JP2022113106A - Water level detection device of dishwasher - Google Patents

Abstract

To provide a water level detection device of a dishwasher which can suppress a movement failure in a vertical direction of a float due to a foreign matter and suppress reduction in detection accuracy of a water level.SOLUTION: A water level detection device 10 comprises: a tank 20; an inflow port 21 which is bored on a lower part of a side wall 27 or a bottom wall 26 of the tank 20; an outflow port 22 which is bored on an upper side with respect to the inflow port 21 on the side wall 27; a float guide 23 which is provided in a detection chamber 20A; a float 30 which is provided in the detection chamber 20A in such a state that the float guide 23 is inserted into a through hole 33 and moves in the vertical direction at an upper limit position or lower; and a water level sensor 11 which detects a position in the vertical direction of the float 30. The outflow port 22 is arranged at the position where a lower end 22D of the outflow port 22 is equal to or lower than a lower surface 30D1 of the float 30 at the upper limit position and an upper end 22U of the outflow port 22 is equal to or higher than a lower surface 30D2 of the float 30 in a washing operation.SELECTED DRAWING: Figure 5

Description

The present invention relates to a water level detection device for a dishwasher.

Patent Literature 1 discloses an example of a conventional water level detection device for a dishwasher. This water level detection device is provided in a dishwasher equipped with a washing tank, washing means and drain means.

An object to be cleaned is accommodated in the cleaning tank. The washing tank can store washing water for washing the object to be washed. The washing means comprise a pump, stationary washing nozzles and rotating washing nozzles. The cleaning means performs a cleaning operation for cleaning the object to be cleaned with cleaning water in the cleaning tank.

The drain means has a drain pipe and a pump shared with the washing means. The drain pipe extends outside from the washing tank. The pump rotates in a direction opposite to that during the washing operation, and pressure-feeds washing water from the washing tank to the drain pipe. Thereby, the drain means drains the washing water in the washing tank.

The water level detection device is arranged in the middle of the drain pipe and detects the water level of the washing water in the washing tank. Specifically, the water level detection device has an auxiliary water tank, a mounting plate, a float guide, a float, and a water level sensor.

A detection chamber is defined inside the auxiliary water tank. The lowermost part of the auxiliary water tank is connected to the middle of the drain pipe via a hose. The mounting plate is provided so as to cover the auxiliary water tank. The float guide protrudes upward from the mounting plate, and has a plurality of guide holes arranged therein in the vertical direction.

The float is provided in the detection chamber in a state in which the shaft portion protruding upward from the upper surface of the float is inserted into each guide hole of the float guide. The float has a smaller specific gravity than the wash water, and moves vertically below the upper limit position by being guided by the guide holes of the float guide according to the increase or decrease in the wash water in the detection chamber. The water level sensor is a reed switch held by the float guide and detects the vertical position of the float.

JP 2014-14585 A

However, in the above-described conventional water level detection device for a dishwasher, washing water flowing into the detection chamber may contain fine and lightweight foreign matter. Specifically, the foreign matter is food, tea leaf dregs, etc. that are mixed in the washing water in the washing tank during the washing operation and are not captured by the leftover food filter during the drainage.

When the cleaning water in the cleaning tank is discharged, the detection chamber is filled with cleaning water containing foreign matter, and if the float rises to the upper limit position, the foreign matter floats above the detection chamber, It easily adheres to the inner wall surface of the float, the shaft of the float, and the guide holes of the float guide. As a result, in this water level detection device, the vertical movement of the float is likely to occur due to foreign matter, and it may be difficult to suppress deterioration in water level detection accuracy.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional situation, and provides a water level detection device for a dishwasher that can suppress vertical movement failure of the float due to foreign matter, and furthermore, can suppress deterioration of water level detection accuracy. The problem to be solved is to provide

A water level detection device for a dishwasher according to the present invention includes a washing tank containing an object to be washed and capable of storing washing water for washing the object to be washed;
a cleaning means for performing a cleaning operation of cleaning the object to be cleaned with the cleaning water in the cleaning tank;
a drainage means for discharging the cleaning water in the cleaning tank, comprising: a drain pipe extending from the cleaning tank to the outside; and a pump for pumping the cleaning water from the cleaning tank to the drain pipe;
is provided in a dishwasher with
A water level detection device for a dishwasher that is arranged in the middle of the drain pipe and detects the water level of the washing water in the washing tank,
a tank having a bottom wall, a top wall facing the bottom wall from above, and a cylindrical side wall connecting the bottom wall and the top wall, and having a detection chamber defined therein;
an inflow port bored in a lower portion of the side wall or the bottom wall and connected to the pump side of the drain pipe;
an outflow port drilled above the inflow port in the side wall and connected to a side of the drain pipe opposite to the pump;
a float guide provided to extend vertically in the detection chamber;
A float having a through hole penetrating in a vertical direction and provided in the detection chamber in a state in which the float guide is inserted into the through hole, the float having a specific gravity smaller than that of the washing water and the float in the detection chamber. the float that is guided by the float guide and moves vertically below the upper limit position according to the increase or decrease of the washing water;
a water level sensor provided in the float guide for detecting the vertical position of the float;
The outflow port is positioned such that the lower end of the outflow port is equal to or lower than the lower surface of the float at the upper limit position, and the upper end of the outflow port is equal to or higher than the lower surface of the float during the cleaning operation. It is characterized in that it is arranged in

In the water level detection device for a dishwasher of the present invention (hereinafter simply referred to as the "water level detection device"), the lower end of the outflow port is positioned below the lower surface of the float at the upper limit position, so that the cleaning inside the washing tank is controlled. When the water is discharged, even if the detection chamber is filled with washing water containing foreign matter and the float rises to the upper limit position, the float does not completely block the outflow port. As a result, foreign matter floating above the detection chamber can be quickly discharged out of the detection chamber. Therefore, foreign matter is less likely to adhere to the inner wall surface of the tank, the through-hole of the float, and the float guide.

Further, during the cleaning operation, the cleaning water stored in the cleaning tank is used by the cleaning means for cleaning, so the water level of the cleaning water in the cleaning tank temporarily drops.

