JP7542440B2 - washing machine - Google Patents

Description

The present invention relates to a washing machine equipped with a safety device that prevents abnormal vibration of the water tub.

During the spin cycle of a washing machine, the uneven distribution of laundry inside the spin tub can cause the spin tub and water tub to shake more, resulting in abnormal vibrations. To prevent such abnormal vibrations, washing machines have traditionally been equipped with a safety device that detects when the water tub's shaking exceeds a specified amount and stops operation.

Patent document 1 discloses a safety device that has a mechanical switch lever on the outside of the tank, and when the tank's shaking exceeds a specified amount, the tank comes into contact with the switch lever, determining that abnormal vibration has occurred.

Japanese Patent Application Publication No. 9-28981

A mechanical switch lever judges abnormal vibration by coming into contact with the outer side of the tub where vibration is occurring. However, because a mechanical switch lever naturally requires a range of motion from the initial position to the vibration detection position, it can only detect vibration that causes a certain degree of large displacement. Furthermore, as the washing machine is used over time, the mechanical switch lever's mounting position may move toward the outer periphery of the tub due to repeated contact with the tub. When the mounting position of the switch lever moves in this way, the detectable displacement of the tub becomes even greater (the accuracy of vibration detection decreases).

Furthermore, to save space in a washing machine, it is desirable to make the space between the water tub and the outer tub (the washing machine housing) as small as possible. If the space between the water tub and the outer tub is small, a safety device using a mechanical switch lever may cause the shaking water tub to collide with the outer tub before abnormal vibrations in the water tub are detected and operation is stopped, resulting in loud noise and, in some cases, deformation of the outer tub.

The present invention has been made in consideration of the above-mentioned problems, and aims to provide a washing machine that can reliably detect abnormal vibrations of the water tub before a collision occurs between the water tub and the outer tub.

In order to solve the above problems, the present invention provides a washing machine having a water tub arranged inside an outer tub and a spin tub arranged inside the water tub, and having at least one distance measuring sensor attached to the water tub, the distance measuring sensor measures the distance between the inner wall of the outer tub and the distance measuring sensor in a predetermined direction, detects abnormal vibrations of the water tub based on the measurement value of the distance measuring sensor, and stops operation if abnormal vibrations of the water tub are detected.

According to the above configuration, a distance sensor is attached to the water tub, and abnormal vibration of the water tub is detected based on the measurement value of the distance sensor (the distance between the inner wall of the outer tub and the distance sensor). In this case, by using a distance sensor that measures distance without contact, it is possible to detect even small displacements of the water tub, and it is possible to reliably detect abnormal vibration of the water tub before a collision between the water tub and the outer tub occurs, thereby preventing a collision between the water tub and the outer tub. In addition, a distance sensor that measures distance without contact does not generally come into contact with the outer tub. Therefore, the mounting position of the distance sensor does not change over time as the washing machine is used, and high detection accuracy can be maintained.

The washing machine may further have two distance measuring sensors, and the two distance measuring sensors may be configured so that their measurement directions are perpendicular to each other when viewed in a plane.

According to the above configuration, two distance measuring sensors can detect shaking in two perpendicular directions, so shaking in the tank can be detected regardless of the direction in which it occurs, and abnormal vibrations in the tank can be prevented more reliably.

In addition, in the above-mentioned washing machine, at least one of the distance measuring sensors can be configured so that its measurement direction faces toward the outer periphery of the water tub and measures the distance between the distance measuring sensor and the inner wall of the outer tub that is closest to the distance measuring sensor.

According to the above configuration, the distance measured by the distance measuring sensor is short, so that an inexpensive sensor such as a triangulation type can be used as the distance measuring sensor.

In addition, in the above-mentioned washing machine, at least one of the distance measuring sensors is attached to the upper surface of the water tub, and its measurement direction faces the inner circumference of the water tub, and it can be configured to measure the distance between the distance measuring sensor and the inner wall of the outer tub that is located furthest away.

According to the above configuration, in addition to detecting abnormal vibrations in the water tub using the distance sensor, it can also detect laundry flying out of the spin tub.

