Control device, mixing device unit, water system device, computer program and control method

Abstract

To provide a technique for avoiding a state where pulsation might occur in a mixing device.SOLUTION: A mixing device may include a mixing chamber to which first water flows in from a first route having a first valve disposed therein and to which second water flows in from a second route having a second valve disposed therein. A control device may execute regulating processing for reducing either one of a first correction amount of a first opening of the first valve for a predetermined period or a second correction amount of a second opening of the second valve for the predetermined period.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The technology disclosed in this specification relates to a control device used in a mixer that mixes water flowing in from multiple routes, a mixer unit equipped with the same, a water-related device, and a computer program and control method for the control device. [Background technology]

[0002] Patent Document 1 describes a mixing device that mixes hot water and cold water. The mixing device includes a water supply path, an oil supply path, and a mixing pipe that mixes the hot water and cold water flowing from each path. Each path is provided with a flow rate control valve that adjusts the opening of each path. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-148985 Summary of the Invention [Problem to be solved by the invention]

[0004] In the mixer described above, which mixes water flowing from multiple paths, the flow rate of water flowing through each path is adjusted by the opening of a valve device disposed in each path. This adjusts the water flow rate of each path to a target flow rate. In this configuration, the water flow rate of the path may not be fixed at the target flow rate, and control of the opening of the valve device may become unstable. As a result, flow rate fluctuations and accompanying pressure fluctuations may occur, causing pulsation in the water flowing from the mixer.

[0005] This specification provides a technique for preventing situations in which pulsation may occur in such a mixing device. [Means for solving the problem]

[0006] The technology disclosed in this specification relates to a control device for controlling a mixing device. The mixing device may have a mixing chamber into which first water flows in through a first path in which a first valve is disposed and into which second water flows in through a second path in which a second valve is disposed. The control device may execute an adjustment process to reduce either a first correction amount for a first opening degree of the first valve during a predetermined period or a second correction amount for a second opening degree of the second valve during the predetermined period.

[0007] Another technology disclosed in this specification relates to a computer program for a control device that controls a mixing device. The mixing device may have a mixing chamber into which a first water flows in through a first path in which a first valve is disposed and a second water flows in through a second path in which a second valve is disposed. The computer program may cause the control device to function to reduce either a first correction amount for a first opening degree of the first valve in a predetermined period or a second correction amount for a second opening degree of the second valve in the predetermined period.

[0008] Another technology disclosed herein is a method executed by a control device that controls a mixing device. The mixing device may have a mixing chamber into which a first water flows in through a first passage having a first valve disposed therein and into which a second water flows in through a second passage having a second valve disposed therein. The method may include decreasing either a first correction amount for a first opening degree of the first valve during a predetermined period of time or a second correction amount for a second opening degree of the second valve during the predetermined period of time. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a schematic front view of a plumbing device according to an embodiment of the present invention; [Figure 2] 1 is a schematic front view of a mixing device according to an embodiment of the present invention; [Figure 3] FIG. 2 shows a block diagram of the mixer unit of the present embodiment. [Figure 4] 3 shows a longitudinal cross-sectional view of region IV in FIG. 2. [Figure 5] 10 shows a plan view of the upper end of the defining portion. [Figure 6]6 shows a cross-sectional view taken along line VI-VI in FIG. [Figure 7] 10 shows a flowchart of a pulsation prevention process executed by the control device. [Figure 8] 10 shows a flowchart of an adjustment process executed by the control device. DETAILED DESCRIPTION OF THE INVENTION

[0010] (Configuration of plumbing equipment) As shown in FIG. 1 , the plumbing device 2 includes a plumbing fixture 4, a bowl 8 that receives water discharged from the plumbing fixture 4 and directs it to a drainage path, and a mixer unit 80. FIG. 1 shows the plumbing fixture 4 and the bowl 8 in perspective views. FIG. 1 illustrates the connection between the plumbing fixture 4 and the upstream side including the mixer 10, with the upstream side including the mixer 10 shown in block diagram form. The plumbing fixture 4 includes a faucet 5 that discharges water flowing from the mixer 10 into the bowl 8, and an operating device 6 that allows a user to adjust the temperature of the water discharged from the faucet 5. The operating device 6 has one or more buttons that can be operated by a user. The user can set the flow rate and temperature of water discharged from the faucet 5 by operating the operating device 6. The operating device 6 transmits a signal indicating the flow rate and temperature set by the user to the mixing device 10. The plumbing device 2 is a household plumbing device used in a washbasin, kitchen unit, bathtub unit, etc. As shown in FIG. 3, the mixer unit 80 includes the mixer 10 and a control device 70 that controls the mixer 10 .

[0011] (Configuration of mixing device) Mixing device 10 is placed between pipe 102, which communicates with a drinking water pipe, and faucet fitting 4. Mixing device 10 is connected to each of pipes 104 and 106. Water is supplied to pipe 104 from pipe 102. Water that has passed through water heater 100 from pipe 102 is supplied to pipe 106. Water heater 100 heats the water supplied from pipe 102. Water that has passed through water heater 100 via pipe 104 flows in pipe 106. In the following, water passing through pipe 106 will be referred to as "hot water" to distinguish it from water flowing through pipe 104. Water discharged from faucet fitting 4 will be referred to as "water" regardless of its temperature.

[0012] In the following, the front-to-back and left-to-right directions are defined in the position shown in Figure 2. The front direction is the direction toward the front of the paper. The rear direction is the direction toward the back of the paper. These directions are defined for the purpose of explaining the embodiment. These directions do not limit the actual usage position. As shown in Figure 2, the mixing device 10 comprises a hot water system 20, a cold water system 30, and a mixing unit 50. The hot water system 20 comprises a valve device 22, a pipe 24, and a detection unit 26. Hot water flowing through the pipe 106 passes through the valve device 22 and flows into the pipe 24. The pipe 24 has a cylindrical shape extending in the vertical direction. The pipe 24 defines a hot water path 24a inside.

[0013] The valve device 22 switches between communication and cut-off between the path in the piping 106 and the hot water path 24a. The valve device 22 has an adjustment valve whose opening is adjusted according to the temperature and flow rate of water to be supplied to the faucet fitting 4. When the valve device 22 is closed, the path in the piping 106 is cut off from the hot water path 24a. When the valve device 22 is open, the path in the piping 106 is connected to the hot water path 24a. The amount of hot water flowing from the path in the piping 106 into the hot water path 24a can be adjusted depending on the opening of the valve device 22. The opening of the valve device 22 can be adjusted in stages. The opening of the valve device 22 can be adjusted by moving the valve body using a stepping motor.

[0014] The path 24a is connected to the mixing section 50. The hot water flowing from the pipe 106 into the hot water path 24a flows through the hot water path 24a and into the mixing section 50. A detection unit 26 that detects the flow rate of the hot water flowing through the hot water path 24a is arranged in the pipe 24. The detection unit 26 is arranged in the hot water path 24a and includes an impeller that is rotated by the hot water flowing through the hot water path 24a. The detection unit 26 detects the flow rate based on the rotation speed of the impeller. The type of the detection unit 26 is not particularly limited. For example, the detection unit 26 may detect the flow rate using ultrasound.

