JP7401524B2 - Liquid detergent detection device and washing machine using it - Google Patents

Description

The present invention relates to a liquid detergent detection device for detecting the presence or absence of liquid detergent flowing through a tube in a washing machine configured to receive liquid detergent by feeding it from a liquid detergent container using a tube, and a washing machine using the same. . This application claims priority to Japanese Patent Application No. 2019-48363 filed in Japan on March 15, 2019, the contents of which are incorporated herein.

Many modern washing machines are equipped with an automatic detergent dispense function. For example, in a commercial washing machine, liquid detergent is supplied by connecting a large liquid detergent container and the washing machine with a tube, and feeding liquid from the liquid detergent container using the tube.

In liquid feeding using such a tube, it is essential to detect the liquid detergent inside the tube in order to detect the presence or absence of liquid detergent in the liquid detergent container and to accurately control the amount of liquid fed. Patent Document 1 discloses a fluid detection device for liquid detergent, shampoo, or the like using a photointerrupter. The detection method in the fluid detection device disclosed in Patent Document 1 is to transmit light emitted from a light emitting element of a photointerrupter through a transparent tube, and detect the amount of transmitted light with a light receiving element. The system detects the presence of detergent or shampoo. Specifically, when fluid is present in the transparent tube, the fluid blocks light and reduces the amount of transmitted light, so the presence or absence of fluid in the transparent tube can be detected by comparing the output of the light receiving element with a threshold value. .

Japanese Patent Application Publication No. 8-292082

In the fluid detection device described in Patent Document 1, a condition for highly accurate detection is that the fluid flowing through the transparent tube has low transparency. However, when applying this fluid detection device to a washing machine, there is a problem that many liquid detergents are highly transparent, making it difficult to detect with high precision. This is because a liquid detergent with high transparency reduces the difference in the amount of transmitted light depending on the presence or absence of the detergent in the transparent tube. Furthermore, the output level of optical sensor devices such as photointerrupters tends to change due to temperature changes and aging, and if the difference in the amount of transmitted light depending on the presence or absence of detergent is small, there is a risk of false detection depending on the conditions of use.

One aspect of the present invention has been made in view of the above problems, and provides a liquid detergent detection device that can highly accurately detect the presence or absence of highly transparent liquid detergent flowing through a transparent tube, and a washing machine using the same. The purpose is to provide.

In order to solve the above problems, a liquid detergent detection device according to a first aspect of the present invention is used by attaching a transparent tube, and the liquid detergent detection device detects the presence or absence of liquid detergent in the transparent tube. The apparatus includes a light emitting element and a light receiving element that are arranged opposite to each other with the transparent tube in between, a tube holding part that holds the transparent tube at an appropriate position with respect to the liquid detergent detection device, and an amount of light received by the light receiving element. a control unit that detects the presence or absence of liquid detergent in the transparent tube based on ) When there is a liquid detergent in the transparent tube, the diffused light irradiated to the transparent tube is refracted and focused by the liquid detergent in the transparent tube, and the light receiving element receives the focused light. (2) If there is no liquid detergent in the transparent tube, the diffused light irradiated onto the transparent tube continues to diffuse after passing through the transparent tube, and the light receiving element detects the light transmitted through the transparent tube. The controller is configured to receive a part of light from the light receiving element, and the control unit detects that there is liquid detergent in the transparent tube when the output of the light receiving element is higher than a first threshold value, and is lower than a first threshold value, it is detected that there is no liquid detergent in the transparent tube.

According to the above configuration, the liquid detergent detection device can cause a change in the output of the light receiving element by utilizing the presence or absence of a light condensing effect depending on whether there is liquid detergent in the transparent tube or not. Therefore, when the liquid detergent flowing through the transparent tube is highly transparent, the output difference of the light receiving element can be made large, and the presence or absence of highly transparent liquid detergent can be detected with high accuracy regardless of the usage conditions of the liquid detergent detection device. can be detected.

Further, the liquid detergent detection device is capable of detecting an end of the bubble using a second threshold value smaller than the first threshold value when air bubbles are mixed in the liquid detergent flowing in the transparent tube, The control unit may be configured to detect the end of the bubble when the output of the light receiving element is lower than a second threshold.

According to the above configuration, when air bubbles are present in the transparent tube, the air bubbles can be detected with high accuracy based on the detection of the end of the air bubbles. When the remaining amount of the liquid detergent container connected to the transparent tube becomes low, air bubbles are generated in the transparent tube, so that it is possible to detect that the remaining amount of the liquid detergent container is low.

