EP2525094B1 - Pump for transporting fluid material from material containers - Google Patents

Description

The invention relates to a pump for conveying fluid material from a material container according to the preamble of claim 1.

Corresponding pumps are used for removing fluid material from material containers and for feeding the material to, for example, a mixing device or processing device. In the further description, reference will be made exclusively to processing devices, whereby mixing devices or similar devices are always included. Usually, such pumps convey the material in working cycles, wherein a working cycle comprises a first step in which for the removal of material from the material container, a pumping chamber of the pump is filled with material, and a second step, in which for supplying the material to a device Material from the pump delivery chamber is emptied.

Conventional pumps are commonly driven by a drive means so that a duty cycle is performed in an operable by the drive means operable frequency. One period of this working frequency refers to the time interval between the beginning of the first working step in one Work cycle and the beginning of the first work step in the subsequent work cycle. Since in conventional pumps, the delivery chamber is set up constant in its geometric dimensions, the conveying speed of conventional pumps with known delivery chamber volume, taking into account the frequency of the drive device can be easily calculated and thus specified by the drive device.

However, it has been found that it is advantageous for many applications if the conveying speed of the pump can be varied within a certain range, without having to change the operating frequency of the working cycles and thus the frequency of the drive device. This is particularly the case when the conveying speed, and thus the amount of material conveyed per time interval, must be precisely determined or controlled, which can not always be guaranteed via the frequency control via the drive device.

For example, there is often a need to set a guide value for a conveying speed for a material and to be able to vary the conveying speed during the conveying process within a certain range. Irrespective of this, there is a need to be able to set the conveying speed as precisely and / or continuously as possible.

Frequently, during a conveying process, process-dependent parameters of the processing device must be reacted to the effect that more or less material is fed to the processing device. The control of the drive device may be too slow, too inaccurate or too expensive for this purpose.

In addition, pumps are often mechanical or driven coupled driven, wherein each pump promotes a different material from a different material container. The delivery speeds of the pumps can thus be changed only together. Again, there is a need to be able to change the conveying speed of the respective coupled driven pump independently of the drive device.

To solve the technical problems mentioned in the document CH 701376 B1 proposed to design a pump so that a part of the first step of the working cycle of the pump pumped into the pumping chamber material is pumped back into the material container and is not emptied in the second step for supplying the material to a processing device from the pumping chamber. As a result, the conveying speed can be varied over the volume of the material which is pumped back from the delivery space into the material container before emptying the delivery space.

However, for the pumping back of the material from the pumping chamber into the material container at the pump, a separate return system is necessary, which communicates with the material container and involves high costs. In addition, when pumping back a high pump pressure must be spent.

Further, the document discloses DE 1703650 A1 a pump for conveying liquids, wherein the conveying speed can be varied by changing the gas pressure in a Zuschaltraum, which is arranged on the pumping chamber. In this case, a piston is arranged in the Zuschaltraum, which is acted upon on one side by the gas pressure in the Zuschaltraum with pressure, wherein the Zuschaltraum is arranged on the delivery chamber, that liquid can pass from the delivery chamber into the Zuschaltraum to the other side of the piston , Furthermore, from the document CH 227216 A one Multi-stage compressor known whose delivery rate can be varied by the delivery chamber of the multi-stage compressor can be connected to non-promotional work spaces. From the document DE 10 2008 005 429 A1 In addition, a compressor is known in which the conveyed air flow can be prevented by the delivery chamber of the compressor can be connected to a non-promotional Zuschaltraum. From document GB 650060 A For example, a pump is known whose delivery speed can be varied by varying the delivery chamber volume by means of a deformable membrane

Based on the prior art, the invention has for its object to provide a pump for conveying a quantity of fluid material from a material container, through which the needs described above at least partially satisfied and / or the problems mentioned in known pumps are at least partially resolved.

As a solution to the aforementioned technical problem, the invention proposes a pump for conveying a quantity of fluid material from a material container having the features of claim 1.

A pump according to the invention is designed such that the size of the delivery chamber of the pump during pump operation is variable so that different volumes of the material can be conveyed in different operating cycles of the delivery process. The delivery chamber comprises a supplementary chamber with additional space, wherein the volume of the supplementary space during operation of the pump is variable. Furthermore, the pump according to the invention is designed as a reciprocating pump whose delivery chamber comprises a first piston chamber, and which has a second piston chamber and a reciprocating piston. At the first piston chamber, the supplementary chamber is provided. The reciprocating piston is movable in the first step for conveying the material from the material container in the first piston chamber from a first dead center to a second dead center and in the second step for discharging the material from the first piston chamber into the second piston chamber from the second dead center to the first dead center movable.

The size of the pumping room refers to the size of the room defined by the geometric dimensions of the pumping room. A change in the size of the delivery chamber can thus be brought about by each change of each extension size of the delivery chamber. In order to change the size of the delivery chamber, the volume of the delivery chamber does not necessarily have to be changed, but also a change in the shape of the delivery chamber must be regarded as a change in the size of the delivery chamber.

