KR20120005869A - Drain pump for dish washer and operating method for dish washer using the same - Google Patents

Abstract

PURPOSE: A drain pump for a dish washer and an operation method for a dish washer using the same are provided to enable a user to easily confirm that excessive foreign materials are collected in an impeller. CONSTITUTION: A drain pump for a dish washer comprises a pump case(18), an impeller(110), a drive motor, and a motor controller. The pump case has a water inlet and a water outlet. The water inlet is connected to the sump of a dish washer. The water outlet discharges washing water to the outside. The impeller is rotatably installed inside the pump case and inhales and discharges the washing water. The drive motor rotates the impeller. The motor controller controls the operation of the drive motor and has unit for measuring the rpm of the drive motor.

Description

DRAIN PUMP FOR DISH WASHER AND OPERATING METHOD FOR DISH WASHER USING THE SAME}

The present invention relates to a drainage pump of a dishwasher and a method of operating the dishwasher using the same, and more particularly, to a drainage pump using a motor capable of controlling the rotation speed as a driving source of the drainage pump and a method of operating the dishwasher using the same. will be.

In general, the dishwasher includes a cabinet forming the outer appearance of the product, a dish holder provided in the cabinet, and a spray nozzle for spraying the washing water into the dish holder.

At this time, the washing water is supplied from an external water source is temporarily stored in the sump located in the lower portion of the cabinet is injected into the dish mounted on the cradle through the injection nozzle, the sprayed washing water is filtered through the filter, etc. Recycled in the state.

When the washing is completed through this process, a drain stroke for draining the wash water stored in the sump to the outside of the cabinet is performed by using a drain pump connected to the sump. The drain pump includes a pump case into which the washing water is introduced and discharged, an impeller rotatably disposed in the pump case, and a driving motor to drive the impeller.

At this time, in the drainage stroke, foreign substances separated from the tableware are discharged together with the washing water. Among the foreign substances, foreign substances such as rubber bands or fish thorns may be caught around the impeller or between the driving motor and the impeller. As such, the amount of foreign matter caught in the impeller increases gradually as the use time of the dishwasher increases, thereby preventing the impeller from rotating. Due to this, the rotational speed of the drive motor is slowed down and the time required for the drainage stroke is increased.

Therefore, it is necessary to remove these foreign substances on a regular basis, but in the case of the drainage pump is installed in a location difficult to access the general user there is a problem that is not easy to remove.

The present invention has been made to overcome the disadvantages of the prior art as described above, the technical problem is to provide a drainage pump of the dishwasher that can easily remove the foreign matter trapped in the impeller.

Another object of the present invention is to provide a method of operating a dishwasher that can easily remove foreign substances caught in the impeller.

According to an aspect of the present invention for achieving the above technical problem, the pump case having an inlet connected to the sump of the dishwasher and the outlet for discharging the introduced washing water; An impeller rotatably installed in the pump case to suck and discharge the washing water; A drive motor for rotating the impeller; And a motor control unit for controlling the operation of the driving motor, the motor control unit including a rotational speed measuring means of the driving motor, wherein the motor control unit comprises a set rotational speed of the driving motor and an actual measured rotational speed. In contrast, when there is a difference over a predetermined level, a drain pump for a dishwasher for driving the drive motor in a reverse direction for a predetermined time is provided.

In the above aspect of the present invention is to determine the degree of the foreign matter stuck to the impeller without using a naked eye or a separate sensor, such as to detect the degree to which the rotational speed of the drive motor is reduced compared to the normal state based on this. That is, when a large amount of foreign matter is collected, these foreign matters act as a resistance to the rotation of the impeller, thereby reducing the rotational speed of the drive motor even when the same current is applied. Therefore, the collection amount of the foreign matter can be determined based on this. In addition, when examining the pattern in which the foreign matter is collected in the impeller, it can be seen that the foreign matter is wound around the axis of rotation of the drive motor by the flow of the washing water generated by the impeller continuously rotating in one direction. By rotating the drive motor in the reverse direction, it was confirmed that much of the collected foreign matter could be removed.

