METERING DEVICE AND METERING METHOD

Abstract

A metering device (4, 82, 96) for metering a fluid includes a common supply line (6) and multiple discharge lines (20). To improve the metering process, the metering device (4, 82, 96) includes multiple delivery devices (18) each having a cavity (24) for receiving the fluid and a piston (26) for displacing the fluid, wherein each of the multiple delivery devices (18) is connected on the inlet side to the common supply line (6) and is connected on the outlet side to one of the multiple discharge lines (20).

Claims

1. A metering device (4, 82, 96) for metering a fluid, comprising a common supply line (6) and a plurality of discharge lines (20), characterized by a plurality of conveying devices (18) having in each case one cavity (24) for receiving the fluid and one piston (26) for displacing the fluid, wherein the plurality of conveying devices (18) on the inlet side are in each case connected to the common supply line (6) and on the outlet side are in each case connected to one of the plurality of discharge lines (20).

2. The metering device (4, 82, 96) as claimed in claim 1, characterized in that at least two of the conveying devices (18), in particular all conveying devices (18), are intercoupled.

3. The metering device (4, 82, 96) as claimed in claim 1 or 2, characterized by a common drive unit (34), wherein the plurality of conveying devices (18) are mechanically connected to the common drive unit (34).

4. The metering device (4, 82, 96) as claimed in one of the preceding claims, characterized in that each of the conveying devices (18) is in each case embodied as a single-action metering cylinder (84) and/or as a double-action metering cylinder (22).

5. The metering device (4, 82, 96) as claimed in one of the preceding claims, characterized by a common return line (8) as well as a plurality of pressure control valves (42) and/or a plurality of switch valves (44), wherein each of the conveying devices (18) is in each case connected to the return line (8) by way of one of the plurality of pressure control valves (42) and/or by one of the plurality of switch valves (44).

6. The metering device (4, 82, 96) as claimed in one of the preceding claims, characterized by a plurality of stop valves (52), wherein at least one of the plurality of stop valves (52) on the inlet side and/or the outlet side is in each case disposed on a respective conveying device (18).

7. The metering device (4, 82, 96) as claimed in one of the preceding claims, characterized by at least one measuring coupling (54) and/or at least one measuring sensor (58), wherein the measuring coupling (54) and/or the measuring sensor (58) are/is disposed in at least one of the plurality of discharge lines (20).

8. The metering device (4, 82, 96) as claimed in one of the preceding claims, characterized by a check unit and/or a controller unit (60) for monitoring and/or controlling a parameter of the outgoing fluid.

9. The metering device (4, 82, 96) as claimed in one of the preceding claims, characterized by a material block (62), wherein the plurality of conveying devices (18) are in each case at least partially disposed in the material block (18).

10. A metering system (2, 80, 94) having a metering device (4, 82, 96) as claimed in one of the preceding claims, characterized by a pump unit (10) which on the discharge side is connected to the supply line (6), and by a fluid tank (16) which on the discharge side is connected to the pump unit (10).

11. A method for metering a fluid, wherein a metering device (4, 82, 96) comprises a common supply line (6) and a plurality of discharge lines (20), in which method the fluid is supplied by way of the common supply line (6) and is dispensed by way of the plurality of discharge lines (20), characterized in that the metering device (4, 82, 96) comprises a plurality of conveying devices (18) having in each case one cavity (24) and one piston (26), in which method the fluid is supplied to the plurality of conveying devices (18), wherein the cavities (24) of the plurality of conveying devices (18) receive the fluid, and each of the conveying devices (18) dispenses a predetermined volumetric flow to in each case one of a plurality of discharge lines (18), wherein the pistons (26) of the plurality of conveying devices (18) displaces the fluid.

12. The method as claimed in claim 11, characterized in that the plurality of conveying devices (18) are driven and/or moved in a synchronous manner.

13. The method as claimed in claim 11 or 12, characterized in that the volumetric flow is at least 1 ml/min and at most 100 l/min.

14. The method as claimed in one of claims 11 to 13, characterized in that receiving of the fluid and displacing of the fluid take place successively.