For example, a change in the size of the delivery chamber can consist in that the extent of the delivery chamber changes such that a chamber or Aussackung is formed or regressed, which is not accessible when emptying the material from the delivery chamber in the second step, so that in a work cycle funded volume of the material can be changed by changing the size of the delivery chamber. A change in the size of the delivery chamber can also consist in particular in that a dividing wall or the like is changed in the delivery chamber or introduced into it, so that certain sections of the delivery chamber in the filling of

Conveying space with material and / or in the emptying of material from the pump room are not accessible. In addition, the size of the pumping chamber can of course also be changed by changing at least one extension of the pumping chamber so that the volume bounded by the pumping chamber changes. For example. it is possible to change the delivery chamber in a scoop pump so that in a work cycle, d. H. in a scooping cycle of the pump, depending on the size of the pumping chamber, a certain amount is conveyed.

The pump according to the invention is characterized in particular by the fact that the size of the delivery chamber of the pump can be changed during pump operation. The pump according to the invention therefore makes it possible to change the volume delivered per working cycle without interrupting the delivery process. As a result, during the operation of the pump, the delivery speed of the pump can be adapted to the respective conditions which may be predetermined, for example, by the processing device to which the pump feeds the material. Because by changing the size of the pumping chamber during pump operation, it is possible to change the volume delivered per working cycle, so that at constant operating frequency of the pump by changing the size of the pumping chamber during pump operation, the conveying speed of the pump is variable. The change in the conveying speed can be carried out continuously or stepwise.

In particular, it may be advantageous that the size of the delivery chamber can be controlled or regulated by a control unit. In this case, the control unit of a pump, for example, the operating parameters of the pump, the operating parameters of the processing device and / or operating parameters of pumps that promote material from further material containers to the processing device, take into account. The Control unit for controlling or regulating the size of the pumping chamber can cooperate in particular with a spreader for controlling or regulating the operating frequency of the pump. This makes it possible to change the delivery speed of the pump quickly and precisely within a wide range of values.

Due to the design as a reciprocating pump, the pump according to the invention can be realized particularly cheap and robust. For example, the pump can be connected to the material container via a follower plate. The reciprocating piston in this case represents the conveying means for filling and emptying the first piston chamber. The second piston chamber can be designed, for example, as an outlet chamber of any desired design. Also, first piston chamber and second piston chamber can be separated from each other by the reciprocating piston. The second piston chamber can also be designed so that it is filled in the second step by the stroke of the piston from the second dead center to the first dead center with material and is emptied during the stroke of the piston in the first step of the subsequent cycle. It may be particularly advantageous that the ratio of the volumes of the first and second piston chamber to each other is two to one, whereby it is possible that the pump during the entire cycle substantially continuously expels material from the second piston chamber.

In an advantageous embodiment, the delivery chamber of the pump comprises means or cooperates with these, by which the size of the delivery chamber is variable, and which are adjustable during a duty cycle for changing the size of the delivery chamber, so that the volume ratio between the material volume, the in the first step is conveyed into the delivery chamber, and the volume of material that is emptied from the delivery chamber in the second step is changeable.

In this case, it is possible, for example, to adjust the means such that a part of the material conveyed into the conveying space during the first working cycle is retained in the conveying space during the emptying of the conveying space in the second working step.

Furthermore, for example, material which has been retained in the conveying space and is located in the conveying space before the start of the first working step of a working cycle can be emptied out of the conveying space together with the material conveyed into the conveying space in the first working step during the subsequent second working step. Accordingly, depending on the setting of the means said volume ratio can be changed so that the volume of material that is conveyed in the first step in the pumping chamber is greater or smaller than the volume of material that is emptied in the second step from the pumping chamber. Due to the means and their different settings can thus the conveying speed of the pump in a wide range be varied.

Advantageously, the delivery chamber of the pump a. Complementary chamber with a supplementary space, wherein the volume of the supplementary space is variable during operation of the pump. As a result, the volume of material that is conveyed into the delivery chamber in the first operating step and the volume of material that is discharged from the delivery chamber in the second operating step can be changed by changing the volume of the supplementary space. By providing a supplementary chamber with additional space in the delivery chamber, a very simple change in the size of the delivery chamber is possible.

The change in the volume of the supplementary room can influence the emptying and / or filling of the pump room. For example, can be changed by a corresponding change in the volume of the supplementary space, the pressure in the pump chamber, whereby, for example, pressure fluctuations in the emptying / filling of the pump chamber can be compensated or at least reduced, so that for example the promotion of material can be made more uniform and / or the conveying speed can be set more precisely. The invention also includes, irrespective of the change in the conveying speed, providing the delivery space so that it comprises a supplementary chamber with supplementary space, and that the volume of the supplementary space during the operation of the pump is variable. As a result, the filling and / or emptying can be influenced as described. The embodiments, features and combinations of features of a pump according to the invention described in the present descriptions are valid accordingly for this independent part of the invention. In particular, the features can also be combined with each other.

In particular, it may be advantageous for the delivery chamber a pump chamber, wherein the volume of the supplementary space is variable independently of the volume of the pump chamber. Thus, for example, the pump room can be continuously filled and emptied with material during the working cycles, wherein the change in the size of the pumping chamber via the change of the supplementary room can be done. It has been found to be particularly advantageous to provide in the pump room, a conveyor which serves to fill and empty the pump chamber with material, without simultaneously causing a filling and emptying of the supplementary chamber of the supplementary chamber. The influence of the change in the size of the delivery chamber on the entire pump construction can be kept low, which allows a simple construction of the pump according to the invention. However, it is also possible to provide a plurality of supplementary chambers with additional chambers on the pump chamber or to design the pump chamber independently of the at least one supplementary space in the at least one supplementary chamber variable in size.

