FI74604B - TYSTGAOENDE DISKMASKIN MED LITEN VATTENFOERBRUKNING. - Google Patents

Description

74604

Dishwasher with quiet running sound and low water consumption

The present invention relates to a dishwasher, the cessation of filling of which is controlled during the filling phase by periodically increasing the pressure in the body of the pump, the body communicating with the ambient air during filling by means of a pipe with the desired end of the dishwasher.

A dishwasher usually comprises an intermittent or cycle pump which lifts water from a tank and sprays it onto the dishes to be washed. After spraying, the water falls back into the tank, from which the pump then sucks it through again. The machine also includes a drain pump that empties the tank at the end of the washing operation.

The aim is, of course, to reduce the amount of water used in the dishwasher in order to reduce the operating costs of water and its heating. For this reason, 20 devices have already been proposed for obtaining exactly the desired amount of water in a dishwasher. U.S. Patent 3,415,261 discloses a dishwasher in which the filling of the machine with water ceases when the water level rises to the level of the top surface of the pipe in question, which corresponds to the desired water level in the tank. The pipes connect the periodically operating pump body to the ambient air when filling the machine. The pump, which rotates during filling, then sucks a certain mixture of air and water at a relatively low pressure in the pump body. The pressure rises sharply as the water enters the pipe, after which the pump exclusively lifts the water. This sharp increase in pressure is used to interrupt the filling of the machine with water.

However, the use of a mixture of air and water during filling causes a cavitation phenomenon, so that, as has been found, the operating sound of the 35 machines is relatively loud, which is very negative for a household machine.

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On the other hand, the machine according to the invention, which corresponds in construction to that described in the above-mentioned patent, does not have this drawback.

The dishwasher according to the invention is characterized in that the intermittent pump comprises auxiliary vanes above the vanes for timing and close to the pipe for air intake during water intake, the pump taking substantially only air during water intake, and these additional vanes allowing the intermittent pump 10 to be emptied during emptying. , and that the body of the intermittent pump is such that, during water intake, water enters the body only through its lower part.

In the structure according to the invention, the draining pump and the intermittent pump are driven by the same motor.

15 Auxiliary wings keep the machine running noise low during emptying. The preferably vertical pipe in communication with the ambient air has two functions. It keeps the intermittent pump from starting for the first time during both filling and emptying. The vertical pipe is preferably the same as the 20-axis with the impeller of the intermittent pump.

Other features and advantages of the invention will be apparent from the description of one of its embodiments, with reference to the accompanying drawings. In them, Fig. 1 is a schematic section of a part of a dishwasher according to the invention, Fig. 2 is a diagram of the impeller of a periodically operating pump of a dishwasher of Fig. 1, and Fig. 3 is a diagram showing the operation of a dishwasher according to the invention.

At the bottom of the dishwasher there is a tank 10 with a drain pump 12 at the bottom. It is driven by a shaft 13 of an electric motor 14 located below the bottom of the tank 10. The shaft 13 is thus a vertical axis and extends above the drain pump 12 and operates a periodically operating pump 15. is to raise the water 11 and spray it with pressure on the baskets (not shown) in which the dishes to be washed are placed. To this end, the body 16 of the pump 15 is connected to a pipe 17 which opens into a rotating vane 18 which sprays water into the containers. The body of the intermittent pump 5 15 is also connected to a second tube 19 which opens into a second vane (not shown) at the upper end of the dishwasher body.

The water sprayed into the vessels falls back into the tank 10. The pump 15 then lifts the water back into the machine after it has first passed through the filter 40.

The pump 15 has an impeller driven by a shaft 13. It has a flange 20 (Fig. 2) with wings 21 on the lower surface, which provide a cycle function. The upper surface of the impeller likewise has vanes 23 which are slightly smaller than the vanes 21 and which serve to remove water from the pump during emptying in order to eliminate disturbing noises and to prevent the pump from starting during filling.

The wings 21 and 23 are not radial, but comprise a specific angular sector. Each wing 21 has 20 circumferential ends 21a and an inner end 21b. The corner sector moves clockwise from 21a to 21b. Respectively, each wing 23 has a circumferential end 23a and an inner end 23b. The corner sector now faces counterclockwise from 23a to 23b, i.e. the direction of the wings 23 is opposite to the direction of the wings 21.

The body 25 of the drain pump 12 is connected to the outlet pipe 26 by a directional valve 27 which prevents the pump 12 from lifting water into the pipe 26.

The suction head 28 of the intermittent pump 15 is at the bottom of its body 16.

30 Po. the pump body 16 extends upwards as a tube 30, the shaft of which is connected to the shaft of the shaft 13 and thus also to the shaft of the impellers of the pumps 12 and 15.