Further, in the liquid detergent detection device, the control unit may be configured to determine, when air bubbles are mixed in the liquid detergent flowing through the transparent tube, an area where air bubbles are not present, an area where air bubbles are present, and an area where air bubble ends are present. It is possible to adopt a configuration in which it is possible to detect the air bubbles separately and calculate the bubble inclusion rate from the ratio of each area.

According to the above configuration, it is possible to calculate the air bubble inclusion rate in the liquid detergent fed through the transparent tube, and use the calculated air bubble inclusion rate to control the amount of liquid detergent supplied to the washing machine.

Further, in order to solve the above problems, a second aspect of the present invention is a washing machine that receives liquid detergent from an external liquid detergent container through a transparent tube, and wherein the washing machine receives liquid detergent from an external liquid detergent container through a transparent tube. The present invention is characterized in that it includes the liquid detergent detection device described above attached to the liquid detergent detection device.

In the washing machine, the transparent tube includes a first upright portion and a second upright portion extending in the vertical direction, and a bent portion connecting the first upright portion and the second upright portion at an upper portion. The liquid detergent detection device may have a substantially inverted U-shaped arrangement portion, and the liquid detergent detection device may be installed downstream of the bent portion in the flow direction of the liquid detergent.

According to the above configuration, in the process in which the liquid detergent flows from the bottom to the top in the first upright portion or in the process in which it flows through the bent portion, a bubble breaking effect occurs that separates the liquid detergent mixed with air bubbles into liquid detergent and air. do. As a result, by installing the liquid detergent detection device downstream of the bend, liquid detergent mixed with small air bubbles is suppressed from flowing to the installation position of the liquid detergent detection device, and the liquid detergent detection device detects when the liquid detergent runs out. It can be detected properly. Alternatively, it is possible to improve the accuracy of detecting the rate of inclusion of air bubbles in the transparent tube.

Further, the washing machine performs an operation after the error is cleared in response to a user's operation to cancel the out-of-detergent error after the liquid detergent detection device detects that the liquid detergent in the transparent tube is out. The post operation may include an initial filling operation of filling the transparent tube with liquid detergent.

According to the above configuration, after it is detected that the liquid detergent in the transparent tube has run out, the liquid detergent is refilled in the liquid detergent container and then the initial filling operation is performed to fill the transparent tube with liquid detergent. I can do it. This prevents the liquid detergent detection device from detecting that the liquid detergent is running out again before the liquid detergent reaches the liquid detergent detection device the next time the washing machine is used.

Further, if the liquid detergent detection device does not detect the presence of liquid detergent in the transparent tube within a predetermined timeout period after starting the initial filling operation, the washing machine ends the initial filling operation, and It can be configured to detect again whether the liquid detergent in the tube has run out.

According to the above configuration, if a washing machine administrator or the like performs a detergent out error release operation without refilling the liquid detergent container with liquid detergent, the transparent tube is not filled with detergent and the It is possible to avoid situations where only the pump continues to operate.

Further, in the washing machine, the initial filling operation is completed after the liquid detergent detection device detects the presence of liquid detergent in the transparent tube, and after the pump connected to the transparent tube is operated for a predetermined time. The post-error release operation may include a washing tub cleaning operation performed after the initial filling operation.

According to the above configuration, even after the presence of liquid detergent in the transparent tube is detected by the liquid detergent detection device, by operating the pump for a predetermined period of time, it is possible to completely fill the tip of the transparent tube with liquid detergent. . Further, in this case, since it is possible that some liquid detergent is contained in the washing tub of the washing machine at the end of the initial filling operation, the washing tub cleaning operation is performed after the initial filling operation.

A liquid detergent detection device and a washing machine that are one aspect of the present invention change the output of a light receiving element by using the presence or absence of a light condensing effect depending on whether there is liquid detergent in the transparent tube or not. As a result, when the liquid detergent flowing through the transparent tube is highly transparent, the output difference of the light receiving element can be made large, and the presence or absence of highly transparent liquid detergent can be detected regardless of the usage conditions of the liquid detergent detection device. This has the effect of enabling accurate detection.

