Pure water supply machine

Abstract

A pure water supply device (40), which is connected to a pure water production device (10) and supplies pure water in accordance with a request of a user, is provided with: a proportional control valve (48) provided in a pure water flow path leading to a discharge section such as a pipe (62) for discharging pure water; a pedal controller (52) which is operated by a foot of a user and generates a signal indicating an operation amount; and a control unit (51) that receives a signal from the pedal controller (52) and controls the proportional control valve (48) so that the opening degree of the proportional control valve becomes an opening degree corresponding to the operation amount.

Description

Technical Field

[0001] The present invention relates to a pure water supply machine which discharges pure water from a nozzle or a front end of a tube according to a user's request. Background Art

[0002] In laboratories and analysis rooms, when pure water is collected from beakers, test tubes, etc., or when pure water is used for cleaning, a pure water supply machine is used. The pure water supply machine is connected to a pure water manufacturing device and receives pure water supply from the pure water manufacturing device, and discharges pure water from the front end of the discharge part as needed. A pure water supply machine is also called a water collection distributor, a pure water distributor, etc. In the discharge part, for example, a nozzle, a tube, a hose, etc. are used. In the pure water supply machine, a valve is provided on the path of the pure water reaching the discharge part, and by controlling the valve, the discharge of pure water from the discharge part and its stop can be switched. If a proportional control valve or the like is used as a valve, the flow rate of pure water during discharge can also be adjusted by the opening of the valve. When cleaning the instrument, the side with a large flow rate of pure water can be easily cleaned. On the other hand, when the operation of injecting pure water to the mark in a volumetric flask or the like is performed, in order to enable the side with a small flow rate to perform accurate operation, it is an important element in the pure water manufacturing machine to be able to adjust the flow rate of pure water during discharge.

[0003] Patent document 1 discloses a water sampling dispenser, wherein a user uses a water sampling gun that can be held by his hand, and the water sampling gun has a nozzle for discharging pure water. In the water sampling dispenser, the water sampling gun is provided with a button switch and a rotary encoder connected to a wheel, and the opening and closing of the valve can be controlled by the button switch, and the opening degree of the valve during discharge can be adjusted according to the rotation direction and rotation amount of the wheel. Patent document 1 also discloses that the discharge of pure water and its stop can be controlled by a foot switch.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2020-81943 Summary of the invention

[0007] Problems to be solved by the invention

[0008] In the water sampling distributor (i.e., pure water supply machine) described in patent document 1, the flow rate of pure water discharged from the nozzle is adjusted by the user rotating the wheel provided in the water sampling gun with his fingers. According to the pure water supply machine, the discharge flow rate of pure water can also be adjusted by operating the touch panel. However, these flow adjustments are manual operations performed by the user's hands and fingers. When pure water is used in trace analysis, the hands, fingers or gloves are contaminated due to the manual operation, which may become the main cause of contamination in the analysis. When the flow rate is adjusted frequently, the possibility of becoming a contamination factor increases. The same is true for the discharge of pure water from the nozzle and its stop by a button switch operated by a finger.

[0009] An object of the present invention is to provide a pure water supply machine capable of adjusting the discharge flow rate of pure water without relying on the operation of hands or fingers.

[0010] Technical solutions to solve problems

[0011] The present invention provides a pure water supply machine, which is connected to a pure water production device and supplies pure water according to the user's requirements. The pure water supply machine comprises: a valve, which is arranged in a pure water flow path to a discharge part, and the discharge part discharges pure water; a foot controller, which is operated by the user's foot to generate a signal representing the operation amount; and a control part, which receives the signal from the foot controller and controls the valve so that the opening of the valve becomes an opening corresponding to the operation amount.

[0012] In the pure water supply machine based on the present invention, when the user operates the foot controller with his foot, for example, by the amount of operation when stepping on the pedal of the foot controller with his foot, the flow rate of pure water discharged from the discharge portion can be adjusted. Therefore, pure water is not discharged from the discharge portion when the foot controller is not operated, and pure water is discharged at the maximum flow rate when the foot controller is operated to the maximum. However, in order to continue to discharge pure water at a constant flow rate, the foot controller must be continuously operated in a manner to maintain a constant amount of operation, for example, the pedal must be continuously stepped on at a constant amount of stepping, which may not be convenient for the user. Therefore, in the pure water supply machine based on the present invention, when the user operates the foot controller at a given timing, control of maintaining the opening of the valve can also be implemented. If such control is implemented, the user can also release the foot from the foot controller after executing the given timing to make the flow rate of pure water a desired flow rate, that is, the execution of the operation can also be released, and even if the foot is released from the foot controller, pure water is continuously discharged at a flow rate set according to the previous timing. In order to stop the discharge of pure water in this state, the user only needs to perform an operation such as stepping on the foot controller again.

