washing machine

Abstract

To provide a washing machine in which water level detection means is miniaturized by being made to be an MEMS sensor and becomes resistant to vibration so that it can be mounted on a vibration body part, and in which detection accuracy and reliability have been improved.SOLUTION: A washing machine includes: a housing; a water tub supported in the housing in a vibration-proof manner; an inner tub rotatably disposed in the water tub; a rotation shaft fixed to a bottom part of the inner tub; a motor for rotationally driving the inner tub via the rotation shaft; and a water level detection unit for detecting the water level of the water stored inside the water tub. At least the water tub and the inner tub constitute a water tub unit. The water level detection unit includes: a hose mounted on the water tub; and a pressure detection part for detecting a pressure change inside the hose. The pressure detection part is mounted on the water tub unit.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to washing machines. [Background technology]

[0002] Patent Document 1 discloses a washing machine in which a water level detection means is attached to the housing of the washing machine.

[0003] The washing machine in Patent Document 1 includes a housing, a water tub supported inside the housing in a vibration-isolating manner, and a water level detection unit that detects the level of water accumulated inside the tub. The water level detection unit has a diaphragm that operates with pressure corresponding to the water level in an air trap that communicates with the outer tub 1, and an oscillation circuit whose oscillation frequency changes with the movement of the diaphragm. The water level detection unit is attached to the housing. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-68736 Summary of the Invention [Problem to be solved by the invention]

[0005] The present disclosure provides a washing machine that suppresses malfunctions caused by vibrations in a water level detection unit. [Means for solving the problem]

[0006] A washing machine according to the present disclosure includes a housing, a water tub supported in the housing with vibration isolation, an inner tub rotatably disposed within the water tub, a rotary shaft fixed to the bottom of the inner tub, a motor that drives the inner tub to rotate via the rotary shaft, and a water level detection unit that detects the level of water accumulated within the water tub, wherein at least the water tub and the inner tub constitute a water tub unit, and the water level detection unit includes a hose attached to the water tub and a pressure detection unit that detects a change in pressure within the hose, Water level detection unit is the above aquarium is attached to the [Effects of the Invention]

[0007] The washing machine according to the present disclosure can prevent malfunctions caused by vibrations in the water level detection unit. [Brief explanation of the drawings]

[0008] [Figure 1] Cross-sectional view of a washing machine according to a first embodiment [Figure 2] FIG. 1 is a perspective view showing a front side of a water tub unit of a washing machine according to a first embodiment; [Figure 3] FIG. 1 is a perspective view showing a rear side of a water tub unit of a washing machine according to a first embodiment; [Figure 4] Schematic diagram showing a water level and vibration detection device for a washing machine according to the first embodiment. [Figure 5] Flowchart showing origin correction processing of the washing machine in the first embodiment DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments will be described in detail with reference to the drawings. However, unnecessary detailed description may be omitted. For example, detailed description of well-known matters or redundant description of substantially the same configuration may be omitted. This is to avoid unnecessary redundancy in the following description and to facilitate understanding by those skilled in the art.

[0010] The accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

[0011] (Embodiment 1) Hereinafter, the first embodiment will be described with reference to FIGS.

[0012] [1. Configuration] [1-1. Basic configuration of washing machine] The washing machine in this embodiment is configured as a drum-type washing machine. As shown in FIG. 1, water tub 102 is disposed inside washing machine housing 110. Water tub 102 is formed in a cylindrical shape with a bottom that opens to the front, and is configured to be able to store water inside. A water supply path (not shown) that supplies tap water and a drain path 112 that drains water from inside water tub 102 are connected to water tub 102. Water is supplied to water tub 102 via the water supply path when a water supply valve (not shown) is open, and water is drained via drain path 112 when a drain valve (not shown) is open.

[0013] Rotating drum 101 is formed in a cylindrical shape with a bottom that opens forward, and is contained within water tub 102 so as to face the opening of water tub 102. Rotating drum 101 is configured to be rotated inside water tub 102 by drum drive motor 108, which will be described later.

[0014] A bearing case 103 having bearings 104 supporting rotating shaft 105 is provided at the bottom on the rear side of water tub 102. Rotating shaft 105 is located at the rotation center of rotating drum 101, with its axis tilting downward from the front side to the rear side. As shown in FIG. 3 , a drum pulley 106 is provided at the bottom on the rear side of water tub 102, at which rotating shaft 105 is located, and a drum drive motor 108 is provided below water tub 102. Drum drive motor 108 is connected to rotating shaft 105 via belt 107 and drum pulley 106, and drives rotating drum 101 to rotate forward and backward. Rotating drum 101, water tub 102, drum drive motor 108, bearing case 103, belt 107, drum pulley 106, etc., constitute water tub unit 109. Water tub unit 109 is a vibrating body that vibrates together with water tub 102 in response to vibrations.