BRIEF DESCRIPTION OF THE DRAWINGS It is a front view which shows the external appearance of the washing system which is one example of application of this invention. FIG. 3 is a perspective view of the inside of the attached device attached to the top surface of the washing machine, viewed from the back side. (a) is an explanatory diagram showing the detection principle when there is liquid detergent in the transparent tube, and (b) is an explanatory diagram showing the detection principle when there is no liquid detergent in the transparent tube. The upper part is a diagram showing the state of bubbles in the transparent tube, and the lower part is a graph showing the relationship between the bubble position and the output (light reception amount) of the light receiving element. FIG. 3 is an explanatory diagram showing the separation effect between liquid detergent and air within a transparent tube. FIG. 2 is an explanatory diagram showing a configuration for securing a predetermined amount of liquid detergent in a transparent tube.

[Embodiment 1]
Embodiments of the present invention will be described in detail below with reference to the drawings. In the first embodiment, a liquid detergent detection device that can detect with high precision the presence or absence of highly transparent liquid detergent flowing through a transparent tube will be described.

FIG. 1 is a front view showing the configuration of a washing system including a washing machine 100, which is an example of application of the present invention. This washing system includes a washing machine 100, a liquid detergent container 200, and a transparent tube 20. The washing machine 100 can be used as a commercial washing machine by mounting an attachment device 120 on the top surface of the washing machine main body 110. Further, the washing machine 100 is configured to receive liquid detergent from a liquid detergent container 200 through a transparent tube 20 . Although FIG. 1 illustrates a configuration in which one washing machine 100 is connected to one liquid detergent container 200, it is also possible to connect a plurality of washing machines 100 to one liquid detergent container 200. You can leave it there.

FIG. 2 is a perspective view of the inside of the attachment device 120 viewed from the back side. Note that in FIG. 2, in order to illustrate the inside of the attached device 120, part of the external casing is omitted. Inside the attachment device 120, a liquid detergent sensing device 10 attached together with a transparent tube 20 is arranged. The attached device 120 also includes a pump 30 for sending liquid detergent from the liquid detergent container 200 to the washing machine 100 via the transparent tube 20, and a billing device 40 for the user of the washing machine 100 to pay charges. It is equipped.

As shown in FIG. 2, the liquid detergent detection device 10 has a tube attachment groove 11 for attaching a transparent tube 20, and a photo interrupter 12. The photointerrupter 12 is an example of a light emitting element and a light receiving element described in the claims. The liquid detergent detection device 10 also includes a control section (not shown) that determines the presence or absence of liquid detergent in the transparent tube 20 based on the output of the photointerrupter 12.

The transparent tube 20 is attached to the liquid detergent detection device 10 by being fitted into the tube attachment groove 11 . In this embodiment, a transparent tube 20 is attached to the liquid detergent detection device 10 so as to extend in the vertical direction. The photointerrupter 12 is arranged so as to be able to detect the transparent tube 20 in the middle of the tube attachment groove 11. The photointerrupter 12 has inside thereof a light emitting element 12a (see FIG. 3) and a light receiving element 12b (see FIG. 3) which are arranged facing each other with the transparent tube 20 interposed therebetween. Further, the photointerrupter 12 has tube holding portions 12c at both ends of the transparent tube 20 in the extending direction (up and down direction in FIG. 1). Note that the light-emitting element 12a and the light-receiving element 12b are not limited to the configuration provided within the photointerrupter 12. For example, the liquid detergent detection device 10 may be configured to hold a light emitting element 12a and a light receiving element 12b, respectively.

Next, the principle of detection in the liquid detergent detection device 10 when there is liquid detergent in the transparent tube 20 and when there is no liquid detergent in the transparent tube 20 will be explained with reference to FIGS. 3(a) and 3(b).

FIG. 3(a) shows the principle of detection when there is liquid detergent in the transparent tube 20. First, the light emitting element 12a irradiates the transparent tube 20 with diffused light. When there is a liquid detergent, the light that passes through the transparent tube 20 is refracted by the liquid detergent inside the transparent tube 20, and is focused toward the light receiving element 12b. As a result, the light receiving element 12b can receive much of the light that has passed through the transparent tube 20. Note that it is preferable that all (or almost all) of the diffused light irradiated from the light emitting element 12a toward the transparent tube 20 be irradiated onto the transparent tube 20. Further, the transparent tube 20 has a cross section having a convex curved surface such as a circle or an ellipse in order to obtain a light condensing effect.

FIG. 3(b) shows the detection principle when there is no liquid detergent in the transparent tube 20. If there is no liquid detergent, the light that passes through the transparent tube 20 continues to be diffused without being focused, and the light receiving element 12b can only receive a portion of the light that passes through the transparent tube 20.

