolic representation is the pump room 31 Assigned fluid lines, of which a first fluid line, from which the delivery piston 27 during operation removes fluid in a pressure-reducing manner, with 35 is designated. A fluid line into which the delivery piston 27 emits fluid in a pressure-increasing manner in operation, is in 1 With 37 designated. The fluid lines 35 . 37 is associated with a valve device, which in each case by a check valve in the first fluid line 35 and in the second fluid line 37 is formed, wherein the check valve of the first fluid line 35 With 39 is designated and opens at the pressure-reducing removal process. That in the second fluid line 37 located, with 41 designated check valve opens when pressure-increasing dispensing operation. The fluid lines 35 . 37 have a common conveyor line, in which the pump room 31 is included, namely one of the check valve 39 the first fluid line 35 to the pump room 31 extending first line route 43 and a second line route 45 that from the pump room 31 to the check valve 41 the second fluid line 37 runs. Both lines 43 . 45 have the same flow cross-section and the same cable length as distances of the common feed line.

The 2 to 4 in which of the actuating magnet 3 the magnet housing 13 and the winding 15 are omitted, show details of the structural design of the piston pump. It shows 2 the operating state of the de-energized actuating magnet 3 in which the anchor 19 of the actuating magnet designed as a so-called pushing magnet 3 in his in 2 located at the bottom end position. This end position takes the anchor 19 in the absence of magnetic force by that of an energy storage on the actuating plunger 21 applied force. This energy storage is as related to 1 already executed, by the compression springs 33 and 25 educated. Of these, the spans the delivery piston 27 as a helical spring surrounding compression spring 33 the delivery piston 27 in the the volume of the pump room 31 magnifying Verfahrrichtung and holds the operating part 26 of the delivery piston 27 in abutment with one in the hole 5 sliding sleeve 47 , for the further compression spring 25 forms a kind of spring housing. The of the compression spring 33 on the sleeve 47 and thus on the other compression spring 25 applied restoring force acts on the pressure hull 23 on the pestle 21 and thus on the magnet armature 19 , In this de-energized operating state is the needle-like extension 29 of the delivery piston 27 in a position where the pump room 31 has its largest volume, as in 2 shown.

The 3 shows the operating state with energized actuating magnet 3 , where the magnet armature 19 moved from the end position (in 3 up). This sliding movement, the pestle 21 on the pressure hull 23 transmits, acts on the on the pressure hull 23 fitting pressure spring 25 on the sleeve 47 and thus on the operating part 26 of the delivery piston 27 , This is done by the over the compression spring 25 applied displacement force in the in 3 shown end position shifted at which the delivery piston 27 in the on the shoulder 28 adjacent end position is moved, in which serving as a displacer extension 29 the fluid from the pump room 31 in the line routes 43 . 45 displaced (at this piston position, the pump chamber 31 even in 3 no longer visible, but only the connection point of the lines 43 . 45 ). This movement of the delivery piston 27 takes place against the spring force of the compression spring 33 ,

The 4 shows an operating state in which the actuating magnet 3 in turn is energized, so that the magnet armature 19 moved from the retracted end position (in 4 up). Unlike in 3 is, however, despite the moving from its end position magnetic piston 19 the delivery piston 27 not in his the volume of the pump room 31 completely displacing end position, but is by the at the connection point 43 . 45 of the pump room 31 currently effective delivery pressure reduced in a pressure-relieving position. This compensating movement which prevents the exceeding of a nominal value of the delivery pressure sets in when the pump space 31 on the extension 29 acting compressive force combined with the spring force of the compression spring 33 the effect of the other compression spring 25 exceeds. In other words, the pressure threshold at which the pressure-limiting return movement of the delivery piston 27 used, by the spring characteristic of the springs 33 . 25 adjustable. Since the pressure limitation thus determined mechanically and is not dependent on the magnetic force of the actuator, a pressure-stable delivery with high periodic repeatability and without hysteresis can be achieved.

Claims (10)

Conveying device, with one in a pump room ( 31 ) by means of an actuating device ( 3 ) movable delivery pistons ( 27 ), which in a conveying direction fluid from a fluid line ( 35 ) takes in a pressure-reducing manner and in a further, preferably opposite conveying direction fluid to another fluid line ( 37 ) in a pressure-increasing manner, characterized in that in the respective fluid line ( 35 . 37 ) a valve device ( 39 . 41 ) is introduced in such a manner with opposite action that in the pressure-reducing removal operation, the respective valve device ( 39 . 41 ) in the one fluid line ( 35 ) opens and in the further fluid line ( 37 ) locks, and in the reverse case in the pressure-increasing dispensing operation, the respective valve device ( 39 . 41 ) in the one fluid line ( 35 ) and in the further fluid line ( 37 ) opens. Conveying device according to claim 1, characterized in that the respective valve device consists of non-return valves ( 39 . 41 ) is formed, the opening directions together in a designated fluid conveying direction in the associated fluid line ( 35 . 37 ) point. Conveying device according to claim 1 or 2, characterized in that the respective fluid lines ( 35 . 37 ), calculated from the pump room ( 31 ) to the respectively assignable check valves ( 39 . 41 ), one and the same line ( 43 . 45 ) having the same flow area. Conveying device according to one of the preceding claims, characterized in that the free cross section of the pump chamber ( 31 ) is equal to or smaller than the free cross section of the respective connected line section ( 43 . 45 ), related to this connection area. Conveying device according to one of the preceding claims, characterized in that the respective fluid line ( 35 . 37 . 43 . 45 ) Component of a common fluid conveyor line ( 43 . 45 ) into which the pump room ( 31 ) with its integrated delivery piston ( 27 ) is switched. Conveying device according to one of the preceding claims, characterized in that the delivery piston ( 27 ) with a needle-like extension ( 29 ) in the pump room ( 31 ) engages in the at its free end the respective fluid lines ( 43 . 45 ). Conveying device according to one of the preceding claims, characterized in that the actuating device consists of an energizable actuating magnet ( 3 ) is formed, in its a currentless or other energized operating state the delivery piston ( 27 ) spends in its pressure-reducing or pressure-increasing displacement position. Conveying device according to one of the preceding claims, characterized in that the at least from the delivery piston ( 27 ) and the Pump room ( 31 ) existing piston pump in such a way with a pressure limiting device ( 33 ) is provided that at an unintentional pressure increase in the fluid-conveying line ( 43 . 45 ) the pressure within the pump room ( 31 ) is limited to a predefinable maximum pressure value. Conveying device according to one of the preceding claims, characterized in that for forming the pressure limiting device of the delivery piston ( 27 ) with the assistance of an energy store, in particular in the form of a compression spring ( 33 ), in a receiving volume of the pump chamber ( 31 ) increase the return range at corresponding pending fluid pressure in the fluid-conveying line ( 43 . 45 ) is movable. Conveying device according to one of the preceding claims, characterized in that on the delivery piston ( 27 ) a further energy store, in particular in the form of another compression spring ( 25 ), permanently acting, the the delivery piston ( 27 ) in a the volume of the pump room ( 31 ) shrinking delivery area seeks to proceed.

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