The washing machine of the present invention has the advantage that, by using a distance measuring sensor that measures distance without contact, it is possible to detect shaking of the water tub, even if the displacement is small, and it is possible to reliably detect abnormal vibration of the water tub before a collision occurs between the water tub and the outer tub. In addition, the distance measuring sensor that measures distance without contact has the additional advantage that the mounting position of the distance measuring sensor does not change over time as the washing machine is used, and high detection accuracy can be maintained.

1A and 1B are diagrams showing the general configuration of a washing machine according to a first embodiment, in which (a) is a schematic cross-sectional view of the washing machine as viewed from the side, (b) is a schematic cross-sectional view of the washing machine as viewed from the front, and (c) is a schematic view of the inside of the washing machine as viewed from the top. A diagram showing the measurement direction of the distance measuring sensor in the washing machine of embodiment 1, and a schematic diagram of the inside of the washing machine viewed from the top. 1A and 1B are diagrams showing a modified example of the washing machine of embodiment 1, in which (a) is a schematic cross-sectional view of the washing machine as viewed from the front side, and (b) is a schematic view of the inside of the washing machine as viewed from above. FIG. 11 is a diagram showing a schematic configuration of a washing machine according to a second embodiment, and is a schematic diagram showing the inside of the washing machine as viewed from above. FIG. 13 is a diagram showing a schematic configuration of a washing machine according to a third embodiment, and is a schematic diagram showing the inside of the washing machine as viewed from above. 13A to 13D are schematic diagrams showing a state in which laundry has been thrown out of a spin tub in a washing machine according to a third embodiment, the diagrams being views of the inside of the washing machine as viewed from above. 13 is a diagram showing an example of the shape of a distance measuring sensor in a washing machine according to embodiment 3, and is a schematic cross-sectional view of the top of the water tub viewed from the side. FIG.

[First embodiment]
Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. Fig. 1 is a diagram showing a schematic configuration of a washing machine 10 according to the first embodiment, in which (a) is a schematic cross-sectional view of the washing machine 10 as seen from the side, (b) is a schematic cross-sectional view of the washing machine 10 as seen from the front, and (c) is a schematic view of the inside of the washing machine 10 (with a lid 16 removed) as seen from the top.

Washing machine 10 is configured with a water tub 12 disposed inside outer tub 11, which is the washing machine housing, and a rotating tub 13 disposed inside water tub 12. Water tub 12 is a tub that stores water during washing and spin-drying and receives water discharged from rotating tub 13. Rotating tub 13 functions as a washing tub during washing and as a spin-drying tub during spin-drying, and is provided rotatably inside water tub 12.

A ring-shaped water tub cover 121 is provided on the top surface of the water tub 12. A ring-shaped balancer 14 is attached to the upper edge of the rotating tub 13 to ensure stable rotation of the rotating tub 13. An openable and closable lid 16 is provided on the top of the washing machine 10.

In the washing machine 10, when the spin tub 13 is rotated during the spin cycle, etc., shaking occurs in the spin tub 13 and the water tub 12 depending on the uneven distribution of laundry in the spin tub 13. If this shaking becomes large, it will cause abnormal vibrations that may cause the water tub 12 to collide with the inner wall of the outer tub 11. For this reason, the washing machine 10 is equipped with a safety device that detects such abnormal vibrations and stops operation (stops the rotation of the spin tub 13) if abnormal vibrations are detected.

The washing machine 10 according to the first embodiment has a distance sensor 15 on the outer circumferential side of the water tub 12 as the main element of the safety device. That is, the safety device in the washing machine 10 is composed of the distance sensor 15 and a control unit (not shown) that detects abnormal vibration based on the measurement value of the distance sensor 15 and stops the operation of the washing machine 10 when the abnormal vibration is detected. As shown in FIG. 2, the measurement direction of the distance sensor 15 (arrow A in the figure) faces the outer circumferential direction of the water tub 12. More specifically, the distance sensor 15 is provided at a position facing one of the inner walls of the outer tub 11, and measures the distance L1 between the distance sensor 15 and the inner wall 111 closest to the distance sensor 15.