[0015] The water system 30 includes a valve device 32, pipes 34 and 40, and a detector 36. Water flowing through the pipe 104 passes through the valve device 32 and flows into the pipe 34. The pipe 34 has a cylindrical shape that extends vertically. The pipe 34 defines a water path 34a therein. The water path 34a is arranged parallel to the hot water path 24a.

[0016] The valve device 32 switches between communication and cut-off between the path in the piping 104 and the water path 34a. The valve device 32 has a configuration similar to that of the valve device 22. The valve device 32 has an adjustment valve whose opening is adjusted according to the temperature and flow rate of water to be supplied to the faucet fitting 4. When the valve device 32 is closed, the path in the piping 104 is cut off from the path 34a. When the valve device 32 is open, the path in the piping 104 is connected to the path 34a. The amount of water flowing from the path in the piping 104 into the path 34a can be adjusted depending on the opening of the valve device 32.

[0017] The pipe 34 is connected at its downstream end, i.e., the upper end in Fig. 2, to a pipe 40 extending perpendicularly from the pipe 34. The pipe 40 is connected to a mixing section 50. The pipe 40 defines a path 40a. The path 40a is disposed perpendicular to the path 34a. The path 34a is bent at the path 40a.

[0018] In the mixing device 10, the opening degrees of the valve devices 22, 32 are adjusted in response to the flow rate and temperature represented by the signals received from the operating device 6.

[0019] (Mixing section configuration) 4 shows a cross section passing through the central axes of the channels 24a and 34a in the mixing section 50. The mixing section 50 includes a partition structure 52 and a mixing chamber 60. The partition structure 52 includes defining portions 54 and 56.

[0020] The defining portion 54 has a cylindrical shape. The defining portion 54 defines a path 54a on an inner circumferential surface 54b. The path 54a is connected to the path 24a. The path 54a extends linearly from the path 24a. The defining portion 54 has a guide portion 54c at its downstream end, i.e., the upper end in FIG. 4. As shown in FIG. 5, the guide portion 54c is formed in a concave shape on the inner circumferential surface 54b at the downstream end of the path 54a. The guide portion 54c has an inclined surface 54d that is inclined in the up-down direction. The defining portion 54 has a plurality of guide portions 54c arranged at equal intervals in the circumferential direction of the inner circumferential surface 54b.

[0021] The defining portion 54 has a smaller outer diameter at a portion located on an extension of the path 40a than at other portions. A guide portion 54f is disposed on the outer peripheral surface 54e of the defining portion 54 at the portion where the outer diameter of the defining portion 54 is smaller. The guide portion 54f has a surface shape that extends spirally along the outer peripheral surface 54e. The guide portion 54f is inclined upward toward the mixing chamber 60. The guide portion 54f goes around the outer peripheral surface 54e.

[0022] The defining portion 56 has a cylindrical shape. The defining portion 56 accommodates the defining portion 54. The defining portion 54 is accommodated in the defining portion 56 and is not exposed to the outside. The defining portion 56 defines a path 56a at its inner circumferential surface 56b together with the outer circumferential surface 54e of the defining portion 54. The path 56a has a circular ring shape that goes around the defining portion 54 outside the defining portion 54 and extends in the up-down direction along the defining portion 54. As shown in FIG. 6 , the central axis X4 of the defining portion 54 is offset from the central axis X6 of the defining portion 56.

[0023] The path 56a is connected to the path 40a. The path 56a extends perpendicularly from the path 40a. The downstream end of the path 40a, i.e., the connection point 40b where the path 40a connects to the path 56a, has an opening 40c that opens into the path 56a. When the defining portion 54 and the defining portion 56 are viewed from the opening 40c along the central axis X8, the defining portion 54 is positioned offset to the left of the center of the path 56a. When the defining portion 54 is viewed from the opening 40c, the central axis X4 of the defining portion 54 is positioned offset from the central axis X8 of the path 40a. The diameter of the path 40a is smaller than the outer diameter of the path 56a. The rear edge of the path 40a extends tangentially to the path 56a.

[0024] As shown in FIG. 4, paths 54a and 56a extend parallel to each other in the vertical direction. A mixing chamber 60 is disposed at the downstream ends of paths 54a and 56a. The mixing chamber 60 is disposed on an extension of path 54a. In the mixing chamber 60, hot water flowing from path 54a to the mixing chamber 60 and cold water flowing from path 56a to the mixing chamber 60 are mixed together. As shown in FIG. 2, a valve device 62 is disposed at the downstream end of the mixing chamber 60. The valve device 62 includes, for example, a solenoid valve. The valve device 62 switches between a state in which the mixing chamber 60 is connected to the faucet fitting 4 and a state in which the mixing chamber 60 is cut off from the faucet fitting 4.

[0025] Path 40a is separated from path 24a by a partition 54. Water flowing from path 40a into path 56a flows along path 56a parallel to path 54a. This configuration reduces the effect of the flow of water flowing from path 40a along path 56a to mixing chamber 60 on the flow of water from path 54a to path 24a. This reduces the possibility that the flow of water in path 24a will be disturbed, causing detection unit 26 to erroneously detect the flow rate of hot water flowing through path 24a.

[0026] The water is maintained at a relatively high pressure due to the water pressure from the tap water pipe. The hot water is heated by the water heater 100, so the water pressure from the tap water pipe is not maintained. When cold water and hot water are mixed by passing them through the same path, the pressure difference between the cold water and the hot water makes it easier for water to flow into the path through which the hot water flows. This may result in an erroneous detection of the amount of hot water. Paths 34a and 40a are bent. Pressure loss occurs in the water flowing through paths 34a and 40a. On the other hand, path 24a is arranged in a straight line. The pressure loss occurring in the hot water flowing through path 24a is smaller than the pressure loss of the water flowing through paths 34a and 40a. This reduces the pressure difference between the cold water and the hot water.

[0027] By opening the opening 40c of the path 40a toward the defining portion 54, the water flowing from the path 40a into the path 56a can be agitated. This makes it easier to mix the hot water and cold water in the mixing chamber 60.

[0028] The lower end of guide portion 54f is disposed at the same height as the lower end of opening 40c. Guide portion 54f can guide water flowing from path 40a into path 56a toward mixing chamber 60 while swirling through path 56a. This agitates the water flowing through path 56a, making it easier to mix hot water and cold water in mixing chamber 60.

[0029] The demarcating portion 54 is disposed relative to the demarcating portion 56 such that the central axis X4 of the demarcating portion 54 is offset from the central axis X6 of the demarcating portion 56. The orientation of the path 40a is offset from the demarcating portion 54. As a result, it is possible to easily stir the water flowing from the path 40a into the path 56a. In the mixing chamber 60, it is possible to easily mix hot water and cold water.

