Electrofluidic unit and method for its operation

Abstract

An electrofluidic unit (1) comprising at least one electrofluidic pump unit (2) and one electrofluidic valve (3), wherein both the pump unit (2) and the valve (3) are actuated by an electromagnet (4, 4') each, characterized in that the pump unit (2) and the valve (3) are arranged on the same center line (10) and use a bearing rod (5) together for the movable mounting of a first magnetic armature (7) actuating a displacement device (6) of the pump unit (2), wherein the first magnetic armature (7) can be actuated by an electromagnet (4) of the pump unit (2), on the one hand, and a second magnetic armature (9) of the valve (3) actuating a group of closing elements (8), wherein the second magnetic armature (9) can be actuated by an electromagnet (4') of the valve (3), on the other hand.

Description

[0001] The invention relates to an electrofluidic unit comprising at least an electrofluidic pump unit and an electrofluidic valve, according to the preamble of the first claim, and to four methods for operating the unit. State of the art:

[0002] Reciprocating piston pumps are well-known, including those driven by an electromagnet. Valves controlled by an electromagnet are also known and widely used. Furthermore, assemblies consisting of a pump and at least one valve are known. However, such assemblies are complex to manufacture. Task:

[0003] The aim is to describe a unit that combines the functions of a piston pump and a valve, and which can be manufactured cost-effectively in high volumes. In particular, the pump and the valve should interact in such a way that few pipe connections are required. Solution:

[0004] The tasks directed to the device are solved by the features of the first claim, advantageous further developments are specified in dependent claims 2 to 10, the last four claims describe methods for operating the device according to the invention.

[0005] The electrofluidic unit according to the invention comprises at least one electrofluidic pump unit and one electrofluidic valve. Both the pump unit and the valve are actuated by an electromagnet each. The pump unit and the valve are arranged on the same centerline and use a bearing rod together for the movable mounting of a first magnetic armature actuating a displacement device of the pump unit on the one hand, and a second magnetic armature of the valve actuating a group of closing elements on the other.

[0006] Preferably, the bearing rod is designed as a tube that fluidically connects the displacement device of the pump unit to one of the fluidic connections, inlet or outlet, of the unit.

[0007] In a first embodiment, the valve, when the associated electromagnet is not energized, fluidically connects the inlet of the unit to the outlet of the unit, bypassing the pump unit, whereby the said connection is closed when the electromagnet is energized.

[0008] In a second embodiment, when the associated electromagnet is energized, the valve fluidically connects the inlet of the unit to the outlet of the unit, bypassing the pump unit, and the connection is closed when the electromagnet is not energized.

[0009] Advantageously, the pump unit features a bellows actuated linearly, either directly or indirectly, by the first electromagnet, which acts as a fluid displacement device. A return spring opposes the force of the electromagnet, and at a suitable frequency of the control pulses to the electromagnet, the spring-mass system, consisting of the return spring and the magnetic armature of the electromagnet, resonates with the control pulses.

[0010] Alternatively, the pump unit has a fluidic displacement device consisting of at least one cylinder and one piston.

[0011] Further advantageously, the pump unit has an inlet valve consisting of a valve seat and a valve body, wherein the valve body has a highly elastic disc and a centrally arranged holder.

[0012] Advantageously, the pump unit also has an outlet valve consisting of a valve seat and a valve body, the valve body having a highly elastic disc and a centrally arranged holder.

[0013] The arrangement of the inlet and outlet valves depends on whether the unit is intended to generate positive or negative pressure in the connected line to a tank or other device. The electrofluidic unit is suitable for both tasks; the valves must be installed in the appropriate orientation.

[0014] Advantageously, the electrofluidic unit includes a pressure sensor that is connected to the outlet of the unit.

[0015] Advantageously, the electrofluidic unit also includes a temperature sensor connected to the outlet of the unit.

