DEVICE AND METHOD FOR THE CONTROLLED SUMPTION OF HIGH-PRESSURE FLUID

Description

[0001] The invention relates to a device for the controlled supply of high-pressure fluid by means of a pressure generator formed with a fluid supply and a fluid inlet in the high-pressure cylinder and a high-pressure plunger movable in the cylinder with a drive thereof and a supply of high-pressure fluid into a high-pressure line, optionally with a pulsation damper in the line, with a pressure sensor for controlling the drive and optionally a switchable pressure relief valve.

[0002] The invention further relates to a method for providing high-pressure fluid to consumers, for example water jet cutting systems with adjustable parameters when using pressure generators with high-pressure cylinders and high-pressure plungers according to the above device.

[0003] Devices for the production of high-pressure fluids of various types are becoming increasingly important in process engineering, and these devices must meet requirements for the highest precision while simultaneously increasing the speed of the controls.

[0004] Especially at high fluid pressures, pressure fluctuations that can originate from pressure intensifiers must be minimized for process engineering reasons, but also for material engineering reasons, because these pressure fluctuations cause alternating mechanical stress on parts of the device and can lead to material fatigue or fatigue fractures.

[0005] US6506030 B1 discloses a method for generating a high-pressure fluid stream.

[0006] In a hydraulic drive for the provision of high-pressure fluid, it was proposed according to EP 2 610 490 B1 to regulate the quantity and / or pressure of the same by using a pressure intensifier having two plungers and a switching block with a pump driven by a controllable servomotor.

[0007] In order to minimize the pressure drop in the high-pressure fluid during the switching of a pressure intensifier for waterjet cutting systems with two plungers, it was suggested according to EP 3 012 453 A2 that the servo drive for a hydraulic pump be bidirectional, i.e., with a reversible motor, and thus provide direct impingement on a hydraulic pressure intensifier.

[0008] From EP 3 012 075 B1, a method for operating a waterjet cutting system with a high-pressure pump comprising several plungers and connected to a water tank is known, wherein the plungers of the high-pressure pump are moved via a crankshaft, stopped, and restarted by a servomotor. Bearing play on the crankshaft and also in the plunger joints, as well as the inertial forces during acceleration and deceleration in the course of controlling the drive, can have a detrimental effect.

[0009] The known devices belonging to the state of the art may have disadvantages with regard to a complicated design, significant wear, complex controllability with potentially insufficient speed, and less-than-ideal economic efficiency.

[0010] The object of the invention is now to provide a new device for regulated

[0011] To provide high-pressure fluid of the type mentioned above, which overcomes the disadvantages of the prior art.

[0012] This problem is solved by the present invention with the method according to claim 1 and the device according to claim 4.

[0013] The object is achieved according to the invention in that the pressure generator or several cooperating pressure generators each have an electric linear motor with stator and forcer for driving the high-pressure plunger in the high-pressure cylinder and the electric linear motor(s) is / are connected to an electrical control unit which includes an electrical power supply, a servo converter for electric linear motors, a programmable computing unit and measured value inputs.

[0014] The advantages achieved with the invention consist in particular of a simple design, economical operation, comprehensive controllability and a high control speed of the device.

[0015] The potentially cooperating pressure generators each have an electric linear motor with stator and forcer, whereby the terms "stator and forcer" do not represent an embodiment of force application, but describe a determination of the motor parts that can be moved relative to each other in the device.

[0016] For a pressure generator with a high-pressure cylinder and a high-pressure plunger movable within it, an axially aligned arrangement of an electric linear motor offers significant functional advantages.

[0017] A force flow occurs directly in the direction of movement of the high-pressure plunger without a conventional path, converting rotational energy into translational energy, thereby minimizing the inertial forces during acceleration or deceleration of the transmission parts.

[0018] For all operating modes and fluid conveyances, a high-pressure plunger driven by an electric linear motor represents a highly economical solution when a reliable supply of high-pressure fluid is ensured in the high-pressure cylinder.

[0019] Electric linear motors offer a simple design and immediate, precise controllability for direct translational work movements using an electrical control unit.

[0020] An electrical control unit, comprising an electrical power supply, a servo inverter for one or more electric linear motors (which may also be positioned in cooperating pressure generators), a programmable computing unit and measured value inputs, can precisely control the respective movement of the individual electric linear motors with the high-pressure plungers in synchronized timing.

