washing machine

Abstract

To provide a washing machine capable of highly accurately detecting presence or absence of a highly transparent liquid detergent flowing through a transparent tube.SOLUTION: A washing machine is supplied with a liquid detergent from an external liquid detergent container through a tube. The tube is fitted with: a pump for feeding the liquid detergent from the liquid detergent container to the washing machine; and a liquid detergent detection device for detecting presence or absence of the liquid detergent in the tube. The absence of the liquid detergent in the tube is determined on the basis of a detection result of the liquid detergent detection device during driving of the pump. After a user is notified of a detergent absence error indicating the absence of the liquid detergent, if operation for cancelling the detergent absence error is performed by the user, the washing machine performs post-error cancellation operation. The post-error cancellation operation includes initial filling operation for driving the pump to fill the tube with the liquid detergent at least up to a detection position of the liquid detergent detection device in the tube.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a washing machine that receives liquid detergent from a liquid detergent container by liquid transfer using a tube. This application claims priority to Japanese Patent Application No. 2019-48363 filed on March 15, 2019, the contents of which are incorporated herein by reference. [Background technology]

[0002] Many washing machines these days are equipped with an automatic detergent dispenser function. For example, in commercial washing machines, a large liquid detergent container is connected to the washing machine with a tube, and liquid detergent is supplied from the liquid detergent container to the washing machine through the tube.

[0003] In such liquid delivery using a tube, it is essential to detect the presence or absence of liquid detergent in the liquid detergent container and to control the amount of liquid delivered accurately. Patent Document 1 discloses a fluid detection device for liquid detergent, shampoo, etc., using a photointerrupter. The detection method of the fluid detection device disclosed in Patent Document 1 is to detect the presence or absence of fluid (liquid detergent or shampoo) in the transparent tube by transmitting light irradiated from a light-emitting element of the photointerrupter through a transparent tube and detecting the amount of transmitted light with a light-receiving element. Specifically, when a fluid is present in the transparent tube, the light is blocked by the fluid and the amount of transmitted light is reduced, so that 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. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 8-292082 Summary of the Invention [Problem to be solved by the invention]

[0005] In the fluid detection device described in Patent Document 1, the condition for highly accurate detection is that the transparency of the fluid flowing through the transparent tube is low. However, when this fluid detection device is applied to a washing machine, there is a problem that many liquid detergents are highly transparent, making highly accurate detection difficult. This is because the difference in the amount of transmitted light due to the presence or absence of detergent in the transparent tube becomes small in highly transparent liquid detergents. In addition, the output level of optical sensor devices such as photointerrupters is easily changed due to temperature changes and deterioration over time, and if the difference in the amount of transmitted light due to the presence or absence of detergent is small, there is a risk of false detection depending on the conditions of use.

[0006] One aspect of the present invention has been made in consideration of the above-mentioned problems, and aims to provide a liquid detergent detection device that can detect with high accuracy the presence or absence of highly transparent liquid detergent flowing through a transparent tube, and a washing machine using the same. [Means for solving the problem]

[0007] 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 detects the presence or absence of liquid detergent in the transparent tube, and includes a light-emitting element and a light-receiving element that are arranged opposite each other across the transparent tube, a tube holding unit that holds the transparent tube in an appropriate position with respect to the liquid detergent detection device, and a control unit 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, and the light-emitting element irradiates diffuse light onto the transparent tube, and the light-emitting element and the light-receiving element (1) emit a diffuse light when liquid detergent is present in the transparent tube, In this case, (1) 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; and (2) when there is no liquid detergent in the transparent tube, the diffused light irradiated to the transparent tube continues to diffuse even after passing through the transparent tube, and the light receiving element receives a portion of the light that has passed through the transparent tube. 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 detects that there is no liquid detergent in the transparent tube when the output of the light receiving element is lower than the first threshold value.