In this way, the liquid detergent detection device 10 according to the first embodiment changes the amount of light received by the light receiving element 12b depending on the presence or absence of the light condensing effect when there is liquid detergent in the transparent tube 20 and when there is no liquid detergent in the transparent tube 20. There is. As a result, the control unit included in the liquid detergent detection device 10 compares the output of the light receiving element 12b with a predetermined first threshold value, and if the output of the light receiving element 12b is larger than the first threshold value, the liquid detergent inside the transparent tube 20 is detected. If it is determined that there is no liquid detergent in the transparent tube 20 and the output of the light receiving element 12b is smaller than the first threshold value, it can be determined that there is no liquid detergent in the transparent tube 20.

In the above detection principle of the liquid detergent detection device 10, when there is liquid detergent in the transparent tube 20, it is necessary to sufficiently focus the light passing through the transparent tube 20 on the light receiving surface of the light receiving element 12b. Therefore, in the photointerrupter 12, the transparent tube 20 needs to be placed at an appropriate position relative to the light emitting element 12a and the light receiving element 12b. In the liquid detergent detection device 10, the photointerrupter 12 is provided with a tube holding section 12c, and the transparent tube 20 is held and fixed by the tube holding section 12c, thereby achieving such an appropriate arrangement.

Further, in the liquid detergent detection device 10, not only the arrangement positions of the light emitting element 12a and the light receiving element 12b but also the area of the light receiving part of the light receiving element 12b are important factors. That is, the amount of light received by the light receiving element 12b when there is no liquid detergent in the transparent tube 20 differs depending on the area of the light receiving part of the light receiving element 12b. Specifically, the smaller the area of the light receiving part of the light receiving element 12b is, the smaller the amount of light received by the light receiving element 12b when there is no liquid detergent. 12b can be made large. Therefore, the light receiving area of the light receiving element 12b may be set depending on the level of the amount of light received by the light receiving element 12b when there is no liquid detergent in the transparent tube 20.

Further, it is preferable that the light receiving portion of the light receiving element 12b has a slit shape in which the direction in which the transparent tube 20 extends (vertical direction in FIG. 2) is the longitudinal direction. Since the transparent tube 20 has a cylindrical shape, the light condensing effect is hardly obtained in the direction in which the transparent tube 20 extends, but the light condensing effect shown in FIG. 3 is obtained in the direction along the cross section of the transparent tube 20. Therefore, by making the light-receiving portion of the light-receiving element 12b have a narrow slit shape in the vertical direction in FIG. In addition, by setting the longitudinal direction of the slit in the direction in which the transparent tube 20 extends (the front-rear direction in the paper plane in FIG. 3), more light can be received from the light-emitting element 12a, so the signal intensity of the light-receiving element 12b can be reduced. You can improve.

Furthermore, in the first embodiment, it is assumed that the transparent tube 20 is used to transfer liquid from the liquid detergent container 200 to the washing machine 100. However, when the remaining amount of liquid detergent in the liquid detergent container 200 decreases, the transparent tube 20 Air bubbles become mixed in the liquid detergent in 20. Such bubbles form a curved interface in the axial direction of the transparent tube 20 so as to separate the air and the liquid detergent.

The liquid detergent detection device 10 according to the first embodiment compares the output (light reception amount) of the light receiving element 12b with a second threshold value (<first threshold value) to detect the bubble interface (bubble edge) in the transparent tube 20. (part area) can also be detected. The detection principle will be explained with reference to FIG. The upper part of FIG. 4 is a diagram showing the state of bubbles in the transparent tube 20, and the lower part of FIG. 4 is a graph showing the relationship between the bubble position and the output (light reception amount) of the light receiving element 12b. In FIG. 4, a region where there is liquid detergent in the transparent tube 20 (no air bubbles are present) is defined as region A, and a region where there is no liquid detergent inside the transparent tube 20 (there are air bubbles and there is no interface between air and liquid detergent). ) is designated as region B, and the region where the end of the bubble exists in the transparent tube 20 (where the interface between air and liquid detergent exists) is designated as region C.

First, in region A, as shown in FIG. 3(a), the amount of light received becomes "large" because the light transmitted through the transparent tube 20 is condensed. Further, in region B, as shown in FIG. 3(b), the amount of light received becomes "medium" because the light passing through the transparent tube 20 is diffused. Therefore, by setting the above-mentioned first threshold between the amount of light received in area A and the amount of light received in area B, if the output of the light receiving element 12b is greater than the first threshold, liquid will flow inside the transparent tube 20. It can be determined that detergent is present.