In addition, the delivery chamber may include a working means by means of which the volume of the supplementary space is variable during a working cycle of the pump between a first volume and a second volume to the funded in a work cycle volume of material by the volume corresponding to the difference between the second and first volume to change, wherein the working means is controlled by a control unit. First and second volumes can be adjusted by the working fluid in a range between 0 to the volume of the supplementary chamber. The first volume may, for example, be the minimum volume of the supplementary room, the second volume the maximum volume of the supplementary room during a working cycle of the pump. Accordingly, the second volume, the minimum volume and the first volume of the Maximum volume to be within a work cycle. The change in the volume of material delivered in one cycle refers to the volume of standard material delivered by the pump when the fluid rests during a closed cycle.

In this case, it can be particularly advantageous to provide a conveying means in the conveying space, which serves to fill and empty the conveying space, without effecting filling and emptying of the supplementary space. For example, the volume of standard material delivered by the pump in one cycle may then be reduced by the difference between the second and first volumes by changing the volume of the supplemental space after filling the delivery space from a smaller first volume to a larger second volume. so that when emptying the delivery chamber, the volume of material that corresponds to the difference between the second and first volume is retained in the supplementary space. The retained volume may then be used in the subsequent cycle, for example, for filling the delivery space, and a corresponding change in the supplemental space by the working fluid from a small first volume to a large second volume may again cause a reduction in the standard volume of material. Accordingly, the standard material volume can be increased by the difference between the second and first volume, when the working means is controlled so that the supplementary space is changed during the filling of the delivery chamber from a small first volume to a larger second volume and during the emptying of the delivery chamber of the larger second volume is changed back to the small first volume.

It may be advantageous that the first and / or the second volume of the supplementary space during operation of the Pump is changeable. As a result, in different working cycles of the pump, the volume of standard material delivered in one working cycle can be changed by a respectively different volume. This allows the control or regulation of the delivery speed of the pump during operation of the pump in an area defined by the variation of the first and second volumes of the supplementary room.

In addition, the pump may comprise a first valve and a second valve, wherein the pumping chamber with the first valve for filling with material material communicates with the material container and with the second valve open for discharging material with an outlet chamber in communication, wherein the first valve and the second Valve during operation of the pump are alternately opened and closed.

The outlet chamber can be designed in any manner and also be realized for example by a conduit, such as a hose or a pipe. In addition, the volume of the delivery chamber with the first valve open can differ from the volume of the delivery chamber when the second valve is open. The provision of corresponding valves ensures that the volume of the delivery chamber during the first step, and thus during the filling of the delivery chamber, separate from the volume during the second step, and thus during the emptying of the delivery chamber, is adjustable, wherein the do not overlap both work steps. As a result, a precise variation of the conveying speed is possible.

The supplemental chamber may in one embodiment comprise a displacement means, wherein the volume of the supplementary space is determined by the position of the displacement means in the supplementary chamber. As a result, the volume of the supplementary room can be particularly simple and be determined inexpensively.

Supplementary chamber and displacement means may be formed as a cylinder-piston arrangement, wherein the displacement means is designed as a displacement piston, through which the supplementary space is limited. Due to the cylinder-piston arrangement, the volume of the supplementary space is very simple and precisely changeable, and the cylinder-piston arrangement can be produced at low cost.

Furthermore, the invention designed as a reciprocating pump pump may include a bypass through which the first piston chamber and the second piston chamber are interconnected, wherein in the bypass, the second valve is arranged, which is designed as a check valve, so that a return flow of material from the second Piston space is prevented in the first piston chamber. The bypass can be formed both as a material line outside the piston chambers, which connects the piston chambers with each other, as well as, for example, by the reciprocating piston and / or a Hubkolbenstange for driving the reciprocating piston. By providing a check valve in the bypass, precise adjustment of the volume of material delivered per working cycle is possible. The check valve and / or the first valve can, for. B. may be formed as a ball valve or as Kugelkalottenventil, which may self-controlling opens and closes.

Furthermore, it may be advantageous that the volume of the supplemental space in the supplementary chamber during operation is variable so that the volume ratio between the volume of the supplementary space in the passage of the first dead center by the reciprocating piston and the volume of the supplementary space in passing the second dead center by the Reciprocating piston is changeable during operation. In this case, the conveying speed of the pump can be changed by changing the volume ratio. For example, for this purpose, the volume of the supplementary room on the position of a Displacer be changed in the supplementary chamber. The position of

Displacer can be changed continuously or only in a time interval during the movement of the reciprocating piston between the two dead centers, and / or passing the respective dead points themselves. Due to the fact that the volume ratio in the operation of the pump is variable, the conveying speed of the pump in operation the pump can be changed.

Advantageously, the volume ratio is adjustable as a function of a predetermined conveying speed during a working cycle. For example, the volume ratio during a work cycle can be changed so that the pump speed influenced by the volume ratio of the pump is changed in the direction of a predetermined conveying speed, or that thereby the predetermined conveying speed is set itself.

