Dishwasher

Abstract

To provide a dishwasher which includes a water level detection device 6, the water level detection device 6 communicating with the bottom of a washing tank through a communication pipe 61 and including a water level detection chamber 62 into which washing water in the washing tank flows through the communication pipe 61, and which can suppress clogging of the communication pipe 61 caused by oily matter deposited on the water surface of the residual water in a configuration in which the washing water remains on the bottom of the washing tank after a drainage operation performed by a pump that discharges the washing water from the washing tank.SOLUTION: A cylindrical connection port 623, to which a communication pipe 61 is connected, is provided in a water level detection chamber 62 so as to protrude in the horizontal direction. The vertical position of the connection port 623 is set such that the height of the lower end of the inner surface of the connection port 623 becomes lower than the height H of the residual water level being the water level of the washing water that remains at the bottom of the washing tank after the drainage operation.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a dishwasher comprising a washing tub for storing dishes, a water level detection device for detecting the level of washing water in the washing tub, and a pump for draining the washing water in the washing tub out of the washing tub. [Background technology]

[0002] Conventionally, in this type of dishwasher, the water level detection device has a water level detection chamber that is connected to the bottom of the washing tub via a connecting pipe and into which washing water from the washing tub flows via the connecting pipe (see, for example, Patent Document 1). In this device, the connecting pipe first descends from the bottom of the washing tub, then extends approximately horizontally from there, and then rises up toward the water level detection chamber.

[0003] Here, after washing the dishes, a drain operation is performed by a pump to drain the wash water from the washing tub, but to prevent the pump from running idle after the drain operation, wash water is left at the bottom of the washing tub. The height of the residual water level, which is the level of wash water remaining at the bottom of the washing tub after the drain operation, is determined by the pump head and the installation height of the pump. Conventionally, the height of the residual water level coincides with the height of a part of the connecting pipe that rises toward the water level detection chamber.

[0004] Incidentally, oil and grease are dissolved in the wash water (residual water) remaining after the drainage operation. After a while, this oil and grease cools and solidifies, and due to its specific gravity, it rises to the surface of the residual water and precipitates. Conventionally, the surface of the residual water exists in a small area roughly equal to the cross-sectional area of ​​the communicating pipe, in the part of the communicating pipe that rises toward the water level detection chamber, which corresponds to the height of the residual water level. Therefore, oil and grease precipitate in high density in this part. As a result, the communicating pipe may become clogged, making it impossible to detect the water level. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-193074 Summary of the Invention [Problem to be solved by the invention]

[0006] In view of the above, an object of the present invention is to provide a dishwasher that can prevent clogging of the communicating pipe and avoid the inability to detect the water level for a long period of time. [Means for solving the problem]

[0007] In order to solve the above problems, the present invention provides a dishwasher comprising a washing tub for storing dishes, a water level detection device for detecting the level of washing water in the washing tub, and a pump for draining the washing water in the washing tub outside the washing tub, wherein the water level detection device has a water level detection chamber that is connected to the bottom of the washing tub via a connecting pipe and into which the washing water in the washing tub flows via the connecting pipe, and wherein the washing water remains at the bottom of the washing tub after a drain operation by the pump that drains the washing water in the washing tub, and wherein a cylindrical connection port for connecting the connecting pipe is provided in the water level detection chamber so as to protrude horizontally, and the vertical position of this connection port is set so that the height of the lower end of the inner surface of the connection port is lower than the height of the residual water level, which is the level of washing water remaining at the bottom of the washing tub after a drain operation.

[0008] According to the present invention, the water level of the remaining water is located above the lower end of the inner surface of the horizontal connection port provided in the water level detection chamber, which prevents the connecting pipe from clogging with oil and grease deposited on the water level, thereby preventing the inability to detect the water level due to clogging of the connecting pipe for a long period of time.