[0016] To operate the electrofluidic unit according to the invention, an electrical control system connected to the electrofluidic unit controls the electromagnets in such a way that • A fluidic pressure difference is built up at the outlet by pulsedly energizing the electromagnet of the pump unit with the valve closed, whereby the magnetic armature moves the displacement device accordingly, thereby pumping fluid and increasing or decreasing the gas pressure in a connected tank, • the pulsed current flow to the electromagnet of the pump unit is terminated and the valve is held closed by a current flow to its electromagnet, • A pressure profile in a connected tank is measured by means of a pressure sensor connected to the outlet or the supply line to the tank transmitting the pressure profile in the tank to the electrical control unit, whereby the pressure profile is recorded in the electrical control unit. • after a predetermined time Tv, a second pressure curve is measured and recorded, the duration Tv depending on the size of the connected tank, • the two pressure curves are compared and the difference between the two pressure curves is used to determine the tightness of the tank, • the pressure in the tank ( 32 ) is removed, the valve ( 3 ) is opened by the associated electromagnet ( 4) is switched off.

[0017] The method for operating the electrofluidic unit can be improved by measuring and recording the temperature of the fluid at the outlet or in the supply line to the tank using a temperature sensor during each measurement and recording of the pressure in the tank, whereby when comparing the pressure curves the temperature curves are also used with the help of the general gas equation to calculate a corrected curve of the pressure curves.

[0018] The method for operating an electrofluidic unit can be further improved in the sense of OBD (On-Board Diagnostics) by having the electrical control system monitor the electrofluidic unit for its intended function, whereby both the current flow to the electromagnet of the pump unit and the pressure measured by the pressure sensor are recorded by the electrical control system, and by comparing these curves with reference to tabularly stored target curves, malfunctions of the pump unit or the valve are detected and reported to at least one higher-level electrical control system.

[0019] After starting operation of the electrofluidic unit at a temperature below a predetermined limit temperature T G controls the electrical control ( 33 ) at least one of the electromagnets ( 4 , 4') with electrical pulses of a frequency greater than a specified cutoff frequency f G until the temperature sensor ( 31 ) measured temperature in the unit, the limit temperature T G exceeds the limit. The high-frequency control of at least one electromagnet does not generate any significant movement of the valve and / or the pump, but the relevant solenoid coil heats up and transfers heat to the working fluid. The limit temperature T G depends on the working fluid and the cutoff frequency f G lies considerably (more than 30%) above the resonant frequency of the spring-mass system, which consists of a magnetic armature and an associated return spring. Application:

[0020] Units of the described type are preferably used for monitoring tank systems, but can also be used where a reciprocating pump and a valve are to be used together at low pressure. List of characters Fig. Figure 1 shows a section through an exemplary unit in the design with a bellows in the pump unit and with a valve that closes when energized. Fig. Figure 2 shows a schematic representation of the unit in the version with one cylinder in the pump unit. Fig. Figure 3 shows a detailed cross-section of an exemplary pump unit.

[0021] The exemplary design of the electrofluidic unit ( 1 ) according to Fig. 1 contains an electrofluidic pump unit ( 2 ) and an electrofluidic valve ( 3 ), whereby both the pump unit ( 2 ) as well as the valve ( 3) of each electromagnet ( 4 , 4' ) are activated. The pump unit ( 2 ) and the valve ( 3 ) are on the same center line ( 10 ) arranged and use a bearing rod ( 5 ) together for the movable mounting of a displacement device ( 6 ) of the pump unit ( 2 ) actuating first magnetic armature ( 7 ) on the one hand and a group of closing elements ( 8 ) actuating second magnetic armature ( 9 ) of the valve ( 3 ) on the other hand.

[0022] The bearing rod ( 5 ) is designed as a pipe that houses the displacement device ( 6 ) of the pump unit ( 2 ) with the entrance ( 11 ) of the aggregate ( 1 ) fluidically connects. The possible alternative arrangement, in which the pipe connects the displacement device to the outlet, is not shown.