Here, depending on the construction of the cleaning means and the drainage means and the usage conditions thereof, the position of the float may or may not be lowered from the upper limit position during the cleaning operation.

As a first specific example, one pump that operates in the normal direction for cleaning and operates in the reverse direction for drainage is shared by the drainage means and the cleaning means, and the discharge pressure during the normal rotation of the pump is increased. Configurations that also act on drain pipes are mentioned. In this configuration, the position of the float may or may not drop from the upper limit position during cleaning operation depending on the usage conditions such as the magnitude of the discharge pressure acting on the drain pipe and the height difference between the pump and the water level detector. be.

As a second specific example, one pump that operates in the normal direction for cleaning and operates in the reverse direction for drainage is shared by the draining means and the cleaning means, and the valve body discharges when the pump rotates in the normal direction. A configuration that closes the entrance of the drain pipe by being pushed by the pressure may be mentioned. In this configuration, while the discharge pressure is rising from zero, the behavior of the valve element becomes unstable and the inlet of the drain pipe is not completely closed. The float position may drop from the upper limit position during operation. Moreover, in this configuration, the valve body may immediately close the inlet of the drain pipe when the discharge pressure rises from zero, which may prevent the float from lowering from the upper limit position during the cleaning operation.

As a third specific example, the cleaning means has a pump in addition to the pump of the drainage means, and when the pump of the cleaning means is in operation and the pump of the drainage means is stopped, the cleaning water in the drainage pipe flows into the drainage means. A configuration that is movable to the pump side is mentioned. In this configuration, the position of the float is lowered from the upper limit position during cleaning operation.

At these times, since the upper end of the outflow port is positioned above the lower surface of the float during cleaning operation, foreign matter is less likely to stay above the upper end of the outflow port during cleaning operation, and the inner wall surface of the tank and the float. Hard to adhere to through holes and float guides.

Therefore, in the water level detection device for a dishwasher of the present invention, it is possible to prevent the vertical movement of the float from being defective due to foreign matter, and furthermore, it is possible to prevent deterioration of the detection accuracy of the water level.

It is desirable that the float position is lowered from the upper limit position during cleaning operation. The outlet is at a position below the middle point between the upper and lower surfaces of the float whose upper end is at the upper limit, and at a position where the lower end of the outlet is above the upper surface of the float during cleaning operation. It is desirable to be placed in

In this case, the upper end of the outflow port is positioned below the middle point between the upper surface and the lower surface of the float at the upper limit position. Even if the detection chamber is filled with washing water and the float rises to the upper limit position, the range of the outlet blocked by the float can be reduced. As a result, the foreign matter floating above the detection chamber can be discharged out of the detection chamber more quickly. As a result, foreign matter is less likely to adhere to the inner wall surface of the tank, the through-hole of the float, and the float guide. In addition, since the lower end of the outflow port is positioned above the upper surface of the float during the cleaning operation, the water level of the cleaning water in the cleaning tank temporarily drops during the cleaning operation, which causes the float to rise. When the position is also lowered, foreign matter is less likely to stay above the lower end of the outflow port and less likely to adhere to the inner wall surface of the tank, the through hole of the float, and the float guide. As a result, in this water level detection device, it is possible to further suppress vertical movement failure of the float due to foreign matter.

It is desirable that the upper wall is provided with a preliminary drainage port through which washing water that has flowed into the detection chamber can be discharged to the outside of the detection chamber.

In this case, even if a large amount of wash water is discharged through the drain pipe and the detection chamber is full, and the wash water containing foreign matter enters above the float that has risen to the upper limit position, it can be quickly removed from the auxiliary drain port. Cleaning water containing foreign matter can be discharged. Therefore, in this water level detection device, it is possible to further prevent foreign matter from adhering to the inner wall surface of the tank, the float, and the float guide, thereby further suppressing failure of the vertical movement of the float due to foreign matter.

It is desirable that a part of the preliminary drainage path extending from the preliminary drainage port to the outside of the detection chamber is reduced in diameter.

In this case, when the detection chamber is filled with water, washing water can be drained preferentially from the outflow port rather than from the preliminary drainage channel, which is partially reduced in diameter. In addition, the other part of the preliminary drainage channel whose diameter is not reduced can quickly return the washing water that has flowed into the preliminary drainage channel into the detection chamber without retaining it in the pipe when the full water condition is avoided. As a result, in this water level detection device, it is possible to prevent foreign matter contained in the wash water from remaining in the preliminary drainage path.

The inlet is preferably formed in the side wall so that the first direction in which the cleaning water flows into the detection chamber from the inlet is one of the circumferential directions of the axis of the float guide. Moreover, it is desirable that the outflow port is formed in the side wall so that the second direction in which the cleaning water flows out from the detection chamber to the outflow port is one direction in the circumferential direction.

In this case, the wash water flowing in the first direction is easily swirled around the axis of the float guide, and the wash water that reaches the outflow port while swirling is discharged in the second direction, thereby promoting the swirling flow. easy. As a result, in this water level detection device, it is possible to prevent foreign matter from adhering to the inner wall surface of the tank, thereby further suppressing the movement failure of the float in the vertical direction caused by the foreign matter. In addition, the swirling flow enables relatively heavy foreign matter to be discharged from the outflow port, so that a wide area including the bottom wall side of the detection chamber can be kept clean. As a result, in this water level detection device, it is possible to further suppress vertical movement failure of the float due to foreign matter.

The float is desirably formed in an annular shape centered on the axis. At least one of the lower surface and the outer peripheral surface of the float is desirably provided with a plurality of protruding blades.

In this case, the swirling flow hits the plurality of blades and rotates the float, thereby suppressing adhesion of foreign matter to the float and the float guide. As a result, in this water level detection device, it is possible to further suppress vertical movement failure of the float due to foreign matter.

According to the water level detection device for a dishwasher of the present invention, it is possible to prevent the vertical movement of the float from being defective due to foreign matter, and furthermore to prevent deterioration in water level detection accuracy.