15. The method as claimed in one of claims 11 to 14, characterized in that receiving of the fluid and displacing of the fluid take place simultaneously.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0060] In the drawings:

[0061] FIG. 1 shows a circuit diagram of a metering system;

[0062] FIG. 2 shows a circuit diagram of a metering device;

[0063] FIG. 3 shows an exemplary design embodiment of the metering device from FIG. 2;

[0064] FIG. 4 shows the exemplary design embodiment of the metering device from FIG. 3 in another perspective;

[0065] FIG. 5 shows a sectional view of the metering device from FIG. 3 and FIG. 4;

[0066] FIG. 6 shows a schematic longitudinal section through one of the conveying devices from FIG. 2 to FIG. 4;

[0067] FIG. 7 shows a schematic longitudinal section through an alternative design embodiment of the conveying devices;

[0068] FIG. 8 shows a circuit diagram of another metering system;

[0069] FIG. 9 shows a circuit diagram of another metering device;

[0070] FIG. 10 shows a schematic longitudinal section through one of the conveying devices from FIG. 8; and

[0071] FIG. 11 shows a circuit diagram of a further metering system.

DESCRIPTION OF EMBODIMENTS

[0072] FIG. 1 shows a schematic circuit diagram of a metering system 2. The metering system 2 has a metering device 4, having a supply line 6 and a return line 8, for metering a fluid. The metering system 2 furthermore comprises a pump unit 10 which on the discharge side is connected to the supply line 6 and on the entry side is connected to the return line 8. The pump unit 10 comprises an initial pressure pump 12 as well as a pressure control valve 14.

[0073] The metering system 2 moreover comprises a fluid tank 16 which on the discharge side as well as on the entry side is connected to the pump unit 10.

[0074] The fluid tank 16 as well as the pump unit 10 supply the metering device 4 with fluid. For example, the fluid on the discharge side of the initial pressure pump 12 of the pump unit 10 is pressurized to approx. 1 bar to 3 bar.

[0075] The metering system furthermore can comprise a spray device (not illustrated) (cf. FIG. 11).

[0076] The metering system 2 in this exemplary embodiment is a metering system 2 in a rolling mill. The fluid is in particular a lubricant, in particular for lubricating rollers of the rolling mill and/or of a rolling gap of the rolling mill. For example, the rolling mill can be a rolling mill for hot rolling and/or cold rolling.

[0077] FIG. 2 shows a circuit diagram of the metering device 4 from FIG. 1. The metering device 4 comprises a plurality of conveying devices 18. The supply line 6 is a common supply line 6.

[0078] The plurality of conveying devices 18 on the inlet side are in each case connected to the common supply line 6. In particular, the common supply line 6 opens into the plurality of conveying devices 18.

[0079] The metering device 4 furthermore comprises a plurality of discharge lines 20. Each of the discharge lines opens into a discharge 21. One of the plurality of conveying devices 18 on the discharge side is in each case connected in each case to one of the plurality of discharge lines 20.

[0080] Each of the conveying devices 18 has a round cross section and is cylindrical. Each of the conveying devices 18 is in each case furthermore embodied as a metering cylinder. Moreover, each of the conveying devices 18 is in each case a piston pump.

[0081] The plurality of conveying devices 18 are of identical configuration and have an identical cross-sectional area and an identical cavity volume.

[0082] Each of the conveying devices 18 is in each case embodied as a double-action metering cylinder 22 (cf. FIG. 6). Each of the double-action metering cylinders 22 comprises two cylinder chambers 24. The two cylinder chambers 24 form the cavity of the respective double-action metering cylinder 22. Each of the double-action metering cylinders 22 furthermore comprises in each case one piston 26 which delimits the respective first cylinder chamber 24 in relation to the respective second cylinder chamber 24. Each of the pistons 26 has a piston seal 27.

[0083] Each of the double-action metering cylinders 22 is configured as a double-rod cylinder, also referred to as a synchronous cylinder. Moreover, each of the double-action metering cylinders 22 (cf. FIG. 6) has a continuous piston rod 28. The piston 26 is fixedly connected to the piston rod 28.

[0084] The plurality of conveying devices 18 (that is all of the latter) are furthermore intercoupled, in particular by way of a coupling unit 30. The coupling unit 30 is embodied as a coupling plate.

[0085] The plurality of conveying devices 18 (that is all of the latter) are in particular mechanically interconnected/connected among one another by way of a rigid mechanical connection 32. The mechanical connection 32 is established by way of the coupling unit 30.

[0086] The metering device 4 moreover comprises a drive unit 34 which is embodied as a common drive unit 34.