Therefore, in this aspect of the present invention, the actual rotational speed of the drive motor is measured, and when the difference between the intended rotational speed and the actual rotational speed is more than a predetermined level, it is determined that excessive foreign matter is collected in the impeller and the drive motor is reversed. By rotating, foreign matter is removed. At this time, the difference between the two rotational speed can be arbitrarily set by those skilled in the art in consideration of the size and shape of the impeller and the rotational speed and torque of the drive motor, the present specification does not limit the specific value.

On the other hand, in order to remove more foreign matter, the motor control unit may repeat the reverse operation a predetermined number of times.

In addition, the motor controller determines that the foreign matter is not removed or an abnormality is generated in the driving motor when the actual rotational speed is different from the predetermined rotational speed by more than a predetermined level even when the reverse operation is repeatedly performed. Can be stopped. In this case, the user may be notified of the occurrence of the abnormality through a display unit or a speaker installed in the dishwasher.

On the other hand, the motor control unit includes a switching unit for converting an input voltage into a voltage in the form of a pulse applied to the drive motor; And a driving unit controlling an operation of the switching unit, the driving unit including an input terminal for receiving counter electromotive force from the driving motor, wherein the driving unit may measure a rotational speed of the driving motor through the input counter electromotive force. That is, as the rotor of the motor rotates, the counter electromotive force is generated in the coil wound on the motor, and the counter electromotive force increases with the rotation speed of the motor, so that the actual rotation speed of the motor can be detected by measuring this.

According to another aspect of the invention, the step of rotating the drive motor by applying a current according to the intended rotational speed to the drive motor; Measuring an actual rotational speed of the drive motor; Comparing the intended rotational speed with the actual rotational speed; And rotating the driving motor in a reverse direction when the intended rotational speed and the actual rotational speed are greater than or equal to a predetermined level.

Here, the step of rotating the drive motor to rotate in the reverse direction can be repeated a predetermined number of times.

In addition, after the repetition of the forward rotation and the reverse rotation measuring the actual rotation speed of the drive motor; Comparing the intended rotational speed with the actual rotational speed; And stopping the rotation of the driving motor when there is a difference between the intended rotational speed and the actual rotational speed by more than a preset level.

According to the aspects of the present invention having the configuration as described above, not only can the user automatically remove the foreign matter without checking separately, but also more easily that the abnormality in the drive motor or excessive foreign matter is collected in the impeller. As it can confirm, it can improve usability.

1 is a cross-sectional view showing the internal structure of a dishwasher equipped with one embodiment of a drain pump according to the present invention.
FIG. 2 is an exploded perspective view illustrating a driving unit of the dishwasher according to FIG. 1.
3 is a plan view illustrating a driving unit of the dishwasher according to FIG. 1.
4 is an exploded perspective view showing an enlarged embodiment of the embodiment shown in FIG.
FIG. 5 is a circuit diagram schematically illustrating a circuit configuration of a control unit of a driving motor in the embodiment shown in FIG. 1.
6 is a flowchart illustrating a process of removing foreign matter in the embodiment.

Hereinafter, with reference to the accompanying drawings, it will be described in detail an embodiment of the drain pump according to the present invention.

1 is a cross-sectional view schematically showing an internal structure of a dishwasher to which an embodiment of a drain pump according to the present invention is applied, FIG. 2 is an exploded perspective view showing a driving unit of the dishwasher, and FIG. 3 is a view of the dishwasher. It is a top view which shows the drive part.

Referring to FIG. 1, a water collecting device 1 is installed inside the dish washing machine. Upper / lower connecting pipes 2.3 are respectively connected to the water collecting device 1, and upper / lower injection arms 4 and 5 are connected to the upper / lower connecting pipes 2.3, respectively.

The upper and lower injection arms 4 and 5 are rotatably installed on the top of the water collecting device 1. A plurality of injection holes (unsigned) are formed in the upper and lower injection arms 4 and 5. The injection hole is formed to be able to spray the washing water at an angle.

An upper rack 6 is provided at an upper portion of the upper injection arm 4, and a lower rack 7 is installed at an upper portion of the lower injection arm 5. The upper rack 6 and the lower rack 7 is formed to hold dishes.