FIG. 1 is a schematic cross-sectional view of a dishwasher to which the water level detection device of the embodiment is applied. FIG. 2 is a perspective view of the water level detection device of the embodiment. FIG. 3 is a perspective view of the tank body, relating to the water level detection device of the embodiment. FIG. 4 is an exploded perspective view of the water level detection device of the embodiment, excluding the tank body. FIG. 5 is a cross-sectional view of the water level detection device of the embodiment.

Hereinafter, embodiments embodying the present invention will be described with reference to the drawings.

(Example)
As shown in FIG. 1, the water level detection device 10 of the embodiment is a specific example of the water level detection device for a dishwasher of the present invention. A water level detection device 10 is provided in the dishwasher 1 . The tableware washing machine 1 is of the front drawer type installed below the top plate CT1 of the system kitchen.

In this embodiment, the side facing the housing 9 by the user who uses the system kitchen, that is, the left side of the paper surface of FIG. defined as behind the 1 is defined as the left side of the housing 9, and the right side, that is, the front side of the paper surface of FIG. defined as the right side of The front-rear direction, the left-right direction, and the up-down direction shown in FIGS.

<Case, cleaning tank and lid>
The dishwasher 1 includes a housing 9 , a washing tank 7 and a lid 8 .

The housing 9 is substantially box-shaped. The top of the housing 9 is covered with a top plate CT1. The housing 9 has a housing opening 9H. The housing opening 9H opens a wide range from the upper end to the lower end of the front portion of the housing 9, and communicates the inside of the housing 9 with the outside.

The cleaning tank 7 is housed inside a housing 9 . Let the position of the washing tank 7 shown in FIG. 1 be an accommodation position. A slide rail mechanism (not shown) is arranged between the side surface of the substantially box-shaped cleaning tank 7 and the inner wall surface of the housing 9 . Although not shown, the cleaning tank 7 is slidable with respect to the housing 9 by its slide rail mechanism.

The cleaning tank 7 has an opening 7H. The opening 7H opens the upper part of the cleaning tank 7 . A handle 7G is provided at the upper end of the front portion of the cleaning tank 7 .

Although not shown, the user grips the handle 7G and manually slides the cleaning tank 7 from the accommodation position to the front of the housing 9, so that the cleaning tank 7 moves forward from the housing opening 9H of the housing 9. It is pulled out. When the user manually slides the cleaning tank 7 in the drawn-out state to the rear of the housing 9, the cleaning tank 7 returns to the accommodation position.

The lid 8 is arranged in the upper part of the housing 9 and can close and open the opening 7H of the cleaning tank 7 . The lid body 8 is interlocked with the sliding of the cleaning tank 7 by an interlocking mechanism (not shown) to rise from the position shown in FIG. 1 and the position shown in FIG. It moves up and down between positions.

The cleaning tank 7 closes the housing opening 9H and the opening 7H is closed by the lid 8 in a state of being in the housed position.

Although not shown, the cleaning tank 7 has an opening 7H exposed to the outside of the housing 9 with the cover 8 remaining inside the housing 9 in a state of being pulled out of the housing 9 . Thereby, the user can store the tableware TW1 in the washing tank 7 or take out the tableware TW1 from the washing tank 7 through the opening 7H.

The tableware TW1 is, for example, eating utensils such as bowls, plates, and glasses, and eating utensils such as chopsticks, spoons, and forks. The tableware TW1 is an example of the "object to be washed" of the present invention.

At the bottom of the washing tank 7, there is provided a water reservoir 71 capable of storing washing water for washing the tableware TW1. A dish basket 70 is arranged in the washing tank 7 . The tableware TW1 is placed in the dishbasket 70 .

An exhaust passage 79 is provided in the cleaning tank 7 . One end of the exhaust passage 79 opens to the inner wall surface of the cleaning tank 7 on the front side. The other end of the exhaust passage 79 opens below the handle 7G on the front surface of the cleaning tank 7 . The air in the cleaning tank 7 passes through the exhaust passage 79 and is discharged to the outside of the machine, that is, to the front of the housing 9 .

<Water supply pipe, water supply solenoid valve, drain pipe, nozzle and pump>
The dishwasher 1 further includes a water supply pipe P1, a water supply solenoid valve 69, a drain pipe P2, a nozzle 61 and a pump 62.

The nozzle 61 and the pump 62 are examples of the "cleaning means" of the present invention. The drain pipe P2 and the pump 62 are examples of the "drainage means" of the present invention. In other words, the pump 62 serves as both a washing means and a draining means.

The water supply pipe P1, the water supply solenoid valve 69, and the drain pipe P2 are provided inside the housing 9. As shown in FIG. The water supply pipe P<b>1 supplies water to the washing tank 7 from a water supply source (not shown) provided outside the dishwasher 1 . The water supply electromagnetic valve 69 opens and closes the water supply pipe P1 to switch between supplying water to the cleaning tank 7 and stopping it.

The drain pipe P<b>2 extends from the lower part of the water storage part 71 of the washing tank 7 , passes through the rear wall of the housing 9 , and extends to the outside of the dishwasher 1 . The drain pipe P2 discharges the washing water stored in the water reservoir 71 of the washing tank 7 to the outside of the dishwasher 1 .

The nozzle 61 is arranged inside the cleaning tank 7 . The pump 62 is attached to the bottom of the water reservoir 71 of the cleaning tank 7 . The nozzle 61 and the pump 62 perform a washing operation for washing the tableware TW1 in the washing tank 7 with washing water.

More specifically, the nozzle 61 can jet cleaning water into the cleaning tank 7 from a plurality of ejection holes. The spray direction of the nozzle 61 can be changed in various directions in order to reliably wash a plurality of dishes TW1 stacked in the washing tank 7 and to wash the inner wall surface of the washing tank 7 and the dish basket 70. It is designed to

The pump 62 normally rotates to supply the nozzle 61 with the washing water stored in the water reservoir 71 of the washing tank 7 and jet it into the washing tank 7 . The jetted cleansing water is stored in the water reservoir 71 and is repeatedly supplied to the nozzle 61 by the pump 62 .

On the other hand, when the pump 62 operates in reverse, the washing water stored in the water reservoir 71 of the washing tank 7 is pressure-fed to the drain pipe P2, and the washing water is discharged to the outside of the dishwasher 1 through the drain pipe P2. .