[0013] Effects of the Invention

[0014] According to the present invention, the discharge flow rate of pure water can be adjusted in the pure water supply machine without relying on the operation of hands or fingers. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a diagram showing a pure water supply system according to one embodiment of the present invention.

[0016] Figure 2 This is a flowchart for explaining the processing in the pure water supply machine.

[0017] Figure 3 This is a timing chart showing an operation example of the pure water supply machine. DETAILED DESCRIPTION

[0018] Next, embodiments of the present invention will be described with reference to the drawings. Figure 1 A pure water supply system according to an embodiment of the present invention is shown. The pure water supply system includes a pure water manufacturing device 10 and a pure water supply machine 40 connected to the pure water manufacturing device 10 and receiving a supply of pure water from the pure water manufacturing device 10. The pure water supply machine 40 is a pure water supply machine based on the present invention. Hereinafter, the pure water supply machine based on the present invention will be described by taking a ventilation chamber 60 provided in a laboratory or an analysis room configured as a clean room as a use point and citing an example in which pure water is supplied from the pure water supply machine 40 to the ventilation chamber 60 according to the user's requirements. A ventilation chamber is also called a fume hood. Of course, in addition to the use of supplying pure water into a ventilation chamber, the present invention can also be applied to various uses of water collection that require pure water.

[0019] Before describing the pure water supply machine 40 , first, the pure water production apparatus 10 will be described. Figure 1The pure water production device 10 shown is configured as a subsystem (secondary pure water system) for producing pure water by circulating and further purifying the produced pure water in the system, and comprises: a storage tank 11 to which primary pure water is supplied; a pump 12 connected to the outlet of the storage tank 11 to feed the pure water in the storage tank 11; a flow sensor (FI) 13 connected to the outlet of the pump 12; an ultraviolet oxidizing device (UV) 14; a non-regenerative ion exchange device (CP: also called a filter element) 15 filled with a strongly acidic cation exchange resin and a strongly basic anion exchange resin in a mixed bed; and an ultrafiltration device (UF) 16. The ultraviolet oxidizing device 14, the non-regenerative ion exchange device 15, and the ultrafiltration device 16 are connected in series with respect to the outlet of the flow sensor 13 in this order. The ultraviolet oxidizing device 14 is used to decompose the total organic carbon (TOC) component in the pure water. The outlet of the ultrafiltration device 16 is connected to a pipe 17, and a pipe 21 is branched from the pipe 17. The pipe 21 is connected to a TOC meter 22 for measuring the TOC concentration of the outlet water of the ultrafiltration device 16. A constant flow valve 23 for making the inflow to the TOC meter 22 constant is connected to the secondary side of the TOC meter 22, and the outlet of the constant flow valve 23 merges with the pipe 20 returning to the storage tank 11.

[0020] The pure water manufacturing device 10 generates pure water by circulating and refining, but in this embodiment, pure water is also circulated including the pure water supply machine 40. Therefore, the outlet of the ultrafiltration device 16 is connected to the circulation outlet 18 of the pure water manufacturing device 10 via the pipe 17. In addition, the pure water manufacturing device 10 is provided with a circulation inlet 19 for receiving the pure water returned from the pure water supply machine 40, and the circulation inlet 19 is connected to the storage tank 11 via the pipe 20. As the primary pure water, for example, water obtained by passing municipal water through a filter, an activated carbon treatment device, and an ion exchange device is used.

[0021] In the pure water production device 10, a circulation purification system is formed in which pure water passes from the storage tank 11 through the pump 12, through the flow sensor 13, the ultraviolet oxidation device 14, the non-regeneration type ion exchange device 15, the ultrafiltration device 16, and the pure water supply machine 40, and returns to the storage tank 11. By operating the pump 12 to circulate the pure water in the circulation purification system, the pure water is further purified.