[0023] In the de-energized state of the valve ( 3 ) actuating electromagnets ( 4' ) connects the valve ( 3 ) bypassing the pump unit ( 2 ) the entrance ( 11 ) of the aggregate ( 1 ) with the outlet ( 13 ) of the aggregate ( 1 ) fluidic, wherein the aforementioned connection is in the energized state of the electromagnet ( 4' ) is locked.

[0024] The possible alternative arrangement, in which the valve is energized ( 3 ) actuating electromagnets ( 4' ) the valve ( 3 ) bypassing the pump unit ( 2 ) the entrance ( 11 ) of the aggregate ( 1 ) with the outlet ( 13 ) of the aggregate ( 1 The fluidic connection is not shown.

[0025] The in Fig. 1 pump unit shown ( 2 ) exhibits a linear path through the electromagnet ( 4) actuated bellows ( 20 ) which acts as a fluidic displacement device ( 6 ) works.

[0026] The possible alternative equipment of the pump unit ( 2 ) with a cylinder ( 21 ) and a piston ( 22 ) is schematically in Fig. 2 shown.

[0027] The pump unit ( 2 ) according to Fig. 1 and Fig. 3 has an inlet valve ( 23 ) that consists of a valve seat ( 24 ) and a valve body ( 25 ) consists of the valve body ( 25 ) a highly elastic disc ( 26 ) and a centrally located holder ( 27 ) exhibits.

[0028] Furthermore, the pump unit ( 2 ) according to Fig. 3 an exhaust valve ( 28 ) that consists of a valve seat ( 24' ) and a valve body ( 25' ) consists of the valve body ( 25' ) a highly elastic disc ( 26') and a centrally located holder ( 27' ) exhibits.

[0029] The electrofluidic unit ( 1 ) according to Fig. 2 contains a pressure sensor ( 30 ) and a temperature sensor ( 31 ), both of which are connected to the outlet ( 13 ) of the aggregate ( 1 are connected. Reference symbol list 1. Aggregat 2. Pump unit 3. Valve 4. Electromagnet 5. Bearing rod 6. Displacement device 7. Magnetic armature 8. Locking element 9. Magnetic armature 11. Admission 12. Magnetic coil 13. Outlet 14. Return spring 20. Bellows 21 . cylinder 22. Piston 23. Inlet valve 24. Valve seat 25. Valve body 26th disc 27. Holder 28. Exhaust valve 30. Pressure sensor 31. Temperature sensor 32. Tank 33. Electrical control