On the other hand, in region C, the irradiated light from the light emitting element 12a hits the edge of the bubble, that is, the interface between the air and the liquid detergent, and is reflected and scattered. The amount of light (light in the direction of the arrow from top to bottom) in region C of No. 4 decreases. As a result, in region C, the amount of light received is "small". Therefore, by setting a second threshold value between the amount of light received in region B and the amount of light received in region C, when the output of the light receiving element 12b is smaller than the second threshold value, the edge of the bubble in the transparent tube 20 can be detected. If the output of the light receiving element 12b is smaller than the first threshold and larger than the second threshold, it can be determined that there is no liquid detergent in the transparent tube 20.

In this way, the liquid detergent detection device 10 according to the first embodiment changes the output of the light-receiving element 12b by using the presence or absence of a light condensing effect depending on whether there is liquid detergent in the transparent tube 20 or not. It is something that causes Therefore, when the liquid detergent flowing through the transparent tube is highly transparent, the output difference of the light receiving element 12b can be made large, and the presence or absence of highly transparent liquid detergent can be detected regardless of the usage conditions of the liquid detergent detection device 10. It can be detected with high precision.

Furthermore, when bubbles are present in the transparent tube 20, the bubbles can also be detected by utilizing the scattering of light at the ends of the bubbles. Thereby, when air bubbles are mixed into the liquid detergent fed through the transparent tube 20, it can be detected that the amount remaining in the liquid detergent container 200 is small. Furthermore, it is also possible to detect the rate of air bubbles in the liquid detergent fed through the transparent tube 20, and to control the amount of liquid detergent supplied to the washing machine 100 more accurately based on this.

[Embodiment 2]
In the second embodiment, a preferred usage pattern of liquid detergent detection device 10 in washing machine 100 will be described.

As shown in FIG. 2, within the attachment device 120, the transparent tube 20 has an approximately inverted U-shaped arrangement portion. The approximately inverted U-shaped disposed portion of the transparent tube 20 has a first erected portion 21 and a second erected portion 22 extending in the vertical direction, and a first erected portion 21 and a second erected portion 22 at the top. It is formed by a connecting bent part 23. In the first upright portion 21 and the second upright portion 22, the second upright portion 22 is located on the downstream side in the flow direction of the liquid detergent. Therefore, when the pump 30 is operated to send liquid from the liquid detergent container 200 to the washing machine 100, the liquid detergent flows down the first upright portion 21 in the approximately inverted U-shaped portion of the transparent tube 20. After flowing upward, the flow direction is changed at the bending part 23 and flows from the top to the bottom in the second standing part 22. The liquid detergent detection device 10 is installed at a position downstream of the bent portion 23 in the flow direction of the liquid detergent. In this embodiment, the liquid detergent detection device 10 is attached to the second upright portion 22 .

When the washing machine 100 is used, an appropriate amount of liquid detergent must be supplied from the liquid detergent container 200 to the washing machine 100, and the amount of liquid detergent supplied is controlled by the driving time of the pump 30. However, when the amount of liquid detergent remaining in the liquid detergent container 200 decreases and air bubbles become mixed in the liquid detergent flowing through the transparent tube 20, the amount of liquid detergent supplied per unit time naturally decreases. In this case, control is performed so that an appropriate amount of liquid detergent is supplied by lengthening the drive time of the pump 30 compared to the case where no air bubbles are mixed into the liquid detergent flowing through the transparent tube 20.

Further, in order to control the supply amount of liquid detergent based on the driving time of the pump 30, it is necessary to detect the rate of air bubbles in the transparent tube 20. For example, if it is detected that 50% of air bubbles are mixed in in the liquid detergent fed through the transparent tube 20, the amount of liquid detergent supplied can be increased by doubling the driving time of the pump 30. It can be made the same as when no air bubbles are mixed in.

As described in Embodiment 1 above, when air bubbles are mixed in the liquid detergent flowing through the transparent tube 20, the liquid detergent detection device 10 distinguishes between an area A where no air bubbles are present and an area B where the center of the air bubbles is present. , and the region C where the bubble end exists can be detected separately. Based on this, it is also possible to detect the rate of air bubbles in the transparent tube 20.

However, if the rate of air bubbles in the transparent tube 20 becomes too high, the time required to supply a predetermined amount of liquid detergent will naturally increase. In such a case, it is preferable to be able to quickly detect when the liquid detergent container 200 is out of liquid detergent.

In the washing machine 100 according to the second embodiment, the transparent tube 20 has a substantially inverted U-shaped arrangement portion (the first upright portion 21, the bent portion 23, and the second upright portion 22), The liquid detergent detection device 10 is attached to the second upright portion 22 through which the liquid detergent flows from top to bottom.