Furthermore, the invention relates to a system comprising at least two pumps, of which at least one as described above formed according to the invention and each associated with a material container, both pumps are driven coupled so that they perform the steps synchronously with the same frequency, the size the delivery chamber of at least one of the two pumps is variable independently of the other. The coupling can be done both mechanically and via an electronic control. This ensures that in the system, the conveying speed of at least one pump is variable independently of the conveying speed of the other pump, while both pumps are driven coupled to the same frequency. Thereby, even in a system with two coupled driven pumps, the conveying speed with which a certain material is conveyed by a certain pump can be changed depending on, for example, the material or operating parameters of the processing unit become. For example, thus different mixing ratios of the materials from the respective material containers associated with the pump can be realized.

In the system, the change of the delivery chamber of one or both of the pumps can also be controlled by means of a control unit in order to change the actual value of the delivery speed of the controlled pump in the direction of a desired value of the delivery speed of the pump. The control unit may possibly calculate the pump speed setpoint as a function of operating parameters of the processing unit or also on characteristics of the material, such as the viscosity of the material. Also, the target value of the conveying speed of the pump can be manually entered. The change in the delivery chamber can then be controllable via the control unit in such a way that the actual value of the delivery speed of the controlled pump can be changed in the direction of the corresponding desired value.

In particular, it may be advantageous that the change of the delivery chamber of one or both of the pumps in dependence on the level of at least one of the two pumps associated material container is controllable. This may possibly also the difference or the ratio of the levels in the material containers are taken into account. By a corresponding adjustment of the conveying speed of the pump on the change of the pumping chamber can thus be ensured, for example, that the material containers are emptied as possible at the same time.

Furthermore, the invention comprises a method for controlling the conveying speed of a pump, which is designed as a reciprocating pump, wherein the pump conveys fluid material from a material container by a delivery chamber is at least partially filled with material in a first step and at least in a second step, the material is partially emptied from the pumping chamber, wherein the first and the second step are each part of a working cycle. In the method according to the invention, in order to change the volume of material delivered per working cycle, the delivery chamber of the pump is changed during operation of the pump, the volume of a supplementary chamber in a supplementary chamber, which is provided by the delivery chamber and provided on a first piston chamber of the pump, during the Operation of the pump is changed, wherein a reciprocating piston of the pump is moved in the first step for conveying the material from the material container in the first piston chamber from a first dead center to a second dead center and in the second step for emptying the material from the first piston chamber into a second piston chamber of the pump is moved from the second dead center to the first dead center.

In the following, the invention will be further explained by describing an embodiment with reference to three figures.

Figur 1:

in einer Prinzipdarstellung vier Zustände einer herkömmlichen Hubkolbenpumpe während eines Arbeitszyklus der Hubkolbenpumpe;

Figur 2:

in einer schematischen Darstellung den Verlauf der Kolbenbewegungen sowie des Materialdrucks in einer herkömmlichen und in einer erfindungsgemäßen Hubkolbenpumpe;

Figur 3:

in einer Prinzipdarstellung zwei Zustände einer erfindungsgemäßen Pumpe während eines Arbeitszyklus der Pumpe;

Figur 4:

in einer Prinzipdarstellung zwei Zustände einer erfindungemäßen Pumpe während eines Arbeitszyklus der Pumpe.

It shows

FIG. 1:

in a schematic representation of four states of a conventional reciprocating pump during a working cycle of the reciprocating pump;

FIG. 2:

in a schematic representation of the course of the piston movements and the material pressure in a conventional and in a reciprocating piston pump according to the invention;

FIG. 3:

in a schematic representation of two states of a pump according to the invention during a working cycle of the pump;

FIG. 4:

in a schematic representation of two states of a erfindungemäßen pump during a duty cycle of the pump.

In the figures, elements having a similar effect are provided with identical reference numerals.

To explain the operation of conventional pumps 100 are in FIG. 1 four states of a conventional pump 100 during a duty cycle of the pump 100 shown. In FIG. 1 is a 100 designed as a reciprocating pump 100 pump shown.

In FIG. 1 states of the pump 100 are shown in a first cycle and at the beginning of the subsequent second cycle. The state diagrams A to C show the pump 100 in the first cycle, the state diagram D at the beginning of the second cycle. In order to make it clear that material 2 is taken from the material container by the pump 100 in the first working cycle and new material 2a is removed in the second working cycle, FIG FIG. 1 the material 2, which is related to the removal in the first cycle, shown rasterized, while the material 2a, which is related to the removal in the second cycle, hatched. This is intended to illustrate schematically how the material 2, 2 a removed from the material container in a specific working cycle is conveyed or ejected by the pump 100 during the working cycles.

In the state A, the conventional reciprocating pump 100 is immersed in the material 2 in the material container. The material container and the material contained in the material container are in FIG. 1 not shown, but only schematic diagrams of pumps 100 and material 2, 2a are shown in the pump 100. This applies correspondingly for the representation of the pump 1 according to the invention in the FIGS. 3 and 4 ,

In the state representation A in FIG. 1 Accordingly, a state of the reciprocating pump 100 is shown at the beginning of the first cycle, in which the reciprocating pump 100 has not yet conveyed material 2 from the material container. Accordingly, the material 2 has entered the reciprocating pump 100 only up to the first valve 6, via which the reciprocating pump 100 can be brought into contact with the material 2 in the material container. The first piston chamber 3 and the second piston chamber 4 are each not filled with material. The reciprocating piston 8 of the pump 100 is in its first dead center. The first valve 6 is opened in the illustrated state A. However, it is also possible that the first valve 6 opens only with the onset of the lifting movement of the reciprocating piston 8.