[0022] The pure water supply machine 40 is connected to the pure water production device 10 through pipes 31 and 32. The pipe 31 connects the circulation outlet 18 of the pure water production device 10 and the circulation inlet 41 of the pure water supply machine 40, and the pipe 32 connects the circulation inlet 19 of the pure water production device 10 and the circulation outlet 42 of the pure water supply machine 40. In the pure water supply machine 40, in order to remove particulates just before reaching the point of use of pure water, a microfiltration device (MF) 45 having a microfiltration membrane with a pore size of, for example, about 20nm to 50nm is provided as a filter cartridge. The microfiltration device 45 also constitutes a part of the above-mentioned circulation purification system, and pure water is supplied to the microfiltration device 45 from the circulation inlet 41 via the pipe 43, and the pure water passing through the microfiltration device 45 is returned to the pure water production device 10 from the pipe 44 via the circulation outlet 42. The microfiltration membrane in the microfiltration membrane device 45 is based on, for example, polyethylene modified with a sulfonic acid group, and has an ion adsorption function. The microfiltration membrane has an ion adsorption function, and can remove extremely small amounts of particles and metal ions generated from the pipes and joints between the pure water production device 10 and the pure water supplier 40, and can provide higher quality pure water to users at the point of use.

[0023] In order to supply the pure water that has passed through the microfiltration membrane device 45 to the point of use, a pipe 46 is branched from the pipe 44, and the pipe 46 is connected to the pure water outlet 47 of the pure water supply machine 40. In addition, in order to control the supply of pure water to the point of use, a proportional control valve 48 as an electromagnetic valve is provided in the pipe 46. Figure 1 In the structure shown, the ventilation chamber 60, which is the point of use, is provided with a glass window 61 that can be opened and closed in front of it. The pure water supply machine 40 is arranged close to the ventilation chamber 60, and a pipe 62 connected to the pure water outlet 47 of the pure water supply machine 40 is introduced into the ventilation chamber 60. In the ventilation chamber 60, pure water is discharged from the front end of the pipe 62. The pipe 62 used near the point of use is preferably made of a material with little dissolution of particles and metal ions, for example, PFA (tetrafluoroethylene-perfluoroalkoxy vinyl ether copolymer) is preferably used. In the case of directly discharging pure water from the pure water supply machine 40, for example, a nozzle is installed at the pure water outlet 47, and pure water is discharged from the nozzle.

[0024] In order to control the flow rate of pure water discharged from the front end of the tube 62, a control unit 51 for controlling the opening of the proportional control valve 48 is provided in the pure water supply machine 40, and a foot controller 52 operated by the user's foot is connected to the control unit 51. The foot controller 52 generates a signal indicating the operation amount based on the operation amount of the user's foot, and sends the signal to the control unit 51. In the device shown in the figure, the foot controller 52 has a pedal 53 that is urged upward by a spring (not shown) or the like, and is configured to send an analog signal of an amplitude corresponding to the amount of the pedal 53 when the user steps on the pedal 53 to the control unit 51. The analog signal from the foot controller 52 to the control unit 51 is, for example, a current loop signal of 4 mA to 20 mA or a voltage signal of 1 V to 5 V. Alternatively, a microprocessor may be provided in the foot controller 52 to generate a digital signal indicating the amount of the pedal 53 and send the digital signal to the control unit 51. As described below, in the pure water supply machine 40, there are several modes for controlling the discharge flow rate of pure water, and therefore, in the pure water supply machine 40, a touch panel 54 is further provided as an operation panel for presenting required information to the user and receiving input of mode selection from the user. The touch panel 54 is connected to the control unit 51. In addition, in the pure water supply machine 40, a buzzer 55 connected to the control unit 51 is further provided in order to notify the user by sound. Instead of the buzzer 55, a lamp or the like for notification by light may be provided.

[0025] Next, the control of the flow rate of pure water by the control unit 51 is described. Here, the foot controller 52 generates a signal corresponding to the amount of pedal 53 stepped on, and the amount of pedal is represented by a range of 0% to 100%. 0% of the amount of pedal represents a state in which the user's foot is off the pedal 53 and the foot controller 52 is not operated. On the other hand, 100% of the amount of pedal represents a state in which the pedal 53 is stepped on to the maximum extent. The control unit 51 is composed of, for example, a microprocessor, etc., receives a signal from the foot controller 52, and controls the proportional control valve 48 so that the opening of the proportional control valve becomes an opening corresponding to the amount of pedaling. For example, the control unit 51 can control the proportional control valve 48 in such a way that the opening of the proportional control valve 48 becomes the same as the amount of pedaling represented by 0% to 100%, so that if the amount of pedaling is 0%, the opening is also 0%, that is, the valve is closed, if the amount of pedaling is 50%, the opening is also 50%, and if the amount of pedaling is 100%, the opening is also 100%, that is, the maximum opening. The control mode in which the opening degree is controlled to be proportional to the pedaling amount is referred to as a simple control mode.