[0021] In one embodiment of the invention, with a secure fluid supply to the high-pressure cylinder, the forcer of the linear motor and thus the high-pressure plunger can be moved at increased speed to any filling position in the high-pressure cylinder by means of the electrical control unit and thus positioned for a programmable or controllable high-pressure stroke.

[0022] According to the aforementioned embodiment of the invention, the device for the controlled supply of high-pressure fluid can be formed with two or more than two pressure generators, which are connected to a common high-pressure line. Connecting the electric linear motors to an electrical control unit enables the pressure generators to be functionally combined with regard to reducing pressure fluctuations in the high-pressure line or eliminating the need for a pulsation dampener.

[0023] In a further embodiment of the invention, the pressure generators are formed with two axially spaced, opposing high-pressure cylinders with high-pressure plungers, and an electric linear motor connected to an electrical control unit is positioned between these high-pressure cylinders. The forcer, or the moving part of the linear motor, has fastening means or force connections for the high-pressure plungers.

[0024] Advantageously, during the movements of the forcer of the electric linear motor, a filling of a high-pressure cylinder with a fluid and a pressure injection of high-pressure fluid into a high-pressure line from the opposite high-pressure cylinder with an intermediate controllable electric linear motor can take place simultaneously.

[0025] It can also be advantageous for the provision of high-pressure fluid with low pressure fluctuations if two or more systems are connected to a high-pressure fluid line and the electric linear motors can be activated in a phase-shifted manner by an electric control unit.

[0026] To intensify the force exerted by the high-pressure plungers in the high-pressure cylinders, the pressure generator(s) can be advantageously driven by two or more coupled electric linear motors with an electric control unit, whereby a parallel or serial arrangement of the forcers of linear motors in the pressure system on the high-pressure plungers can be used to increase the translational forces.

[0027] The present invention also relates to a method for providing high-pressure fluid with adjustable parameters for consumers of the type mentioned above, for example for waterjet cutting systems.

[0028] Due to general technological developments in process engineering, particularly in the aforementioned plants, the shortcomings of previous methods for providing high-pressure fluid with adjustable parameters for consumers when using pressure generators with high-pressure cylinders and high-pressure plungers movable within them must also be eliminated, which is the further objective of the invention.

[0029] This objective is achieved by moving the high-pressure plunger(s) with an electric linear motor(s), with the process parameters being controlled by an electrical control unit. The control unit comprises a power supply, a servo inverter for the electric linear motor(s), a programmable logic controller (PLC) with input values ​​for at least the high-pressure fluid and plunger position in the high-pressure cylinder(s), and it controls the servo inverter.

[0030] The advantages achieved with the method according to the invention are essentially in that the electric linear motor(s) provide a direct drive to the high-pressure plunger(s), thus achieving an advantageous direct translational movement of the high-pressure plunger and forcer or drive.

[0031] The force flow into the high-pressure plunger is thus achieved in a favorable manner without converting rotational energy into linear energy, while also providing a simple, robust, compact design of the transmission means, high accuracy due to increased detection of the current position of the parts, improved precision of the motion control at high speed, and also force impulses of the stator into an anchoring of the same during high acceleration of the forcer, which occur in fractions of milliseconds.

[0032] In a preferred embodiment of the method according to the invention, it is provided that the high-pressure plunger transmits a signal to the control unit when a definable penetration depth into the high-pressure cylinder is reached, and the servo inverter is controlled in such a way that the forcer of the linear motor moves the high-pressure plunger at increased speed into a changed position, in particular into the starting position for a maximum pressure stroke.

[0033] Using the above embodiment of the method, it is advantageously possible to reduce the filling time of a high-pressure cylinder of the pressure generator and thereby limit the pressure drop in the high-pressure fluid when using a high-volume pulsation dampener.

[0034] When using two pressure generators in the system, which are phased by a control unit and operated with linear motors regulated according to the above procedure, a pulsation damper in the high-pressure line can be dispensed with because the pressure in the high-pressure fluid is maintained even when the pressure generators change direction due to a faster filling of the high-pressure cylinder followed by pressurization by the high-pressure plunger.

[0035] In order to provide a high-pressure fluid with minimal fluctuations in two or more cooperating devices, each consisting of axially spaced, opposing high-pressure cylinders with high-pressure plungers and linear motors moving the high-pressure plungers, it is advantageously provided that a control unit with a servo inverter synchronizes the linear motor movements of the individual devices and regulates them according to an actual pressure measurement in the high-pressure line and the set specifications.