The washing machine 10 detects abnormal vibrations in the water tub 12 based on the measurement value of the distance sensor 15 (the distance L1 between the distance sensor 15 and the inner wall 111 of the outer tub 11), and stops operation when abnormal vibrations in the water tub 12 are detected. Note that the specific method of detecting abnormal vibrations based on the distance L1 measured by the distance sensor 15 is not particularly limited in the present invention, but two methods are shown below as examples.

(First Example)
When shaking occurs in the water tank 12, the measurement value of the distance measuring sensor 15, i.e., the distance L1, vibrates. In a first example, the distance L1 is compared with a predetermined threshold value Lth1, and abnormal vibration is detected when the distance L1 is smaller than the threshold value Lth1. In this case, the threshold value Lth1 is the distance at which the water tank 12 becomes too close to the inner wall 111 of the outer tank 11. In the first example, the distance L1, which is the measurement value of the distance measuring sensor 15, is directly compared with the threshold value Lth1, so the load on the control unit that makes the judgment is reduced.

(Second Example)
In the second example, the control unit to which the distance L1 is input calculates the difference between the maximum value Lmax and minimum value Lmin of the vibrating distance L1 as the vibration amplitude Lw of the water tank 12. The calculated vibration amplitude Lw is then compared with a predetermined threshold value Lth2, and abnormal vibration is detected when the vibration amplitude Lw is greater than the threshold value Lth2. In the second example, the control unit needs to perform a calculation process to calculate the vibration amplitude Lw, but since detection can be performed based on the displacement to both sides from the center of vibration, detection accuracy is increased.

The shaking of the water tub 12 in the washing machine 10 is mainly caused by the uneven distribution of laundry in the rotating tub 13. However, even if the laundry is uneven when the rotating tub 13 starts to rotate, the uneven distribution may be evened out as the rotation continues to some extent, and the shaking of the water tub 12 may become smaller. For this reason, in the first example, abnormal vibration may not be detected immediately when the distance L1 becomes smaller than the threshold value Lth1, but may be detected when the distance L1 becomes smaller than the threshold value Lth1 a specified number of times or more. Similarly, in the second example, abnormal vibration may be detected when the vibration width Lw becomes larger than the threshold value Lth2 a specified number of times or more.

As described above, the washing machine 10 according to the first embodiment is configured to attach the distance sensor 15 to the water tub 12, measure the distance L1 between the inner wall of the outer tub 11 and the distance sensor 15 in a predetermined direction using the distance sensor 15, and detect abnormal vibration of the water tub 12 based on the measurement value of the distance sensor 15. By using the distance sensor 15 that measures distance without contact, the washing machine 10 can detect even shaking of the water tub 12, which has a small displacement. Therefore, the washing machine 10 can reliably detect abnormal vibration of the water tub 12 before a collision occurs between the water tub 12 and the outer tub 11, and prevent a collision between the water tub 12 and the outer tub 11.

In addition, the distance sensor 15, which measures distance without contact, does not generally come into contact with the outer tub 11. Therefore, the mounting position of the distance sensor 15 does not change over time as the washing machine 10 is used, and high detection accuracy can be maintained.

Furthermore, the measurement direction of the distance measuring sensor 15 faces the outer periphery of the aquarium 12, and the distance measuring sensor 15 measures the distance L1 to the nearest inner wall 111, so the measured distance L1 is a short distance. In this case, an inexpensive sensor such as a triangulation type can be used for the distance measuring sensor 15. Of course, the type of sensor used for the distance measuring sensor 15 is not particularly limited, and ultrasonic sensors, laser sensors, etc. can also be used.

1, the washing machine 10 is illustrated with the distance sensor 15 attached to the outer circumferential side of the water tub 12. However, in the washing machine 10 according to embodiment 1, the attachment location of the distance sensor 15 is not limited to this. For example, the distance sensor 15 may be attached to the top surface of the water tub 12 (i.e., the top surface of the water tub cover 121) as shown in FIG. 3.

Second Embodiment
FIG. 4 is a diagram showing a schematic configuration of a washing machine 10A according to the second embodiment, and is a schematic diagram showing the inside of washing machine 10A (with lid portion 16 removed) as viewed from above.