The body of the intermittent pump 15 communicates with a pressure regulator 31a which detects the water pressure generated by the pump and controls the solenoid valve 32 which is open when it is desired to fill the tank 10 with water.

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The pressure regulator is adjusted so that as long as the water pressure indicated by it is lower than the value (Fig. 3), the solenoid valve 32 remains open po. when the valve closes again when the pressure has risen to p ^.

5 The machine operates as follows: To fill the tank 10, the solenoid valve 32 is open. The motor 14 is then closed and rotates in the direction of the arrow F (Figure 2), which is responsible for periodically operating the pump 15 and the normal operation of the drain pump 10 nor-empty operation with respect to the opposite direction.

Because the machine has a tube 30 that connects the pump 15 to the air surrounding the body 16 and additional vanes 23 that provide little air suction during filling, the pump 15 cannot be started for the first time as long as the top of the tube 30 15 is in the air. The pressure of the water raised by this pump is then relatively low, Pj in Fig. 3. Although this value does not produce water jets with the necessary washing pressure for the vessels, the pump nevertheless generates smaller jets which rinse the vessels. These small jets cause the vessels to progressively heat when hot water is fed directly to the machine, and when the vessels are washed with hot water, they progressively cool before being rinsed in cold water.

The pump 15 is only first started (primed) 25 after the free surface of the filling water has risen to the head 31 and the water enters the body 16 along the pipe 30. The pump outlet pressure indicated by the pressure regulator 31a then rises sharply and reaches the value pN. Thereafter, the solenoid valve 32 closes and filling is complete.

30 In Fig. 3, the pressure p is shown as the y-axis and the amount of water fed to the tank 10 as the x-axis. The amount qj corresponds to the moment when the water starts to flow into the pipe 30. The free surface of the water has then risen to the head 31.

Once the pump is pre-filled, it now raises a larger amount of water 35 so that the free surface of the water drops sharply below the level of the head 31. However, this is not harmful because the pump is already pre-filled.

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If the solenoid valve 32 is closed as soon as the pressure detected by the pressure regulator 31a reaches the value p1, then the amount of water is q1.

If more water is needed, e.g. q2 (Fig. 3), the control device in the machine 5 keeps the solenoid valve 32 open for some time after the pump is primed, so that the free water level can be above the level of the head 31 when the machine is running.

The filling function does not make a noise, because the pump 15 has 10 mainly air. Namely, it has been found that the pump makes a noise when it raises the mixture of water and air. As can be seen from Figure 3, there is practically never a mixture of air and water in the pump, because the transition from the pre-filled state to the pre-filled state takes place very quickly. This displacement is shown in Figure 3 by a straight line 35 parallel to the y-axis (P).

In addition, the amount of water entering the machine is very accurate, so you don't have to use more water than you need.

20 When the machine is emptied, the direction of rotation of the motor is reversed. The pump rotates in the direction of the arrow F (Figure 2). Since the pipe 31 communicates with the pump body 16 and since the vanes 23 rotate in the opposite direction to the vanes 21, the pump 15 remains unfilled 25 when the machine is emptied and then makes little noise. When the cycle operation stops, the machine has not yet been emptied, so that the sprayed water falls back into the tank 10, whereby the pipe 30 can remain under water and make a sound immediately at the beginning of the emptying phase. If this happens, however, there is no harm in it, as it only takes a fraction of a second.

Claims (7)

1. Dishwasher, in which the interruption of water filling is controlled when the pressure in the storage tank (16) is heated by the cyclic pump (15) operating during filling, this body (16) during the filling being connected with the atmosphere via a pipe (30), the upper end of which (31) is substantially in level with the desired free water surface of the dishwasher, characterized in that the cyclic pump (15) comprises the blades intended for cycling (21) above and adjacent to the tube (30) auxiliary wings (23) for air intake during the water filling, the pump below the water filling essentially only consuming air and these auxiliary wings enable the discharge of the cyclic pump during discharge and the body of the cyclic pump (15) being such that water (11) during water filling only enters the body (16) through its lower part (28). Dishwasher according to claim 1, characterized in that the pipe (30) is vertical. 3. A dishwasher according to claim 2, characterized in that the pipe (30) is coaxial with the wheel (20, 21, 23) in the cyclic pump (15). Dishwasher according to claim 3, characterized in that the cyclic pump (15) is driven by a shaft (13), which also drives the discharge pump (12), the shaft itself being driven by an electric motor (14) which rotates in it. one direction during the loading cycle and in the other direction during emptying. Dishwasher according to any of the preceding claims, characterized in that the cyclic pump (15) generates a low water pressure during filling, which however allows the vessels to be sprayed. 6. A dishwasher according to any of the preceding claims, characterized in that a pressure regulator (31a) which responds to the pressure rescuing in the body (16) of the cyclic pump (15) is provided and that the