[0008] According to the above configuration, the liquid detergent detection device can change the output of the light receiving element by utilizing the presence or absence of the light collecting effect depending on whether or not there is liquid detergent in the transparent tube. 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 a highly transparent liquid detergent can be detected with high accuracy regardless of the conditions of use of the liquid detergent detection device.

[0009] In addition, the liquid detergent detection device can detect the end of the air bubble using a second threshold value smaller than the first threshold value when air bubbles are mixed in the liquid detergent flowing through the transparent tube, and the control unit can be configured to detect the end of the air bubble when the output of the light receiving element is lower than the second threshold value.

[0010] 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 bubble. 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.

[0011] In addition, in the above liquid detergent detection device, the control unit can be configured to distinguish and detect areas where no air bubbles are present, areas where air bubbles are present, and areas where the ends of air bubbles are present when air bubbles are mixed in the liquid detergent flowing through the transparent tube, and to calculate the rate of air bubbles from the proportion of each of these areas.

[0012] According to the above configuration, the rate of air bubbles in the liquid detergent delivered through the transparent tube can be calculated, and the calculated rate of air bubbles can be used to control the amount of liquid detergent supplied to the washing machine.

[0013] In addition, in order to solve the above problems, a washing machine according to 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 is characterized in that it includes the above-described liquid detergent detection device attached to the transparent tube.

[0014] In addition, in the above-mentioned washing machine, the transparent tube has an approximately inverted U-shaped arrangement formed by first and second upright portions extending in the vertical direction and a bent portion connecting the first and second upright portions at the upper part, and the liquid detergent detection device can be configured to be attached downstream in the flow direction of the liquid detergent than the bent portion.

[0015] According to the above configuration, when the liquid detergent flows from bottom to top through the first standing section or flows through the bent section, a bubble-breaking effect occurs that separates the liquid detergent containing air bubbles into liquid detergent and air. As a result, by installing the liquid detergent detection device downstream of the bent section, liquid detergent containing small air bubbles is prevented from flowing to the installation position of the liquid detergent detection device, and the liquid detergent detection device can properly detect the liquid detergent running out. Alternatively, the detection accuracy of the rate of air bubbles in the transparent tube can be improved.

[0016] In addition, after the liquid detergent detection device detects that the transparent tube has run out of liquid detergent, the washing machine performs an operation after the error has been cleared in response to a user's operation to clear the out-of-detergent error, and the operation after the error has been cleared can be configured to include an initial filling operation of filling the transparent tube with liquid detergent.

[0017] According to the above configuration, after it is detected that the liquid detergent in the transparent tube is depleted, the liquid detergent container is refilled with liquid detergent and then the initial filling operation is performed, so that the liquid detergent can be filled into the transparent tube. This prevents the liquid detergent detection device from detecting the liquid detergent depletion again before the liquid detergent reaches the liquid detergent detection device the next time the washing machine is used.

[0018] In addition, the washing machine can be configured to terminate the initial filling operation and again detect the absence of liquid detergent in the transparent tube if the liquid detergent detection device does not detect the presence of liquid detergent in the transparent tube within a predetermined timeout period after the start of the initial filling operation.

[0019] According to the above configuration, if a washing machine manager or other person performs an operation to clear the detergent out error without refilling the liquid detergent container with liquid detergent, it is possible to prevent the pump from continuing to operate without detergent being filled into the transparent tube.

[0020] In addition, in the above-mentioned 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 then operates the pump connected to the transparent tube for a predetermined period of time, and the operation after the error is released can be configured to include a washing tub cleaning operation that is performed after the initial filling operation.