[0030] Guide portion 54c allows hot water in path 54a to flow at an angle relative to path 54a. This causes the hot water to be stirred, making it easier to mix hot water and cold water in mixing chamber 60.

[0031] (Control device configuration) As shown in FIG. 3, the control device 70 is communicatively connected to each of the valve devices 22, 32, 62 and the detection units 26, 36. The control device 70 controls the valve devices 22, 32, 62 and the detection units 26, 36. The control device 70 acquires the flow rates detected by the detection units 26, 36. The opening degrees of the valve devices 22, 32 are determined from the rotational positions of the rotors of each stepping motor. The control device 70 acquires information indicating the open / closed states of the valve devices 22, 32. The control device 70 is communicatively connected to a temperature detection unit (not shown) that detects the temperature of hot water flowing into the path 24a and a temperature detection unit (not shown) that detects the temperature of water flowing into the path 34a. The control device 70 acquires the temperatures of the hot water and the water from the two temperature detection units.

[0032] The control device 70 is communicably connected to an operation device 6 operated by a user. The control device 70 acquires from the operation device 6 the set flow rate and set temperature set by the user.

[0033] The control device 70 includes a CPU and a memory. The memory has volatile and non-volatile storage sections. The control device 70 stores various data in the memory, including the temperature and flow rate of the hot water flowing through the path 24a, the temperature and flow rate of the water flowing through the path 34a, and information on the opening degrees of the valve devices 22, 32, and 62. The control device 70 controls the valve devices 22, 32, and 62 by executing processing in accordance with a computer program pre-stored in the memory.

[0034] (Processing by the control device) (Mixing treatment) When the target flow rates Qhd and Qcd are calculated, the control device 70 controls the mixer 10 to execute a mixing process for supplying water to the faucet fittings 4.

[0035] The control device 70 calculates the target flow rate Qhd of hot water to flow through path 24a and the target flow rate Qcd of water to flow through path 34a. The control device 70 calculates the target flow rate Qhd of hot water and the target flow rate Qcd of water based on the set temperature Tm and set flow rate Qm, the hot water temperature Th and the water temperature Tc, the hot water flow rate Qh flowing through path 24a (hereinafter simply referred to as the "hot water flow rate Qh") and the water flow rate Qc flowing through path 34a (hereinafter simply referred to as the "water flow rate Qc"), and the opening degrees of the valve devices 22 and 32. The target flow rate Qhd of hot water and the target flow rate Qcd of water are calculated using the method described in Patent Document 1 (JP 2022-148985 A).

[0036] In the mixing process, the control device 70 adjusts the amount of correction per unit time of the opening of the valve device 22 and the amount of correction per unit time of the opening of the valve device 32 based on the calculated target hot water flow rate Qhd and target water flow rate Qcd. The control device 70 adjusts the amount of correction per unit time of the opening of the valve device 22 so that the hot water flow rate Qh approaches the target hot water flow rate Qhd. The control device 70 adjusts the amount of correction per unit time of the opening of the valve device 32 so that the water flow rate Qc approaches the target water flow rate Qcd.

[0037] Specifically, the control device 70 controls the stepping motors of the valve devices 22 and 32 to perform stepping operations that rotate the stepping motors stepwise every first time. The opening degrees of the valve devices 22 and 32 are adjusted according to the amount of rotation of the stepping motors. The first time is shorter than the unit time. The amount of rotation of the stepping motor in one stepping operation is calculated by multiplying the stepping angle by the number of steps. The number of steps in the first time is determined according to the number of input pulses input to the stepping motor in the first time. For example, when a predetermined number (e.g., two) of input pulses are input to the stepping motor, the motor rotates one step. When a predetermined number of input pulses X times (X is an integer greater than or equal to 1) are input to the stepping motor in the first time, the motor rotates X steps. As the number of input pulses decreases, the number of steps also decreases. In other words, the amount of rotation of the stepping motor in one stepping operation is determined according to the number of input pulses. The control device 70 controls the amount of correction of the opening of the valve device 22 per unit time by adjusting at least one of the number of steps and the period between one step operation and the next step operation.

[0038] The control device 70 determines that mixing is unnecessary when the hot water flow rate Qh is approximately equal to the target hot water flow rate Qhd and the water flow rate Qc is approximately equal to the target water flow rate Qhd. The flow rates Qh and Qc being approximately equal to the target flow rates Qhd and Qcd means that the ratio of the difference between the hot water flow rate Qh and the target hot water flow rate Qhd to the target hot water flow rate is within approximately 10%, and the ratio of the difference between the water flow rate Qc and the target water flow rate Qcd to the target water flow rate is within 10%. At this time, the control device 70 locks the control of the mixing process and stops the mixing process. That is, the control device 70 fixes the opening of the valve devices 22 and 32. While the mixing process is locked, the control device 70 does not calculate the target flow rates Qhd and Qcd.

[0039] The control device 70 determines that the openings of the valve devices 22 and 32 need to be adjusted when at least one of the difference between the hot water flow rate Qh and the target hot water flow rate Qhd and the difference between the water flow rate Qc and the target water flow rate Qcd is greater than approximately 10%, and unlocks the locked state of the mixing process. For example, the control device 70 unlocks the locked state of the mixing process when the user operates the operating device 6 to change the set flow rate, set temperature, etc. For example, the control device 70 unlocks the locked state of the mixing process when the difference between the actual mixed temperature of the water flowing from the mixing device 10 and the set temperature is equal to or greater than a first predetermined value (e.g., 1°C) due to, for example, an unintended change in the hot water supply temperature, hot water supply flow rate, water supply flow rate, etc. The mixed temperature of the water flowing from the mixing device 10 is calculated from the hot water temperature, hot water flow rate Qh, water temperature, and water flow rate Qc. In a modified example, the mixed temperature of the water flowing from the mixing device 10 may be actually detected by a temperature detection unit. When the locked state is released, the control device 70 calculates the target flow rates Qhd and Qcd and resumes the mixing process.

[0040] (Pulsation prevention treatment) After the mixing process, the control device 70 executes a pulsation prevention process. In the pulsation prevention process, a specification process is executed to specify in advance the conditions under which pulsation may occur, and if it is specified that pulsation may occur, a pulsation prevention process is executed to prevent pulsation.

[0041] As shown in Fig. 7, in the pulsation prevention process, in S10, the control device 70 monitors whether the target hot water flow rate Qhd, the target water flow rate Qcd, the hot water flow rate Qh, and the water flow rate Qc are all greater than 0. If the target hot water flow rate Qhd, the target water flow rate Qcd, the hot water flow rate Qh, and the water flow rate Qc are all greater than 0 (YES in S10), the control device 70 proceeds to the identification process in S20. If any of the target hot water flow rate Qhd, the target water flow rate Qcd, the hot water flow rate Qh, and the water flow rate Qc is 0 (NO in S10), the control device 70 ends the pulsation prevention process.