In the process in which the liquid detergent flows from the bottom to the top through the first standing portion 21, the liquid detergent spreads along the inner wall of the transparent tube 20. When the mixing rate of bubbles in the transparent tube 20 is high and the amount of liquid detergent between adjacent bubbles is small, as shown in FIG. 5, the liquid detergent between the bubbles spreads along the inner wall of the tube. The vertical width of is decreased. When the width of the liquid detergent becomes insufficient to maintain the interface with the bubbles, the liquid detergent forming the interface with the bubbles falls down along the inner wall of the tube. That is, in the first upright portion 21, a so-called bubble breakage effect occurs in which small-scale interfaces between bubbles disappear.

Furthermore, the washing machine 100 according to the second embodiment has a bent portion 23 above the first upright portion 21, that is, on the downstream side in the flow direction of the liquid detergent. In the upper part of the first standing portion 21, the vertical width of the liquid detergent decreases as described above. When this liquid detergent flows into the bent portion 23, the width direction of the liquid detergent changes from the vertical direction to the horizontal direction. At this time, the width of the liquid detergent in the bent portion 23 in the left and right direction becomes non-uniform due to gravity. Specifically, within the transparent tube 20 of the bent portion 23, the liquid detergent is concentrated in the lower part, and the liquid detergent in the upper part is insufficient. As a result, the liquid detergent cannot maintain an interface with the air bubbles above the bent portion 23 in the transparent tube 20, and the interface with the air bubbles disappears. Therefore, the so-called bubble breakage effect, which eliminates small-scale interfaces between bubbles, can be enhanced within the bent portion 23.

As a result, the liquid detergent mixed with air bubbles is separated into liquid detergent and air by the first upright portion 21 and the bent portion 23, and only large air bubbles are sent to the liquid detergent detection device 10. As a result, in the liquid detergent detection device 10, the liquid detergent mixed with many small bubbles is prevented from continuing to flow for a long period of time, and it is possible to appropriately detect when the liquid detergent container 200 is out of liquid detergent.

As described above, in order to supply a predetermined amount of liquid detergent to the washing machine 100 when air bubbles are mixed in the liquid detergent flowing through the transparent tube 20, it is necessary to detect the rate of air bubbles in the transparent tube 20. be. To detect the rate of air bubbles in the transparent tube 20, the liquid detergent detection device 10 detects each of the regions A to C described above, and calculates the cumulative amount of liquid detergent and air from the ratio of each region. , calculate the bubble inclusion rate.

However, when calculating the cumulative amount of liquid detergent and air, the detection error increases as more small bubbles are included, even if the actual bubble inclusion rate is the same. This is because when a large number of small bubbles are included, the number of cumulative calculations for areas A to C increases, and the accumulation of errors also increases. Furthermore, in a state where many small air bubbles are included, the proportion of the region C where both liquid detergent and air are present increases, which also leads to an increase in error.

On the other hand, when the transparent tube 20 is provided with a substantially inverted U-shaped arrangement part (particularly the first standing part 21 and the bent part 23), the process of flowing from the bottom to the top of the first standing part 21 and the bending In the process of changing the flow direction from the vertical direction to the horizontal direction by the portion 23, the liquid detergent between the bubbles becomes unable to maintain an interface with the bubbles, and a phenomenon occurs in which small bubbles combine to form large bubbles. That is, even if the first upright portion 21 contains many small air bubbles, the second upright portion 22 where the liquid detergent detection device 10 is provided has fewer small air bubbles and an increased number of large air bubbles. . As a result, it is possible to improve the accuracy of detecting the rate of air bubbles in the transparent tube 20.

Further, as described above, the first upright portion 21 and the bent portion 23 largely eliminate the interface with the air bubbles on the downstream side thereof. Therefore, when the pump 30 is stopped, the probability that an interface with air bubbles exists in the transparent tube 20 at the detection location of the liquid detergent detection device 10 can be significantly reduced. If liquid detergent remains at the interface with air bubbles, it tends to stick to the inside of the transparent tube 20 and become dirty, but with the above configuration, it is possible to prevent the inside of the transparent tube 20 from getting dirty at the detection location of the liquid detergent detection device 10. , the detection accuracy of the liquid detergent detection device 10 can be maintained.

[Embodiment 3]
In Embodiment 3, a preferred usage pattern of washing machine 100 will be described.