[0021] According to the above configuration, the liquid detergent can be completely filled up to the tip of the transparent tube by operating the pump for a predetermined time even after the liquid detergent detection device detects the presence of liquid detergent in the transparent tube. In this case, since it is considered that some liquid detergent remains 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. Effect of the Invention

[0022] The liquid detergent detection device and washing machine according to one embodiment of the present invention change the output of the light receiving element by utilizing the presence or absence of light collecting effect depending on whether or not liquid detergent is present in the transparent tube. This provides the effect of making it possible to obtain a large difference in the output of the light receiving element when the liquid detergent flowing through the transparent tube is highly transparent, and thus enabling the presence or absence of a highly transparent liquid detergent to be detected with high accuracy regardless of the conditions under which the liquid detergent detection device is used. [Brief description of the drawings]

[0023] [Figure 1] 1 is a front view showing the appearance of a laundry system according to an embodiment of the present invention; [Diagram 2] 1 is a perspective view of the inside of an attachment device attached to the top surface of the washing machine, seen from the rear side. [Diagram 3] FIG. 1A is an explanatory diagram showing the detection principle when liquid detergent is present in the transparent tube, and FIG. 1B is an explanatory diagram showing the detection principle when no liquid detergent is present in the transparent tube. [Figure 4] The upper part is a diagram showing the state of air bubbles in a transparent tube, and the lower part is a graph showing the relationship between the air bubble position and the output (amount of received light) of the light receiving element. [Diagram 5] 10 is an explanatory diagram showing the separation action between liquid detergent and air inside a transparent tube. FIG. [Figure 6] FIG. 13 is an explanatory diagram showing a configuration for securing a predetermined amount of liquid detergent in a transparent tube. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] [First embodiment] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In this embodiment, a liquid detergent detection device capable of detecting with high accuracy the presence or absence of a highly transparent liquid detergent flowing through a transparent tube will be described.

[0025] FIG. 1 is a front view showing the configuration of a washing system including a washing machine 100, which is an application example of the present invention. This washing system is composed of 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 upper surface of a washing machine main body 110. The washing machine 100 is also configured to receive liquid detergent from the liquid detergent container 200 via the transparent tube 20. Note that, although FIG. 1 shows an example of a configuration in which one washing machine 100 is connected to one liquid detergent container 200, a plurality of washing machines 100 may be connected to one liquid detergent container 200.

[0026] Fig. 2 is a perspective view of the inside of the attachment device 120 as seen from the rear side. In Fig. 2, in order to illustrate the inside of the attachment device 120, a part of the external housing is omitted. Inside the attachment device 120, the liquid detergent detection device 10 attached together with the transparent tube 20 is disposed. The attachment device 120 also includes a pump 30 for sending the liquid detergent from the liquid detergent container 200 to the washing machine 100 through the transparent tube 20, and a billing device 40 for allowing a user of the washing machine 100 to pay the fee.

[0027] 2, the liquid detergent detection device 10 has a tube mounting groove 11 for mounting the transparent tube 20, and a photointerrupter 12. The photointerrupter 12 is an example of a light emitting element and a light receiving element as set forth in the claims. The liquid detergent detection device 10 also has a control unit (not shown) that determines the presence or absence of liquid detergent in the transparent tube 20 based on the output of the photointerrupter 12.

[0028] The transparent tube 20 is attached to the liquid detergent detection device 10 by being fitted into the tube mounting groove 11. In this embodiment, the 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 mounting groove 11. The photointerrupter 12 has therein a light emitting element 12a (see FIG. 3) and a light receiving element 12b (see FIG. 3) that are arranged facing each other so as to sandwich the transparent tube 20. Furthermore, the photointerrupter 12 has tube holding portions 12c at both ends in the extending direction of the transparent tube 20 (the vertical direction in FIG. 1). The light emitting element 12a and the light receiving element 12b are not limited to being included in the photointerrupter 12. For example, the liquid detergent detection device 10 may hold the light emitting element 12a and the light receiving element 12b, respectively.

[0029] Next, the detection principle of the liquid detergent detection device 10 when there is or is not a liquid detergent in the transparent tube 20 will be described with reference to FIGS.