[0042] (Specific processing) In steps S20 to S22, the control device 70 executes a determination process. In the determination process, the control device 70 determines whether a predetermined pulsation generation condition that may cause pulsation to occur in the mixer 10 is satisfied.

[0043] The predetermined pulsation generation condition includes a first pulsation generation condition and a second pulsation generation condition. The first pulsation generation condition is that the ratio of the target hot water flow rate Qhd to the sum of the target hot water flow rate Qhd and the target water flow rate Qcd is equal to or less than a second predetermined value. In a modified example, the first pulsation generation condition may be that the result of comparing the target hot water flow rate Qhd with the target water flow rate Qcd satisfies a predetermined condition.

[0044] The second pulsation generation condition is that the ratio of the hot water flow velocity Vh in path 24a to the cold water flow velocity Vc in path 34a is equal to or less than a third predetermined value. The hot water flow velocity Vh in path 24a is calculated by the formula Vh = Qh / Ah using the hot water flow rate Qh and the opening area Ah of path 24a based on the opening degree of valve device 22. The water flow velocity Vc in path 34a is calculated by the formula Vc = Qc / Ac using the water flow rate Qc and the opening area Ac of path 34a based on the opening degree of valve device 32. The control device 70 stores a table in which the opening degrees of valve devices 22 and 32 and the opening areas Ah and Ac of paths 24a and 34a are recorded in combination. The control device 70 identifies the opening area recorded in the table in combination with the acquired opening degree. In a modified example, the second pulsation generation condition may be that the result of comparing the flow velocity Vh of the hot water in the path 24a with the flow velocity Vc of the cold water in the path 34a satisfies a predetermined condition.

[0045] In this embodiment, the first and second pulsation generating conditions are exemplified as a case where the hot water flow rate Vh is lower than the water flow rate Vc. If the hot water flow rate Vh is equal to or higher than the water flow rate Vc, the first pulsation generating condition is a fourth predetermined value or less in the ratio of the target water flow rate Qcd to the sum of the target hot water flow rate Qhd and the target water flow rate Qcd, and the second pulsation generating condition is a fifth predetermined value or less in the ratio of the water flow rate Vc to the hot water flow rate Vh.

[0046] In S20, the control device 70 determines whether the first pulsation generation condition is met. Specifically, using the target hot water flow rate Qhd and the target water flow rate Qcd calculated at the start of the pulsation prevention process, it determines whether the ratio of the target hot water flow rate Qhd to the sum of the target hot water flow rate Qhd and the target water flow rate Qcd is equal to or less than a second predetermined value. If the ratio calculated in S20 is equal to or less than the second predetermined value, the control device 70 determines that the first pulsation generation condition is met (YES in S20) and proceeds to the process of S22. If the ratio calculated in S20 is greater than the second predetermined value, the control device 70 determines that the first pulsation generation condition is not met (NO in S20) and ends the pulsation prevention process.

[0047] In S22, the control device 70 determines whether the second pulsation generation condition is satisfied. Specifically, the control device 70 determines whether the ratio of the hot water flow rate Vh to the cold water flow rate Vc is equal to or less than a third predetermined value. If the ratio calculated in S22 is equal to or less than the third predetermined value, the control device 70 determines that the second pulsation generation condition is satisfied (YES in S22) and proceeds to the adjustment process in S30. If the ratio calculated in S22 is greater than the third predetermined value, the control device 70 determines that the second pulsation generation condition is not satisfied (NO in S22) and ends the pulsation prevention process.

[0048] (Adjustment processing) 8, in S30, the control device 70 executes an adjustment process. In the adjustment process, the control device 70 reduces the opening correction amount per unit time of the opening of either the valve device 22 or the valve device 32.

[0049] In S32, the control device 70 calculates the hot water flow rate Vh and the water flow rate Vc. The control device 70 determines whether the hot water flow rate Vh is equal to or less than the water flow rate Vc. If the hot water flow rate Vc is equal to or less than the water flow rate Vc, the control device 70 determines to adjust the valve device 32 (YES in S32) and proceeds to processing in S33. If the hot water flow rate Vc exceeds the water flow rate Vc (NO in S32), the control device 70 determines to adjust the valve device 32 and proceeds to processing in S39.

[0050] In S33, the control device 70 calculates the reduced number of steps Nc2 when the number of steps Nc1 in the first time period Tc1 of the valve device 22 is reduced. Specifically, the reduced number of steps Nc2 is calculated by the formula Nc2=Nc1*(Vh / Vc)*pulsation prevention strength coefficient. The number of steps Nc2 is an integer, and any fractional part of the calculated value is rounded down. The pulsation prevention strength coefficient may be preset when the control device 70 is shipped, or may be set by the user.

[0051] In S34, the control device 70 determines whether the number of steps Nc2 calculated in S33 is greater than a predetermined number. If the number of steps Nc2 calculated in S33 is greater than the predetermined number, the control device 70 decides to reduce the number of steps Nc1 to the number of steps Nc2 calculated in S33 (YES in S34), and proceeds to the processing of S36. If the number of steps calculated in S33 is equal to or less than the predetermined number (NO in S34), the control device 70 proceeds to the processing of S37.

[0052] In S36, the control device 70 reduces the number of steps Nc1 in the first time period Tc1 to the number of steps Nc2 calculated in S33. That is, the control device 70 reduces the number of input pulses input to the stepping motor in the first time period Tc1. This reduces the opening correction amount per unit time of the valve device 32. When the processing of S36 ends, the control device 70 ends the adjustment processing.

[0053] In S37, the control device 70 reduces the number of steps Nc1 in the first time Tc1 to a predetermined number. That is, the control device 70 reduces the number of input pulses input to the stepping motor during the first time Tc1. After reducing the number of steps in S37, the control device 70 then reduces the opening correction amount per unit time of the valve device 22 by lengthening the period between one step operation and the next step operation in S38. Specifically, the control device 70 changes the period between two subsequent step operations of the valve device 32 from the first time Tc1 to a second time Tc2 that is longer than the first time Tc1. The second time Tc2 is shorter than the unit time. The second time Tc2 of the valve device 32 is calculated using the formula: Tc2 = predetermined number * Tc1 / ((Vh / Vc) * Nc1). When the process of S38 is completed, the control device 70 terminates the adjustment process. According to the processing from S37 to S38, even if the calculated number of steps Nc2 of the valve device 22 is less than a predetermined number and the number of steps cannot be reduced to the calculated number of steps, the opening correction amount per unit time of the valve device 22 can be sufficiently reduced by extending the period of the step operation.

[0054] In S39, the control device 70 calculates the reduced number of steps Nh2 when the number of steps Nh1 in the first time Th1 of the valve device 22 is reduced. Specifically, the reduced number of steps Nh2 is calculated by the formula Nh2=Nh1*(Vc / Vh). The number of steps Nh2 is an integer, and the decimal point of the calculated value is rounded down.