In the state diagram B, a state of the pump 100 is shown at the end of the first working step. Between state A and state B, the reciprocating piston 8 moves from the first dead center toward the second dead center, whereby the first piston chamber 3 is filled with material 2. The direction of movement of the reciprocating piston 8 is indicated in the figures in each case by an arrow in the reciprocating piston 8. During the movement of the reciprocating piston 8, material 2 is thus scooped up from the material container into the first piston chamber 3, the first valve 6 being opened in a controlled manner during the scooping process in accordance with the scooping direction.

In the state diagram C, a state of the pump 100 during the second operation is shown. The reciprocating piston 8 moves from the second dead center in the direction of the first dead center, whereby the reciprocating piston 8 exerts pressure on the material 2 in the first piston chamber 3, so that the first valve 6 is closed automatically and the second valve 7 is self-controlling open. Accordingly, material passes through the bypass 9, in which the second valve 7 is arranged, into the second piston chamber 4, wherein both the first piston chamber 3 and the second piston chamber 4 extend in sections into the bypass 9. Since the volume of the first piston chamber 3 is greater than that of the second piston chamber 4, the pump 100 still ejects material 2 through the outlet 5 after the filling of the second piston chamber 4 during the second working step. The material ejection is indicated by an arrow in the outlet 5.

In the state diagram D, a state of the pump 100 after the execution of the first duty cycle and during the first step of the second cycle. The reciprocating piston 8 moves from the first dead center toward the second dead center, and both the first valve 6 and the second valve 7 are closed.

Since the volume of the first piston chamber 3 is greater than that of the second piston chamber 4, the second piston chamber 4 is filled with material 2 even in the state D after completion of the first working cycle of the pump 100. With the onset of the first operation of the second cycle of the pump 100, the reciprocating piston 8 again moves from its first dead center toward the second dead center, whereby material 2a is filled from the material container into the first piston chamber 3. To explain the principle of operation of the pump 100, only the material 2a is shown in the state diagram D in the first piston chamber 3 for the sake of simplicity. This makes it clear that in the first step of the second cycle of the material container, the material 2a is scooped into the first piston chamber 3. It should be noted that in the first step of the second cycle, the material 2 from the first piston chamber 3 is continuously displaced by material 2a in the second piston chamber. At the same time during the first work step of the second cycle of the pump 100 material 2 is discharged from the outlet 5, since, as explained, even at the end of the first cycle of the second piston chamber 4 is filled with material 2 and during the first step of the second cycle in Substantially the remaining material 2 from the first piston chamber 3 is displaced into the second piston chamber 4, so that the reciprocating piston 8 displaces material 2 in the second piston chamber 4 during its movement from the first dead center to the second dead center and thus the expulsion of material 2 from the outlet 5 causes.

From the illustration of the operation of the conventional pump 100 in FIG. 1 It becomes clear that with the conventional pump 100 in a work cycle a predetermined, not variable volume of material is conveyed.

The pressure curve 32 of the material pressure in the material 2, 2a in the second piston chamber 4 of the pump 100 is in FIG. 2 shown. The reciprocating curve 31 represents the lifting movement of the reciprocating piston 8 of the pump 100. The arrows indicate the direction of movement of the reciprocating piston 8. An upward arrow indicates the movement of the reciprocating piston 8 from the first dead center toward the second dead center, a downward arrow from the second dead center toward the first dead center. The first dead center is thus shown as a minimum, the second dead center as the maximum of the reciprocating curve 31. From the pressure curve 32, a problem of a conventional pump is apparent: At the second dead center of the reciprocating piston 8 is a pressure drop, so that the promotion of the material 2, 2a can not be continuous and thus not precise over the duty cycle of the pump 100 is adjustable. This problem can be with a like in the FIGS. 3 and 4 illustrated pump 1 according to the invention are at least partially resolved. This will become later in connection with the description of the operation of a pump 1 according to the invention FIG. 3 further explained.

In FIG. 3 states of a pump 1 according to the invention during a working cycle of the pump 1 are shown. At the first piston chamber 3 of the pump 1 according to the invention, a supplementary chamber 10 with a supplementary chamber 12 is arranged, which comprises a displacement piston 11.

The pump 1 is in the in FIG. 3 illustrated duty cycle controlled so that per working cycle of the pump 1 more volume of the material 2 is promoted as the standard volume after FIG. 1 illustrated conventional pump 100 of identical construction, in which not according to the invention, a supplementary chamber 10 is provided with displacement piston 11 and supplementary chamber 12.

In the state diagram A 'of the pump 1 according to the invention, a state of the pump 1 is shown at the end of the first working step, in which material 2 is scooped into the first piston chamber 3 via the open first valve 6. The reciprocating piston 8 is near its second dead center, and the first piston chamber 3 is substantially filled with material 2. The second valve 7 is closed automatically.