[0030] FIG. 3(a) shows the detection principle when liquid detergent is present in the transparent tube 20. First, the light-emitting element 12a irradiates the transparent tube 20 with diffused light. When liquid detergent is present, the light passing through the transparent tube 20 is refracted by the liquid detergent in the transparent tube 20 and is focused toward the light-receiving element 12b. As a result, the light-receiving element 12b can receive most of the light passing through the transparent tube 20. It is preferable that all (or almost all) of the diffused light irradiated from the light-emitting element 12a toward the transparent tube 20 is irradiated onto the transparent tube 20. In addition, the cross section of the transparent tube 20 has a convex curved shape such as a circle or an ellipse in order to obtain a light-focusing effect.

[0031] 3(b) shows the detection principle when there is no liquid detergent in the transparent tube 20. When there is no liquid detergent, the light passing through the transparent tube 20 continues to diffuse without being condensed, and the light receiving element 12b can only receive a portion of the light passing through the transparent tube 20.

[0032] In this way, the liquid detergent detection device 10 according to the first embodiment varies the amount of light received by the light receiving element 12b depending on the presence or absence of a light collecting effect depending on whether or not there is liquid detergent in the transparent tube 20. 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 can determine that there is liquid detergent in the transparent tube 20 when the output of the light receiving element 12b is greater than the first threshold value, and can determine that there is no liquid detergent in the transparent tube 20 when the output of the light receiving element 12b is less than the first threshold value.

[0033] In the above detection principle of the liquid detergent detection device 10, when liquid detergent is present in the transparent tube 20, the light passing through the transparent tube 20 must be sufficiently concentrated on the light receiving surface of the light receiving element 12b. For this reason, the transparent tube 20 must be disposed in an appropriate position relative to the light emitting element 12a and the light receiving element 12b in the photointerrupter 12. In the liquid detergent detection device 10, the photointerrupter 12 is provided with a tube holding portion 12c, which holds and fixes the transparent tube 20, thereby achieving such appropriate positioning.

[0034] Furthermore, in the liquid detergent detection device 10, not only the positions of the light-emitting element 12a and the light-receiving element 12b but also the light-receiving area 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 varies depending on the light-receiving area of ​​the light-receiving element 12b. Specifically, the smaller the light-receiving area 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, and the larger the difference in output of the light-receiving element 12b between when there is and is not liquid detergent in the transparent tube 20 can be made. For this reason, 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.

[0035] In addition, the light receiving portion of the light receiving element 12b is preferably shaped like a slit whose longitudinal direction is the direction in which the transparent tube 20 extends (the vertical direction in FIG. 2). Since the transparent tube 20 is cylindrical, almost no light collecting effect is obtained in the direction in which the transparent tube 20 extends, but the light collecting effect shown in FIG. 3 is obtained in the direction along the cross section of the transparent tube 20. Therefore, by forming the light receiving portion of the light receiving element 12b into a narrow slit shape in the vertical direction in FIG. 3, the difference in output of the light receiving element 12b between when there is liquid detergent in the transparent tube 20 and when there is not can be made large, and by setting the longitudinal direction of the slit in the direction in which the transparent tube 20 extends (the front-back direction on the paper surface in FIG. 3), more light can be received from the light emitting element 12a, thereby improving the signal strength of the light receiving element 12b.

[0036] In the present embodiment 1, the transparent tube 20 is assumed to deliver liquid from the liquid detergent container 200 to the washing machine 100, but when the remaining amount of liquid detergent in the liquid detergent container 200 becomes low, air bubbles become mixed in the liquid detergent in the transparent tube 20. Such air bubbles form a curved interface in the axial direction of the transparent tube 20 so as to separate the air and the liquid detergent.