The washing machine 10A according to the second embodiment is provided with two distance measuring sensors 15a and 15b for the water tub 12, and the distance measuring sensors 15a and 15b are attached 90° apart from each other along the outer periphery of the water tub 12. Similarly to the distance measuring sensor 15 in the first embodiment, the measurement direction of each of the distance measuring sensors 15a and 15b faces the outer periphery of the water tub 12. Therefore, the distance measuring sensor 15a measures the distance to the inner wall 111 shown in FIG. 4, and the distance measuring sensor 15b measures the distance to the inner wall 112.

Since the distance measuring sensors 15a and 15b are attached 90° apart from each other along the outer periphery of the aquarium 12, the measurement directions of the two distance measuring sensors 15a and 15b are perpendicular to each other in a plan view. Specifically, the distance measuring sensor 15a can detect left-right shaking of the aquarium 12, and the distance measuring sensor 15b can detect front-back shaking of the aquarium 12.

The washing machine 10A is configured to stop operation (stop rotation of the spin tub 13) if abnormal vibrations are detected by either of the distance sensors 15a or 15b.

In this way, the washing machine 10A of this embodiment 2 is provided with two distance measuring sensors 15a, 15b to detect shaking in two directions for the following reasons.

The shaking of the water tub 12 that occurs during the spin cycle is mainly caused by the centrifugal force of the spin tub 13 when the laundry is unevenly distributed inside the spin tub 13. However, due to the influence of mechanisms such as the drive unit and drain hose attached to the water tub 12 and the inclination of the installation surface of the washing machine 10A, the shaking of the water tub 12 does not necessarily occur evenly in all directions, and the shaking in one direction may be greater than the shaking in the other directions. For example, the shaking in the front-back direction may be greater than the shaking in the left-right direction.

In embodiment 1, the single distance measuring sensor 15 can detect shaking in the left-right direction but cannot detect shaking in the front-back direction. Therefore, if the water tank 12 shakes significantly in the front-back direction, operation cannot be stopped appropriately and abnormal vibrations of the water tank 12 may occur.

In contrast, the washing machine 10A according to the second embodiment is equipped with two distance measuring sensors 15a and 15b, and is capable of detecting shaking in two perpendicular directions. Therefore, shaking of the water tub 12 in any direction can be detected, and abnormal vibration of the water tub 12 can be prevented more reliably.

In addition, the washing machine 10A according to the second embodiment may use a distance measuring sensor to detect shaking in only one direction, and a mechanical switch lever used in a conventional safety device to detect shaking in the other direction when detecting shaking in two orthogonal directions. In this case, it is possible to deal with this by adding one distance measuring sensor to a conventionally designed washing machine, making it easy to change the design of the washing machine. In this case, it is preferable to use a conventional mechanical sensor in the direction where the distance between the water tub 12 and the outer tub 11 is relatively large, and to use a distance measuring sensor with high detection accuracy in the direction where the distance between the water tub 12 and the outer tub 11 is relatively small.

Third Embodiment
FIG. 5 is a diagram showing a schematic configuration of a washing machine 10B according to the third embodiment, and is a schematic diagram showing the inside of washing machine 10B (with lid portion 16 removed) as viewed from above.

The washing machine 10B according to the third embodiment has a distance sensor 15 on the top surface of the water tub 12 (i.e., the top surface of the water tub cover 121). As shown in Fig. 5, the measurement direction of the distance sensor 15 (arrow B in the figure) faces the inner circumference of the water tub 12. This allows the distance sensor 15 to measure the distance L2 between the distance sensor 15 and the inner wall 113 located farthest from the distance sensor 15.

Although distance L2 measured by distance sensor 15 of washing machine 10B is longer than distance L1 in embodiment 1, displacement of water tub 12 occurs in response to shaking, similar to distance L1. Therefore, washing machine 10B according to embodiment 3 can detect abnormal vibration of water tub 12 based on distance L2 measured by distance sensor 15 using the same principle as embodiment 1.