In state A 'of the pump 1, the supplementary space whose volume is defined by the position of the displacement piston 11 in the supplementary chamber 10 is filled with material 2. In the described embodiment, the position of the displacement piston 11 is between a first position, which in FIG. 3 in the state diagram B ', and a second position shown in FIG FIG. 3 in the state representation A ', changeable. In the first position of the displacement piston 11, the supplementary chamber 12 has a first volume, in the second position of the displacement piston 11 has a second volume.

In the described inventive pump 1 with the in FIG. 3 illustrated operation, the filling of the supplementary space 12 with material 2 is ensured by the fact that the displacement piston 11 is moved during the first step from the first position to the second position and thereby changes the volume of the supplementary chamber 12 from the first to the second volume. Depending on the nature of the material 2, such as the viscosity, and the arrangement of the supplementary chamber 10, the volume of the material 2, which is in the state A 'in the supplementary space, by the difference between the second and first volume of the supplementary space 12 or be determined solely by the second position of the displacement piston 11. In the illustrated embodiment, the volume of the material 2 in the supplemental space 12 in the state A 'by the second position of the displacement piston 11 is fixed.

The change in the position of the displacement piston 11 can be carried out both simultaneously and before or after the movement of the reciprocating piston 8 from the first dead center to the second dead center. The position of the displacement piston 11 can in particular take place when the reciprocating piston remains at a dead center. The first valve 6 is open when changing the position. The material volume filled by the change in the position of the displacement piston 11 into the supplementary space 12, which corresponds to the difference between the second and first volumes of the supplementary space 12, is thus removed from the material container during the first working step. By controlling the position of the displacement piston 11 can thus be changed in the first step in the first piston chamber 3 funded material volume.

In the state B 'in FIG. 3 the pump 1 is in a state during the second operation. In this case, the reciprocating piston 8 moves from the second dead center to the first dead center and thereby causes as to FIG. 1 explains the at least partially emptying of material 2 from the first piston chamber 3 in the second piston chamber 4 and an ejection of material 2. As explained above, in the second step, the first valve 6 is closed and the second valve 7 is opened. During the second working step, in the described pump 1 according to the invention the displacement piston 11 is actuated such that it moves from the second position to the first position, whereby the supplementary space 12 in the supplementary chamber 10 is reduced. The volume of the material 2, which corresponds to the difference between the additional volume spaces formed in the first position and the second position of the displacement piston 11, is thus conveyed from the supplementary chamber 10 into the first piston space 3 during the second working step. Since the material 2 in the first piston chamber 3 during the second step by the movement of the reciprocating piston 8 from the second dead center to the first dead center is under pressure and thereby as above described in the second piston chamber 4 is conveyed, the volume of the material 2, which is emptied during the second step of the supplementary chamber 10 in the first piston chamber 3, also in the second piston chamber. 4 promoted. The displacement piston 11 may be controlled so that it moves to reduce the supplementary space 12 from the second position to the first position when the reciprocating piston 8 at the beginning of the second step in the second dead center, at the end of the second step in the first Dead center is or while the reciprocating piston 8 moves from the second dead center to the first dead center. In this case, the first valve 6 is always closed and the second valve 7 is opened.

In the described embodiment of a pump 1 according to the invention, the displacement piston 11 can be controlled so that first position and second position of the displacement piston 11 between a first and a second end position of the displacement piston 11 are continuously selectable. If the position of the displacement piston 11 is not changed during a work cycle, the material 2, which enters the supplementary space 12 in the first step, is essentially not conveyed into the second piston chamber 4 in the second step, since the piston 8 is the material 2 in the supplemental space 12 during the second step in the direction of the displacement piston 11 under pressure. Accordingly, the pump 1 according to the invention, if the position of the displacement piston 11 is not changed during the working cycle, promotes substantially the same standard volume of material per working cycle, which is replaced by a corresponding conventional one FIG. 1 described pump 100 is conveyed in a working cycle.

At the in FIG. 3 described operation of the pump 1 according to the invention can therefore be promoted in addition to the standard material volume in a working cycle of the pump 1, the volume of the difference between the second volume of the supplementary space 12 in the second position of the displacement piston 11 and the first volume of the supplementary space 12 in the first position of the displacement piston 11 corresponds. Accordingly, by changing the first position and the second position of the displacement piston 11 in the supplementary chamber 10, the volume of material delivered per working cycle of the pump 1 can be changed by controlling the displacement piston 11. Accordingly, the conveying speed of the pump 1 according to the invention is variable.

In FIG. 2 is exemplary of the displacement piston curve 21 after the in FIG. 3 described functioning working pump 1 shown. The position of the displacement piston 11 is thereby changed during the first working step from the first position to the second position to the effect that the volume of the supplementary space 12 is increased from the first volume to the second volume. After passing through the second dead center by the reciprocating piston 8, the position of the displacement piston 11 is then changed from the second position in the direction of the first position. The volume of the supplemental space 12 is thus reduced from the second volume to the first volume at the beginning of the second working step. As a result, pressure is applied to the material 2 in the first piston chamber 3 at the beginning of the second working step, and therefore also to the material 2 in the second piston chamber 4 via the second valve 7. This allows the pressure drop in the pressure curve 32 of a conventional pump 100 in FIG. 2 is shown, according to the course of the pressure curve 22 of a pump 1 according to the invention can be significantly reduced. This can lead to a continuous delivery of material 2 and to a more precise adjustment. contribute to the conveying speed. This advantage can be provided by a pump 1 according to the invention even at a constant conveying speed.

