EP2584109B1 - Fill level sensor - Google Patents

Description

The invention relates to a sewage lifting plant with a filling level sensor according to the preamble of claim 1.

Wastewater lifting plants are used to raise sewage, which is at a level below a sewer, to the level of the sewer system. This wastewater lifting system are known, which have a container in which flows in the water to be lifted. In the container or on the container at least one pump is arranged, which then pumps the wastewater from the container to the desired higher level. In order to switch on and off the at least one pump as needed, a level sensor is arranged on or in the container, which detects the water level inside the container and the pump on and off depending on the water level: see, for. B. US 2,922,002 , Level sensors are z. In GB 2 032 178 . FR 2 772 917 disclosed. In EP 1 775 476 is a control device for motor-driven pump, as used in the water supply described. Ie. this control device is provided for controlling pressurized systems. For a wastewater lifting plant, the in EP 1 775 476 disclosed device can not be used.

In these sewage lifting units, the pump is switched on at a certain water level. However, there are applications for sewage lifting systems, in which due to the connected sanitary objects, a lower water level for activating the pump is desired. In other cases it is desired to choose a higher water level.

The document US 2,922,002 is considered to be the closest prior art. This document corresponds to the preamble of claim 1.

The object is therefore to provide a sewage lifting plant with a level sensor, which makes it possible to easily define different starting levels in a container, without the To replace the level sensor. This object is achieved by a wastewater lifting plant having the features specified in claim 1.

The wastewater lifting plant according to the invention has a container or collecting container, in which the waste water to be lifted can flow through an inlet. In or on the container, a pump is arranged, which pumps the liquid from the container in a higher-lying sewer line. The pump is driven by an electric drive motor, which can be switched on and off via the level sensor described below.

The level sensor has at least one movable pressure surface. The pressure surface is arranged in the interior of the container such that it is located below the liquid surface at least when a predetermined filling level of the container is exceeded. Thus, the fluid pressure of the liquid in the container acts on this pressure surface. Depending on the fluid pressure, the pump can then be switched on or off. For this purpose, an electrical switch is provided, which is coupled to the pressure surface, so that the switch can be actuated by movement of the pressure surface at least in a first direction of movement. This direction of movement is preferably a direction of movement which results when the level of liquid in the container rises. As the liquid level in the container rises, the fluid pressure acting on the pressure surface increases. The pressure creates a force on the pressure surface which moves this pressure surface in the first direction of movement, whereby the switch is then actuated to turn on the drive motor of the pump.

According to the invention, it is possible to adjust the liquid level or liquid level at which the switch for switching on the pump is actuated. For this purpose, in the level sensor according to the invention, a force generating means is provided, with which a counterforce can be exerted on the pressure surface, which is opposite to the force generated by the fluid pressure. This counterforce causes the counterforce to be overcome when the pressure surface moves in the first direction of movement. Ie. it is a higher, acting on the pressure surface fluid pressure required to move the pressure surface in the first direction of movement. In this way, the liquid level at which the switch is actuated is changed, namely displaced upwards, i. H. only at a higher liquid level, the pressure surface is moved after overcoming the force generated by the force generating means and the switch is turned on.

In order to be able to change the liquid level at which the pump is switched on with the counterforce generated by the force generating means, according to the invention a selection device is provided which has at least two selectable states. These at least two states correspond to two different fluid levels at which the pump is to be turned on. The selection device is designed such that it can be moved or switched over between the two states. In this case, in a first state, the force generating means generates a force acting on the pressure surface or opposing force, as described above. In a second state, the force generating means produces less or no force acting on the pressure surface. Ie. in the second state, the opposing force acting on the pressure surface counter to the first direction of movement is smaller or non-existent, so that a lesser pressure of the liquid is sufficient to move the pressure surface, ie the pressure surface already moved at a lower liquid level in the container and thus the coupled switch is actuated to turn on the pump. The selection device is thus designed such that the counterforce generated by the force generating means can be switched on or off or changed.

The force generating means may preferably be a spring, in particular a compression spring, which generates a force directly or indirectly on the pressure surface opposite to the first actuating direction.

The pressure surface is preferably coupled to the electrical switch via an actuating element, in particular an actuating rod. According to a particularly preferred arrangement, this actuating rod extends vertically and is moved in the first direction of movement up to turn on the pump. As the level of liquid in the container drops, the actuator rod is moved vertically down to turn off the switch. The actuating rod preferably extends upward out of the container, so that the electrical switch, which is actuated by the actuating element and in particular the actuating rod, can be arranged outside the container protected from moisture. The pressure surface preferably extends to the lower side of the filling level sensor, essentially in the horizontal direction, so that the liquid pressure acts upwards on the pressure surface and the pressure surface is moved vertically upwards in the first movement direction and the actuating element or the actuating rod then moves in the appropriate direction.