[0026] According to the simple control mode, the user can change the flow rate of pure water discharged from the front end of the tube 62 in the ventilation chamber 60 by changing the degree of stepping on the pedal 53 of the foot controller 52 without operating with hands or fingers, thereby forming a desired discharge flow rate.

[0027] However, in the case of performing operations using pure water, depending on the content of the operation, it is sometimes desired to keep the flow rate of pure water constant for more than ten seconds to several minutes. In such a case, in the simple control mode, the user must keep the degree of stepping on the pedal 53 of the foot controller 52 constant for a long time, which increases the burden on the user. Therefore, the pure water supply machine 40 of the present embodiment has an opening fixed mode as a control mode. The opening fixed mode is a control mode that maintains the opening of the proportional control valve 48 based on a given sequence in the user's operation of the foot controller 52. The given sequence mentioned here is, for example, a given sequence in the stepping on the pedal 53. In the opening fixed mode, once the opening of the proportional control valve 48 is set, even if the user releases his foot from the foot controller 52, that is, the stepping amount is 0%, the set opening is maintained, so the discharge of pure water continues. When stopping the discharge of pure water, the user can step on the pedal 53 of the foot controller 52 again. When the user wants to switch between the simple control mode and the opening fixed mode, a given input is made in the touch panel 54. The touch panel 54 is operated by hands or fingers, but the switching of the control mode is low frequency, and even if the touch panel 54 is operated by hands or fingers accompanying the switching of the control mode, there is no problem of contamination.

[0028] The opening fixing mode is a control mode that combines the maximum opening fixing function and the adjustment opening fixing function to perform control. The maximum opening fixing function is a function that sets the opening of the proportional control valve 48 to the maximum opening when the stepping amount becomes greater than the operation determination threshold A within a given operation determination time B from the start of the operation of the foot controller 52, i.e., the start of stepping, as a given timing, and then maintains the opening after such a timing exists. The maximum opening fixing function is a function that sets the discharge flow rate of pure water to the maximum flow rate when the user suddenly steps on the pedal 53 of the foot controller 52 to the maximum, so the operation determination time B is preferably set to less than 1 second, for example, to 0.5 seconds. In addition. The operation determination threshold A is a threshold for determining whether it is stepped on to the maximum, so it is expressed by the stepping amount and set to 95%, for example.

[0029] In addition, in the foot controller 52, in addition to the mechanism for outputting the stepping amount as an analog signal, a switch that is disconnected when the stepping amount is above a given value and not turned on can also be provided, and a signal from the switch can be sent to the control unit 51. Such a switch is also called a foot switch when used alone. In the case of providing such a switch, it is also possible to determine whether the switch is stepped on to the maximum extent based on the given value that becomes the threshold of the switch being turned on / off as the operation determination threshold A, and when the switch becomes turned on within the operation determination time B from the start of stepping on the foot controller 53, control is performed to maintain the opening of the proportional control valve 48 at the maximum opening.

[0030] The function of adjusting the opening degree is as follows: the change amount of the stepping amount across the entire given change judgment time D is within a given change judgment threshold C as a given timing. When such a timing exists, the opening of the proportional control valve 48 is set to an opening corresponding to the stepping amount during the change judgment time D, and the opening is maintained. The set opening can correspond to the stepping amount at the beginning of the corresponding change judgment time D, or to the stepping amount at the end of the change judgment time D. The function of adjusting the opening degree is a function of allowing pure water to continue to flow at the flow rate at this time when the user keeps the flow rate of pure water approximately constant within a constant time, that is, the change judgment time D. In order to avoid a collision with the aforementioned maximum opening degree fixing function, the change judgment time D is set to be longer than the operation judgment time B. When the change amount of the stepping amount exceeds the change judgment threshold C during the change judgment time D, the timing of the change judgment time D is stopped at this time point and the timing is restarted. The change judgment threshold C is set to 5%, for example. If the change determination threshold C is too large, even if the user intentionally changes the pure water flow rate, the opening degree may be fixed against the user's intention, thereby fixing the flow rate. If the change determination threshold C is too small, it is difficult to fix the flow rate by adjusting the opening degree fixing function, increasing the burden on the user.