In FIG. 4 the states A "and B" are one pump according to the invention shown, wherein the pump according to the invention is controlled so that the funded per working cycle material volume is smaller than the per working cycle funded standard material volume of a corresponding conventional pump 100.

In the state A ", the pump 1 is in a state at the end of the first operation, the first valve 6 is opened and the second valve 7 is closed, and material 2 is fed from the material container into the first piston space 3. In the state B "is the pump 1 shown during the second step, in which is promoted by the force exerted on the displacement piston 11 pressure on the material 2 material 2 from the first piston chamber 3 in the second piston chamber 4. In the state B ", the first valve 6 is closed and the second valve 7 is opened.

At the in FIG. 4 described operation of the pump 1 according to the invention, the displacement piston 11 is controlled in the supplementary chamber 10 so that the first volume of the supplementary chamber 12 in the first position of the displacement piston 11 during the first step of the pump 1 is smaller than the second volume of the supplementary space 12 in the second Position of the displacement piston 11 during the second step of the pump 1. As described above, the position of the displacement piston 11 can take place both during the movement of the reciprocating piston 8 and then when the reciprocating piston 8 is in its first or second dead center or remains.

At the in FIG. 4 described operation of the pump 1 according to the invention thus reaches a volume of the material 2, which corresponds to the difference between the first and second volumes of the supplementary space 12, after the completion of the first step, and thus after filling the first piston chamber 3 with material 2, from the first Piston chamber 3 in the supplementary room 12 in the supplementary chamber 10. The Pump 1 is designed in such a way that, when the material 2 is emptied from the first piston chamber 3 into the second piston chamber 4, the piston 8 does not simultaneously discharge material 2 from the supplementary chamber 12 into the second piston chamber 4. Accordingly, the in FIG. 4 described inventive pump 1 per duty cycle a volume of material that corresponds to the standard material volume minus the difference between the first volume and the second volume of the supplementary space 12. Thus, the conveying speed of the pump 1 according to the invention is after FIG. 4 reduced compared to a corresponding conventional pump 100.

During the first operation of a working cycle following a first working cycle, the position of the displacement piston 11 can be moved back from the second position to the first position. Thereby, the volume of the material 2, which corresponds to the difference between the first and second volumes of the supplementary space 12, during the first step, and thus in the filling of the first piston chamber 3 with material 2, emptied from the supplementary space 12 into the first piston chamber 3. This emptying takes place before the reciprocating piston 8 reaches the second dead center. Accordingly, in this first step, a volume is taken from the material container, which corresponds to the difference between the volume of the serious piston chamber 3 and the volume of material emptied from the supplementary space 12. The. Conveying speed of the pump 1 is thus effectively reduced.

In the described embodiment of the pump 1, the filling and emptying of the first piston chamber 3 with material 2 takes place by the movement of the reciprocating piston 8. The reciprocating piston 8 at least does not cause the emptying of the supplementary chamber 12 simultaneously with the emptying of the first piston chamber 3. In the described This embodiment is ensured by the fact that the reciprocating piston 8 in the second step, and thus in the movement for conveying material 2 from the first piston chamber 3 in the second Piston chamber 4, pressure on the material 2 from the first piston chamber 3 away in the direction of the supplementary chamber 10 exerts. However, it is also possible to realize a erfindungemäße pump 1 by dividing walls are provided, whose position is variable and which can prevent or allow a corresponding emptying and / or filling of the supplementary space 12 depending on their position. The supplementary chamber 10 does not necessarily have to be designed as a cylinder-piston device, but can also be realized, for example, by corresponding diaphragms whose position can be controlled. Also, the supplementary chamber 10 may be arranged in a reciprocating piston pump 1 according to the invention within the first piston chamber 3.

At the in FIGS. 3 and 4 described functions of a pump 1 according to the invention, the displacement piston 11 in the supplementary chamber 10 can be controlled by a control unit. The control unit may possibly also be coupled to a control or drive device of the reciprocating piston 8.

In an embodiment, not shown, of a pump 1 according to the invention, the position of a displacement means in a supplementary chamber 10 can be kept constant during a working cycle, wherein by means of the position of the displacement means in the supplementary chamber 10, the volume of material delivered per working cycle is variable.

LIST OF REFERENCE NUMBERS

1

Pump, reciprocating pump

2, 2a

material

3

first piston chamber

4

second piston chamber

5

outlet

6

first valve

7

second valve

8th

reciprocating

9

bypass

10

supplementary chamber

11

displacement piston

12

supplement room

100

conventional pump, conventional reciprocating pump

21

Displacement piston curve

22

Pressure curve according to the invention

31

Hubkolbenkürve

32

conventional pressure curve

Claims (15)