The force-applying means may comprise a pressure pin, which preferably presses from above onto the end face of the actuating rod facing away from the pressure surface when the selection device is in a first state in which a counterforce or a larger force is present Counterforce to be applied to the printing surface. The pressure pin can be supported on a spring element, in particular a compression spring, which is compressed during movement of the actuating rod by moving the pressure pin so as to generate the counterforce on the actuating rod.

The force generating means engages the actuating element for introducing force, at least in the first state, for example in the manner described above. In the second state of the selector device, it either does not attack the actuating element at all, so that no force or counterforce is generated on it, or it acts on the actuating element in such a way that in the second state a smaller force acts on the actuating element acting on the pressure surface pressure force acts.

According to a preferred embodiment, the selection device is designed in such a way that the force-generating means can be changed by the selection device in its position relative to the actuating element. Ie. by actuating the selector, the force generating means may be changed in position to engage or disengage the actuator. When engaged with the actuator, it produces the counter force described above which counteracts the compressive force acting on the pressure surface. If it is disengaged, no such counterforce is generated. Instead of completely disengaging the force generating means from the actuator, it is also possible for the force generating means to change in position relative to the actuator by the winder so that only the force generated changes, ie, in a condition a greater force on the actuator Actuator acts as in another second state. It can also be more than two states with different forces as opposing forces be provided so that more than two different switching levels can be defined.

Preferably, the selection device is designed such that in its first state, the force generating means is positioned so that it acts on the actuating device for introducing force and in its second state, the force generating means does not attack on the actuating element. Ie. in the first state, a counterforce is generated, not in the second state. In addition, it is conceivable to provide a third and even more states between the first and second states in which a force is generated which is less than the force in the first state. For example, the force can be generated by a spring which is compressed to different degrees or is positioned so that it is compressed to a different extent by the actuating element upon reaching the first switching position in which the switch is actuated.

The counterforce described above, which is generated by the force generating means, does not have to act on the actuating element or the pressure surface over the entire movement of the pressure surface or of an actuating element coupled to the pressure surface. Rather, it is conceivable that this counterforce acts only in an end region of the movement before the switch is actuated. Ie. the force generating means is designed and arranged so that the counterforce generated by the force generating means must first be overcome to operate the switch.

The actuating element can be supported according to an embodiment of the invention, at least in the first direction of movement of the pressure surface at an axial end of a compression spring, while the opposite end of the pressure surface of the compression spring is supported on a contact surface. This contact surface can, for example, on a Sensor housing be formed or be firmly connected to the sensor housing. Upon movement of the actuating element, the compression spring is then compressed at least in an end region of the movement near the first switching position in which the switch is actuated to turn on the pump, so that the compression spring generates a counterforce, which initially overcome by a higher pressure in the container must be to move the actuator further and to operate the switch.

Preferably, the compression spring in the axial direction by means of the selector is movable. In this case, either the entire compression spring can be moved or only one of the actuating element facing the end of the compression spring. If only this end of the compression spring is moved, the compression spring is compressed by the selector. However, this is irrelevant if at the same time the axial end of the compression spring is removed far enough from the actuating element that the actuating element can no longer come into contact with the compression spring. In this case, the actuating element come directly or via intermediately mounted components with the compression spring in contact. If there is no engagement or contact, the compression spring causes no counterforce on the actuator and it is so defined a lower level in the container for switching on the switch. When the compression spring, or at least its axial end facing the actuator, is moved to a second position where it is closer to the actuator, it is achieved that the actuator directly or indirectly engages the compression spring and moves it into movement in the first Shift position in which the switch is actuated to turn on the pump is compressed. Thus, the counterforce described above is generated, which requires a higher level in the container for switching on the pump.

Particularly preferably, the selector is rotatably formed and guided on a housing part of the level sensor in the axial direction on a helical or stepped backdrop or track. Ie. About this backdrop or track the selector is simultaneously displaced axially during rotation. This axial displacement brings the force generating means into or out of engagement with the actuating element, which transmits the movement of the pressure surface to the switch, so that, as described above, optionally a counterforce can be exerted on the actuating element or not.