[0055] In S40, the control device 70 determines whether the number of steps Nh2 calculated in S39 is greater than a predetermined number. If the number of steps Nh2 calculated in S39 is greater than the predetermined number, the control device 70 decides to reduce the number of steps Nh1 to the number of steps Nh2 calculated in S39 (YES in S40), and proceeds to the processing of S42. If the number of steps calculated in S39 is equal to or less than the predetermined number (NO in S40), the control device 70 proceeds to the processing of S43.

[0056] In S42, the control device 70 reduces the number of steps Nh1 during the first time Th1 to Nh2 calculated in S39. That is, the control device 70 reduces the number of input pulses input to the stepping motor during the first time Th1. This reduces the opening correction amount per unit time of the valve device 22. When the processing of S42 ends, the control device 70 ends the adjustment processing.

[0057] In S43, the control device 70 reduces the number of steps Nh1 in the first time Tc1 to a predetermined number. That is, the control device 70 reduces the number of input pulses input to the stepping motor during the first time Tc1. After reducing the number of steps in S43, the control device 70 further reduces the opening correction amount per unit time of the valve device 22 by lengthening the period between one step operation and the next in S44. Specifically, the control device 70 changes the period between two subsequent step operations of the valve device 32 from the first time Th1 to a second time Th2 that is longer than the first time Th1. The second time Th2 is shorter than the unit time. The second time Th2 of the valve device 32 is calculated using the formula: Th2 = predetermined number * Th1 / ((Vc / Vh) * Nh1). When the process of S44 is completed, the control device 70 terminates the adjustment process. According to the processing from S43 to S44, even if the calculated number of steps Nh2 of the valve device 32 is equal to or less than a predetermined number and the number of steps Nh1 cannot be reduced to the calculated number of steps Nh2, the opening correction amount per unit time of the valve device 32 can be sufficiently reduced.

[0058] This completes the pulsation prevention process. After the pulsation prevention process is completed, the control device 70 repeatedly executes the above-described mixing process and pulsation prevention process. While the pulsation prevention process is being executed, the control device 70 constantly monitors whether a predetermined stop condition is met. If the predetermined stop condition is met, the control device 70 stops the pulsation prevention process.

[0059] The predetermined stop condition includes the first pulsation generation condition not being satisfied. The control device 70 calculates the target hot water flow rate Qhd and the target water flow rate Qcd, and determines whether the first pulsation generation condition is not satisfied using the calculated target hot water flow rate Qhd and target water flow rate Qcd. Specifically, the control device 70 uses the calculated target hot water flow rate Qhd and target water flow rate Qcd to determine whether the ratio of the target hot water flow rate Qhd to the sum of the target hot water flow rate Qhd and the target water flow rate Qcd is greater than a second predetermined value. If the calculated ratio is greater than the second predetermined value, the control device 70 stops the pulsation prevention process.

[0060] The predetermined stop condition includes not satisfying the second pulsation generation condition. The control device 70 determines whether the second pulsation generation condition is satisfied. Specifically, the control device 70 determines whether the ratio of the hot water flow velocity Vh to the cold water flow velocity Vc is greater than a third predetermined value. If the ratio of the hot water flow velocity Vh is greater than the third predetermined value, the control device 70 stops the pulsation prevention process.

[0061] The predetermined stop conditions include at least one of the hot water flow rate Qh and the cold water flow rate Qc being 0. When at least one of the hot water flow rate Qh and the cold water flow rate Qc is 0, the control device 70 determines that the supply of hot water to path 24a and the supply of hot water to path 34a have been stopped, and terminates the pulsation prevention process. Situations in which the supply to either path 24a or 34a has been stopped include situations unintentionally caused by the user, such as a hot water outage caused by the hot water heater, and situations intentionally caused by user operation, etc. In these situations, pulsation does not occur, so the pulsation prevention process can be stopped.

[0062] The predetermined stop condition includes obtaining an instruction regarding the water flowing from the mixing device 10 through a user operation. If at least one of the set flow rate and set temperature of the water to be flowing from the mixing device 10 is changed through a user operation, the control device 70 stops the pulsation prevention process. This allows the subsequent mixing process to be executed with priority. The instruction regarding the water flowing from the mixing device 10 through a user operation also includes a water supply instruction to supply water from the mixing device 10 and a stop instruction to stop the water supply from the mixing device 10.

[0063] The predetermined stopping condition includes that the locked state of the mixing process is released. If it is determined that the locked state has been released, the control device 70 stops the pulsation prevention process. This allows the subsequent mixing process to be executed with priority.

[0064] (Effects of the embodiment) Pressure fluctuations in each path 24a, 34a cause pulsation. To identify the possibility of pulsation in advance, it is possible to monitor the pressure fluctuations in each path 24a, 34a. According to this embodiment, it is possible to determine whether a predetermined pulsation generation condition is met using the target hot water flow rate Qhd, the target cold water flow rate Qcd, the hot water flow rate Qh and cold water flow rate Qc, the opening area Ah based on the opening degree of the valve device 22 for path 24a, and the opening area Ac based on the opening degree of the valve device 32 for path 34a. In other words, it is possible to identify the possibility of pulsation without directly obtaining pressure fluctuations in each path 24a, 34a. This eliminates the need to install a pressure detection unit in the paths 24a, 34a. The target flow rates Qhd, Qcd, flow rates Qh, Qc, and opening areas Ah, Ac used to determine whether the pulsation generation condition is met are all indicators for mixing hot and cold water. Therefore, it is not necessary to install a new detection unit in the mixer unit 80 to determine whether the pulsation generation condition is met.

[0065] In this embodiment, the predetermined pulsation occurrence condition is defined using both an index related to the water flow in the path 24a and an index related to the water flow in the path 34a. Pulsation may occur particularly when there is a difference between the pressure in the path 24a and the pressure in the path 34a. In such a pulsation occurrence situation, the flow velocity in one of the path 24a and the path 34a may be slower than the flow velocity in the other of the path 24a and the path 34a. Therefore, by comparing the indexes related to the water flow in the paths 24a and 34a, it is possible to identify the possibility of pulsation occurrence.

[0066] According to this embodiment, it is possible to identify in advance whether pulsation may occur. Therefore, if it is determined that the mixing device 10 satisfies the pulsation occurrence condition, the occurrence of pulsation can be avoided by performing an adjustment process. In the adjustment process, the means for reducing the opening correction amount per unit time of the valve devices 22, 32 prioritizes adjusting the number of steps of the stepping motor over adjusting the period between two successive step operations of the valve devices 22, 32. Therefore, the opening correction amount per unit time of the valve devices 22, 32 can be stably reduced regardless of the timing of the step operation of the stepping motor.