[0015] Water tub unit 109 is elastically supported within washing machine housing 110 by a plurality of suspensions 111. The lower ends of suspensions 111 are connected to the top of water tub 102, and the upper ends of suspensions 111 are connected to the top of washing machine housing 110.

[0016] 2, a water tank cover 115 is attached to the front side of water tank 102. A water level detection unit 130 is attached to the top of water tank cover 115.

[0017] The water level detection unit 130 includes a water level and vibration detection device 113 (described later) and a hose 114. One end of the hose 114 is connected to the lower rear side of the water tub 102, allowing water from the water tub 102 to flow in. The other end of the hose 114 is connected to the water level detection unit 123 on the left side of the water tub cover 115.

[0018] [1-1-2. Configuration of water level and vibration detection device] As shown in FIG. 4, the water level and vibration detection device 113 includes a printed circuit board 125, a water level detection unit 123, a vibration detection unit 124, and a case 122.

[0019] The water level detection unit 123 is configured by a MEMS sensor, which is a piezoresistive pressure sensor using silicon. The vibration detection unit 124 is configured by a MEMS sensor, which is a three-axis acceleration sensor. The printed circuit board 125 is connected to a control means 127 by lead wires 126, and performs power supply control and transmits and receives communication signals. The lead wires 126 are, for example, a power supply line, a GND line, a pressure detection serial communication line, a vibration detection serial communication line, etc. The water level detection unit 123 and the vibration detection unit 124 are mounted on the printed circuit board 125. The printed circuit board 125 is enclosed in a case 122 so that the surface on which the water level detection unit 123 is mounted faces downward.

[0020] Hose 114 connected to water level detection unit 123 is fixed to case 122 by fixing means 121. Fixing means 121 is configured with, for example, an insulation lock. Hose 114 passes through an opening (not shown) provided on the bottom surface of case 122 and extends to the outside of case 122.

[0021] As in this embodiment, by mounting the water level detection unit 123 and the vibration detection unit 124 on a printed circuit board 125, it is possible to reduce the number of lead wires, etc., compared to when the water level detection unit 123 and the vibration detection unit 124 are provided independently.

[0022] [1-2. Operation] The operation and function of the drum type washing machine configured as above will now be described.

[0023] [1-2-1. Washing operation] The washing operation will be described below.

[0024] When the washing operation starts, the washing cycle is first performed. In the washing cycle, water is supplied into the water tub 102, followed by an agitation operation in which the rotating drum 101 rotates forward, stops, reverses, and stops repeatedly for a predetermined period of time. In the agitation operation, the clothes stored in the rotating drum 101 are lifted in the direction of rotation by several protruding plates for agitating the clothes and then dropped from the lifted height. This causes the clothes stored in the rotating drum 101 to be beaten. Then, the spin-drying operation is performed. In the spin-drying operation, the drain valve is opened, and water in the water tub 102 is drained to the outside via the drain path 112. With the drain valve open, the rotating drum 101 is rotated at high speed for a predetermined period of time. As a result, the water contained in the clothes is dehydrated by centrifugal force and drained via the drain path 112. In the spin-drying operation, the water tub unit 109 vibrates violently.

[0025] The rinse cycle is then performed. In the rinse cycle, similar to the wash cycle, a water supply operation is performed, followed by a stirring operation for a predetermined time. This dilutes the detergent components contained in the clothes and rinses them away.

[0026] Then, the spin cycle is executed. In the spin cycle, the final spin cycle is executed. After the final spin cycle is executed, the origin correction process described later is executed. After the final spin cycle is finished, the washing operation ends.

[0027] [1-2-2. Operation of water level detection unit] When water reaches a predetermined level or higher in water tub 102, the water in water tub 102 flows into hose 114, and the internal pressure of hose 114 rises in accordance with the amount of water flowing in. Water level detection unit 123 detects the rise in internal pressure of hose 114 and outputs an electrical signal in accordance with the amount of rise in internal pressure. Control means 127 receives the absolute value of the electrical signal from water level detection unit 123 via lead wire 126 and calculates the water level based on the absolute value and a reference value. Control means 127 receives the electrical signal via lead wire 126 and calculates the water level of water tub 102.

[0028] In this embodiment, the water level detection unit 123 is configured by a MEMS sensor. Conventionally, water level detection means have been configured to detect the expansion and contraction of a diaphragm using an analog oscillator circuit. The expansion and contraction of a diaphragm is easily affected by vibrations and external noise, leading to problems with detection results that are prone to errors. For this reason, conventional water level detection means had to be attached to a housing. By configuring water level detection unit 123 using a MEMS sensor, it can be placed on vibrating water tank unit 109. By providing water level detection unit 123 on the vibrating body of water tank unit 109, both ends of hose 114 are placed on water tank unit 109, preventing hose 114 from coming loose from water level detection unit 123 due to vibration of water tank unit 109. Because hose 114 is configured to be less likely to come loose from water level detection unit 123, fixing means 121 for fixing hose 114 can be constructed using inexpensive components. Furthermore, because hose 114 is less likely to vibrate relative to water tank unit 109, the accuracy of water level detection by water level detection unit 123 is improved.