[0009] Furthermore, if the vertical position of the connection port is set so that the height of the upper end of the connection port's inner surface is higher than the residual water level, it is desirable that the communicating pipe be positioned approximately horizontally over a predetermined length from the end connected to the connection port so that the upper end of the pipe's inner surface is higher than the residual water level. In this way, the water surface of the residual water extends from the connection port to the horizontally disposed portion of the communicating pipe, increasing the area of ​​the water surface. This reduces the density of oil deposition on the water surface, making it possible to more effectively prevent the communicating pipe from becoming clogged with oil. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a perspective view of a dishwasher according to an embodiment of the present invention; [Figure 2] FIG. 2 is a cross-sectional side view taken along line II-II in FIG. [Figure 3] 2 is a perspective view of components of a water level detection device provided in the dishwasher according to the embodiment. FIG. [Figure 4] FIG. 4 is a cross-sectional side view taken along line IV-IV in FIG. 3 . [Figure 5] FIG. 5 is an enlarged cross-sectional front view taken along line VV in FIG. 4. DETAILED DESCRIPTION OF THE INVENTION

[0011] 1 and 2, a dishwasher according to an embodiment of the present invention includes a washing tub 2 for storing dishes, which is built into a housing 1. The front of the washing tub 2 is covered by a front door 3 that can be pulled down forward to open and close freely. A dish basket (not shown) is arranged in the washing tub 2 along a guide portion 21 so that it can be pulled out forward, and a lower nozzle 22 and an upper nozzle 23 are also arranged to spray washing water onto dishes placed in the dish basket.

[0012] A cleaning water reservoir 24 is recessed in the front part of the bottom wall of the cleaning tank 2, and communicates with the inside of the cleaning tank 2. Two pumps 4 and 5, front and rear, are disposed below the bottom wall of the cleaning tank 2, which suck cleaning water from reservoir 24 via water supply pipes 41 and 51, respectively. The front pump 4 supplies cleaning water to the lower nozzle 22 via water supply pipe 42, and the rear pump 5 supplies cleaning water to the upper nozzle 23 via water supply pipe 52. Furthermore, by reversing the rotation of the rear pump 5, the cleaning water in the cleaning tank 1 is drained out of the cleaning tank 2 via drain pipe 53.

[0013] The dishwasher is further equipped with a water level detection device 6 that detects the level of wash water in wash tub 1. Referring to Figures 3 to 5, water level detection device 6 has a water level detection chamber 62 that communicates with reservoir 24, which is the bottom of wash tub 2, via a communication pipe 61, and into which wash water in wash tub 2 flows via communication pipe 61. A pair of first and second floats 63, 64 that move up and down depending on the water level in water level detection chamber 62 are housed in water level detection chamber 62. Each float 63, 64 is provided with a rod portion 631, 641 that protrudes upward through a respective slit 621a formed in upper lid 621 of water level detection chamber 62 and has magnet holders 632, 642 at its upper end. A first reed switch 65 is arranged on a mounting plate 622 erected on the upper cover 621, facing the rod portion 631 of the first float 63 at a relatively low position above the rod portion 631, and a second reed switch 66 is arranged on a mounting plate 622 erected on the upper cover 621, facing the rod portion 631 of the first float 63 at a relatively high position above the rod portion 641 of the second float 64.

[0014] Cleaning water is supplied into the cleaning tank 2 via a water supply valve (not shown). When the level of cleaning water in the cleaning tank 2 reaches a predetermined cleaning water level, a magnet held in a magnet holder 632 on a rod portion 631 of the first float 63 approaches a first reed switch 65, turning on the first reed switch 65, which closes the water supply valve and stops the supply of water to the cleaning tank 2. If the water supply valve malfunctions and the water level in the cleaning tank 2 reaches the cleaning water level but the water supply is not stopped, and the water level reaches the overflow level, a magnet held in a magnet holder 642 on a rod portion 641 of the second float 64 approaches a second reed switch 66, turning on the second reed switch 66, which issues an abnormality alert and starts draining the water using the rear pump 5.