[0067] (Correspondence) Path 24a is an example of a "first path." Path 34a is an example of a "second path." Hot water flow rate Qh is an example of a "first actual flow rate." Cold water flow rate Qc is an example of a "second actual flow rate." Hot water target flow rate Qhd is an example of a "first target flow rate." Cold water target flow rate Qcd is an example of a "second target flow rate." Valve device 22 is an example of a "first valve." The opening degree of valve device 22 is an example of a "first opening degree." Valve device 32 is an example of a "second valve." The opening degree of valve device 32 is an example of a "second opening degree." The mixed temperature is an example of an "actual temperature." Faucet fitting 4 is an example of a "water discharge section." The first time and the second time are examples of a "specific period." The unit time is an example of a "predetermined period."

[0068] Aspects of the technology disclosed in this specification are listed below.

[0069] In a first aspect, there is provided a control device for controlling a mixing device, the mixing device having a mixing chamber into which first water flows in from a first path in which a first valve is disposed and into which second water flows in from a second path in which a second valve is disposed, and the control device may execute an adjustment process to reduce either a first correction amount of a first opening degree of the first valve during a predetermined period or a second correction amount of a second opening degree of the second valve during the predetermined period.

[0070] In a second aspect, in the first aspect, the adjustment process may reduce either the first correction amount or the second correction amount using a first index related to the first water flow in the first path and a second index related to the second water flow in the second path.

[0071] In a third aspect, in the second aspect, the first indicator may use at least one of a first actual flow rate of the first water flowing through the first path and the first opening, and the second indicator may use at least one of a second actual flow rate of the second water flowing through the second path and the second opening.

[0072] In a fourth aspect, in any one of the first to third aspects, the adjustment process may reduce either the first correction amount or the second correction amount using a first actual flow rate of the first water flowing through the first path, the first opening, and a second actual flow rate of the second water flowing through the second path, and the second opening.

[0073] In a fifth aspect, in the fourth aspect, in the adjustment process, either the first correction amount or the second correction amount may be reduced depending on the ratio of the other of the first flow velocity and the second flow velocity to either a first flow velocity calculated from the first actual flow rate and a first opening area of ​​the first path based on the first opening degree, or a second flow velocity calculated from the second actual flow rate and a second opening area of ​​the second path based on the second opening degree.

[0074] In a sixth aspect, in any one of the first to third aspects, the adjustment process may reduce either the first correction amount or the second correction amount using a first target flow rate of the first water to flow through the first path and a second target flow rate of the second water to flow through the second path.

[0075] In a seventh aspect, in the sixth aspect, the adjustment process may reduce either the first correction amount or the second correction amount depending on the ratio of one of the first target flow rate and the second target flow rate to the sum of the first target flow rate and the second target flow rate.

[0076] In an eighth aspect, in any one of the first to third aspects, the adjustment process may reduce either the first correction amount or the second correction amount using a first actual flow rate of the first water flowing through the first path and a second actual flow rate of the second water flowing through the second path.

[0077] In a ninth aspect, in the eighth aspect, the adjustment process may reduce either the first correction amount or the second correction amount depending on a ratio of one of the first actual flow rate and the second actual flow rate to the sum of the first actual flow rate and the second actual flow rate.

[0078] In a tenth aspect of the present invention, in any one of the first to ninth aspects, the adjustment process may further include increasing the other of the first correction amount and the second correction amount.

[0079] In an eleventh aspect, in any one of the first to tenth aspects, the control device controls the rotation amount of the stepping motor by controlling the number of input pulses input to the stepping motor during a specific period included in the predetermined period, and the first opening is adjusted according to the rotation amount of the stepping motor, and in the adjustment process, the control device may reduce either the first correction amount or the second correction amount by at least one of reducing the number of input pulses during the specific period and lengthening the specific period.

[0080] In a twelfth aspect, in the eleventh aspect, the control device may, in the adjustment process, reduce the first correction amount by reducing the number of input pulses in the specific period when the number of input pulses in the specified period is greater than a predetermined number, and, when the number of input pulses in the specified period is equal to or less than a predetermined number, reduce the number of input pulses in the specific period to the predetermined number and reduce either the first correction amount or the second correction amount by lengthening the specific period.

[0081] In a thirteenth aspect, in any one of the first to twelfth aspects, the control device may stop the adjustment process if a combination of at least two of the first target flow rate of the first water to flow through the first path, the second target flow rate of the second water to flow through the second path, the first actual flow rate of the first water flowing through the first path, the second actual flow rate of the second water flowing through the second path, the first opening, and the second opening satisfies a predetermined condition.

[0082] In a 14th aspect, in any one of the 1st to 12th aspects, the control device may stop the adjustment process when at least one of a first actual flow rate of the first water flowing through the first path and a second actual flow rate of the second water flowing through the second path is 0.

[0083] In a fifteenth aspect, in any one of the first to twelfth aspects, the control device may stop the adjustment process when a user instruction regarding water flowing from the mixing chamber is obtained.

[0084] In a 16th aspect, in any one of the first to 12th aspects, the control device may stop the adjustment process when the difference between the set temperature of the water to flow from the mixing chamber and the actual temperature of the water flowing from the mixing chamber is greater than or equal to a predetermined value.

[0085] In a seventeenth aspect, in any one of the first to sixteenth aspects, the temperature of the first water may be different from the temperature of the second water.

[0086] In an 18th aspect, a mixing device unit may include a control device according to any one of the first to seventeenth aspects, and a mixing device controlled by the control device, the mixing device including a first path in which a first valve is disposed, a second path in which a second valve is disposed, and a mixing chamber into which first water flows from the first path and second water flows from the second path.

[0087] In a 19th aspect, a plumbing device may include a control device in any one of the 1st to 17th aspects, a mixing device controlled by the control device, the mixing device having a first path in which a first valve is arranged, a second path in which a second valve is arranged, and a mixing chamber into which first water flows in from the first path and second water flows in from the second path, and a water discharge section that discharges water flowing from the mixing device.

[0088] In a twentieth aspect, there is provided a computer program for a control device that controls a mixing device, the mixing device having a mixing chamber into which first water flows in through a first path in which a first valve is disposed and into which second water flows in through a second path in which a second valve is disposed, and the computer program may cause the control device to function to reduce either a first correction amount of a first opening degree of the first valve in a predetermined period of time or a second correction amount of a second opening degree of the second valve in the predetermined period of time.

[0089] In a 21st aspect, there is provided a method executed by a control device that controls a mixing device, the mixing device having a mixing chamber into which first water flows in from a first path in which a first valve is disposed and second water flows in from a second path in which a second valve is disposed, and the method may include reducing either a first correction amount of a first opening degree of the first valve in a predetermined period of time or a second correction amount of a second opening degree of the second valve in the predetermined period of time.

[0090] Specific examples of the technology disclosed in this specification have been described in detail above. These are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and variations of the specific examples exemplified above. Modifications of the above embodiments are listed below.