1. Pump (1) for conveying a volume of fluid material (2, 2a) from a material container in a conveying operation comprising a plurality of work cycles, wherein said pump (1) comprises a conveying space that is filled with material (2, 2a) at least in sections in a first working step of the pump and that is emptied at least in sections in a second working step of the pump in order to convey said material (2, 2a), wherein the first and the second working steps are respectively part of a working cycle, wherein the size of the conveying space of the pump is variable during the operation of the pump in such a manner that different volumes of the material (2, 2a) can be conveyed in various working cycles, wherein said conveying space includes a supplementary chamber (10) with a supplementary space (12),
   characterized in
   that the volume of the supplementary space (12) is variable during the operation of the pump (1), wherein said pump (1) is constructed as a reciprocating piston pump (1) the conveying space of which comprises a first piston space (3), and which comprises a second piston space (4) as well as a reciprocating piston (8), that a supplementary chamber (10) is provided at the first piston space (3) and that the reciprocating piston (8) is movable from a first dead center to a second dead center for conveying the material (2, 2a) from the material container to the first piston space (3) in a first working step, and is movable from the second dead center to the first dead center for discharging the material (2, 2a) from the first piston space (3) to the second piston space (4) in the second working step.
2. Pump (1) according to claim 1,
   characterized in that the conveying space includes or cooperates with means with which the size of the conveying space can be varied and which for varying the size of the conveying space during a work cycle are adjustable in a manner such that the volume ratio between the material volume that is conveyed to the conveying space in the first working step and the material volume that is discharged from the conveying space in the second working step is variable.
3. Pump (1) according to claim 1 or 2,
   characterized in that the conveying space comprises a pump space, wherein the volume of the supplementary space (12) is variable independently of the volume of the pump space.
4. Pump (1) according to one of the preceding claims,
   characterized in that the conveying space includes a working medium with which the volume of the supplementary space (12) can be varied between a first volume und a second volume during a working cycle of the pump (1) in order to change the material volume conveyed in one working cycle by the volume that corresponds to the difference between said first and second volumes, wherein said working medium is controlled by a control unit.
5. Pump (1) according to claim 4,
   characterized in that the first and/or the second volume of the supplementary space (12) is/are variable during the operation of pump (1).
6. Pump (1) according to one of the preceding claims,
   characterized in that the pump (1) comprises a first valve (6) and a second valve (7), wherein the conveying space with the first valve (6) open communicates with the material container for filling it with material (2, 2a), and with the second valve (7) open communicates with an outlet chamber for discharging material (2, 2a), wherein the first valve (6) and the second valve (7) are alternatingly open and closed during the operation of pump (1).
7. Pump (1) according to one of the preceding claims,
   characterized in that the supplementary chamber (10) includes a displacement device, wherein the volume of the supplementary space (12) is fixed by the posture of said displacement device within supplementary chamber (10).
8. Pump (1) according to claim 7,
   characterized in that said supplementary chamber (10) and displacement device are constructed as a cylinder-piston assembly, wherein the displacement device is constructed as a displacement piston (11), which defines the supplementary space (12).
9. Pump (1) according to one of the preceding claims,
   characterized in that the pump (1) comprises a bypass interconnecting said first piston space (3) and said second space (4), that in said bypass (9) the second valve (7) is disposed, which is constructed as a check valve so as to prevent any backflow of material (2, 2a) from the second piston space (4) to the first piston space (3).
10. Pump (1) according to one of the preceding claims,
    characterized in that the volume of the supplementary space (12) inside supplementary chamber (10) is variable during operation in a manner such that the volume ratio between the volume of the supplementary space (12) at the time of passing the first dead center through the reciprocating piston (8) and the volume of the supplementary space (12) at the time of passing the second dead center through the reciprocating piston (8) is variable during operation.
11. Pump (1) according to claim 10,
    characterized in that the volume ratio is adjustable as a function of a predetermined conveying speed during a working cycle.
12. System, comprising at least two pumps (1), at least one thereof being constructed in accordance with one of the preceding claims, and said pumps being respectively associated with a material container,
    characterized in
    that both pumps (1) are driven in a coupled manner such that the pumps perform the working steps synchronously at the same frequency and that the size of the conveying space of at least one of said two pumps (1) is variable independently of that of said other pump.
13. System according to claim 12,
    characterized in that varying the conveying space of one or both pumps (1) is controllable by means of a control unit in order to change the actual value of the conveying speed of the controlled pump (1) towards a desired value of the conveying speed of pump (1).
14. System according to one of the claims 12 or 13,
    characterized in that varying the conveying space of one or both pumps (1) is controllable as a function of the fill level of at least one of said two material containers associated with said two pumps (1).
15. Method for controlling the conveying speed of a pump (1) that is constructed as a reciprocating piston pump (1), wherein said pump (1) conveys fluid material (2, 2a) from a material container by filling a conveying space with material (2, 2a) at least in sections in a first working step and by discharging said material (2, 2a) from said conveying space at least in sections in a second working step, wherein said first and said second working steps are respectively part of a working cycle, wherein for changing the material volume conveyed in each working cycle, the conveying space of pump (1) is changed during the operation of the pump (1),
    characterized in
    that the volume of a supplementary space (12) inside a supplementary chamber (10) that is comprised by and provided at a first piston space (3) is changed during the operation of pump (1), wherein a reciprocating piston (8) of pump (1) is moved from a first dead center to a second dead center, for conveying the material (2, 2a) from the material container to the first piston space (3) in a first working step, and from the second dead center to the first dead center for discharging the material (2, 2a) from the first piston space (3) to second piston space (4) of pump (1) in a second working step.

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