As described above, in the washing machine 100, it is possible to detect when the liquid detergent container 200 is out of detergent by detecting the liquid detergent in the transparent tube 20 by the liquid detergent detection device 10. When the liquid detergent detection device 10 detects that the detergent is running out, the administrator of the washing machine 100 or the like replenishes the liquid detergent container 200 with liquid detergent.

However, if the liquid detergent container 200 is simply replenished with liquid detergent, at that point, there is no liquid detergent filled between the end of the transparent tube 20 on the liquid detergent container 200 side and the liquid detergent detection device 10. It becomes. Therefore, if the washing machine 100 is used in such a state, even if the pump 30 is activated to supply liquid detergent, the liquid detergent will not reach the liquid detergent detection device 10 for a while, and the liquid detergent detection device 10 will not reach the liquid detergent detection device 10. There is a possibility that the detergent shortage will be detected again.

In the washing machine 100 according to the third embodiment, the liquid detergent detection device 10 detects that the detergent is running out, and after the administrator of the washing machine 100 replenishes the liquid detergent container 200, the detergent runs out. An operation after error cancellation is performed by performing an error cancellation operation (such as a predetermined button operation). The operation after error cancellation includes at least an initial filling operation into the transparent tube 20.

Such an initial filling operation is performed by operating the pump 30 until the transparent tube 20 is filled with liquid detergent. Specifically, the pump 30 is operated to start filling the transparent tube 20 with liquid detergent, and after the liquid detergent detection device 10 detects the presence of liquid detergent, the pump 30 is further operated for a predetermined period of time. Thereby, the liquid detergent can be filled up to the tip of the transparent tube 20 (the end on the washing machine main body 110 side).

Further, in the initial filling operation, the liquid detergent detection device 10 may not perform the detection operation for a predetermined time after the pump 30 starts operating, and may start the detection operation after the predetermined time has elapsed. This is because even if the pump 30 is operated when there is no liquid detergent in the transparent tube 20, the liquid detergent will not reach the liquid detergent detection device 10 for a while, and there is no need to perform a detection operation. . Therefore, by stopping the detection operation of the liquid detergent detection device 10 during a period when the liquid detergent is not expected to reach the liquid detergent detection device 10, it is possible to suppress unnecessary operations of the liquid detergent detection device 10.

In the initial filling operation, a predetermined timeout period is provided from the start of operation of the pump 30 to the detection of liquid detergent by the liquid detergent detection device 10, and if no liquid detergent is detected within the timeout period, the initial filling operation is terminated. However, it is preferable to detect the detergent shortage again. As a result, for example, if the administrator of the washing machine 100 performs a detergent out error release operation without refilling the liquid detergent container 200 with liquid detergent, the pump 30 may It is possible to avoid situations where only the machine continues to operate.

Furthermore, in the initial filling operation, even after the liquid detergent detection device 10 detects the presence of liquid detergent, so that the liquid detergent is completely filled up to the tip of the transparent tube 20 (the end on the washing machine main body 110 side). Furthermore, the pump 30 is operated for a predetermined period of time. In this case, it is conceivable that some liquid detergent is in the washing tub of the washing machine main body 110 at the end of the initial filling operation. Therefore, the operation after the error is cleared includes a washing tub cleaning operation of the washing machine main body 110, and it is preferable that the washing tub cleaning operation is performed after the initial filling operation.

In addition, in the washing machine 100, as shown in FIG. 6, for example, the transparent tube 20 has a length on the downstream side of the liquid detergent detection device 10, and the point at which the liquid detergent detection device 10 detects that the liquid detergent is running out is Preferably, a predetermined amount (preferably about one load of laundry) of liquid detergent is secured in the transparent tube 20 downstream of the liquid detergent detection device 10. With this configuration, even if it is detected that the user is running out of liquid detergent when using the washing machine 100, the amount of liquid detergent required for one wash is secured in the transparent tube 20, and the user can pay for it. You can avoid situations where you run out of liquid detergent. Note that the method for securing a predetermined amount of liquid detergent in the transparent tube 20 is not particularly limited, and in addition to the method of making the transparent tube 20 longer, for example, a reserve tank may be provided in the middle of the transparent tube 20. Other methods can also be considered.