[0091] (1) In the above embodiment, the temperatures of the water flowing through path 24a and path 34a are different. However, a situation may occur in which water of the same temperature flows through path 24a and path 34a. For example, if water is not heated by water heating apparatus 100, water of the same temperature flows through path 24a and path 34a. If the temperature of the water to be supplied to faucet fitting 4 is the same as or lower than the temperature of the water supplied from the tap water pipe, water heating apparatus 100 does not need to heat the water.

[0092] (2) The specified pulsation generation conditions can be defined using at least two indicators among the target hot water flow rate Qhd, the target water flow rate Qcd, the hot water flow rate Qh, the water flow rate Qc, the opening degree of valve device 22, and the opening degree of valve device 32.

[0093] The predetermined pulsation generation condition may be a comparison between the hot water flow rate Qh and the water flow rate Qc, and the result of the comparison satisfies a predetermined condition. For example, the predetermined pulsation generation condition may be a ratio of the hot water flow rate Qh to the sum of the hot water flow rate Qh and the water flow rate Qc that is equal to or less than a sixth predetermined value. In another variation, the predetermined pulsation generation condition may be defined using a first index Uh calculated from the hot water flow rate Qh and the opening of the valve device 22, and a second index Uc calculated from the water flow rate Qc and the opening of the valve device 32. The predetermined pulsation generation condition may be a comparison between the first index Uh and the second index Uc that satisfies a predetermined condition. For example, the predetermined pulsation generation condition may be a ratio of the first index Uh to the second index Uc that is equal to or less than a seventh predetermined value. The first index Uh may be calculated by dividing the hot water flow rate Qh by the opening of the valve device 22. The second index Uc may be calculated by dividing the water flow rate Qc by the opening of the valve device 32. In another variation, the predetermined pulsation generation condition may be defined using the opening degree of valve device 22 and the opening degree of valve device 32. The predetermined pulsation generation condition may be a comparison between the opening degree of valve device 22 and the opening degree of valve device 32, and the result of the comparison satisfies a predetermined condition. For example, the predetermined pulsation generation condition may be a ratio of the opening degree of valve device 22 to the opening degree of valve device 32 being equal to or less than an eighth predetermined value. The predetermined pulsation generation condition may be defined by replacing the ratio of the water flow index of path 34a to the water flow index of path 24a described above with the ratio of the water flow index of path 34a to the water flow index of path 24a.

[0094] (3) In another variation, the predetermined pulsation generation condition may be determined using only one of the indicators related to the water flow in path 24a and the indicators related to the water flow in path 34a. For example, the predetermined pulsation generation condition may be that either the hot water flow velocity Vh or the water flow velocity Vc is equal to or less than a ninth predetermined value. When pulsation occurs, either the hot water flow velocity Vh in path 24a or the water flow velocity Vc in path 34a may become extremely slow. Therefore, it is possible to determine whether pulsation may occur depending on whether either the hot water flow velocity Vh or the water flow velocity Vc is equal to or less than the ninth predetermined value.

[0095] (4) Each of the predetermined values ​​described in this specification may be preset when the control device 70 is shipped, or may be set by the user through the operation device 6. Alternatively, each predetermined value may be set through other external input means capable of communicating with the control device 70, or may be set based on a numerical value calculated from the user's usage history stored in memory, etc.

[0096] (5) The predetermined pulsation generating condition may include one or more specific pulsation generating conditions.

[0097] (6) In S32, the control device 70 may determine which of the valve devices 22, 32 to reduce the per-unit opening correction amount by comparing the flow rates of hot and cold water other than the flow velocity. In a modified example, the control device 70 may determine which of the valve devices 22, 32 to reduce the per-unit opening correction amount by using the flow rates of hot and cold water, the openings of the valve devices 22, 32, or the indexes Uh, Uc obtained by dividing the flow rates of the paths 24a, 34a by the openings. The user may be free to set which of the flow velocity, flow rate, opening, or the index (Uh, Uc) to use in determining which of the valve devices 22, 32 to adjust. In another modified example, the user may be free to set which of the valve devices 22, 32 to reduce the per-unit opening correction amount.

[0098] (7) In steps S33 to S38, the control device 70 may use an index related to the water flow in the path 24a other than the hot water flow rate Vh and the water flow rate Vc, and an index related to the water flow in the path 34a, to reduce the amount of correction of the opening of the valve device 22 per unit time. The index related to the water flow may be determined using at least two of the target hot water flow rate Qhd, the target water flow rate Qcd, the hot water flow rate Qh, the water flow rate Qc, the opening of the valve device 22, and the opening of the valve device 32. The amount of correction of the opening of the valve device 22 per unit time may be reduced using the hot water flow rate Qh, the opening of the valve device 22, the water flow rate Qc, and the opening of the valve device 32. In this case, in a modified example, the control device 70 may reduce the opening of the valve device 22 using a first index Uh obtained by dividing the hot water flow rate Qh by the opening of the valve device 22 and a second index Uc obtained by dividing the water flow rate Qc by the opening of the valve device 32, instead of using the hot water and cold water flow rates Vh and Vc. For example, the amount of opening correction per unit time of the valve device 22 may be reduced according to the ratio between the first index Uh and the second index Uc. In a modified example, the amount of opening correction per unit time of the valve devices 22 and 32 may be reduced using the hot water flow rate Qh and the water flow rate Qc. For example, the amount of opening correction per unit time of the valve devices 22 and 32 may be reduced according to the ratio of the hot water flow rate Qh to the sum of the hot water flow rate Qh and the water flow rate Qc. The amount of opening correction per unit time of the valve device 22 may be reduced using the target hot water flow rate Qhd and the target water flow rate Qcd. For example, the amount of correction of the opening degree per unit time of the valve device 22 may be reduced in accordance with the ratio of the hot water flow rate Qh to the sum of the hot water flow rate Qh and the cold water flow rate Qc. In S39 to S48, the control device 70 may reduce the amount of correction of the opening degree per unit time of the valve device 32 using a combination of the index related to the water flow of path 24a and the index related to the water flow of path 34a, as in S33 to S38. The amount of correction of the opening degree per unit time of the valve device 32 may be reduced in accordance with the ratio of the index related to the water flow of path 24a to the index related to the water flow of path 34a.

[0099] (8) After decreasing the amount of opening correction per unit time of the cold water side valve device 32 through adjustment processes S36 and S38, the control device 70 may further increase the amount of opening correction per unit time of the hot water side valve device 22. For example, after processing S36, the control device 70 may increase the number of steps of the valve device 22 during the first time period Tc1. On the other hand, if the increased number of steps of the valve device 22 is equal to or greater than a second predetermined number, the control device 70 may increase the number of steps to the predetermined number and shorten the period between two successive step operations of the valve device 22. The control device 70 may execute a similar process to the above, for example, after processing S38. As with the processes S36 and S38, after decreasing the amount of opening correction per unit time of the hot water side valve device 22 through S42 and S44, the control device 70 may further increase the amount of opening correction per unit time of the cold water side valve device 32. According to this process, the overall flow rate of hot and cold water is reduced in processes S36 to 38 and S42 to 44, thereby preventing the time required for the water supplied from the mixing device 10 to reach the set flow rate and set temperature from increasing.

