EP3049673A1

EP3049673A1 - Delivery device for discharging a fluid to a fluid line

Info

Publication number: EP3049673A1
Application number: EP14758507.9A
Authority: EP
Inventors: Norbert BÖHMER; Stephan Peter KROTTEN; Christian Groh
Original assignee: Hydac System GmbH
Current assignee: Hydac Systems and Services GmbH
Priority date: 2013-09-26
Filing date: 2014-09-03
Publication date: 2016-08-03
Also published as: DE102013016030A1; CN205677777U; WO2015049021A1; JP2016532042A; US20160230750A1

Abstract

A delivery device, with a delivery piston (27) which is movable in a pump chamber (31) by means of an actuation device (3) and which, in one delivery direction, removes fluid from a fluid line (35) in a pressure-reducing manner and, in a further and preferably opposite delivery direction, discharges fluid into a further fluid line (37) in a pressure-increasing manner, is characterized in that a valve device (39, 41) is introduced into the respective fluid line (35, 37), each with an opposite mode of action, in such a way that, in the pressure-reducing removal process, the respective valve device (39, 41) opens in one fluid line (35) and closes in the further fluid line (37) and, in the reverse case, in the pressure-increasing discharging process, the respective valve device (39, 41) closes in one fluid line (35) and opens in the further fluid line (37).

Description

CONVEYOR DEVICE FOR DELIVERING A FLUID TO A FLUID PIPE

The invention relates to a conveyor, with a movable in a pump chamber by means of an actuator delivery piston which removes fluid in a conveying direction of a fluid line in a pressure-reducing manner and in a further, preferably opposing Förderrich- 5 device delivers 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 operated by means of

10 th are actuated, such conveyors come in many cases

electrically controlled operating systems are used. In such applications, high demands are to be placed on the operating behavior, in particular with regard to the tolerances of the delivery pressure, the fast response with high repeatability and without hysteresis

1 5 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.

20

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 respectively 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 can be made 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, in which the respective fluid lines einmün- at its free end.

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 with regard to response precision, 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 in this case is such that on the delivery piston, a further energy storage, in particular in the form of another pressure spring, permanently acting, which seeks to move the delivery piston in a volume of the pump chamber reducing 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:

Fig. 1 in a highly schematically simplified representation in the manner of a

Longitudinal section of an embodiment of the conveyor according to the invention;

Figure 2 is 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.

Fig. 3 is a longitudinal section corresponding to FIG. 2, wherein the operating state of the energized actuating magnet is shown, and

Fig. 4 is a FIGS. 2 and 3 corresponding longitudinal section, wherein the operating state of the energized actuating magnet is shown with active pressure limiting. In Fig. 1, a pump housing with 1 and provided as an electrical actuator actuating magnet 3 are designated. The pump housing 1 has a bore 5, on whose right end in FIG. 1, an internal thread 7 is formed. The actuating magnet 3 is attached by screwing an extension 9 of its pole core 1 1 with the internal thread 7 of the bore 5 on the pump housing 1. The actuating magnet 3 has, within its magnet housing 13, a coil winding 1 5, which surrounds parts of the pole core 1 1 and a pole tube 1 7 in the usual manner in such actuating magnet 3, in which a magnet armature 19 is axially movable, on which a to the longitudinal axis of Bore 5 coaxial actuating rod 21 is firmly attached.

The actuating plunger 21 rests with its free end against a pressure body 23, on which a compression spring 25 is supported with one end, the other end of an actuating part 26 of the pump delivery piston 27 abuts the axially movable with its actuating part 26 in the bore 5 is guided. The delivery piston 27 has at its end remote from the actuating member 26 a needle-like extension 29 which engages as the actual displacer part of the delivery piston 27 in a pump chamber 31 which is formed in the housing 1 as a diameter greatly reduced continuation of the bore 5. A further compression spring 33, which surrounds the delivery piston 27 between the actuating part 26 and the step 28 formed in the bore 5 at the transition to the pump chamber 31, is clamped between this step 28 and the actuating part 26.

As is indicated in symbol representation only in FIG. 1, fluid lines are assigned to the pump chamber 31, of which a first fluid line, from which the delivery piston 27 draws fluid in a pressure-reducing manner during operation, is designated by 35. A fluid line into which the delivery piston 27 delivers fluid in a pressure-increasing manner during operation is shown in FIG. 1 denoted by 37. The fluid lines 35, 37 is associated with a valve device which is formed by a respective check valve in the first fluid line 35 and in the second fluid line 37, wherein the check valve of the first fluid line 35 is designated 39 and opens in the pressure-reducing removal operation. Located in the second fluid line 37, designated 41 check valve opens when pressure-increasing dispensing operation. The fluid lines 35, 37 have a common feed line, into which the pump chamber 31 is included, namely a first line 43 running from the check valve 39 of the first fluid line 35 to the pump chamber 31 and a second line section 45 from the pump chamber 31 to the check valve 41 the second fluid line 37 extends. Both line sections 43, 45 have the same flow cross section and the same line length as sections of the common conveyor line.