[0037] The liquid detergent detection device 10 according to the first embodiment can also detect the interface of the air bubbles (air bubble end region) in the transparent tube 20 by comparing the output (amount of light received) of the light receiving element 12b with a second threshold value (<first threshold value). The detection principle will be described with reference to FIG. 4. The upper part of FIG. 4 is a diagram showing the state of the air bubbles in the transparent tube 20, and the lower part of FIG. 4 is a graph showing the relationship between the air bubble position and the output (amount of light received) of the light receiving element 12b. In FIG. 4, the area where the liquid detergent is present in the transparent tube 20 (no air bubbles are present) is designated as area A, the area where the liquid detergent is not present in the transparent tube 20 (air bubbles are present and no interface between the air and the liquid detergent is present) is designated as area B, and the area where the air bubble end is present in the transparent tube 20 (an interface between the air and the liquid detergent is present) is designated as area C.

[0038] First, in region A, as shown in Fig. 3(a), the amount of received light is "large" due to the light passing through the transparent tube 20 being concentrated. In region B, as shown in Fig. 3(b), the amount of received light is "medium" due to the light passing through the transparent tube 20 being diffused. Therefore, by setting the above-mentioned first threshold between the amount of received light in region A and the amount of received light in region B, it is possible to determine that liquid detergent is present in the transparent tube 20 when the output of the light receiving element 12b is greater than the first threshold.

[0039] On the other hand, in region C, the light emitted from the light-emitting element 12a is reflected and scattered by the end of the air bubble, i.e., the interface between the air and the liquid detergent, and the amount of light that travels straight through the transparent tube 20 (light in the direction of the arrow from top to bottom in region C in FIG. 4) decreases. As a result, the amount of light received in region C is "small." Therefore, by setting a second threshold between the amount of light received in region B and the amount of light received in region C, it is possible to detect the end of the air bubble in the transparent tube 20 when the output of the light-receiving element 12b is smaller than the second threshold. Then, when the output of the light-receiving element 12b is smaller than the first threshold and larger than the second threshold, it is possible to determine that there is no liquid detergent in the transparent tube 20.

[0040] In this way, the liquid detergent detection device 10 according to the first embodiment changes the output of the light receiving element 12b by utilizing the presence or absence of a light collecting effect depending on whether or not there is liquid detergent in the transparent tube 20. Therefore, when the liquid detergent flowing through the transparent tube is highly transparent, a large difference in output from the light receiving element 12b can be obtained, and regardless of the conditions under which the liquid detergent detection device 10 is used, the presence or absence of a highly transparent liquid detergent can be detected with high accuracy.

[0041] Furthermore, when air bubbles are present in the transparent tube 20, the air bubbles can be detected by utilizing the scattering of light at the air bubble end. This makes it possible to detect that the remaining amount of liquid detergent in the liquid detergent container 200 is low when air bubbles are mixed in the liquid detergent delivered by the transparent tube 20. Furthermore, it is possible to detect the rate of air bubbles mixed in the liquid detergent delivered by the transparent tube 20 and, based on this, more accurately control the amount of liquid detergent supplied to the washing machine 100.

[0042] [Embodiment 2] In the second embodiment, a preferred mode of use of the liquid detergent detection device 10 in the washing machine 100 will be described.

[0043] As shown in FIG. 2, in the attachment device 120, the transparent tube 20 has a substantially inverted U-shaped arrangement portion. The substantially inverted U-shaped arrangement portion of the transparent tube 20 is formed by a first standing portion 21 and a second standing portion 22 extending in the vertical direction, and a bent portion 23 connecting the first standing portion 21 and the second standing portion 22 at the upper portion. The first standing portion 21 and the second standing portion 22 are arranged such that the second standing portion 22 is downstream in the flow direction of the liquid detergent. Therefore, when the pump 30 is operated to send the liquid detergent from the liquid detergent container 200 to the washing machine 100, in the substantially inverted U-shaped arrangement portion of the transparent tube 20, the liquid detergent flows from the bottom to the top in the first standing portion 21, and then the flow direction is changed at the bent portion 23 and flows from the top to the bottom in the second standing portion 22. The liquid detergent detection device 10 is attached 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.