At this time, most of the foreign substances contained in the washing water are captured by the residual vegetable filter 67 provided in the water storage section 71 . However, fine and lightweight foreign matter such as food and tea leaf dregs may be pressure-fed to the drain pipe P2 without being caught by the leftover food filter 67. FIG.

<Heater, temperature sensor and drying fan>
The dishwasher 1 further comprises a heater 63, a temperature sensor 63S and a drying fan 68.

The heater 63 is arranged at the bottom of the water reservoir 71 . A drying fan 68 is attached to the rear wall of the cleaning tank 7 . The temperature sensor 63S is provided at a position below the heater 63 at the bottom of the water reservoir 71 .

The heater 63 heats the cleaning water stored in the water reservoir 71 of the cleaning tank 7 or the air in the cleaning tank 7 .

The temperature sensor 63</b>S detects the temperature of the cleaning water stored in the water storage portion 71 of the cleaning tank 7 or the temperature of the air in the cleaning tank 7 near the heater 63 .

The drying fan 68 rotates with the heater 63 in operation to send heated air into the washing tub 7 to dry the tableware TW1. The air sent into the washing tank 7 by the drying fan 68 is exhausted to the outside of the dishwasher 1 through the exhaust passage 79 .

<Water level detector>
The water level detection device 10 is a float type sensor that detects the water level of the cleaning water in the cleaning tank 7 . The water level detection device 10 is attached to the lower part of the rear wall of the cleaning tank 7 and arranged in the middle of the drain pipe P2.

The pump 62 side of the water level detection device 10 in the drain pipe P2 is defined as a first drain pipe P21. The side opposite to the pump 62 with respect to the water level detection device 10 in the drain pipe P2 is a second drain pipe P22.

In FIG. 1, the position of the water level detection device 10 is shown farther from the rear wall of the cleaning tank 7 than it actually is, and the preliminary drainage path P3 is also longer in the front-rear direction than it actually is. Illustrated.

As shown in FIGS. 2 to 5, the water level detection device 10 has a tank 20, an inlet 21, an outlet 22, a float guide 23, a float 30, and a water level sensor 11. FIG.

The tank 20 has a tank body 25 shown in FIGS. 2, 3 and 5, and an upper lid 29 and a cap 29C shown in FIGS. The upper lid 29 is an example of the "upper wall" of the present invention.

In this embodiment, the tank main body 25, the upper lid 29, and the cap 29C are resin molded products manufactured by injection molding or the like of thermoplastic resin.

As shown in FIG. 3, the tank body 25 integrally has a bottom wall 26 and side walls 27 . The bottom wall 26 is a substantially square flat plate with four rounded corners when viewed from above and below. The side wall 27 has a tank front wall 27A, a tank rear wall 27B, a tank left wall 27L and a tank right wall 27R, and has a rectangular cylindrical shape. The side wall 27 extends vertically, and its lower end is connected to the bottom wall 26 .

A pedestal 24 is formed in the center of the upper surface of the bottom wall 26 . The pedestal 24 protrudes upward in a cylindrical shape around an axis X23 extending in the vertical direction. The interior of the pedestal 24 is closed by a partition wall 24W.

A lower limit stopper 26S is formed around the pedestal 24 on the upper surface of the bottom wall 26 . The lower limit stopper 26S is a plurality of ribs protruding from the outer peripheral surface of the pedestal 24 radially outward of the axis X23.

As shown in FIGS. 3 and 5, a circular inlet 21 is formed in the lower and rear portion of the tank right wall 27R. In FIG. 5, since the tank right wall 27R is located on the front side of the paper, the inflow port 21 is illustrated with a chain double-dashed line. As shown in FIG. 3, the inlet 21 protrudes cylindrically rightward from the tank right wall 27R. As shown in FIGS. 1 and 2, the inflow port 21 is connected to a first drain pipe P21 on the pump 62 side of the drain pipe P2.

As shown in FIG. 5, a circular outlet 22 is formed above and behind the inlet 21 in the left wall 27L of the tank. As shown in FIG. 3, the outflow port 22 protrudes leftward cylindrically from the tank left wall 27L. As shown in FIGS. 1 and 2, the outflow port 22 is connected to a second drain pipe P22 on the side opposite to the pump 62 in the drain pipe P2.

As shown in FIG. 3, the direction in which the wash water pumped through the first drain pipe P21 flows from the inflow port 21 into the detection chamber 20A is defined as a first direction DR1. The direction in which the wash water flows out from the detection chamber 20A to the outflow port 22 is defined as a second direction DR2.

The inlet 21 is formed in the right wall 27R of the tank so that the first direction DR1 is the direction R1 toward one side of the axis X23 of the float guide 23 in the circumferential direction.

The outflow port 22 is perforated in the tank left wall 27L so that the second direction DR2 is the direction R1 toward one side of the circumferential direction. In this embodiment, the first direction DR1 and the second direction DR2 are the same leftward direction.

With this configuration of the inlet 21 and the outlet 22, the wash water flowing into the detection chamber 20A in the first direction DR1 can be easily swirled around the axis X23 of the float guide 23, and reaches the outlet 22 while swirling. It is easy to promote the swirl flow by causing the washed water to flow out in the second direction DR2.

As shown in FIG. 4, the upper cover 29 is a substantially square flat plate with four rounded corners when viewed from above and below. A rectangular ring-shaped fitting rib 29R is formed on the lower surface of the upper lid 29 so as to protrude downward.

A float guide 23 is formed in the center of the lower surface of the upper lid 29 . The float guide 23 protrudes cylindrically downward about the axis X23. As shown in FIG. 5, the interior of the float guide 23 is closed by a partition wall 23W. The internal space above the partition wall 23W in the float guide 23 serves as a sensor housing portion 23S.

As shown in FIGS. 4 and 5, an upper limit stopper 29S is formed around the float guide 23 on the lower surface of the upper lid 29. As shown in FIGS. The upper limit stopper 29S is a plurality of ribs protruding radially outward of the axis X23 from the base of the outer peripheral surface of the float guide 23. As shown in FIG.

