DE6915619U - DEVICE FOR CONTROLLING THE LIQUID LEVEL IN THE SOAP RESERVOIR OF A WASHING MACHINE OR DISHWASHER - Google Patents

Description

SIEMENS-ELECTROGERÄTE GMBH Erlangen, 15 Λ, 1969 Berlin and Munich Werner-von-Siemens-Str ,, 50

Our reference: PLA 69/5040 Gre / Zp

Device for controlling the liquid level in the The tub of a washing machine or dishwasher

For the control of washing machines or dishwashers, program control devices are mostly used, through which one time-dependent switching of the power consumers of the machine is effected according to the respective operating phases. Besides individual operating phases are also dependent on certain operating conditions, such as the temperature, the lye level or the like., Controlled.

In the known washing machines, it is generally customary to switch the drain pump, which is used to pump out the liquid, on and off time-dependently from the irogram control device »while doing this Of course, a time reserve must be provided so that the tub is also emptied with certainty. i) as conditional, that the drain pump runs empty for a longer or shorter period of time each time it is pumped out, whereby the washing program is adjusted accordingly is extended.

However, it is also known that the pumping-out process is state-dependent to monitor. In a known washing machine of this type (German patent specification 1 124 915), the end of the pumping process determined by a pressure switch dependent on the liquid level, the measuring chamber of which is in front of a throttle point of a measuring line is branched off, one of which is the "liull level", d = ho the connection point determining the emptiness of the tub with a connection point located in the suction line of the drain pump »through a connection point from the liquid level dependent control of the drain pump, you can

PLA 69/5040

reduce gram duration «You can also change the length of time of the individual program steps when the pumping process does not need to be temporally monitored »

However, the known arrangement is disadvantageous in that connection points are required on the tub. aside from that there is a risk that the throttle point will quickly become clogged by settling laundry fluff or incrustations will.

The innovation relates to a device for controlling the liquid level in the tub of a washing machine or dishwasher, in which the drain pump effecting the pumping out by a monitoring the liquid level, with a pressure switch connected to an air chamber is switched off, the measuring line for the liquid level in the tub to the drain line of the machine like this connected is that the "zero level", that is, the emptiness of the suds container can be determined.

The aim of the innovation is to design the measuring device monitoring the drain pump in such a way that functional errors due to encrustation, Lint or the like are as good as impossible »

For this purpose it is proposed according to the innovation that a riser pipe branches off from the measuring line in front of the air chamber is, on the upper side of which a float-actuated ventilation valve is arranged. In this way, the Strong suction occurring at the beginning of the pumping does not affect the measuring device (pressure monitor) monitoring the water level, because the column of liquid present in the riser pipe at this point prevents this. Only when this pillar is like that If it has sunk far enough that the ventilation valve opens, the air vessel acting on the level switch is removed from the water emptied, which ends the pumping process or the next

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Program step is initiated. The ventilation valve arranged at the top of the riser pipe ensures that any puncture errors in the arrangement caused by incrustations or by the settling of lint in the area of the measuring device can come about are as good as impossible, because the ventilation valve itself does not contain any liquid comes into contact.

In the development of the innovation, the riser pipe which receives the float and the ventilation valve is preferred lead to above the highest water level in the machine, in order to create the largest possible column of liquid in this way as a "dampening agent". It is advisable furthermore, to arrange the part which actuates the ventilation valve at the upper end of a rod which is fixedly connected to the float.

In the drawing is an embodiment of the innovation shown. The single figure shows a schematic vertical section through a drum washing machine a device according to the innovation.

The tub 10 with the drum 11 arranged therein has at its bottom 12 a drain opening 14, which is connected via a drain line 16 with the one directly at its Housing attached electric motor 17 driven drain pump 15 is connected. On the one behind the pump housing A hose is connected to the pressure port of the drain pump, through which the liquid from the tub 10 into a higher-lying outlet 19 can be pumped v / ground.

A measuring line is connected to the drain line 16 in front of the drain pump 21 connected, which under Zv / i schens ehalt ung an air vessel 22 and a pressure line 23 with a membrane

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switch 24 is in connection, which controlled the inlet valve, not shown. From the measuring line branches off in front of the air chamber a riser pipe 25 in which there is a float 26, which is connected to a ventilation valve via a rod 27. The float is through the rod and the guide 28 prevented from sinking down to the bottom of the riser pipe.

Working method:

1 . Viasser inlet:

When the machine is pulled, it rises from the tub and the drainage line 16 water coming into the measuring line 21 and the riser pipe 25. The tub and the measuring system are communicating when the valve 29 is open Vessels, v / eil the air present in the riser pipe can escape via the valve as long as the float 26 is still is not lifted. Since the ventilation valve is designed with a small stroke (approx. 0.5 mm), it almost closes same point in time at which the float is lifted «At this point the connection of the air chamber is also activated 22 interrupted with the outside air »The measuring process of the water level begins« When the machine is filled again the water level in the riser pipe also rises to the required level 13, but reaches due to the compressed air is not quite as high as in the suds container. This difference in height is all the less , the higher the valve body compared to the height of the The suds container is, at the same time the water level in the air tank rises and generates the required amount Switching pressure for the membrane holder. Upon reaching of level 13, the inlet valve is switched off.

2. Pumping:

When the pump is switched on, the closed ventilation valve 29 prevents the riser pipe from running empty.

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finally the measuring line, this prevents the membrane switch from reaching the lower Fourth of its switching width to switch because one in the suds level The water level that is no longer present is simulated ο Only when the pump is also in the drain line The water that is located there can be pumped out through the air inlet into the measuring line and into the riser pipe Drain the water. Only now does the float sink down and the ventilation valve 29 opens, whereby the water drainage is still accelerated from the riser and the measuring line. The membrane switch 24 can now switch back. This switching process can be used, for example, to stop the drain pump or to continue the program to be drawn in by a step »

Expectations
figure

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Claims (3)

PLA 69/5040 - 6 - S chut ζ ans ρ rü ch e 1 . Device for controlling the * liquid level in the tub of a washing machine or dishwasher, in which the drain pump that effects the pumping is switched off by a pressure switch that monitors the liquid level and is connected to an air chamber, whereby the measuring line for the liquid level in the tub is connected to the drain line of the machine is connected such that the "zero level", that is, the emptiness of the tub is detected, dadurch_gekennzeichne t _y that in the measuring line (21), a riser (25) is diverted before the air chamber (22), on its upper side a of a float ( 26) actuated ventilation valve (29) is arranged » 2. Apparatus according to claim 1, characterized in that the float (26) and the ventilation valve (29) receiving Riser pipe (25) is guided to above the highest water level (13) in the machine. 3. Apparatus according to claim 1 or 2, characterized in that the vent valve (29) actuating part at the top The end of a rod (27) fixedly connected to the float (26) is arranged. r.
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