[0015] Furthermore, even after the washing operation, a drainage operation is performed by the rear pump 5 to drain the washing water from the washing tank 2. Then, to prevent the pump 5 from running idle after the drainage operation, washing water is left at the bottom of the washing tank 2, i.e., in the reservoir 24. The height H of the remaining water level, which is the level of washing water remaining in the washing tank 2 after the drainage operation, is determined by the head of the rear pump 5 when it rotates in reverse and the height at which this pump 5 is installed.

[0016] Here, a cylindrical connection port 623 to which the communicating pipe 61 is connected is provided at the lower end of the water level detection chamber 62 so as to protrude horizontally. In this embodiment, the water level detection chamber 62 is extended downward more than in conventional cases. The vertical position of the connection port 623 of the water level detection chamber 62 is set so that the height of the inner surface lower end 623a of the connection port 623 is lower than the height H of the remaining water level, and the height of the inner surface upper end 623b of the connection port 623 is higher than the height H of the remaining water level.

[0017] This makes it possible to prevent the communication pipe 61 from being clogged with oil and grease that precipitates as described above on the draft surface of the remaining water that matches the height H of the remaining water level. Therefore, it is possible to avoid for a long period of time the inability to detect the water level due to clogging of the communication pipe 61. Furthermore, even if the draft surface becomes completely filled with oil and grease, the flushing water in the communication pipe 61 below the draft surface flows into the connection port 623, so the water level will not become impossible to detect.

[0018] In this embodiment, the communicating pipe 61 is disposed substantially horizontally over a predetermined length from the end connected to the connection port 623 so that the upper end 61a of the pipe inner surface is higher than the height H of the residual water level. This means that the draft surface of the residual water exists from the connection port 623 to the horizontally disposed portion of the communicating pipe 61, increasing the area of ​​the draft surface. This reduces the density of oil and grease deposition on the draft surface, making it possible to more effectively prevent the communicating pipe 61 from being clogged with oil and grease.

[0019] Although the embodiments of the present invention have been described above with reference to the drawings, the present invention is not limited thereto. For example, the position of the connection port 623 may be lower than in the above embodiment so that the height of the inner surface upper end 623b of the connection port 623 is lower than the height H of the remaining water level. Also, in the above embodiment, the pump 5 that supplies cleaning water to the upper nozzle 23 in the cleaning tank 2 is also used for drainage, but it is also possible to provide a pump dedicated to drainage. [Explanation of symbols]

[0020] 2...cleaning tank, 24...storage section (bottom of cleaning tank), 5...pump, 6...water level detection device, 61...connecting pipe, 61a...upper end of inner surface of pipe, 62...water level detection chamber, 623...connection port, 623a...lower end of inner surface of connection port, 623b...upper end of inner surface of connection port, H...height of remaining water level.

Claims

1. A dishwasher comprising a washing tub for storing dishes, a water level detection device for detecting the level of washing water in the washing tub, and a pump for draining the washing water in the washing tub to the outside of the washing tub, The water level detection device has a water level detection chamber that communicates with the bottom of the cleaning tank via a communication pipe and into which cleaning water from the cleaning tank flows via the communication pipe; In a cleaning tank in which cleaning water remains at the bottom after drainage operation by a pump that drains cleaning water from the cleaning tank, This dishwasher is characterized in that a cylindrical connection port for connecting a communicating pipe is provided in the water level detection chamber so as to protrude horizontally, and the vertical position of this connection port is set so that the height of the lower end of the inner surface of the connection port is lower than the height of the residual water level, which is the water level of the washing water remaining at the bottom of the washing tank after the drain operation.

2. A dishwasher as described in claim 1, wherein the vertical position of the connection port is set so that the height of the upper end of the inner surface of the connection port is higher than the height of the residual water level, and the connecting pipe is arranged approximately horizontally over a predetermined length from the end connected to the connection port so that the upper end of the inner surface of the pipe is higher than the height of the residual water level.

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