In the front part of the upper lid 29, a rectangular preliminary drainage port 28 extending in the left-right direction is bored. The auxiliary drain port 28 protrudes upward at a position adjacent to the front portion of the fitting rib 29R extending in the left-right direction from the rear.

A connection portion 28C is formed integrally with the upper portion of the auxiliary drain port 28 . The connecting portion 28C communicates with the auxiliary drain port 28 and protrudes forward in a cylindrical shape.

The cap 29C is fastened to the upper lid 29 with a screw 29B in a state of closing the sensor accommodating portion 23S from above.

The upper lid 29 is connected to the side wall 27 via a sealant (not shown) or a sealing member such as an elastic seal ring in a state in which the fitting rib 29R is fitted to the upper edge of the side wall 27 and faces the bottom wall 26 from above. ing.

As shown in FIG. 5, a detection chamber 20A is defined inside the tank 20 . The detection chamber 20</b>A is a space surrounded by a bottom wall 26 , side walls 27 and a top lid 29 . The float guide 23 extends vertically within the detection chamber 20A, and its lower end is fitted into and held by the pedestal 24 .

The tank 20 has a fixing protrusion 20D protruding forward from the tank front wall 27A and a fixing piece 20E protruding upward from the upper lid 29. As shown in FIG. A connection recess 7F, a fixed recess 7D located below the connection recess 7F, and a fastening portion 7E located above the connection recess 7F are formed in the rear wall of the cleaning tank 7. As shown in FIG.

In the tank 20, the connection portion 28C is fitted into the connection recess 7F, the fixing protrusion 20D is fitted into the fixation recess 7D, and the fixing piece 20E is fastened to the fastening portion 7E by the screw 20B, whereby the rear wall of the cleaning tank 7 is fixed. is assembled to.

A communication hole 7C is provided through the rear wall of the cleaning tank 7 in the front-rear direction. The communication hole 7C allows communication between the lower end of the connection portion 28C fitted in the connection recess 7F and the inside of the cleaning tank 7. As shown in FIG. The connecting portion 28C and the communication hole 7C form a preliminary drainage path P3 extending from the preliminary drainage port 28 to the outside of the detection chamber 20A. A communication hole 7C, which is a part of the preliminary drainage path P3, has a reduced diameter with respect to the connecting portion 28C.

The preliminary drainage port 28 can discharge the cleaning water that has flowed into the detection chamber 20A to the outside of the detection chamber 20A, more specifically, into the cleaning tank 7 via the preliminary drainage path P3. Further, the preliminary drain port 28 also serves as an air vent for discharging the air inside the detection chamber 20A to the outside of the detection chamber 20A.

The float 30 is formed in an annular shape having a through-hole 33 extending vertically around the axis X23. The outer peripheral surface of the float 30 is a cylindrical surface centered on the axis X23.

As shown in FIG. 4, the lower surface 30D of the float 30 is provided with a plurality of blades 35 projecting downward. Each blade 35 extends like a rib in the radial direction of the axis X23.

As shown in FIG. 5, the upper surface 30U of the float 30 also has a plurality of blades 35 protruding upward. The vanes 35 on the upper surface 30U have the same configuration except that the protruding direction of the vanes 35 on the lower surface 30D is opposite to that of the vanes 35 on the lower surface 30D.

The float 30 is, for example, a closed-cell foam made of resin, rubber, soft material, etc., a hollow-shaped resin molded article by blow molding, or a hollow shape formed by connecting two members such as "monaka-no-hi". , the specific gravity is smaller than that of the washing water. Although not shown, the float 30 contains a permanent magnet.

The float 30 is provided in the detection chamber 20A with the float guide 23 inserted through the through hole 33 . The float 30 is guided by the float guide 23 according to the increase or decrease in the washing water in the detection chamber 20A, and moves vertically below the upper limit position and above the lower limit position.

As indicated by the two-dot chain line in FIG. 5, the upper limit position of the float 30 is the position where the upper surface 30U of the float 30 contacts the upper limit stopper 29S. Although not shown, the lower limit position of the float 30 is the position where the lower surface 30D of the float 30 contacts the lower limit stopper 26S.

The water level sensor 11 is a well-known reed switch arranged on the substrate and accommodated in the sensor accommodating portion 23S of the float guide 23. As shown in FIG. The signal wiring of the water level sensor 11 is drawn out from a wiring lead-out hole formed in the cap 29C and connected to the control section C1, which will be described later.

The water level sensor 11 detects the vertical position of the float 30 by connecting and disconnecting internal contacts according to the approach and separation of the permanent magnets built into the float 30 . In this embodiment, the water level sensor 11 is arranged at a position where it can detect whether or not the float 30 is at the upper limit position indicated by the two-dot chain line in FIG.

The float 30 reaches the upper limit position when the amount of wash water stored in the water reservoir 71 of the wash tank 7 reaches the amount necessary for executing the wash operation. When the wash water stored in the water reservoir 71 of the wash tank 7 is drained through the drain pipe P2, the float 30 is moved to the upper limit position when a large amount of wash water is pumped into the detection chamber 20A. reach.

During the cleaning operation, the water level of the cleaning water in the cleaning tank 7 is temporarily lowered according to the amount of cleaning water sprayed from the nozzle 61, and the cleaning water in the detection chamber 20A is also temporarily reduced. Here, in this embodiment, one pump 62, which rotates in the normal direction for cleaning and operates in the reverse direction for draining, is shared by the draining means and the cleaning means, and discharges when the pump 62 rotates in the normal direction. Pressure also acts on the first drain pipe P21. Further, the position of the float 30 is lowered from the upper limit position during the cleaning operation depending on the usage conditions such as the magnitude of the discharge pressure acting on the first drain pipe P21 and the height difference between the pump 62 and the water level detection device 10. Therefore, the float 30 temporarily descends from the upper limit position indicated by the two-dot chain line in FIG. 5 to the position indicated by the solid line in FIG. 5 during the cleaning operation.