[0044] When the washing machine 100 is in use, an appropriate amount of liquid detergent needs to be supplied from the liquid detergent container 200 to the washing machine 100, and the amount of liquid detergent supplied is controlled by the drive time of the pump 30. However, when the remaining amount of liquid detergent in the liquid detergent container 200 becomes low and air bubbles start to be 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, the drive time of the pump 30 is lengthened compared to when no air bubbles are mixed in the liquid detergent flowing through the transparent tube 20, thereby controlling the supply of an appropriate amount of liquid detergent.

[0045] Furthermore, to control the amount of liquid detergent supplied by 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 the rate of air bubbles is detected to be 50% in the liquid detergent delivered through the transparent tube 20, the driving time of the pump 30 can be doubled to make the amount of liquid detergent supplied the same as when no air bubbles are present.

[0046] As explained in the above-mentioned first embodiment, when air bubbles are mixed in the liquid detergent flowing through the transparent tube 20, the liquid detergent detection device 10 can distinguish and detect the area A where no air bubbles exist, the area B where the center of the air bubbles exists, and the area C where the end of the air bubbles exists. Based on this, the rate of air bubbles mixed in the transparent tube 20 can also be detected.

[0047] 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 has run out of liquid detergent.

[0048] In the washing machine 100 of this embodiment 2, the transparent tube 20 has an approximately inverted U-shaped arrangement (a first upright portion 21, a bent portion 23 and a second upright portion 22), and the liquid detergent detection device 10 is attached to the second upright portion 22 through which the liquid detergent flows from top to bottom.

[0049] As the liquid detergent flows from bottom to top through the first standing portion 21, it spreads along the inner wall of the transparent tube 20. When the rate of air bubbles mixed in the transparent tube 20 is high and the amount of liquid detergent between adjacent air bubbles is small, the liquid detergent between the air bubbles spreads along the inner wall of the tube as shown in FIG. 5, and the vertical width of the liquid detergent decreases. When the width of the liquid detergent is no longer enough to maintain an interface with the air bubbles, the liquid detergent forming the interface with the air bubbles falls downward along the inner wall of the tube. That is, in the first standing portion 21, a so-called bubble breaking effect occurs, which eliminates small interfaces between air bubbles.

[0050] Furthermore, the washing machine 100 according to the second embodiment has a bent portion 23 at the upper portion of the first standing portion 21, that is, downstream of the flow direction of the liquid detergent. At the upper portion of the first standing portion 21, the vertical width of the liquid detergent is reduced as described above. When the 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 liquid detergent in the bent portion 23 has an uneven horizontal width due to gravity. Specifically, the liquid detergent is concentrated at the lower portion in the transparent tube 20 of the bent portion 23, and the liquid detergent is insufficient at the upper portion. As a result, the liquid detergent cannot maintain an interface with the air bubbles at the upper portion in the transparent tube 20 of the bent portion 23, and the interface with the air bubbles disappears. Therefore, the bent portion 23 can enhance the so-called foam breaking effect, which eliminates small-scale interfaces between air bubbles.

[0051] As a result, the liquid detergent containing 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. This prevents the liquid detergent containing many small air bubbles from continuing to flow for a long period of time in the liquid detergent detection device 10, and allows the liquid detergent container 200 to properly detect when the liquid detergent has run out.

[0052] 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. To detect the rate of air bubbles in the transparent tube 20, the liquid detergent detection device 10 detects each of the above-mentioned areas A to C, calculates the cumulative amount of liquid detergent and air from the proportions of each of these areas, and calculates the rate of air bubbles.

[0053] However, when calculating the cumulative amount of liquid detergent and air, even if the actual mixing rate of air bubbles is the same, the more small bubbles there are, the larger the detection error becomes. This is because when many small bubbles are included, the cumulative calculation of areas A to C increases, and the accumulated error also increases. Also, when many small bubbles are included, the proportion of area C, where both liquid detergent and air exist, increases, which also leads to an increase in error.