2 and 3, the water collecting device 1 includes a sump 11, a washing pump 12 and 15, a flow path switching motor 13, a heater 14, a valve 16, and drainage. Motor 17, filtering housing 20, and filtering panel 27.

The sump 11 is formed with a predetermined space to collect the washing water therein. In the lower part of the sump 11, a washing motor 12 for supplying washing water, a flow path switching motor 13 for selectively or simultaneously opening and closing the main flow passages 22 and 23 to be described later, and a drainage motor for drainage ( 17) is installed. In addition, a heater 14 is installed in the sump 11 to heat the washing water, and a filtering housing 20 is installed above the heater 14.

The lower part of the filtering housing 20 is provided with a washing impeller 15 which is axially coupled to the washing motor 12 to rotate. As the washing motor 12 is operated, the washing impeller 15 is rotated to pump the washing water collected in the sump 11 into the filtering housing 20.

In addition, a valve 16 is installed in the filtering housing 20, and the valve 16 is axially coupled to the flow path switching motor 13.

The filtering panel 27 is installed above the filtering housing 20. The filtering panel is generally formed in a disc shape and installed to cover the upper end of the sump 11. A plurality of drain holes 28 are formed at the edge of the filtering panel, and a filter 29 having a predetermined mesh is installed at the center of the drain holes 28.

A dirt chamber 26 is formed in the filtering housing 20. A filter of the filtering panel 27 is disposed above the dirt chamber 26, and a drainage hole 28 is formed outside the dirt chamber 26. The drain hole 28 collects the wash water dropped from the upper / lower racks 6 and 7 back to the sump 11 and allows the wash water filtered by the filter to be recovered to the sump 11.

The filter 29 is filtered, and the lower injection arm 5 installed on the upper side of the filtering panel 27 sprays washing water onto the filter 29 as shown in FIG. 1 to drop the dirt.

The washing water inlet 21 is formed in the filtering housing 20 such that the washing water pumped from the washing impeller 15 is introduced.

Two main flow paths 22 and 23, which are passages for guiding the washing water to the respective injection arms 5 and 6, are branched to the washing water inlet 21. Each of the main flow paths 22 and 23 is connected to the upper and lower connection pipes 2.3.

In addition, a sampling passage 24 is formed in the washing water inlet 21 so that a portion of the pumped washing water is introduced, and a dirt chamber 26 is formed to be connected to the sampling passage 24.

A pollution degree sensor 25 is installed in the sampling flow passage 24 to measure the contamination of the washing water. The pollution sensor 25 measures the pollution level of the washing water by the light emitting unit and the light receiving unit.

The washing water introduced into the sampling flow passage 24 flows into the dirt chamber 26. The wash water of the dirt chamber 26 is overflowed so that the dirt contained in the wash water is filtered out. The filtered wash water flows back into the sump 11 through the drain hole 28 of the filtering panel.

A drain hole 26a is formed in a predetermined portion of the dirt chamber 26. The drain hole 26a is protruded downward by a predetermined length from the lower surface of the filtering housing 20 so as to be located in the pump case 18 which will be described later.

The pump case 18 may be integrally installed on one side of the lower part of the sump 11, but may be formed as a separate component, and the drain motor 17 is coupled to the opening side of the pump case 18. do. And a water discharge pipe 19 is formed on one side outer circumferential surface of the pump case 18, the drain hose 9 is connected to the discharge pipe 19 to discharge the washing water to the outside.

Referring to FIG. 4, the pump case 18 includes a substantially cylindrical body portion 18a having a space in which washing water is introduced and discharged therein, and an outer peripheral portion of a lower end of the body portion 18a. 18b) is formed. In addition, three protrusions 18c are disposed on the outer circumferential surface of the flange 18b at intervals of about 120 ° so that they may be coupled to the drainage motor 17 to be described later. In addition, an inlet pipe 18d communicating with the sump 11 is formed in the body portion 18a so as to extend in a radial direction, and a water outlet tube 19 extending in the tangential direction of the body portion 18a on the opposite side thereof. ) Is formed.