<Arrangement of outflow port>
The outflow port 22 is located at a position where the lower end 22D of the outflow port 22 is below the lower surface 30D1 of the float 30 at the upper limit position, and the upper end 22U of the outflow port 22 is in the washing operation, that is, the washing water is sprayed from the nozzle 61. It is disposed at a position above the lower surface 30D2 of the float 30 during operation.

More preferably, the outlet 22 is at a position below the middle point 30C1 between the upper surface 30U1 and the lower surface 30D1 of the float 30 where the upper end 22U of the outlet 22 is at the upper limit position, and the lower end 22D of the outlet 22 is It is arranged at a position above the upper surface 30U2 of the float 30 during the cleaning operation.

<Control unit and input/output unit>
As shown in FIG. 1, the dishwasher 1 further includes a control section C1 and an input/output section 40. As shown in FIG. The control unit C1 is arranged below the handle 7G on the front side of the cleaning tank 7 . The input/output unit 40 is arranged at the upper end portion on the front side of the cleaning tank 7 .

The control unit C1 includes a CPU (not shown), a memory configured by storage elements such as ROM and RAM, an interface circuit for transmitting and receiving signals to and from a controlled object, and a power supply circuit for controlling power supply to the controlled object. is an electronic circuit unit comprising: The memory stores programs and setting information for operating the dishwasher 1 .

The control unit C1 controls and operates the pump 62, the heater 63, the drying fan 68, and the like, and receives detection signals from the temperature sensor 63S and the water level sensor 11 of the water level detection device 10. FIG. The control unit C1 also controls sensors (not shown) such as a position sensor for detecting whether the cleaning tank 7 is in the accommodation position and a lock sensor for detecting whether the cleaning tank 7 is locked in the accommodation position. Receive detection signals.

The input/output unit 40 has a plurality of buttons (not shown) for user's input operation. The input/output unit 40 also has a lamp, a display device capable of displaying numbers, characters, and the like for transmitting various information to the user. The input/output unit 40 transmits a user's input operation to the control unit C1 and displays information transmitted from the control unit C1.

When the washing tank 7 is in the housed position, the entire input/output unit 40 is hidden by the top plate CT1 of the system kitchen. Therefore, the user cannot operate or visually recognize the input/output unit 40 .

On the other hand, although not shown, the input/output unit 40 as a whole moves forward from the top plate CT1 of the system kitchen by pulling out the washing tank 7 from the accommodation position. Therefore, the user can operate and visually recognize the input/output unit 40 .

<Washing operation>
In the dishwasher 1 having the above configuration, the washing operation is performed in the following procedure. That is, after the user operates the input/output unit 40 to instruct the start of the cleaning operation while the cleaning tank 7 is pulled out from the housing position, the cleaning tank 7 is pushed into the housing position.

As a result, the controller C1 operates on the condition that a position sensor (not shown) detects that the cleaning tank 7 is in the accommodation position and that a lock sensor (not shown) detects that the cleaning tank 7 is locked at the accommodation position. , the pump 62 is operated to perform a washing operation in which washing water is sprayed from the nozzle 61 into the washing tank 7 . In other words, after confirming that the opening 7H of the cleaning tank 7 is blocked by the lid 8, the controller C1 operates the pump 62 to perform the cleaning operation.

In the washing operation, the control unit C1 sequentially performs a washing step using washing water containing detergent and a rinsing step using clean washing water to wash the tableware TW1 in the washing tank 7 cleanly.

The controller C1 appropriately opens the water supply electromagnetic valve 69 at the start and during these steps to supply water to the cleaning tank 7 via the water supply pipe P1. At this time, based on the detection signal from the water level sensor 11, the control unit C1 determines whether or not the amount of cleaning water stored in the water storage unit 71 of the cleaning tank 7 has reached the amount required for executing the cleaning operation. and closes the water supply electromagnetic valve 69 when it reaches.

In addition, during and at the end of these processes, the control unit C1 appropriately reversely operates the pump 62 to pressure-feed the washing water from the water reservoir 71 of the washing tank 7 to the drain pipe P2, thereby washing the dishes through the drain pipe P2. It is discharged outside the machine 1. At this time, based on the detection signal from the water level sensor 11, the control unit C1 determines the discharge state and discharge end of the wash water discharged through the drain pipe P2, and controls the reverse operation of the pump 62.

At the end of the washing operation, the control unit C1 executes the drying process, appropriately operates the heater 63 and the drying fan 68, and after drying the tableware TW1 in the washing tank 7, ends the washing operation.

<Effect>
In the water level detection device 10 of the embodiment, as shown in FIG. 5, the lower end 22D of the outflow port 22 is positioned below the lower surface 30D1 of the float 30 at the upper limit position, so that the washing water in the washing tank 7 is discharged. At this time, even if the detection chamber 20A is filled with washing water containing foreign matter and the float 30 rises to the upper limit position, the float 30 does not completely block the outflow port 22.例文帳に追加As a result, foreign matter floating above the detection chamber 20A can be quickly discharged out of the detection chamber 20A. Therefore, foreign matter is less likely to adhere to the inner wall surface of the tank 20, the through hole 33 of the float 30, and the float guide 23.

During the washing operation, the washing water stored in the washing tank 7 is used for washing by the nozzle 61 and the pump 62, so that the water level of the washing water in the washing tank 7 temporarily drops. The position of the float 30 is also lowered. At this time, the configuration in which the upper end 22U of the outflow port 22 is positioned above the lower surface 30D2 of the float 30 during the cleaning operation makes it difficult for foreign matter to stay above the upper end 22U of the outflow port 22 during the cleaning operation. , the through hole 33 of the float 30 and the float guide 23.

Therefore, in the water level detection device 10 of the embodiment, it is possible to suppress the vertical movement failure of the float 30 due to the foreign matter, and furthermore, it is possible to suppress the deterioration of the water level detection accuracy.