2 to 4, in which the magnet housing 1 3 and the winding 15 are omitted from the actuating magnet 3, show details of the structural design of the piston pump. 2 shows the operating state of the de-energized actuation magnet 3, in which the armature 19 of the actuating magnet 3 designed as a so-called pushing magnet is in its end position lying in FIG. 2 at the bottom. This end position takes the armature 19 in the absence of magnetic force by the force exerted by an energy storage on the actuating plunger 21 a force. This energy storage is, as already described with reference to FIG. 1, formed by the compression springs 33 and 25. Of these, the pressure piston 33 surrounding the delivery piston 27 as a helical spring biases the delivery piston 27 into the direction of travel which increases the volume of the pump chamber 31 and holds the operating part 26 of the delivery piston 27 in abutment with a sleeve 47 which is displaceable in the bore 5 and which is responsible for the further compression spring 25 forms a kind of spring housing. The force exerted by the compression spring 33 on the sleeve 47 and thus on the further compression spring 25 restoring force acts In this de-energized operating state, the needle-like extension 29 of the delivery piston 27 is in a position in which the pump chamber 31 has its largest volume, as shown in Fig. 2.

FIG. 3 shows the operating state when the actuating magnet 3 is energized, the magnet armature 19 having moved out of the end position (upward in FIG. 3). This displacement movement, which the plunger 21 transmits to the pressure body 23, acts on the sleeve 47 and thus on the actuating part 26 of the delivery piston 27 via the compression spring 25 resting on the pressure body. This is actuated by the displacement force exerted by the compression spring 25 3 displaced in the end position, in which the delivery piston 27 is moved into the voltage applied to the shoulder 28 end position in which serving as a displacer extension 29, the fluid from the pump chamber 31 in the pipe sections 43, 45 displaced (at this piston position the pump chamber 31 itself in Fig. 3 is no longer visible, but only the connection point of the line sections 43, 45). This movement of the delivery piston 27 takes place against the spring force of the compression spring 33.

FIG. 4 shows an operating state in which the actuation magnet 3 is again energized so that the magnet armature 19 has moved out of the retracted end position (upward in FIG. 4). Unlike in FIG. 3, however, despite the magnetic piston 19 moved out of its end position, the delivery piston 27 is not in its end position completely displacing the volume of the pump chamber 31, but is up-to-date by the connection point 43, 45 of the pump space 31 reduced effective delivery pressure in a pressure-relieving position. This compensation movement which prevents the exceeding of a nominal value of the delivery pressure sets in when the compressive force acting on the extension 29 in the pump chamber 31 combined with the spring force of the compression spring 33 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 starts is adjustable by the spring characteristic of the compression springs 33, 25. 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

P a n t a n s p r e c h e

Conveyor, with a in a pump chamber (31) by means of an actuating device (3) movable delivery piston (27) in a conveying direction fluid from a fluid line (35) removes in a pressure-reducing manner and in a further, preferably opposite conveying direction fluid to a further fluid line (37) discharges in a pressure-increasing manner, characterized in that in the respective fluid line (35, 37) a valve means (39, 41) is introduced with opposite action, that in the pressure-reducing removal operation, the respective valve means (39, 41) in 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) locks in the further fluid line (37) in the pressure-increasing dispensing operation.

Conveying device according to claim 1, characterized in that the respective valve device from check valves (39, 41) is formed, the opening directions together in a designated fluid conveying direction in the associated fluid line (35, 37) have.

Conveying device according to claim 1 or 2, characterized in that the respective fluid lines (35, 37), calculated from the pump chamber (31) to the respectively assignable non-return valves (39, 41), one and the same line section (43, 45) with the same flow cross-section exhibit. Conveying device according to one of the preceding claims, characterized in that the free cross-section of the pump space (31) is equal to or smaller than the free cross-section of each ange- closed line (43, 45), based on this connection area.

5. Conveying device according to one of the preceding claims, characterized in that the respective fluid line (35, 37, 43, 45) is part of a common fluid conveying line (43, 45), in which the pump chamber (31) with its integrated delivery piston ( 27) is switched. 6. Conveying device according to one of the preceding claims, characterized in that the delivery piston (27) engages with a needle-like extension (29) in the pump chamber (31), open into the at its free end, the respective fluid lines (43, 45). 7. Conveying device according to one of the preceding claims, characterized in that the actuating device is formed from an energizable actuating magnet (3), which spends the delivery piston (27) in its pressure-reducing or pressure-increasing travel position in its one currentless or other energized operating state.

8. Conveying device according to one of the preceding claims, characterized in that the at least from the delivery piston (27) and the pump chamber (31) existing piston delivery pump is provided with a pressure limiting device (33) that at an unintentional pressure increase in the fluid delivery line (43 , 45) the pressure within the pump chamber (31) is limited to a predefinable maximum pressure value. 9. Conveying device according to one of the preceding claims, characterized in that the formation of the pressure limiting device of the delivery piston (27) in cooperation with an energy store, in particular in the form of a compression spring (33), in a receiving Lumen of the pump chamber (31) magnifying Rückstel Ibereich in accordance with pending fluid pressure in the fluid conveying line (43, 45) is movable. 10. A conveyor according to one of the preceding claims, characterized in that on the delivery piston (27) a further energy storage, in particular in the form of another compression spring (25), permanently acting, the the delivery piston (27) in a the volume of the pump chamber (31 ) seeks to reduce the size of the delivery area.