On the other hand, the drain motor 17 is coupled to the rotor at the top of the motor case 100 and the motor case 100 having a stator and a rotor (not shown) therein impeller to rotate with the rotor 110. The impeller 110 includes a boss portion 112 positioned at the center and four blades 114 extending radially from the outer circumferential surface of the boss portion 112. In addition, three locking portions 116 are formed at the vicinity of an upper edge of the motor case 100 to engage the above-described protrusion 18c. The protrusion part 18c is inserted into the locking part 116 while being rotated, and thus the pump case 18 and the motor case 100 are coupled to each other.

Here, since the water outlet pipe 19 extends in the tangential direction, the amount of water discharged when the impeller 110 rotates in the counterclockwise direction when viewed downward from the upper portion of FIG. do. Therefore, the impeller 110 is controlled to be rotated counterclockwise during the drain stroke.

The drain motor 17 is a so-called BLDC motor, and a circuit diagram of the motor controller is shown in FIG. 5. Referring to FIG. 5, the motor controller 150 receives a DC voltage (Vm) and controls a power IC 152 and a driver that controls the power IC 152 as a switching unit for switching the voltage into a pulse type voltage. A driver IC 154 functioning as a chip is included. The driver IC 154 is connected to the drainage motor 17 to measure the counter electromotive force generated when the drainage motor 17 rotates, thereby sensing the actual rotation speed of the drainage motor 17. Then, the rotation speed of the drain motor 17 is controlled by controlling the power IC 152 based on the detected actual rotation speed.

The dishwasher as described above is operated as follows.

That is, the dish washing machine washes the dishes while sequentially or selectively performing pre-washing, main washing, rinsing, heating rinsing and drying. Between these strokes, a drain stroke is performed using the drain pump. Hereinafter, the main washing operation will be described.

When the main washing stroke is started, the washing impeller 15 rotates as the washing pump 12 is rotated to pump the washing water (including the detergent) of the sump 11 into the filtering housing 20. The wash water flows into the wash water inlet 21 of the filtering housing 20.

Subsequently, as the flow path switching motor 13 is rotated, the valve 16 selectively opens or closes the two main flow paths 22 and 23. In this case, a part of the washing water is selectively or simultaneously introduced into the upper injection arm 4 and the lower injection arm 5 through the main flow passages 22 and 23. At the same time, the remaining portion of the wash water flows into the waste chamber 26 through the sampling flow passage 24. Subsequently, the washing water having washed the dishes falls on the filtering panel 27, and the washing water is recovered to the sump 11 through the drain hole 28 of the filtering panel 27.

Here, when the dishes are placed in the upper and lower racks 6 and 7 and washed simultaneously, the valve is rotated to open both main flow passages 22 and 23 and flows into the washing water inlet 21. The washed water is supplied to the upper and lower spray arms 4 and 5 simultaneously to simultaneously wash the dishes stored in the upper rack 6 and the lower rack 7.

On the other hand, when the dishes are placed only on the upper rack 6 or the lower rack 7 and only the dishes of one rack are washed, the valve 16 opens the main flow path 23 connected to the lower injection arm 5. It is rotated to close or rotated to close the main flow passage 22 which is connected to the upper injection arm 4. The washing water introduced into the washing water inlet 21 is supplied only to the upper spray arm 4 or the lower spray arm 5 to selectively wash the dishes stored in the upper rack 6 or the lower rack 7.

On the other hand, the remaining portion of the wash water is introduced into the waste chamber 26 through the sampling flow path 24, the pollution sensor 25 measures the contamination level of the wash water and transmits information about it to the control unit, the control unit of the wash water The drainage hole 26a of the dirt chamber 26 is opened and closed according to the degree of contamination.

The washing water of the sampling flow passage 24 is introduced into the waste chamber 26 through the pollution degree sensor 25, and the washing water overflows through the filter 29 located above the waste chamber 26. At this time, the filter 29 filters out foreign substances contained in the washing water. The filtered wash water flows back into the sump 11 through the drain hole 28 of the filtering panel 27.

As this washing process is performed for a predetermined time, a larger amount of food waste is collected in the filter device 170. The wash stroke is then completed and the drain stroke begins.