Further, in the water level detection device 10, the upper end 22U of the outflow port 22 is arranged at a position below the middle point 30C1 between the upper surface 30U1 and the lower surface 30D1 of the float 30 at the upper limit position. Even if the detection chamber 20A is full of washing water containing foreign matter and the float 30 rises to the upper limit position when the washing water is discharged, the range of the outflow port 22 blocked by the float 30 is reduced. can. As a result, foreign matter floating above the detection chamber 20A can be more quickly discharged out of the detection chamber 20A. Therefore, foreign matter is less likely to adhere to the inner wall surface of the tank 20 , the through hole 33 of the float 30 and the float guide 23 . In addition, the lower end 22D of the outflow port 22 is arranged at a position above the upper surface 30U2 of the float 30 during the cleaning operation, so that the water level of the cleaning water in the cleaning tank 7 temporarily drops during the cleaning operation. When the position of the float 30 is lowered accordingly, foreign matter is less likely to stay above the lower end 22D of the outflow port 22 and adhere to the inner wall surface of the tank 20, the through hole 33 of the float 30, and the float guide 23. As a result, in this water level detection device 10, it is possible to further suppress vertical movement failure of the float 30 due to foreign matter.

Further, in the water level detection device 10, the upper lid 29 is provided with a preliminary drainage port 28 through which washing water that has flowed into the detection chamber 20A can be discharged to the outside of the detection chamber 20A. With this configuration, even if a large amount of washing water is discharged through the drain pipe P2 and the detection chamber 20A is filled with water, and the washing water containing foreign matter enters above the float 30 that has risen to the upper limit position, it can be quickly removed. Washing water containing foreign matter can be discharged from the preliminary drain port 28 . Therefore, the water level detection device 10 can further prevent foreign matter from adhering to the inner wall surface of the tank 20, the float 30, and the float guide 23, and can further prevent the vertical movement of the float 30 from being defective due to the foreign matter.

Further, in the water level detection device 10, a part of the preliminary drainage path P3 extending from the preliminary drainage port 28 to the outside of the detection chamber 20A, that is, the communication hole 7C, is reduced in diameter with respect to the other part of the preliminary drainage path P3, that is, the connection portion 28C. It is With this configuration, when the detection chamber 20A is filled with water, washing water can be drained preferentially from the outflow port 22 rather than the preliminary drain path P3 in which the diameter of the communication hole 7C is reduced. In addition, when the full water condition is avoided, the connecting portion 28C of the preliminary drainage path P3, which is not diameter-reduced, quickly returns the wash water flowing into the preliminary drainage path P3 to the detection chamber 20A without retaining it in the pipe. be able to. As a result, in the water level detection device 10, it is possible to prevent foreign substances contained in the washing water from remaining in the preliminary drainage path P3.

Further, in the water level detection device 10, as shown in FIG. 3, the inflow port 21 is mounted on the tank right wall 27R so that the first direction DR1 is the direction R1 toward one of the circumferential directions of the axis X23 of the float guide 23. is drilled in the lower and rear part of the The outflow port 22 is formed above and behind the inflow port 21 in the tank left wall 27L so that the second direction DR2 is the direction R1 toward one side of the circumferential direction. With this configuration, the wash water flowing in the first direction DR1 can be easily swirled around the axis X23 of the float guide 23, and the wash water reaching the outflow port 22 while swirling can be discharged in the second direction DR2. It is easy to promote the swirling flow. As a result, in the water level detection device 10, it is possible to prevent foreign matter from adhering to the inner wall surface of the tank 20, thereby further suppressing the movement failure of the float 30 in the vertical direction caused by the foreign matter. In addition, the swirling flow enables relatively heavy foreign matter to be discharged from the outflow port 22, so that a wide area including the bottom wall side in the detection chamber 20A can be kept clean. As a result, in the water level detection device 10, it is possible to further suppress vertical movement failure of the float 30 due to foreign matter.

Further, in the water level detection device 10, as shown in FIG. 4, the float 30 is formed in an annular shape around the axis X23. A plurality of blades 35 are protruded from the lower surface 30D and the upper surface 30U of the float 30. As shown in FIG. With this configuration, the float 30 is rotated by the swirling flow hitting the plurality of blades 35 , thereby suppressing adhesion of foreign matter to the float 30 and the float guide 23 . As a result, in the water level detection device 10, it is possible to further suppress vertical movement failure of the float 30 due to foreign matter.

Although the present invention has been described above with reference to the embodiments, it goes without saying that the present invention is not limited to the above embodiments, and can be modified and applied without departing from the scope of the invention.

The positional relationship between the inflow port 21 and the outflow port 22 according to the embodiment is an example, and the present invention is not limited to this configuration. For example, the outflow port 22 may be formed in the left portion of the tank front wall 27A, and the second direction DR2 may be changed to the forward direction R1 toward one side of the circumferential direction. In this case, the second direction DR2 is orthogonal to the first direction DR1. Alternatively, the outflow port 22 may be formed in the front portion of the tank right wall 27R, and the second direction DR2 may be changed to the right, which is the direction R1 toward one side of the circumferential direction. In this case, the second direction DR2 is opposite to the first direction DR1. Furthermore, the outflow port 22 may be formed in the right portion of the tank rear wall 27B, and the second direction DR2 may be changed to the rearward direction R1 toward one side of the circumferential direction. In this case, the second direction DR2 is orthogonal to the first direction DR1.

In the embodiment, the side wall 27 has a rectangular cylindrical shape, but the invention is not limited to this configuration, and the side wall may have a cylindrical shape, for example.

In the example, the inlet 21 is drilled in the lower portion of the side wall 27, but the invention is not limited to this configuration. For example, the inlet may be drilled into the bottom wall.

In the embodiment, the inlet 21 has a round hole shape, but the present invention is not limited to this configuration, and for example, the inlet may have a rectangular hole shape or a polygonal hole shape. The same applies to the outflow port.

In the embodiment, the float guide 23 extends downward from the top lid 29 and is held by a pedestal 24 projecting from the bottom wall 26, but the present invention is not limited to this configuration. For example, the present invention includes a configuration in which the pedestal 24 is removed from the bottom wall 26 and the lower end of the float guide 23 is not held.

In the example, the float 30 is annular, but the invention is not limited to this configuration. For example, the float may have any shape as long as it has a through hole, and may be polygonal ring such as square ring.