[0087] The plurality of conveying devices 18 are mechanically connected to the drive unit 34. The drive unit 34 drives the plurality of conveying devices 18 in a synchronous manner. In particular, the piston rod 28 by the drive unit 34 is in each case driven or moved, respectively, conjointly with the piston 26.

[0088] The drive unit 34 comprises a linear drive 36 which can convert a rotary movement to a linear movement. The drive unit 34 furthermore has a shaft 38 which is embodied as a spindle. The drive unit 34 by way of the shaft 38 is mechanically connected to the coupling unit 30.

[0089] A sensor 40 is integrated in the drive unit 34. The sensor 40 is configured as a rotation speed sensor. A drive speed of the drive unit 34 can first be determined with the aid of the sensor 40. Furthermore, a speed of one of the pistons 26, in particular of all pistons 26, and thus a momentary volumetric flow, can be determined with the aid of the sensor 40.

[0090] The metering device 4 moreover comprises a plurality of pressure control valves 42. The return line 8 is a common return line 8. Each of the conveying devices 18 by way of one of the plurality of pressure control valves 42 is connected to the return line 8. Should a pressure in one of the discharge lines 20 exceed a threshold value, the respective pressure control valve 42 ensures that the fluid can run off by way of the return line 8.

[0091] Fluid which is dispensed by/conveyed out of the respective conveying device 18 but is not dispensed by way of the respective discharge line 20 is returned to the pump unit by the common return line 8.

[0092] The metering device 4 furthermore comprises a plurality of switch valves 44. For example, one of the switch valves 44 is in each case disposed in each discharge line 20. Each of the switch valves 44 has an electric solenoid 46 by which the respective switch valve 44 is switched.

[0093] Each of the switch valves 44 in each case has two positions. The first position of the switch valve 44 is a passing position at which the respective conveying device 18 is connected to the respective discharge 21 of the metering device 4. The second position of the switch valve 44 is a return flow position at which the respective conveying device 18 is connected to the return line 8. Accordingly, each of the conveying devices 18 by way of the respective switch valve 44, and depending on the position of the respective switch valve 44 can be connected to the return line 8.

[0094] The metering device 4 furthermore comprises a check unit 48 which is connected to the plurality of switch valves 44 by a data connection 50. The data connection 50 can be established by a cable and/or in a wireless manner. The switch valves 44 are actuated and/or switched while using the check unit 48.

[0095] When rolling a wide strip, for example, all switch valves 44 can be at the passing position. Furthermore, when rolling a narrow strip, for example, the switch valves 44 that are located on the right and the left according to the drawing can be moved to the return flow position, while the switch valves 44 that are disposed in the center according to the drawing are at a passing position. Moreover, in the event of maintenance of the rolling mill and/or in the event of maintenance of the metering device, for example, all switch valves can be moved to the return flow position.

[0096] The metering device 4 has a plurality of check valves 52 which are in each case disposed on the inlet side or on the outlet side of a respective conveying device 18.

[0097] The metering device 4 furthermore comprises a plurality of measuring couplings 54 and a plurality of measuring sensors 56. One of the plurality of measuring couplings 54 and one of the plurality of measuring sensors 56 are in each case disposed in each of the plurality of discharge lines 20. Each of the measuring sensors 56 is in each case a volumetric flow sensor, for example. Furthermore, a further measuring sensor 58 which is a pressure sensor and/or a temperature sensor, for example, is disposed on/connected to one of the measuring couplings 54. In principle, a further measuring sensor 58 can in each case be disposed on each of the measuring couplings 54.

[0098] The metering device 4 comprises a controller unit 60 for monitoring and/or controlling a parameter of the outgoing fluid. The parameter can be a pressure, a temperature, and/or a volumetric flow, for example.

[0099] The controller unit 60 is connected to each of the volumetric flow sensors 56 by a data connection 50. In this way, the volumetric flow can be monitored at each of the discharge lines 20, in particular while using the controller unit 60. The controller unit 60 is furthermore connected to the drive unit 34 by a data connection 50, in particular for controlling a drive speed of the drive unit 34. The volumetric flow can be set or regulated, respectively, in this way.

[0100] The controller unit 60 is furthermore connected to the further measuring sensor 58 which is a pressure sensor and/or a temperature sensor. The pressure and/or the temperature at one of the discharge lines 20 can be monitored in this way, in particular while using the controller unit 60. A malfunction, for example an increase in pressure by virtue of clogging, and/or a drop in pressure by virtue of leaking, can be identified in a timely manner in this way.