[0029] In this embodiment, the water level and vibration detection device 113 includes a water level detection unit 123 and a vibration detection unit 124. If the vibration detection unit were provided independently at a different location from the water level detection unit, it would be necessary to add one power line and one GND line to connect the vibration detection unit and the control unit. Furthermore, it would be necessary to add means for fixing the added power line and GND line. By mounting the water level detection unit 123 and the vibration detection unit 124 on the same printed circuit board 125, it is possible to reduce one power line and one GND line.

[0030] [1-2-2. Origin correction process for water level detection unit] Even if the absolute value of the electrical signal changes due to aging, the amount of deviation from the reference value remains approximately constant. Therefore, by acquiring the absolute value of the electrical signal under predetermined conditions and calculating the reference value based on the acquired absolute value of the electrical signal, it is possible to correct the deviation of the absolute amount of the reference value due to aging. In this embodiment, an origin correction process is executed to correct the reference value based on the electrical signal output from the water level detection unit 123 when no water is flowing into the hose 114, i.e., when the pressure due to the flowing water is not applied to the water level detection unit 123.

[0031] The origin correction process will be described below with reference to FIG.

[0032] The control means 127 starts the origin correction process when the final spin-drying operation is completed, that is, when the drum drive motor 108 is stopped (S100).

[0033] The control means 127 determines whether the washing step, the rinsing step, and the spin-drying step have been executed in the current washing operation (S101). If it determines that all steps have not been executed (S101, No), the origin correction process ends (S107).

[0034] If it is determined that all steps have been performed (S101, Yes), it is determined whether or not the temperature is within the set temperature range of the pressure sensor of the water level detection unit 123 (S102). The set temperature may be a value that does not cause a malfunction in the pressure sensor. If the temperature is not within the set temperature range, the absolute value of the electrical signal output by the pressure sensor may not be reliable. If it is determined that the temperature is not within the set temperature range (S102, No), the origin correction process is terminated (S107).

[0035] If the temperature is within the set temperature range of the pressure sensor (Yes in S102), an origin correction value is acquired from the pressure sensor (S103). The origin correction value is the absolute value of an electrical signal under predetermined conditions.

[0036] The control means 127 determines whether the origin correction value is within a set range (S104). The set range is a range that takes into account the accuracy error range of the MEMS sensor, which is a pressure sensor. If the origin correction value is not within the set range (S104, No), the origin correction process ends (S107).

[0037] If the origin correction value is within the set range (S104, Yes), a new reference value is calculated based on the origin correction value (S105). The reference value may be, for example, a moving average value of multiple origin correction values. The control means 127 stores the calculated reference value (S106). Thereafter, the origin correction process ends (S107).

[0038] As described above, in the origin correction process of this embodiment, when a series of sequences including a washing step, a rinsing step, and a spin-drying step is executed, the process starts after the final spin-drying step is completed. By configuring the origin correction process to be performed only when a series of sequences including a washing step, a rinsing step, and a spin-drying step is executed, it is possible to prevent the origin correction process from being started while detergent foam or water remains inside water tub 102. By configuring the origin correction process to be performed after the final spin-drying step is completed, it is possible to start the origin correction process when water tub 102 is not vibrating and the water in water tub 102 has been drained to the maximum extent.

[0039] [1-3. Effects, etc.] As described above, the washing machine in this embodiment includes washing machine housing 110, water tub 102 supported in a vibration-isolating manner inside washing machine housing 110, rotating drum 101 rotatably disposed inside water tub 102, a rotating shaft fixed to the bottom of rotating drum 101, a motor that rotates rotating drum 101 via the rotating shaft, and water level detection unit 130 that detects the level of water accumulated inside water tub 102. At least water tub 102 and rotating drum 101 constitute water tub unit 109, and water level detection unit 130 includes hose 114 attached to water tub 102 and water level detection unit 123 that detects pressure changes inside hose 114, and water level detection unit 123 is attached to water tub unit 109.

[0040] As a result, water level detection unit 123 is disposed in water tub unit 109 together with hose 114, and therefore can be disposed in the same vibration system of water tub unit 109 as hose 114.

[0041] This makes it possible to suppress vibration of hose 114 relative to water level detection unit 123, thereby improving the durability of hose 114. Furthermore, as fixing means 121 for hose 114, inexpensive fixing means such as an insulation lock can be used.

[0042] As in this embodiment, water level detection unit 130 may include vibration detection section 124 that detects vibration of water tub unit 109.