In the embodiment, a plurality of blades 35 protrude from the lower surface 30D and the upper surface 30U of the float 30, but the present invention is not limited to this configuration. For example, a plurality of blades may protrude only from the lower surface of the float, or may protrude from the outer peripheral surface of the float.

In this embodiment, one pump 62, which rotates in the normal direction for cleaning and operates in the reverse direction for drainage, is shared by the draining means and the cleaning means, and the discharge pressure when the pump 62 rotates in the normal direction is the second highest. 1 drain pipe P21. Further, the position of the float 30 is lowered from the upper limit position during the cleaning operation depending on the usage conditions such as the magnitude of the discharge pressure acting on the first drain pipe P21 and the height difference between the pump 62 and the water level detection device 10. The present invention is not limited to the configuration of such an embodiment. Three specific examples are given below.

For example, in the present invention, the discharge pressure during forward rotation of the pump acts on the drain pipe as in the embodiment. The position of the float does not need to be lowered from the upper limit position during the cleaning operation depending on the usage conditions such as height difference.

In addition, in the present invention, one pump that operates in the normal direction for cleaning and in the reverse direction for drainage is shared by the draining means and the cleaning means, and the valve body is adjusted to the discharge pressure during the normal rotation of the pump. It may be configured such that it is pushed to close the entrance of the drain pipe. In this configuration, while the discharge pressure is rising from zero, the behavior of the valve element becomes unstable, and the cleaning water in the drain pipe moves to the pump side in a state in which the inlet of the drain pipe is not securely closed. , the position of the float may be lowered from the upper limit position during the cleaning operation. Moreover, in this configuration, the valve body immediately closes the inlet of the drain pipe when the discharge pressure rises from zero, so that the position of the float does not have to fall from the upper limit position during the cleaning operation.

Further, according to the present invention, the cleaning means has a pump in addition to the pump of the drainage means, and when the pump of the cleaning means is in operation and the pump of the drainage means is stopped, the cleaning water in the drainage pipe is discharged from the pump side of the drainage means. and the position of the float may be lowered from the upper limit position during cleaning operation.

The present invention can be used, for example, in dishwashers, dishwashers, and the like.

DESCRIPTION OF SYMBOLS 1... Dishwasher 10... Water level detector TW1... Object to be washed (tableware)
7... Cleaning tank 61, 62... Cleaning means (61... Nozzle, 62... Pump)
P2, 62... drainage means (P2... drainage pipe, 62... pump)
26... Bottom wall 29... Top wall (upper lid)
27 Side wall 20A Detection chamber 20 Tank 21 Inflow port 22 Outflow port 23 Float guide 33 Through hole 30 Float 11 Water level sensor 22D Lower end of outflow port 22U Upper end of outflow port 30D Lower surface of float 30U... Upper surface of float 30D1... Lower surface of float at upper limit position 30U1... Upper surface of float at upper limit position 30D2... Lower surface of float during cleaning operation 30U2... Upper surface of float during cleaning operation 30C1... Upper surface of float at upper limit position and the lower surface 28... Preliminary drainage port P3... Preliminary drainage path X23... Axial center of float guide R1... Direction toward one side of circumferential direction of axial center of float guide DR1... First direction DR2... Second direction 35... multiple feathers

Claims (6)

a washing tank containing an object to be washed and capable of storing washing water for washing the object to be washed;
a cleaning means for performing a cleaning operation of cleaning the object to be cleaned with the cleaning water in the cleaning tank;
a drainage means for discharging the cleaning water in the cleaning tank, comprising: a drain pipe extending from the cleaning tank to the outside; and a pump for pumping the cleaning water from the cleaning tank to the drain pipe;
is provided in a dishwasher with
A water level detection device for a dishwasher that is arranged in the middle of the drain pipe and detects the water level of the washing water in the washing tank,
a tank having a bottom wall, a top wall facing the bottom wall from above, and a cylindrical side wall connecting the bottom wall and the top wall, and having a detection chamber defined therein;
an inflow port bored in a lower portion of the side wall or the bottom wall and connected to the pump side of the drain pipe;
an outflow port drilled above the inflow port in the side wall and connected to a side of the drain pipe opposite to the pump;
a float guide provided to extend vertically in the detection chamber;
A float having a through hole penetrating in a vertical direction and provided in the detection chamber in a state in which the float guide is inserted into the through hole, the float having a specific gravity smaller than that of the washing water and the float in the detection chamber. the float that is guided by the float guide and moves vertically below the upper limit position according to the increase or decrease of the washing water;
a water level sensor provided in the float guide for detecting the vertical position of the float;
The outflow port is positioned such that the lower end of the outflow port is equal to or lower than the lower surface of the float at the upper limit position, and the upper end of the outflow port is equal to or higher than the lower surface of the float during the cleaning operation. A water level detection device for a dishwasher, characterized in that it is disposed in the configured such that the position of the float is lowered from the upper limit position during the cleaning operation;
The outflow port is located at a position where the upper end of the outflow port is at or below an intermediate point between the upper surface and the lower surface of the float at the upper limit position, and the lower end of the outflow port is positioned during the cleaning operation. 2. A water level detector for a dishwasher according to claim 1, wherein said water level detector is disposed at a position above said upper surface of said float. 3. A water level detecting device for a dishwasher according to claim 1, wherein said upper wall is provided with a preliminary drainage port through which washing water flowing into said detecting chamber can be discharged outside said detecting chamber. 4. The water level detection device for a dishwasher according to claim 3, wherein a part of the preliminary drainage path extending from the preliminary drainage port to the outside of the detection chamber has a reduced diameter. the inlet is formed in the side wall so that the first direction in which the cleaning water flows into the detection chamber from the inlet is one of the circumferential directions of the axis of the float guide;
5. The method according to claim 1, wherein the outlet is formed in the side wall so that a second direction in which the cleaning water flows out from the detection chamber to the outlet is the one of the circumferential directions. A water level detection device for a dishwasher according to any one of claims 1 to 3. The float is formed in an annular shape centering on the axis,
6. The water level detector for a dishwasher according to claim 5, wherein a plurality of blades are protrudingly provided on at least one of the lower surface and the outer peripheral surface of the float.

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