[0101] The previously mentioned sensor 40 is also connected to the controller unit 60 by way of a data connection 50. The sensor measures the current rotations of the drive unit 34, or the drive speed of the drive unit 34, respectively. The rotations or drive speed are monitored by the control unit 60.

[0102] The controller unit 60 in this exemplary embodiment comprises the above-mentioned check unit 48 for setting the switch valves 44.

[0103] The width of a rolled strip which is to be rolled/is being rolled is known to the controller unit 60, or to the check unit 48, respectively. The switch valves are switched in a corresponding manner. Furthermore, a rolling speed is known to the controller unit 60, from which the controller unit 60 can draw a conclusion in terms of a required volumetric flow of fluid. A required drive speed of the drive unit 34 is calculated from the required volumetric flow. The controller unit 60 actuates the drive unit 34 in a corresponding manner. The drive speed set is verified and optionally readjusted by means of the sensor 40. If a volumetric flow that deviates from the required volumetric flow is measured by means of one of the volumetric flow sensors 56, the controller unit 60 in this instance can in turn readjust the drive speed of the drive unit 34.

[0104] The metering device 4 is used for rolling a continuous rolled strip, for example.

[0105] FIG. 3 schematically shows an exemplary design embodiment of the metering device 4 from FIG. 2. FIG. 4 shows the same exemplary design embodiment of the metering device 4 as in FIG. 3, but from another perspective.

[0106] The metering device 4 in FIG. 3 and FIG. 4 comprises a material block 62. The material block is a block of solid material, for example of steel, in particular of stainless steel. The plurality of conveying devices 18 are in each case at least in part disposed in the material block 62. The material block 62 comprises in particular cylindrical bores 64 (cf. FIG. 5 and FIG. 6) which penetrate the material block 62. One of the conveying devices 18 is disposed in each of the bores 64.

[0107] Each of the conveying devices 18 furthermore comprises two fixing elements 66 which are in each case configured as a cylinder head. Each of the conveying devices 18 at both ends of the bore 64 is in each case fixed or held, respectively, by one of the fixing element 66. The fixing elements 66 are connected, in particular screw-fitted, to the material block 62. A simple and rapid replacement of the individual conveying devices 18 or of parts thereof is enabled in this way.

[0108] The material block 62 furthermore comprises clearances which are in each case configured as a blind bore. Moreover, the pressure control valves 42, the switch valves 44, the check valves 52, the measuring coupling 54, the measuring sensors 56 are at least in part disposed, for example screw-fitted, in the material block 62, in particular in the clearances.

[0109] The material block 62 is in this way configured as a cylinder and valve housing.

[0110] The material block 62 enables a compact and robust construction mode of the metering device 4. Lines or ducts, respectively, between individual components are embodied by bores in the material block 62, and on account of this construction mode, are kept short such that leakages can be reduced and/or avoided.

[0111] The metering device 4 furthermore comprises linear guides 68. The coupling unit 30 is guided with the aid of the linear guides 68. The linear guides 68 increase the mechanical stability of the metering device 4 in this way.

[0112] The coupling unit in FIG. 3 and FIG. 4 is illustrated so as to be transparent in order for the linear guides 68 and the piston rods 28 to be better visible.

[0113] The material block 62 having the bores 64 and clearances thereof can be manufactured in a cost-effective and automated manner.

[0114] FIG. 5 shows a section through the metering device 4 from FIG. 3 and FIG. 4 along two conveying devices 18.

[0115] The material block 62 in this image is illustrated so as to be transparent. Furthermore, hatching of the sectioned elements has been dispensed with for the sake of better clarity.

[0116] The cylindrical bores 64 which penetrate the material block 62 can be seen in this image. One of the conveying devices 18 is disposed in each of said bores 64.

[0117] It can be further seen in this image that the pressure control valves 42, the switch valves 44, check valves 52, and the measuring coupling 54 are at least in part disposed in the material block 62, in particular in the clearances which are in each case configured as a blind bore.

[0118] The check valves 52 are disposed completely in the material block 62. In the case of the switch valves 44, a part, in particular the electrical part (solenoid 46 and the electrical connector) of the switch valves protrudes from the material block 62. The pressure control valves 42 also protrude in part from the material block 62, in particular so as to be able to set the threshold value, or the switching time, respectively, of the pressure control valves 42. The measuring couplings 54 likewise protrude in part from the material block 62. A measuring sensor 58 (cf. FIG. 2) can thus be connected to the respective measuring coupling 54.