[0043] This allows water tank unit 109 to have the function of detecting both the water level and vibrations.

[0044] Therefore, the lead wires connecting the control means 127 and the water level and vibration detection device 113 can be consolidated, and the number of lead wires and fixing means for fixing the lead wires can be reduced.

[0045] As in this embodiment, the water level detection unit 130 may include a printed circuit board 125 on which the water level detection section 123 and the vibration detection section 124 are mounted.

[0046] As a result, the water level detection unit 123 and the vibration detection unit 124 are mounted on the same printed circuit board 125, which allows for miniaturization.

[0047] Therefore, the lead wires connecting the control means 127 and the water level and vibration detection device 113 can be unified, and the number of lead wires and fixing means for fixing the lead wires can be reduced.

[0048] As in this embodiment, the water level detection unit 123 may be configured with an MEMS sensor.

[0049] As a result, water level detection unit 123 is packaged as a MEMS sensor, and can be mounted on the same printed circuit board 125 as vibration detection unit 124. Furthermore, by configuring water level detection unit 123 as a MEMS sensor, water level detection unit 123 can be placed on water tank unit 109.

[0050] (Other embodiments) As described above, the first embodiment has been described as an example of the technology disclosed in the present application. However, the technology in the present disclosure is not limited to this, and can be applied to embodiments in which modifications, substitutions, additions, omissions, etc. are made. Furthermore, it is also possible to combine the components described in the first embodiment above to create new embodiments.

[0051] In the first embodiment, a drum-type washing machine has been described as an example of a washing machine. The washing machine is not limited to a drum-type washing machine as long as it generates vibrations as the rotating drum rotates. The washing machine may also be a vertical washing machine.

[0052] In the first embodiment, an example of the origin correction process was described in which, when a washing cycle, a rinsing cycle, and a spin cycle are all included, a reference value is set based on the value detected by the pressure detection unit after the final spin cycle in the spin cycle is completed. The origin correction process may be performed when the water tub is not vibrating and there is no water remaining in the water tub. The origin correction process may be performed, for example, before the start of a washing operation or after the end of the washing operation.

[0053] In the first embodiment, the washing operation has been described as an example of a course. The course is not limited to the washing operation as long as it includes a washing step, a rinsing step, and a spin-drying step. For example, in the case of a drum-type washer-dryer equipped with a drying function, the drying step may be executed after the spin-drying step is completed. After the drying step is completed, the washing and drying operation ends. After that, the origin correction process may be executed.

[0054] In the first embodiment, a configuration has been described in which the washing operation ends after the final spin-drying operation is completed. Although not described in the first embodiment, an operation different from the spin-drying operation may be executed after the final spin-drying operation is completed. For example, following the final spin-drying operation, an operation may be executed to loosen clothes stuck to the inner circumferential surface of the rotating drum 101, and then the washing operation may end. Then, an origin correction process may be executed. [Industrial Applicability]

[0055] The present disclosure is applicable to devices in which vibrations occur due to the rotation of a rotary drum, specifically, drum-type washing machines, top-loading washing machines, etc. [Explanation of symbols]

[0056] 101 Rotating Drum 102 Aquarium 103 Bearing case 104 Bearings 105 Rotational Axis 106 Drum pulley 107 Belt 108 Drum drive motor 109 Aquarium Unit 110 Washing machine housing 111 Suspension 112 Drainage route 113 Water level and vibration detection device 114 Hose 115 Aquarium cover 121 Fixing means 122 cases 123 Water level detection unit 124 Vibration detection unit 125 Printed Circuit Board 126 Lead Wire 127 Control Means 130 Water level detection unit

Claims

1. The housing and a water tank supported inside the housing in a vibration-proof manner; an inner tank rotatably disposed inside the water tank; a rotating shaft fixed to the bottom of the inner tank; a motor that rotates the inner tank via the rotation shaft; a water level detection unit that detects the level of water accumulated inside the water tank; Equipped with At least the water tank and the inner tank constitute a water tank unit, The water level detection unit a hose attached to the water tank; and a pressure detection unit that detects a change in pressure inside the hose, The water level detection unit is attached to the water tank. washing machine.

2. The water level detection unit includes a vibration detection unit that detects vibrations of the water tub unit. The washing machine according to claim 1.

3. The water level detection unit a substrate on which the pressure detection unit and the vibration detection unit are mounted, The washing machine according to claim 2.

4. The pressure detection unit is composed of a MEMS sensor. The washing machine according to any one of claims 1 to 3.

5. A control unit is provided for controlling a course including a washing step, a rinsing step, and a spin-drying step, The control unit When the course includes all of the washing step, the rinsing step, and the spin-drying step, after the final spin-drying operation in the spin-drying step is completed, a process of setting a reference value based on the value detected by the pressure detection unit is executed. The washing machine according to claim 4.

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