[0036] The invention will be explained in more detail below with reference to schematic diagrams and schematic representations, which at most only show one possible embodiment.

[0037] They show: Fig. 1 High-pressure pump with a pressure generator and electric linear motor drive. Fig. 1A High-pressure curve of pump acc. Fig. 1 Fig. 2 High-pressure pump with phased pressure generator Fig. 2A High-pressure curve pump acc. Fig. 2 Fig. 3 High-pressure pump with two pressure generators arranged in opposite directions with electric linear motor drive. Fig. 3A High-pressure profile of pump according to... Fig. 3 Fig. 4 High-pressure pump with synchronized pressure generators Fig. 5 High-pressure pump with coupled linear motor drive Fig. 6 High-pressure pump with longitudinally coupled linear motor drive Fig. 7 High-pressure pump with two-stage pressure boosting

[0038] The following list of reference symbols should facilitate the identification of parts and components in the illustrations and sketches: D, D', D", D‴Pressure generator L, L', L"Electric linear motor p 1 , p 2 Generator pressure [p]Pressure in high-pressure fluid [t]Time 1Fluid inlet 2Shut-off valve 3Pressure reducer 4Pre-pressure pump 5Filter unit 6Base plate 7Guide rail 8Guide carriage 9Stator 10Forcer 11Control line 12Electrical control unit 13Suction valve 14Pressure valve 15High-pressure cylinder 16Connection flange 17High-pressure plunger 18Plunger mounting 19Connecting plate 20Pulsation damper 21Pressure sensor 22High-pressure connection 23Pressure relief valve 24Drainage connection

[0039] Fig. 1 Figure 1 shows a high-pressure pump with a fluid inlet 1, a pressure generator D, an electric linear motor L and a high-pressure connection 22.

[0040] Because the schematic diagrams ( Fig. 1 bis Fig. 7 Since the high-pressure pumps shown can also be advantageously used as high-pressure pumps for water jet cutting systems, a water supply in the usual way was schematically drawn for the fluid supply.

[0041] They mean: Shut-off valve for the fluid: 2; Pressure reducing device (if required): 3; Pre-charge pump: 4 for rapid filling of the high-pressure cylinder: 15 of the pressure generator: D; Filter unit for cleaning the fluid: 5; Non-return valve: 13.

[0042] However, it is expressly stated that the high-pressure pumps according to the invention can be used advantageously for all fluid media.

[0043] After Fig.1 A pressure generator D with a high-pressure cylinder 15 and a high-pressure plunger 17 that can be inserted into it is fixed to a base plate 6 via a connecting flange 16. The high-pressure plunger 17 is moved directly in its axial direction by a forcer 10 of an electric linear motor L via a plunger mounting 18, with a stator 9 connected to the base plate 6.

[0044] In the present description of an electric linear motor, the terms forcer and stator refer to the moving part and the stationary part, respectively, regardless of their physical construction. It is also possible for the stator to be the moving part and the forcer to be stationary.

[0045] The electric linear motor L is connected to an electrical control unit 12, which includes at least an electrical power supply, a servo converter for the electric linear motor L, a programmable computing unit and measured value inputs.

[0046] An electrical control unit 12 regulates the direction of movement of the forcer and a direct force effect on the high-pressure plunger 17 in a high-pressure cylinder 15 of a pressure generator D, wherein in principle a non-return suction valve 13 in the fluid inlet and a further non-return valve 14 for conveying high-pressure fluid are provided.

[0047] Pressure fluctuations in the supply area of ​​a high-pressure fluid connection 22 are to be kept low, which is achieved by a pulsation damper 20.

[0048] A pressure sensor 21 transmits measured values ​​for a respective fluid pressure in the high-pressure range to the control unit 12, which measured values ​​can contribute to the control of the linear motor movement.

[0049] As is known, a pressure relief valve 23 with a drainage connection 24 can be provided in the line 20 of the high-pressure fluid.

[0050] In Fig. 1A The diagram schematically shows the pressure [p] profile in the high-pressure line 22 of a device according to Fig. 1 represented as a function of time [t].

[0051] By means of a movement of the forcer 10 of the electric linear motor L controlled by the control unit 12, the high-pressure plunger 17 is pressed into the high-pressure cylinder 15, whereby the fluid pressure [p] in the high-pressure line 20 in the area α rises to a predetermined pressure p 1.