[0119] FIG. 6 shows a schematic longitudinal section through one of the conveying devices 18 from FIG. 2 to FIG. 5. The conveying device 18 is disposed in the cylindrical bore 64 which penetrates the material block 62.

[0120] The conveying device 18 is embodied as a double-action metering cylinder 22. The double-action metering cylinder furthermore comprises the piston rod 28 which is fixedly connected to the piston 26, and a cylinder tube 70 which forms the external wall. The piston 26 within the cylinder tube 70 moves in a reciprocating manner in the direction of the longitudinal axis of the cylinder tube 70. According to the drawing, the piston 26 within the cylinder tube 70 moves in the vertical direction toward the right and the left.

[0121] The double-action metering cylinder 22 comprises two cylinder chambers 24. The piston 26 separates the first cylinder chamber 24 from the second cylinder chamber 24. Each of the cylinder chambers by way of an inlet 72 is connected to the supply line 6, and by way of an outlet 74 is connected to the respective discharge line 20. While the first cylinder chamber 24 of the double-action metering cylinder 22 receives the fluid, the second cylinder chamber 24 of the same metering cylinder 22 simultaneously dispenses the fluid, and vice versa.

[0122] The conveying device 18 is fixed with the aid of the two fixing elements 66 (here cylinder heads). The fixing elements 66 are screw-fitted to the material block 62. Each of the fixing elements 66 furthermore comprises a plurality of seals 76 which are configured as annular seals. The seals guarantee a tightness of the conveying device 18. Moreover, each of the fixing elements 66 comprises a scraper 78. The respective scraper 78 is configured as a rubber ring. The scrapers 78 likewise ensure a tightness of the conveying device 18. The cylinder tube 70 also comprises a seal 76 which seals the fixing element 66 in relation to the material block 62.

[0123] In FIG. 6 the left cylinder chamber 24 according to the drawing, which represents the first cylinder chamber 24, is completely filled. Furthermore, the right cylinder chamber 24 according to the drawing, which represents the second cylinder chamber 24, is completely emptied. The piston 26 accordingly is located in the terminal position on the right according to the drawing. The piston rod 28, conjointly with the piston 26, is subsequently moved by the drive unit toward the left according to the drawing, such that the left, first cylinder chamber 24 of the double-action metering cylinder dispenses the fluid by way of the left outlet 74 according to the drawing. The right, second cylinder chamber 24 simultaneously receives the fluid by way of the right inlet 72 according to the drawing. The piston rod 28, conjointly with the piston 26, is thus moved to the left until the left, first cylinder chamber 24 is completely emptied and the right cylinder chamber is completely filled.

[0124] The piston rod 28, conjointly with the piston 26, then moves toward the right such that the left, first cylinder chamber 24 of the double-action metering cylinder receives the fluid by way of the left inlet 72 according to the drawing, and the right, second cylinder chamber 24 simultaneously dispenses the fluid by way of the right outlet 74 according to the drawing, until the left, first cylinder chamber 24 according to the drawing is completely filled, and the right, second cylinder chamber 24 according to the drawing is completely emptied. The procedure is repeated as a circulatory system. Continuous metering is possible in this way.

[0125] The piston 26 in an exemplary manner has an external diameter of 14 mm. The piston rod 28 in a furthermore exemplary manner has a diameter of 10 mm. The so-called stroke of the conveying device 18 is, for example, 160 mm. The distance which the piston 26 can cover at most in one direction can be referred to as the stroke. The cavity volume of the conveying device 18 is thus 12 ml, for example.

[0126] The fluid that is received by the respective cylinder chamber 24 is pressurized to 1 bar to 3 bar, for example. Furthermore, the fluid that is dispensed by the respective cylinder chamber is pressurized to 5 bar to 10 bar, for example. The threshold value of the check valves 52 is adapted to the pressure conditions of the fluid in a corresponding manner. Accordingly, the respective check valve 52 that is disposed on the outlet side of the respective cylinder chamber 24 has a higher threshold value than the respective check valve 52 that is disposed on the inlet side of the respective cylinder chamber 24.

[0127] The volumetric flow which can in each case be conveyed by a conveying device 18 (hereunder simply referred to as the volumetric flow) in this exemplary embodiment corresponds to the volumetric flow which in each case can be dispensed by way of one of the discharge lines 20. The volumetric flow can be set so as to depend on the drive speed of the drive unit 34. For example, the volumetric flow can be set in a range from 3.5 ml/min to 64 ml/min.