The pressure surface may preferably be formed as a membrane to an otherwise closed sensor housing. The liquid pressure acts on this membrane from the outside, which leads to a displacement of the membrane and the actuating elements, in particular an actuating rod, coupled to the membrane in the interior of the sensor housing. Alternatively, the pressure surface may also be formed on a float, d. H. in particular, form the bottom of the float, which is moved up and down with the liquid level in the container. When a counter force is exerted on the float by a force generating means as described above, even in a float, the liquid level at which the pump is turned on can be changed.

The force generating means, according to a preferred embodiment, a compression spring, which is supported with a first axial end to a stationary spring holder, such as a wall of a sensor housing, and abuts with its opposite axial end of a contact shoulder of a pressure pin or pressure element. This pressure pin or this pressure element can with an actuating element, when it is moved by the pressure surface, come into contact and thus generated on the actuating element of the compression spring Transfer force or transmit the movement of the actuating element on compression spring, so that it is compressed and then generates the desired reaction force. In order to reduce or eliminate the possible compression of the compression spring, a pressure body or pressure pin can be connected to the selection device in such a way that the pressure body or pressure pin is moved away from the actuating element by movement of the selection device. Preferably, the pressure body or the pressure pin is integrally connected to the selector and is moved together with this.

Figur 1

eine Explosionsansicht einer Abwasserhebeanlage;

Figur 2A

eine Schnittansicht eines Füllstandsensors, bei dem sich eine Betätigungsstange in einer ersten Schaltposition befindet;

Figur 2B

eine Außenansicht des Füllstandsensors, bei dem sich die Wähleinrichtung in einem ersten Zustand befindet;

Figur 2C

eine Draufsicht auf die Wähleinrichtung in dem ersten Zustand;

Figur 3A

eine Schnittansicht des Füllstandsensors, wobei sich die Betätigungsstange in einer zweiten Schaltposition befindet;

Figur 3B

eine Außenansicht des Füllstandsensors, wobei sich die Wähleinrichtung in dem ersten Zustand befindet;

Figur 3C

eine Draufsicht auf die Wähleinrichtung in dem ersten Zustand;

Figur 4A

eine Schnittansicht des Füllstandsensors, wobei sich die Betätigungsstange in einer ersten Schaltposition befindet;

Figur 4B

eine Außenansicht des Füllstandsensors, wobei sich die Wähleinrichtung in dem zweiten Zustand befindet;

Figur 4C

eine Draufsicht auf die Wähleinrichtung in dem zweiten Zustand;

Figur 5A

eine Schnittansicht des Füllstandsensors, wobei sich die Betätigungsstange in der zweiten Schaltposition befindet;

Figur 5B

eine Außenansicht des Füllstandsensors, wobei sich die Wöhleinrichtung in dem zweiten Zustand befindet;

Figur 5C

eine Draufsicht auf die Wähleinrichtung in dem zweiten Zustand;

Preferred embodiments of the invention are explained below with reference to the accompanying drawings. Show it

FIG. 1

an exploded view of a wastewater lifting plant;

FIG. 2A

a sectional view of a level sensor, wherein an actuating rod is in a first switching position;

FIG. 2B

an outside view of the level sensor, wherein the selector is in a first state;

Figure 2C

a plan view of the selector in the first state;

FIG. 3A

a sectional view of the level sensor, wherein the actuating rod is in a second switching position;

FIG. 3B

an outside view of the level sensor, wherein the selector is in the first state;

FIG. 3C

a plan view of the selector in the first state;

FIG. 4A

a sectional view of the level sensor, wherein the actuating rod is in a first switching position;

FIG. 4B

an outside view of the level sensor, wherein the selector is in the second state;

FIG. 4C

a plan view of the selector in the second state;

FIG. 5A

a sectional view of the level sensor, wherein the actuating rod is in the second switching position;

FIG. 5B

an outside view of the level sensor, wherein the Wöhleinrichtung is in the second state;

FIG. 5C

a plan view of the selector in the second state;

FIG. 1 shows an exploded view of a wastewater lifting plant. The wastewater lifting plant has a container 2, which is preferably made of plastic. The container 2 has in a wall on an inlet opening 4, to which an input-side sewer line can be connected, through which wastewater can flow into the interior of the container 2. In the container 2, a pump 6 is also provided. The pump 6 serves to pump the waste water from the container 2 via the outlet line 7 arranged in the container 2 and the outlet connection 8 provided in the container 2 into a pressure or wastewater line connected to the outlet connection 8. At the top of the container 2, an opening 10 is formed. The opening 10 is closed by a flange plate 11, on which a pump unit or the pump 6 and the level sensor 14 are arranged. In this case, the level sensor 14 and the pump 6 are arranged so that their electrical components, that is, an electric drive motor and a switching element of the level sensor are arranged above the flange plate 11 and thus outside of the container 2. The level sensor 14 is placed in an opening 12 in the flange plate 11. The level sensor 14 has a sensor housing 16, which is inserted into the opening 12.