[0052] After a conveying phase of fluid in the area β, the return stroke of the high-pressure plunger 17 is carried out by the forcer 10 of the electric linear motor L, which return stroke can optionally be carried out at an increased speed or in a shortened time controlled by the electrical control unit 12.

[0053] The pressure valve 14 closes and the fluid pressure in the pump system would decrease as a result of a withdrawal in the area γ as shown in the illustration. Fig. 1A The pressure drops to ambient pressure. However, a pulsation dampener 20 in the high-pressure line ensures a supply of high-pressure fluid to the system, thus delaying a pressure drop p 2 in the region δ.

[0054] When the high-pressure plunger 17 reaches its starting position in the high-pressure cylinder 15, a new pressure phase of the forcer 10 immediately follows, whereby the pressure drop p 2 in the fluid in the region δ of the diagram is absorbed and the specified delivery pressure p 1 is readjusted.

[0055] In Fig. 2 Figure 1 shows a high-pressure pump with a phased, or phase-operated, pressure generator D.

[0056] The individual print generators D, D', D" are each constructed identically to the one used in Fig. 1 As shown, however, the associated electric linear motors L, L', L" are connected to a control unit 12, which regulates the movement of the high-pressure plungers 17, 17', 17" as a function of time. In this way, fluid delivery to the high-pressure line 20 is coordinated and pressure fluctuations in this line are minimized, as shown in Fig. 2A is shown.

[0057] Fig. 3 The figure schematically shows a high-pressure pump with two pressure generators D and D' positioned opposite each other in the axial direction, with an electric linear motor positioned between them. While such a positioning of pressure generators D and D' is known per se, the arrangement of an intermediate electric linear motor L with a control unit 12 achieves significant advantages in terms of plant engineering and process engineering, which also solve problems in the prior art from an economic perspective.

[0058] In detail, the forcer 10 of an electric linear motor L is connected by means of plunger fixings 18, 18' to the respective opposing high-pressure plungers 17, 17' of the two high-pressure cylinders 15, 15' of the pressure generators D,D' to form a highly advantageous, compact, backlash-free, lightweight unit.

[0059] When high-pressure fluid is drawn from a port 22, the function of the electric linear motor L is immediately regulated by the electrical control unit 12. A linear movement of the forcer 10, in whichever direction, causes fluid to be conveyed to a pressure generator D and simultaneously fills the high-pressure cylinder 17' in the opposite pressure generator D'.

[0060] A representation of the pressure [p] over time [t] of a aforementioned high-pressure pump in operation shows Fig. 3A .

[0061] The two alternatively conveying and fluid-filled high-pressure cylinders 15,15' result in a largely stable conveying pressure p 1 in the high-pressure fluid with small pressure drops p 2 , caused by a switching of the two pressure generators D, D'.

[0062] In Fig. 4 A high-pressure pump with synchronized pressure generators can be schematically removed.

[0063] Such a fluid conveying device, exhibiting minimal pressure fluctuations in the area of ​​the high-pressure connection 22, is formed with four synchronously operating pressure generators D, D', D", D‴ or with two devices with pressure generators positioned opposite each other in the axial direction.

[0064] In a high-pressure pump like the one in Fig. 4 As shown, the electric linear motors L, L' are synchronously controlled by the electrical control unit 12 such that at least one pressure generator D delivers high-pressure fluid at all times under the conditions determined by the electrical control unit 12.

[0065] The following schematic representations reveal an intensification of the pressure forces on the high-pressure cylinders 17 from the pressure generator D by means of coupled electric linear motors.

[0066] In Fig. 5 A high-pressure pump with two pressure generators D, D' positioned opposite each other in the axial direction is shown, wherein an arrangement of electric linear motors L parallel to the axis is provided to increase the translational forces between the hydraulic pressure generators D, D'.

[0067] Fig. 6 The figure schematically shows a serial arrangement of electric linear motors L, L' between the hydraulic pressure generators D, D'.

[0068] In Fig. 7 Figure 1 shows a high-pressure pump with double pressure increase by means of two pumps driven by electric linear motors L, L'.

[0069] The initial pressure increase of the fluid from an inlet pressure 1 to a high-pressure area is achieved by means of a first linear motor pump system. From this high-pressure area, a further pressure increase of the high-pressure fluid is achieved by means of a second electric linear motor pump system. The control unit 12 regulates and coordinates the two electric linear motors L and L' of the two pumps.