[0128] FIG. 7 shows a schematic longitudinal section through an alternative design embodiment of the conveying devices 18 from FIG. 6. The description hereunder is substantially limited to the points of differentiation in relation to the conveying devices 18 from FIG. 6, to which reference is made in terms of features and functions that remain the same. Elements that substantially remain the same are in principle identified by the same reference signs, and features which are not mentioned are incorporated in the following exemplary embodiment without being described once again.

[0129] Each of the cylinder chambers 24 has an inlet 72 which simultaneously functions as an outlet 74.

[0130] FIG. 8 shows a schematic circuit diagram of a further metering system 80 having another metering device 82 for metering a fluid. The description hereunder is substantially limited to the points of differentiation in relation to the exemplary embodiment from FIG. 1 to FIG. 6, reference being made to the latter in terms of features and functions that remain the same. Elements that substantially remain the same are in principle identified by the same reference signs, and features which are not mentioned are incorporated in the following exemplary embodiment without being described once again.

[0131] The supply line 6 of the metering device 82 simultaneously functions as a return line 8. In principle, a design embodiment in which the supply line 6 and the return line 8 are present so as to be separate from one another (in a manner analogous to that of the first exemplary embodiment) would in principle also be possible.

[0132] FIG. 9 shows a circuit diagram of the metering device 82 from FIG. 8.

[0133] Each of the conveying devices 18 is in each case embodied as a single-action metering cylinder 84 (cf. FIG. 10). Each of the single-action metering cylinders 84 expediently comprises a single cylinder chamber 24. Each of the single-action metering cylinders 84 furthermore comprises in each case one piston 26 and one piston rod 86. The piston 26 is fixedly connected to the piston rod 86, wherein the piston rod 86 is located only on one side of the piston 26.

[0134] Each of the conveying devices 18 has one leakage bore 88. The metering device 82 furthermore comprises a collector line 90 which is connected to the leakage bores 88.

[0135] A sensor 92 is disposed on the mechanical connection 32, in particular on the coupling unit 30 (instead of the sensor 40 on the drive unit 34 in the first exemplary embodiment). The sensor 92 is a position sensor. The sensor 92 can determine the position of the coupling unit 30 and thus the speed of the coupling unit 30 or the speed of the pistons 26, respectively, and/or the volumetric flow.

[0136] The sensor 92 is also connected to the controller unit 60 by way of a data connection 50. The sensor 92 measures the position of the coupling unit 30 and thus the speed of the coupling unit 30, or the speed of the pistons 26, respectively, said speed being monitored by means of the control unit 60.

[0137] The metering device 82 in this exemplary embodiment does not comprise any pressure control valves (as opposed to the first exemplary embodiment in FIG. 1 to FIG. 6), although this would be possible in principle.

[0138] The metering device 82 is used in a hot-rolling process, for example, in particular for rolling individual rolled strips from slabs. If the respective conveying devices 18 are completely filled with fluid, the quantity of fluid is sufficient for an entire rolled strip. The filling of the conveying devices 18 in this instance can be performed between rolling a first strip and rolling a second strip, for example.

[0139] FIG. 10 shows a longitudinal section through one of the conveying devices 18 from FIG. 9. The conveying device 18 is embodied as a single-action metering cylinder 84 and comprises a single cylinder chamber 24. The cylinder chamber 24 forms the cavity of the single-action metering cylinder 84. The cylinder chamber 24 can successively receive and dispense the fluid.

[0140] The cylinder chamber 24 in FIG. 10 is partially filled. The piston 26 is located in the center according to the drawing.

[0141] The piston rod 86, conjointly with the piston 26, subsequently moves to the right such that the cylinder chamber 24 receives the fluid by way of the inlet 72 until the cylinder chamber 24 is completely filled.

[0142] The piston rod 86, conjointly with the piston 26, is subsequently moved by the drive unit to the left according to the drawing such that the cylinder chamber 24 dispenses the fluid by way of the outlet 74. The metering of the fluid is performed in this way. The piston rod 86, conjointly with the piston 26, can move to the left until the cylinder chamber 24 is completely emptied. The cylinder chamber 24 subsequently has to be refilled. The procedure is repeated as a circulatory system. Discontinuous metering is possible in this way.