Claims

[1] Electrofluidic assembly (1) comprising at least one electrofluidic pump assembly (2) and one electrofluidic valve (3), wherein both the pump assembly (2) and the valve (3) are actuated by an electromagnet (4, 4') each, characterized by , that the pump unit (2) and the valve (3) are arranged on the same center line (10) and use a bearing rod (5) together for the movable support of a first magnetic armature (7) actuating a displacement device (6) of the pump unit (2) on the one hand and a second magnetic armature (9) of the valve (3) actuating a group of closing elements (8) on the other hand. [2] Electrofluidic assembly (1) according to claim 1, characterized by , that the bearing rod (5) is designed as a tube which fluidically connects the displacement device (6) of the pump unit (2) to one of the fluidic connections inlet (11) or outlet (13) of the unit (1). [3] Electrofluidic assembly (1) according to any one of the preceding claims, characterized by , that in the unenergized state of the electromagnet (4') actuating the valve (3) the valve (3) bypasses the pump assembly (2) fluidically connects the inlet (11) of the assembly (1) with the outlet (13) of the assembly (1), wherein said connection is closed in the energized state of the electromagnet (4'). [4] Electrofluidic assembly (1) according to one of claims 1 to 2, characterized by , that in the energized state of the electromagnet (4') actuating the valve (3) the valve (3) fluidically connects the inlet (11) of the unit (1) with the outlet (13) of the unit (1) by bypassing the pump unit (2), wherein said connection is closed in the unenergized state of the electromagnet (4'). [5] Electrofluidic assembly (1) according to any one of the preceding claims, characterized by, that the pump unit (2) has a bellows (20) actuated linearly by the electromagnet (4) directly or indirectly, which acts as a fluidic displacement device (6). [6] Electrofluidic assembly (1) according to any one of claims 1 to 4, characterized by , that the pump unit (2) has a fluidic displacement device (6) consisting of at least one cylinder (21) and one piston (22). [7] Electrofluidic assembly (1) according to any one of the preceding claims, characterized by , that the pump unit (2) has an inlet valve (23) consisting of a valve seat (24) and a valve body (25), wherein the valve body (25) has a highly elastic disc (26) and a centrally arranged holder (27). [8] Electrofluidic assembly (1) according to any one of the preceding claims, characterized by, that the pump unit (2) has an outlet valve (28) consisting of a valve seat (24') and a valve body (25'), wherein the valve body (25') has a highly elastic disc (26') and a centrally arranged holder (27'). [9] Electrofluidic assembly (1) according to any one of the preceding claims, characterized by , that it contains a pressure sensor (30) which is connected to the outlet (13) of the unit (1). [10] Electrofluidic assembly (1) according to any one of the preceding claims, characterized by , that it contains a temperature sensor (31) which is connected to the outlet (13) of the unit (1). [11] Method for operating an electrofluidic unit (1) comprising at least one electrofluidic pump unit (2) and one electrofluidic valve (3), wherein both the pump unit (2) and the valve (3) are actuated by an electromagnet (4) or by one electromagnet each (4, 4'), characterized by, that an electrical control (33) connected to the electrofluidic unit (1) controls the electromagnets (4, 4') such that • a fluidic pressure difference is built up at the outlet (13) by pulsedly energizing the electromagnet (4) of the pump unit (2) with the valve (3) closed, whereby the magnetic armature (7) moves the displacement device (6) accordingly and fluid is pumped, thereby increasing or decreasing the gas pressure in a connected tank (32), • the pulsed current flow to the electromagnet (4) of the pump unit is terminated and the valve (3) is held closed by a current flow to its electromagnet (4'), • a pressure profile in a connected tank (32) is measured by a pressure sensor (30) connected to the outlet (13) or to the supply line to the tank (32) transmitting the pressure profile in the tank (32) to the electrical control (33), whereby the pressure profile is recorded in the electrical control (33), • after a predetermined time Tv, a second pressure curve is measured and recorded, • the two pressure curves are compared and the tightness of the tank (32) is determined from the difference between the two pressure curves, • the pressure in the tank (32) is reduced, the valve (3) is opened by switching off the associated electromagnet (4). [12] Method for operating an electrofluidic unit (1) according to claim 11, characterized by, that during each measurement and recording of the pressure in the tank (32) the temperature of the fluid at the outlet (13) or in the supply line to the tank (32) is also measured and recorded by means of a temperature sensor (31), whereby when comparing the pressure profiles the temperature profiles are also used to calculate a corrected profile of the pressure profiles using the general gas equation. [13] Method for operating an electrofluidic unit (1) according to one of claims 11 or 12, characterized by, that the electrical control (33) monitors the electrofluidic unit for its intended function by recording both the current flow of the electromagnet (4) of the pump unit (2) and the pressure flow measured by the pressure sensor (30) and by comparing the aforementioned flows with reference to tabularly stored target flows, malfunctions of the pump unit (2) or the valve (3) are detected and reported to at least one higher-level electrical control. [14] Method for operating an electrofluidic unit (1) according to any of the preceding method claims, characterized by that after starting operation at a temperature below a predetermined limit temperature T Gthe electrical control (33) at least one of the electromagnets (4, 4') with electrical pulses of a frequency greater than a predetermined cutoff frequency f G continues to operate until the temperature measured by the temperature sensor (31) in the unit reaches the limit temperature T G exceeds.

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