FIG. 2A shows a sectional view of a level sensor 14, in which an actuating rod 18 is in a first switching position. The sensor housing 16 has at its lower end an opening which is covered or closed by a membrane 20. At the Membrane 20, the actuating rod 18 is attached. The membrane 20 forms a pressure surface on which the fluid pressure in the container acts. The actuating rod 18 extends through a part of the sensor housing 16 and has a magnet 22 at its upper end. In a region of the sensor housing 16, which is adjacent to the upper end of the actuating rod 18, a switch 24 is provided. The upper end of the actuating rod 18 abuts against a pressure pin 26. The pressure pin 26 is provided with a washer 28 and a clamping washer 30. On the washer 28 is formed as a compression spring coil spring 32 with a first end. The second opposite end of the coil spring 32 bears against a surface of the sensor housing 16, which thus forms a contact surface for the helical spring 32. The upper end of the pressure pin 26 is connected to a rotatable dial 34. In this case, the selector 34 is rotatable about the longitudinal or action axis of the coil spring 32. This is also the axis along which the actuating rod 18 is movable.

The selection device 34 has on its outer circumference a projection extending parallel to the axis of rotation, which forms a contact point 36. This slides on an arcuate guideway or gate 37, which is formed at the upper end of the sensor housing 16. In this case, in particular, the height of the guide track 37 changes in a direction parallel to the rotational axis of the selector 34 over the circumference, so that the support point 36 depending on the angular position of the selector 34 on an upper Arretierungspunkt 38 of the guideway 37 or a lower locking point 40 of the guideway 37 lie comes, as in FIG. 4B is shown. In the first state, which in the Figures 2A, 2B, and 2C is shown, the support point 36 is located on the upper Arretierungspunkt 38th

Figure 2C shows that the selector 34 is in position 1 when the liquid level in the sewage lifting station increases, the pressure on the membrane 20 increases. From a certain fluid pressure, the membrane 20 moves with the actuating rod 18 upwards. The magnet 22 is thereby moved to an area where it turns on the switch 24. As a result of the switch 24 being switched on, the pump 6 is supplied with power and pumps the liquid located in the container 2 via the outlet line 7 and the outlet connection 8 into a sewage pipe.

The fact that the selector 34 is in position 1, the pressure pin 26 is kept out of the operating range of the actuating rod 18, d. H. the actuating rod 18 does not press in its vertical upper position against the pressure pin 26, so that the pressure pin 26 is not moved in this second state of the selector 34 of the actuating rod 18. The selector 34 pulls the push pin 26 upwards. In this case, the selection device 34 is supported by the support point 36 on the upper locking point 38.

FIG. 3A shows a sectional view of the in the FIGS. 2A and 2B shown fill level sensor 14, in which the actuating rod 18 is in a second switching position, in which no pressure from the outside acts on the membrane 20. This second switching position is below the first switching position. The membrane 20 connected to the actuating rod 18 is in a state in which it protrudes partially downward from the sensor housing 16. The magnet 22 located in the actuating rod 18 is outside the range in which it acts on the switch 24, so that the switch 24 opens and interrupts a circuit. As a result, the pump 6 is turned off. The pressure pin 26 is at the same height as in FIG. 2A shown. Also in the FIGS. 3B and 3C is the selector 34 like in the FIGS. 2A, 2B and 2C in position 1, ie their second state.

FIG. 4A shows a sectional view of the level sensor 14, in which the actuating rod 18 is in a first switching position. In the FIG. 4A shown switching position corresponds to the in FIG. 2A shown switching position. One difference is that in FIG. 4A the actuating rod 18 presses against the pressure pin 26. This is achieved in that the selector 34 in the FIGS. 4A-4C in its first state (position 2). Ie. it is opposite to the second state, which in FIGS. 2A-3C is shown rotated, so that the support point 36 has moved from the upper locking point 38 in the lower locking point 40 of the guide rail 37. Thus, the entire selector 34 has shifted with the pressure pin 26 arranged thereon and the coil spring 32 in the direction of movement of the actuating rod 18, that is vertically, downwards. The pressure pin 26 thus projects further down into the sensor housing 16 as in FIG. 2A , In order to reach the first switching position, in which the magnet 22 actuates the switch 24, the actuating rod 18 must therefore push the pressure pin 26 upwards. In this case, the coil spring 32 is tensioned between the washer 28 and the sensor housing 16.