[0143] The cylinder chamber 24 can be completely filled in 11 s, for example. Furthermore, the cylinder chamber is completely emptied in, for example, 11 s to 205 s, depending on the volumetric flow set.

[0144] The conveying device 18 has a leakage bore 88 for identifying leakages. Furthermore, the conveying device 18 is connected to the collector line 90 of the metering device 82 by way of the leakage bore 88.

[0145] In the event of a leakage from the conveying device 18, some fluid exits by way of the leakage bore 88. The fluid that has exited by virtue of the leakage accumulates in the collector line 90 and can be detected visually and/or by way of a measuring apparatus. In the event of a defect in one of the conveying devices 18, a timely replacement of the defective conveying device 18 can be guaranteed in this way.

[0146] FIG. 11 shows a further metering system 94 having a metering device 96. The description hereunder is substantially limited to the points of differentiation in relation to the exemplary embodiment from FIG. 8 to FIG. 10, reference being made to the latter in terms of features and functions that remain the same. Elements that substantially remain the same are in principle identified by the same reference signs, and features which are not mentioned are incorporated in the following exemplary embodiment without being described once again.

[0147] Some elements (such as, for example, a pump unit, a fluid tank, a drive unit, a return line, pressure control valves, switch valves, measuring couplings, measuring sensors, etc.) are not shown in FIG. 11 but could in principle be incorporated individually or in any arbitrary combination from the other exemplary applications.

[0148] The metering system 94 comprises a spray device 98 having a plurality of nozzles 100. The spray device 98 is furthermore connected to the plurality of discharge lines 20 of the metering device 96.

[0149] The metering device 96 comprises a plurality of conveying devices 18 which at least in part differ from one another, for example in terms of the cross-sectional area thereof and in terms of the cavity volume thereof. For example, the respective cross-sectional area and the respective cavity volume of the conveying devices 18 disposed on the right and on the left according to the drawing is smaller than in the conveying devices 18 disposed in the center according to the drawing. The cross-sectional areas of the conveying devices 18, or the different cavity volumes of the conveying devices 18, respectively, enable different volumetric flows.

[0150] Furthermore, more nozzles 100 of the spray device are connected to the conveying devices 18 that are disposed in the center according to the drawing than are connected to the conveying devices 18 that are disposed on the right and on the left according to the drawing.

[0151] A desired spatial spray profile can be set by way of a corresponding circuit design including the nozzles 100 and of a corresponding disposal of the nozzles 100.

[0152] Even though the invention has been illustrated and described in more detail by way of the preferred exemplary embodiments, the invention is not restricted by the examples disclosed, and other variations may be derived therefrom by a person skilled in the art without departing from the scope of protection of the invention.

LIST OF REFERENCE SIGNS

[0153] 2 Metering system

[0154] 4 Metering device

[0155] 6 Supply line

[0156] 8 Return line

[0157] 10 Pump unit

[0158] 12 Initial pressure pump

[0159] 14 Pressure control valve

[0160] 16 Fluid tank

[0161] 18 Conveying device

[0162] 20 Discharge line

[0163] 21 Discharge

[0164] 22 Metering cylinder

[0165] 24 Cylinder chamber

[0166] 26 Piston

[0167] 27 Piston seal

[0168] 28 Piston rod

[0169] 30 Coupling unit

[0170] 32 Mechanical connection

[0171] 34 Drive unit

[0172] 36 Linear drive

[0173] 38 Shaft

[0174] 40 Sensor

[0175] 42 Pressure control valve

[0176] 44 Switch valve

[0177] 46 Solenoid

[0178] 48 Check unit

[0179] 50 Data connection

[0180] 52 Check valve

[0181] 54 Measuring coupling

[0182] 56 Measuring sensor

[0183] 58 Measuring sensor

[0184] 60 Controller unit

[0185] 62 Material block

[0186] 64 Bore

[0187] 66 Fixing element (cylinder head)

[0188] 68 Linear guides

[0189] 70 Cylinder tube

[0190] 72 Inlet

[0191] 74 Outlet

[0192] 76 Seal

[0193] 78 Scraper

[0194] 80 Metering system

[0195] 82 Metering device

[0196] 84 Metering cylinder

[0197] 86 Piston rod

[0198] 88 Leakage bore

[0199] 90 Collector line

[0200] 92 Sensor

[0201] 94 Metering system

[0202] 96 Metering device

[0203] 98 Spray device

[0204] 100 Nozzles