[0054] In contrast, when the transparent tube 20 is provided with a substantially inverted U-shaped arrangement (particularly the first standing portion 21 and the bent portion 23), the liquid detergent between the air bubbles cannot maintain an interface with the air bubbles when the liquid detergent flows from bottom to top through the first standing portion 21 or when the flow direction changes from vertical to horizontal through the bent portion 23, causing small air bubbles to merge and become large bubbles. That is, even if the first standing portion 21 contains many small air bubbles, the second standing portion 22, where the liquid detergent detection device 10 is provided, will have fewer small air bubbles and more large air bubbles. As a result, the detection accuracy of the air bubble mixing rate in the transparent tube 20 can be improved.

[0055] As described above, the interface with air bubbles is largely removed downstream by the first upright portion 21 and the bent portion 23. Therefore, the probability that an interface with air bubbles will be present inside the transparent tube 20 at the detection point of the liquid detergent detection device 10 when the pump 30 is stopped can be greatly reduced. If liquid detergent remains at the interface with air bubbles, it tends to adhere 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 becoming dirty at the detection point of the liquid detergent detection device 10, and the detection accuracy of the liquid detergent detection device 10 can be maintained.

[0056] Third Embodiment In the third embodiment, a preferred mode of use of the washing machine 100 will be described.

[0057] As described above, in the washing machine 100, it is possible to detect that the liquid detergent container 200 has run out of detergent by detecting the liquid detergent in the transparent tube 20 using the liquid detergent detection device 10. When the liquid detergent detection device 10 detects that the detergent has run out, the manager of the washing machine 100 or the like refills the liquid detergent container 200 with liquid detergent.

[0058] However, simply refilling the liquid detergent container 200 with liquid detergent means that at that point in time, no liquid detergent has been filled between the end of the transparent tube 20 on the liquid detergent container 200 side and the liquid detergent detection device 10. Therefore, if the washing machine 100 is used in this state, even if the pump 30 is operated 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 may again detect that the detergent has run out.

[0059] In the washing machine 100 according to the third embodiment, after the liquid detergent detection device 10 detects that the detergent has run out and the manager of the washing machine 100 refills the liquid detergent container 200 with liquid detergent, an operation after the error is cleared is performed by performing an operation to clear the detergent out error (such as by operating a predetermined button). The operation after the error is cleared includes at least an initial filling operation into the transparent tube 20.

[0060] 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 time. This allows the liquid detergent to be filled up to the tip of the transparent tube 20 (the end on the washing machine main body 110 side).

[0061] Furthermore, 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, it is considered that the liquid detergent will not reach the liquid detergent detection device 10 for a while, making it unnecessary to perform the detection operation. Therefore, by stopping the detection operation of the liquid detergent detection device 10 during the period when it is expected that the liquid detergent will not reach the liquid detergent detection device 10, unnecessary operation of the liquid detergent detection device 10 can be suppressed.

[0062] In the initial filling operation, it is preferable to provide a predetermined timeout period from when the pump 30 starts to operate until the liquid detergent detection device 10 detects the liquid detergent, and if the liquid detergent is not detected within the timeout period, to terminate the initial filling operation and detect the detergent shortage again. This makes it possible to prevent, for example, a situation in which the manager of the washing machine 100 resets the detergent shortage error without refilling the liquid detergent container 200 with liquid detergent, and the pump 30 continues to operate without filling the transparent tube 20 with detergent.

[0063] Furthermore, in the initial filling operation, pump 30 is operated for a predetermined time even after liquid detergent detection device 10 detects the presence of liquid detergent so that liquid detergent is completely filled up to the tip of transparent tube 20 (the end on the washing machine main body 110 side). In this case, it is considered that some liquid detergent remains in the washing tub of washing machine main body 110 at the end of the initial filling operation. Therefore, it is preferable that the operation after error release includes a washing tub cleaning operation of washing machine main body 110, and that the washing tub cleaning operation is performed after the initial filling operation.