The compression spring thus generates a force which is directed counter to the upward movement of the actuating rod 18. Ie. a downward pressure force acting on the membrane 20 is produced, which thus opposes the pressure in the interior of the container 2, which acts on the membrane 20.

In the in FIG. 4A Thus, a larger force is required to bring the operating rod 18 in the first switching position shown in the state shown in FIG FIG. 2A shown state. To the first switching position Therefore, a higher pressure on the membrane 20 is required. This higher pressure corresponds to a higher liquid level in the container.

FIG. 5A shows a sectional view of the level sensor 14, in which the actuating rod 18 is in the second switching position. The state of the level sensor 14 corresponds to the FIG. 3A shown state with the difference that the selector 34, as in FIG. 4 in its first state and the pressure pin 26 protrudes further into the sensor housing 16. The second switching position of the actuating rod 18 is in the Figures 5A and 3A identical.

By the rotation of the selector 34, it is thus possible to move the compression spring or coil spring 32 and the pressure pin 26 between two vertically different positions, so that in one position against one of the liquid pressure inside the container 2, the actuating rod 18 acting force directed force is generated, whereby a higher switching level is achieved. It can thus be easily switched by rotation of the selector 34 between two different start levels. It should be understood that by appropriate design of the guideway 34 with a plurality of vertically different locking points also more than two states of the selector 34 could be selected. Thus, several selectable starting levels can be achieved with the same level sensor 14.

LIST OF REFERENCE NUMBERS

2

container

4

inlet port

6

pump

7

outlet pipe

8th

outlet

10

opening

11

flange

12

opening

14

level sensor

16

sensor housing

18

actuating rod

20

membrane

22

magnet

24

switch

26

pushpin

28

washer

30

clamping disc

32

coil spring

34

dialer

36

support point

37

Guide track; scenery

38

upper locking point

40

lower locking point

Claims (9)

1. A waste water lifting installation, with at least one pump (6) and with a level sensor (14), wherein the pump (6) can be switched on and off by the level sensor, and the level sensor comprises at least one movable pressure surface (20) and at least one electrical switch (24) which is coupled to the pressure surface (20) in a manner such that the switch (24) can be actuated by way of movement of the pressure surface (20) in a first movement direction and with a force production means (32), by way of which in at least one part region of the movement of the pressure surface (20) in the first movement direction, a force acting on the pressure surface (20) and directed opposite to the first movement direction can be produced, characterised by
   a selection device (34) which has at least two selectable conditions, wherein in a first condition, the force production means (32) produces a force acting on the pressure surface (20), and in a second condition produces a lower force or no force, acting on the pressure surface.
2. A waste water lifting installation according to claim 1, characterised in that the force production means comprises a spring (32).
3. A waste water lifting installation according to one of the preceding claims, characterised in that the pressure surface (20) is coupled to the electrical switch (24) via an actuation element (18), in particular via an actuation rod (18).
4. A waste water lifting installation according to claim 3, characterised in that the force production means (32) at least in the first condition engages on the actuation element (18) for force application.
5. A waste water lifting installation according to claim 4, characterised in that the selection device (34) is designed in a manner such that the force production means (32) can be changed in its position relative to the actuation element (18), by way of the selection device (34).
6. A waste water lifting installation according to claim 5, characterised in that the selection device (34) is designed in a manner such that in its first condition, the force production means (32) is positioned such that it engages on the actuation device (18) for force application, and in its second condition, the force production means (32) does not engage on the actuation element (18).
7. A waste water lifting installation according to one of the claims 3 to 6, characterised in that the actuation element (18) at least in the first movement direction of pressure surface (20) is supported on an axial end of a compression spring (32), and an opposite end of the compression spring (32) is supported on a contact surface.
8. A waste water lifting installation according to claim 7, characterised in that the compression spring (32) is movable in the axial direction by way of the selection device (34).
9. A waste water lifting installation according to one of the preceding claims, characterised in that the selection device (34) is rotatable and is guided on a housing part of the level sensor (14) in the axial direction, on a helical or stepped motion link (37).

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