Further, in the washing machine 100 described in the first to third embodiments above, the type of pump 30 used to feed the liquid detergent is not particularly limited, but different effects may occur depending on the type of pump 30 used. do. For example, if the pump 30 is of a type that does not generate pulsations, the velocity change in the liquid detergent flowing through the transparent tube 20 will be small. In this case, in a state where air bubbles are mixed in the liquid detergent flowing through the transparent tube 20, the detection accuracy of the air bubble mixing rate in the transparent tube 20 becomes high. On the other hand, if the pump 30 is of a type that generates pulsations, the speed change in the liquid detergent flowing through the transparent tube 20 will be large. In this case, the bubbles are more likely to collapse during the process in which the flow of the liquid detergent in the transparent tube 20 is intermittently accelerated/decelerated, and the bubble breaking effect at the first upright portion 21 of the transparent tube 20 is enhanced.

The embodiment disclosed this time is an illustrative example in all respects, and is not a basis for restrictive interpretation. Therefore, the technical scope of the present invention should not be interpreted only by the above-described embodiments, but should be defined based on the claims. Furthermore, all changes within the meaning and scope of the claims are included.

Claims (6)

A liquid detergent detection device that is used by attaching a transparent tube and detects the presence or absence of liquid detergent in the transparent tube,
a light emitting element and a light receiving element arranged opposite to each other with the transparent tube in between;
A tube holding section that holds the transparent tube at an appropriate position with respect to the liquid detergent detection device; and a control section that detects the presence or absence of liquid detergent in the transparent tube based on the amount of light received by the light receiving element. ,
The light emitting element irradiates the transparent tube with diffused light,
The light emitting element and the light receiving element are
(1) When there is liquid detergent in the transparent tube, the diffused light irradiated onto the transparent tube is refracted and focused by the liquid detergent in the transparent tube, and the light receiving element receives the focused light. receives light,
(2) When there is no liquid detergent in the transparent tube, the diffused light irradiated onto the transparent tube continues to diffuse even after passing through the transparent tube, and the light receiving element detects a portion of the light transmitted through the transparent tube. It is configured to receive light from the
The control unit detects that liquid detergent is present in the transparent tube when the output of the light receiving element is higher than a first threshold, and detects that liquid detergent is present in the transparent tube when the output of the light receiving element is lower than the first threshold. detects that there is no liquid detergent in the
When air bubbles are mixed in the liquid detergent flowing in the transparent tube, the end of the air bubble can be detected using a second threshold value that is smaller than the first threshold value,
The control unit includes:
detecting the edge of the bubble when the output of the light receiving element is lower than a second threshold;
When air bubbles are mixed in the liquid detergent flowing through the transparent tube, the area where there are no air bubbles, the area where air bubbles are present, and the area where air bubble edges are present are distinguished and detected, and the air bubbles are detected based on the ratio of each area. It is possible to calculate the contamination rate of
During the transition from a state in which it is detected that there is liquid detergent in the transparent tube to a state in which it is detected that there is no liquid detergent in the transparent tube, and a state in which it is detected that there is no liquid detergent in the transparent tube. When an end of air bubbles of the liquid detergent flowing inside the transparent tube is detected at least on one side during the transition from the state in which the presence of liquid detergent in the transparent tube is detected, the incorporation of air bubbles is detected. A liquid detergent detection device characterized by calculating the air bubble inclusion rate . A washing machine that receives liquid detergent from an external liquid detergent container through the transparent tube,
A washing machine comprising the liquid detergent detection device according to claim 1 attached to the transparent tube. The washing machine according to claim 2 ,
The transparent tube has a substantially inverted U-shape formed by a first upright part and a second upright part extending in the vertical direction, and a bent part connecting the first upright part and the second upright part at the upper part. It has a shaped arrangement part,
The washing machine, wherein the liquid detergent detection device is installed downstream of the bent portion in the flow direction of the liquid detergent. The washing machine according to claim 2 or 3 ,
After the liquid detergent detection device detects that the liquid detergent in the transparent tube has run out, a post-error clearing operation is performed in response to a user's operation to clear the detergent running out error;
The washing machine is characterized in that the operation after error cancellation includes an initial filling operation of filling liquid detergent into the transparent tube. The washing machine according to claim 4 ,
After starting the initial filling operation, if the liquid detergent detection device does not detect the presence of liquid detergent in the transparent tube within a predetermined timeout period, the initial filling operation is ended and the liquid detergent in the transparent tube is exhausted. A washing machine characterized by re-detection. The washing machine according to claim 4 or 5 ,
The initial filling operation is completed after the presence of liquid detergent in the transparent tube is detected by the liquid detergent detection device, and after the pump connected to the transparent tube is operated for a predetermined time,
The washing machine is characterized in that the post-error release operation includes a washing tub cleaning operation performed after the initial filling operation.

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