[0100] (9) The mixer controlled by the control device 70 is not limited to the mixer 10 exemplified in this embodiment. The control device 70 may control another mixer that mixes water flowing in from multiple paths.

[0101] The technical elements described in at least one of the specification and drawings exhibit technical utility alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. The technology exemplified in at least one of the specification and drawings can achieve multiple objectives simultaneously, and achieving one of those objectives itself has technical utility. [Explanation of symbols]

[0102] 2: plumbing equipment, 4: faucet fittings, 10: mixing device, 20: hot water system, 22, 32: valve device, 24, 34, 40: piping, 24a, 34a, 40a: path, 26, 36: detection unit, 40b: connection point, 40c: opening, 50: mixing unit, 52: partition structure, 54, 56: partition part, 54a, 56a: path, 54b, 56b: inner peripheral surface, 54c: guide part, 54d: inclined surface, 54e: outer peripheral surface, 54f: guide part, 56b: inner peripheral surface, 60: mixing chamber, 62: valve device, 70: control device, 80: mixing device unit

Claims

1. A control device for controlling a mixing device, the mixing device has a mixing chamber into which a first water flows in through a first passage in which a first valve is disposed and into which a second water flows in through a second passage in which a second valve is disposed; The control device a control device that executes an adjustment process to reduce either a first correction amount of a first opening degree of the first valve during a predetermined period or a second correction amount of a second opening degree of the second valve during the predetermined period.

2. 2. The control device according to claim 1, wherein the adjustment process reduces either the first correction amount or the second correction amount using a first index related to the first water flow in the first path and a second index related to the second water flow in the second path.

3. the first indicator uses at least one of a first actual flow rate of the first water flowing through the first path and the first opening degree, The control device according to claim 2 , wherein the second indicator uses at least one of a second actual flow rate of the second water flowing through the second path and the second opening.

4. 4. A control device according to claim 1, wherein the adjustment process reduces either the first correction amount or the second correction amount using a first actual flow rate of the first water flowing through the first path, the first opening, a second actual flow rate of the second water flowing through the second path, and the second opening.

5. 5. The control device according to claim 4, wherein the adjustment process reduces one of the first correction amount and the second correction amount in accordance with a ratio of the other of a first flow velocity calculated from a first opening area of ​​the first path based on the first actual flow rate and the first opening degree, and a second flow velocity calculated from a second opening area of ​​the second path based on the second actual flow rate and the second opening degree.

6. 4. A control device according to claim 1, wherein the adjustment process reduces either the first correction amount or the second correction amount using a first target flow rate of the first water to flow through the first path and a second target flow rate of the second water to flow through the second path.

7. 7. The control device according to claim 6, wherein the adjustment process reduces one of the first correction amount and the second correction amount in accordance with a ratio of one of the first target flow rate and the second target flow rate to a sum of the first target flow rate and the second target flow rate.

8. 4. A control device according to claim 1, wherein the adjustment process reduces either the first correction amount or the second correction amount using a first actual flow rate of the first water flowing through the first path and a second actual flow rate of the second water flowing through the second path.

9. 9. The control device according to claim 8, wherein the adjustment process reduces one of the first correction amount and the second correction amount in accordance with a ratio of one of the first actual flow rate and the second actual flow rate to a sum of the first actual flow rate and the second actual flow rate.

10. The adjustment process further includes: The control device according to claim 1 , wherein the other of the first correction amount and the second correction amount is increased.

11. the control device controls the number of input pulses input to the stepping motor during a specific period included in the predetermined period, thereby controlling the rotation amount of the stepping motor; the first opening degree is adjusted in accordance with the rotation amount of the stepping motor, 4. The control device according to claim 1, wherein, in the adjustment process, the control device reduces either the first correction amount or the second correction amount by at least one of reducing the number of the input pulses in the specific period and lengthening the specific period.

12. In the adjustment process, the control device When the number of the input pulses in the predetermined period is greater than a predetermined number, the number of the input pulses in the specific period is decreased to decrease the first correction amount; 12. The control device according to claim 11, wherein, when the number of the input pulses in the predetermined period is equal to or less than the predetermined number, the number of the input pulses in the specific period is reduced to the predetermined number, and the specific period is lengthened to reduce one of the first correction amount and the second correction amount.

13. The control device A control device as described in any one of claims 1 to 3, wherein the adjustment process is stopped when a combination of at least two of the first target flow rate of the first water to flow through the first path, the second target flow rate of the second water to flow through the second path, the first actual flow rate of the first water flowing through the first path, the second actual flow rate of the second water flowing through the second path, the first opening, and the second opening satisfies a predetermined condition.

14. A control device as described in any one of claims 1 to 3, wherein the control device stops the adjustment process when at least one of a first actual flow rate of the first water flowing through the first path and a second actual flow rate of the second water flowing through the second path is 0.

15. The control device according to claim 1 , wherein the control device stops the adjustment process when a user's instruction regarding the water flowing from the mixing chamber is obtained.

16. The control device according to any one of claims 1 to 3, wherein the control device stops the adjustment process when a difference between a set temperature of the water to be flowed from the mixing chamber and an actual temperature of the water flowing from the mixing chamber is equal to or greater than a predetermined value.

17. The control device according to claim 1 , wherein the temperature of the first water is different from the temperature of the second water.

18. The control device according to any one of claims 1 to 3; A mixing device controlled by the control device, a first path in which a first valve is disposed; a second path in which a second valve is disposed; a mixing chamber into which the first water flows from the first passage and the second water flows from the second passage;

19. The control device according to any one of claims 1 to 3; A mixing device controlled by the control device, a first path in which a first valve is disposed; a second path in which a second valve is disposed; the mixing device including a mixing chamber into which the first water flows in through the first passage and the second water flows in through the second passage; A plumbing device comprising: a water discharge section that discharges water flowing from the mixing device.

20. A computer program for a control device that controls a mixing device, the mixing device has a mixing chamber into which a first water flows in through a first passage in which a first valve is disposed and into which a second water flows in through a second passage in which a second valve is disposed; The computer program causes the control device to: a first correction amount of a first opening degree of the first valve during a predetermined period of time, and a second correction amount of a second opening degree of the second valve during the predetermined period of time;

21. 1. A method performed by a controller controlling a mixing device, comprising: the mixing device has a mixing chamber into which a first water flows in through a first passage in which a first valve is disposed and into which a second water flows in through a second passage in which a second valve is disposed; The method comprises: A method for reducing either a first amount of correction of a first opening degree of the first valve during a predetermined period of time or a second amount of correction of a second opening degree of the second valve during the predetermined period of time.

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