[0064] In addition, in the washing machine 100, it is preferable that the transparent tube 20 has a length at the downstream side of the liquid detergent detection device 10 as shown in FIG. 6, so that a predetermined amount of liquid detergent (preferably about one wash load) is secured in the transparent tube 20 downstream of the liquid detergent detection device 10 at the time when the liquid detergent detection device 10 detects that the liquid detergent has run out. In this configuration, even if the liquid detergent is detected to be out while the user is using the washing machine 100, the amount of liquid detergent required for that one wash load is secured in the transparent tube 20, so that a situation in which the user has paid the fee but there is not enough liquid detergent can be avoided. The method of securing a predetermined amount of liquid detergent in the transparent tube 20 is not particularly limited, and in addition to the method of providing the transparent tube 20 with a length, for example, a method of providing a reserve tank midway along the transparent tube 20 can be considered.

[0065] In addition, in the washing machine 100 described in the above-mentioned first to third embodiments, the type of the pump 30 used to deliver the liquid detergent is not particularly limited, but different effects are also produced depending on the type of the pump 30 used. For example, if the pump 30 is of a type that does not generate pulsation, the speed change in the liquid detergent flowing through the transparent tube 20 is small. In this case, in a state in which air bubbles are mixed in the liquid detergent flowing through the transparent tube 20, the detection accuracy of the mixing rate of air bubbles in the transparent tube 20 is high. On the other hand, if the pump 30 is of a type that generates pulsation, the speed change in the liquid detergent flowing through the transparent tube 20 is large. In this case, air bubbles are easily crushed in the process in which the flow of the liquid detergent in the transparent tube 20 is intermittently accelerated / decelerated, and the foam breaking effect at the first standing portion 21 of the transparent tube 20 is improved.

[0066] The embodiments disclosed herein are illustrative in all respects and are not intended to be limiting. Therefore, the technical scope of the present invention is not interpreted solely by the above-described embodiments, but is defined by the claims. Also, all modifications within the scope and meaning equivalent to the claims are included. [Explanation of symbols]

[0067] 10 Liquid detergent detection device 12 Photointerrupter 12a Light emitting element 12b Photodetector 12c Tube holder 20 Transparent tube 21 First erection section 22 Second erection section 23 Bend 30 Pump 100 Washing Machine 110 Washing machine body 120 Attached Equipment 200 Liquid detergent containers

Claims

1. A washing machine that receives liquid detergent from an external liquid detergent container through a tube, A pump for pumping the liquid detergent from the liquid detergent container to the washing machine and a liquid detergent detection device for detecting the presence or absence of the liquid detergent in the tube are attached to the tube, determining whether the liquid detergent in the tube has run out based on a detection result of the liquid detergent detection device while the pump is in operation; After notifying the user of the detergent out error indicating that the liquid detergent has run out, if the user performs an operation to reset the detergent out error, an operation after the error is reset is performed; The washing machine, characterized in that the operation after the error is released includes an initial filling operation of driving the pump to fill the liquid detergent in the tube at least up to the detection position of the liquid detergent detection device.

2. 2. The washing machine according to claim 1, This washing machine is characterized in that if the liquid detergent detection device does not detect the presence of liquid detergent in the tube within a predetermined time-out period after the start of the initial filling operation, the initial filling operation is terminated and the detergent out error is notified again.

3. The washing machine according to claim 1 or 2, The washing machine is characterized in that the initial filling operation is terminated after the liquid detergent detection device detects the presence of liquid detergent in the tube and then the pump is driven for a predetermined time.

4. A washing machine according to any one of claims 1 to 3, The washing machine, wherein the post-error release operation includes a washing tub cleaning operation performed after the initial filling operation.

5. A washing machine according to any one of claims 1 to 4, The liquid detergent detection device is capable of calculating a rate of air bubbles in the tube, The washing machine is characterized in that, when the mixing rate exceeds a predetermined value, it is determined that the liquid detergent has run out.

6. The washing machine according to claim 5, When the mixing rate is equal to or less than the predetermined value, a driving time of the pump is controlled according to the mixing rate.

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