Furthermore, the washing machine 10B according to the third embodiment has the advantage that the distance sensor 15 can detect laundry popping out of the spin tub 13. In a typical washing machine, laundry pops out of the spin tub when the washing or spin-drying operation starts, and part of the popped out laundry may end up on the top surface of the water tub cover. Such popping out laundry does not particularly increase the shaking of the water tub, so it cannot be detected by a conventional safety device that detects the shaking of the water tub. However, it is easy to imagine that if the washing machine continues to operate with laundry popped out of the spin tub, damage will occur to the popped out laundry. Therefore, if laundry pops out of the spin tub, it is desirable to detect this and stop operation.

In the washing machine 10B according to the third embodiment, the measurement direction of the distance measuring sensor 15 faces the inner circumference of the water tub 12. Therefore, as shown in Figures 6(a) and (c), when the protruding laundry LD is in the measurement direction of the distance measuring sensor 15, the distance measuring sensor 15 measures the distance to the laundry LD, and the measured value becomes significantly shorter. This allows the washing machine 10B to detect the protruding laundry from the spin tub 13 by the distance measuring sensor 15, and to stop operation when this is detected.

6(b) and (d), if the protruding laundry LD is not in the measurement direction of the distance sensor 15, the protruding laundry from the rotating tub 13 cannot be detected at this point. However, even in this case, the protruding laundry LD moves on the top surface of the water tub cover 121 along with the rotation of the rotating tub 13, and eventually reaches the state shown in Fig. 6(a) and (c). Therefore, it is possible to prevent the laundry from continuing to operate for a long time with the laundry protruding from the rotating tub 13.

In the washing machine 10B according to the third embodiment, the distance sensor 15 is disposed on the upper surface of the water tub cover 121. In this case, it is preferable that the distance sensor 15 is covered by an inclined cover on the upstream side of the distance sensor 15 in the direction of rotation of the rotating tub 13 (arrow C in the figure), as shown in Fig. 7. This makes it possible to prevent the protruding laundry LD from getting caught on the distance sensor 15.

In the above embodiments 1 to 3, the present invention is exemplified as being applied to a vertical washing machine or a vertical washer-dryer, but the present invention is not limited to this and can also be applied to drum-type washing machines and dryers.

The embodiments disclosed herein are illustrative in all respects and are not intended to be a basis for a restrictive interpretation. Therefore, the technical scope of the present invention is not to be interpreted solely by the above-described embodiments, but is defined based on the description of the claims. Furthermore, all modifications within the meaning and scope equivalent to the claims are included.

[References]
This international application claims priority based on Japanese Patent Application No. 2018-218365 filed with the Japan Patent Office on November 21, 2018, the entire contents of which are incorporated herein by reference.

10, 10A, 10B Washing machine 11 Outer tub 111, 112, 113 Inner wall 12 Water tub 121 Water tub cover 13 Rotating tub 14 Balancer 15, 15a, 15b Distance measurement sensor 16 Lid

Claims (4)

A washing machine having a water tub disposed inside an outer tub and a rotating tub disposed inside the water tub,
At least one distance measuring sensor is attached to the top surface of the water tank,
the distance measuring sensor has a measurement direction facing an inner periphery of the water tank,
The distance measuring sensor measures a distance between the object and the distance measuring sensor in the measurement direction;
A washing machine characterized in that it detects abnormal vibration of the water tub and/or laundry flying out of the spin tub based on the measurement value of the distance measuring sensor, and stops operation when abnormal vibration of the water tub and/or laundry flying out of the spin tub is detected. 2. The washing machine according to claim 1,
The distance measuring device has two of the distance measuring sensors,
A washing machine characterized in that the two distance measuring sensors have measurement directions that are perpendicular to each other in a planar view. 2. The washing machine according to claim 1 ,
A washing machine characterized in that it has a distance measurement sensor other than the distance measurement sensor, the measurement direction of the other distance measurement sensor facing toward the outer periphery of the water tub, and measuring the distance between the distance measurement sensor and the inner wall of the outer tub that is closest to the distance measurement sensor. A washing machine having a water tub disposed inside an outer tub and a rotating tub disposed inside the water tub,
At least one distance measuring sensor is attached to the top surface of the water tank,
The distance measuring sensor is characterized in that its measurement direction faces the inner circumference of the water tub and detects laundry flying out of the rotating tub and/or measures the distance to the inner wall of the outer tub.

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