That is, when the drain motor 17 is operated, the washing water of the sump 11 is introduced into the waste chamber 26 by the suction force of the drain motor 17, and the washing water is collected in the waste chamber 26 and the waste water. Into the pump case 18 together, the dirt and washing water of the pump case 18 is discharged to the outside through the discharge pipe 19 and the drain hose (9).

When this process is repeatedly performed, foreign matters such as thread, rubber band or fish barbed are caught between the lower part of the impeller 110 and the upper surface of the motor case 100, and these foreign matters are rotated by the impeller. It is wound around the axis of rotation of the drive motor. These wounds are difficult to discharge along the flow of the wash water, so the amount gradually increases over time. Thus, they hinder the rotation of the impeller at the bottom of the impeller, causing a decrease in the driving speed.

A process of removing such foreign matter will be described with reference to FIG. 6.

When the drain stroke starts, the motor controller 150 applies a pulse current according to the desired rotational speed Vd set at the drain stroke to the driving motor (step S01). Thereafter, the counter electromotive force input from the driving motor is measured to measure the actual rotation speed Va (step S02), and it is compared with the desired rotation speed Vd to check whether the ratio between the two is 0.5 or more ( Step S03). Here, 0.5 is a numerical value set arbitrarily and can be arbitrarily changed by those skilled in the art in consideration of the shape and size of the impeller, the rotation speed and the torque of the driving motor, and the like.

If the ratio of the two is 0.5 or more, since the foreign matter is not collected much, the drainage operation is continued (step S04). If the ratio of the two is less than 0.5, the foreign matter is collected too much, which corresponds to a state in which the driving motor is not normally rotated. Then, the process of rotating the driving motor in reverse (clockwise) for 10 seconds and then again rotating forward is repeated about 5 times (S05). step). Here, the reverse rotation time and the number of repetitions can also be arbitrarily changed by those skilled in the art.

After that, in contrast to the actual rotation speed Va and the desired rotation speed Vd (step S06), if the ratio of both is 0.5 or more, the foreign matter is sufficiently removed, so the flow proceeds to step S04 to proceed with the drainage stroke. If the ratio between the two is still less than 0.5, the foreign matter is not enough to be removed by the reverse rotation, or if the abnormality occurs in the drive motor. Therefore, the rotation of the drive motor is stopped (step S07), and the dishwasher The user is informed that the abnormality has occurred in a visual or audio manner through a display device or a speaker provided at step S08.

Claims (7)

A pump case having an inlet connected to the sump of the dishwasher and an outlet for discharging the introduced washing water;
An impeller rotatably installed in the pump case to suck and discharge the washing water;
A drive motor for rotating the impeller; And
A drainage pump of a dishwasher including;
The motor control unit is a drain pump of the dishwasher for driving the drive motor in the reverse direction for a predetermined time when there is a difference between the set rotation speed of the drive motor and the actual measured rotation speed more than a predetermined level. The method of claim 1,
The motor control unit is a drain pump of the dishwasher, characterized in that for repeating the reverse operation a predetermined number of times. The method of claim 2,
The motor controller stops the driving of the drainage pump when the actual rotational speed is different from the predetermined rotational speed by more than a predetermined level even when the reverse operation is repeatedly performed. The method of claim 1,
The motor control unit
A switching unit converting an input voltage into a voltage in a pulse form and applying the same to the driving motor; And
And a driving unit controlling an operation of the switching unit and including an input terminal to which back electromotive force from the driving motor is input.
The driving unit drain pump of the dishwasher, characterized in that for measuring the rotational speed of the drive motor through the input back electromotive force. Rotating the drive motor by applying a current corresponding to the intended rotation speed to the drive motor;
Measuring an actual rotational speed of the drive motor;
Comparing the intended rotational speed with the actual rotational speed; And
Rotating the drive motor in the reverse direction when the intended rotational speed and the actual rotational speed is more than a predetermined level difference. The method of claim 5,
And rotating the driving motor in a reverse direction from rotating the driving motor a predetermined number of times. The method of claim 6,
Measuring the actual rotational speed of the drive motor after the repetition of the forward rotation and the reverse rotation;
Comparing the intended rotational speed with the actual rotational speed; And
Stopping the rotation of the drive motor when the intended rotational speed and the actual rotational speed differ by more than a predetermined level.

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