Claims

1. Method for supplying high-pressure fluid with controllable parameters to consumers using at least one pressure generator (D, D', D', D") with a high-pressure cylinder (15) and a high-pressure plunger (17) moved therein, wherein the high-pressure plunger (17) is moved by at least one electric linear motor (L, L', L''), wherein the method parameters are controlled by means of an electric control unit (12), which control unit (12) comprises a power supply, a servo converter for the electric linear motor (L, L', L"), a programmable computing unit with measured value inputs of at least high-pressure fluid (21) and plunger position in the high-pressure cylinder (15), and controls the servo converter, characterized in that when a definable immersion depth in the high-pressure cylinder (15) is reached the high-pressure plunger (17) transmits a signal to the control unit (12), and the servo converter is controlled in such a way that the forcer (10) of the linear motor (L) moves the high-pressure plunger (17) at increased speed into a different position, in particular to the starting position for a maximum pressure stroke.

2. Method according to any one of the preceding claims, wherein two or more than two pressure generators (D, D', D", D‴) having a function according to claim 1 are combined in a high-pressure fluid line (22) with the proviso that the electric linear motors (L, L', L") are operated in a phased manner by means of a control unit (12) by servo converters, i.e. after a pressure phase or delivery phase of a first pressure generator (D), during which at least one further pressure generator (D') conveys high-pressure fluid, the high-pressure cylinder (15) is filled and pressure is built up in the fluid in the first pressure generator (D) in such a way that, towards the end of the pressure phase of the further pressure generator(s) (D', D") the first pressure generator (D) takes over the delivery of fluid and a drop in pressure in the high-pressure fluid line (22) is avoided.

3. Method according to any one of the preceding claims, wherein two or more than two cooperating devices, which are each formed with high-pressure cylinders (15) with high-pressure plungers (17) spaced apart in axial direction and positioned opposite one another, and have with linear motors (L, L') in between, which move the high-pressure plungers (17) with the proviso that a control unit (12) with a servo converter synchronizes the linear motor movements of the individual devices and regulates them in accordance with an actual pressure determination (21) in the high-pressure fluid (22) and the pressure specifications.

4. Device for the controlled supply of high-pressure fluid by means of at least one pressure generator (D) formed with a fluid supply and a fluid inlet (1) in a high-pressure cylinder (15) and a high-pressure plunger (17) movable therein with a drive therefor and a supply of high-pressure fluid into a high-pressure line (22), in particular with a pulsation damper (20) therein, with a pressure sensor (21) for controlling the drive and, in particular, with a switchable pressure relief valve (23), characterized in that the at least one pressure generator (D) has an electric linear motor (L) with a stator (9) and a forcer (10) for driving the high-pressure plunger (17) in the high-pressure cylinder (15), and the electric linear motor (L, L') is connected to an electric control unit (12), which comprises an electric power supply, a servo converter for electric linear motors (L), a programmable computing unit and measured value feeds, wherein the device is configured to perform the method according to any one of claims 1 to 3.

5. Device according to claim 4, characterized in that the pressure generator (D) is formed by a high-pressure cylinder (15) and the high-pressure plunger (17) can be moved from any determined position in the high-pressure cylinder (15) with a secured fluid inlet (1) therein by means of an electric linear motor drive (L) by an electric control unit (12) and can be positioned in such a way for a programmed and controllable high-pressure stroke.

6. Device according to any one of claims 4 or 5, characterized in that this device is formed with two or more than two pressure generators (D, D', D") according to claim 2, which pressure generators (D) are connected to a common high-pressure line (22) and the electric linear motors (L) have a connection to an electric control unit (12) and can be coordinated in function.

7. Device according to any one of claims 4 to 6, characterized in that the pressure generators (D, D') are formed by two high-pressure cylinders (15, 15') with high-pressure plungers (17, 17') spaced apart in axial direction and positioned opposite one another, and between these high-pressure cylinders (15, 15') a linear motor (L) connected to an electric control unit (12) is positioned and on the forcer (10) of the linear motor (L) spaced apart in longitudinal direction force connections or plunger fastenings (18, 18') are arranged, which are connected to the respective connecting parts for a plunger movement.

8. Device according to claim 7, characterized in that two systems are connected to a high-pressure fluid line (22) and the electric linear motors (L, L') can be driven in a phase-shifted manner by an electric control unit (12).

9. Device according to any one of claims 4 to 8, characterized in that the pressure generator(s) (D) can be driven in a controlled manner by two or more coupled electric linear motors (L, L') with an electric control unit (12).