[0031] It is preferable that after the opening of the proportional control valve 48 is fixed in both the maximum opening fixing function and the adjustable opening fixing function, the user is notified of this by light or sound. Compared with the maximum opening fixing function in which the opening of the proportional control valve 48 is set to the maximum opening by suddenly stepping on the pedal 53 of the foot controller 52 to the maximum, in the adjustable opening fixing function, the user cannot easily determine whether the opening is fixed when the pedal 53 is stepped on, so it is particularly preferable to notify the user that the opening is fixed in the adjustable opening fixing function.

[0032] Figure 2An example of the processing performed by the control unit 51 in the fixed opening mode is shown. Since the amount of the user's stepping on the foot controller 52 can change according to time, it is considered as a function of time t, and the stepping amount is represented by F(t). In the initial state, the proportional control valve 48 is closed, the flow rate of pure water is 0, and the foot controller 52 is in an unoperated state, specifically, in a state where the stepping amount is 0%. First, in step 101, the control unit 51 detects whether the user has stepped on the pedal 53 of the foot controller 52, that is, whether F(t)>0. The control unit 51 waits until there is a step of pedaling, and after detecting the step of pedaling, in step 102, similarly to the case of the simple control mode, starts to control the opening of the proportional control valve 48 to follow the pedaling amount F(t), then in step 103, the control unit 51 starts the timer T1 for measuring the operation determination time B and the timer T2 for measuring the change determination time D from 0, and in step 104, stores the current pedaling amount F(t) as a variable F0. Hereinafter, the timed values ​​based on the timers T1 and T2 are also represented by T1 and T2, respectively.

[0033] Next, the control unit 51 determines in step 105 whether the current stepping amount F(t) is greater than or equal to the operation determination threshold value A, that is, whether F(t)≥A. In the case of F(t)≥A, the control unit 51 determines in step 106 whether the value of the timer T1 is within B, that is, whether T1≤B. Here, when T1≤B, it is a case that the stepping amount is greater than or equal to the operation determination threshold value A within the operation determination time B from the start of stepping, so based on the maximum opening fixing function, the control unit 51 starts the control of maintaining the opening of the proportional control valve 48 at the maximum opening in step 107. When T1≤B is not satisfied in step 106, the operation determination time B has passed, so in order to perform processing based on the adjustment opening fixing function, the processing of the control unit 51 enters step 121.

[0034] If F(t) ≥ A is not true in step 105, the control unit 51 determines in step 111 whether the change in the pedaling amount is within the change determination threshold C, that is, whether |F(t)-F0|≤C is established, in order to perform processing based on the adjustment opening fixing function. If the change is within the change determination threshold C, that is, |F(t)-F0|≤C, the control unit 51 proceeds to step 114. If the change exceeds the change determination threshold C in step 111, the control unit 51 restarts the timer T2 in step 112 to restart the timing of the change determination time D from this time point and repeat the processing, and substitutes the current pedaling amount F(t) into the variable F0 in step 113, and proceeds to step 114. In step 114, the control unit 51 determines whether T1>B in order to determine whether the operation determination time B, that is, the time for performing control based on the maximum opening fixing function, has passed. Here, if T1>B is not satisfied, the control unit 51 repeats the process from step 105 in order to repeat the process based on the fixed opening fixing function. If T1>B is satisfied in step 114 and the operation determination time B has elapsed, the control unit 51 proceeds to step 121 in order to continue the process based on the adjustable opening fixing function. If the pedaling amount continues to change, the process from step 121 to step 123 is repeated, so that the opening of the proportional control valve 48 is not fixed.

[0035] Similar to step 111, in step 121, the control unit 51 determines whether the change amount of the pedaling amount is within the change determination threshold value C, that is, whether |F(t)-F0|≤C. When |F(t)-F0|≤C, in step 124, the control unit 51 determines whether T2>D in order to determine whether the change determination time D has passed. When T2>D, the change determination time D has passed. Therefore, based on the adjustment opening fixing function, the pedaling amount F(t) at this time is substituted into the variable F1 in step 125, and in step 126, the control of maintaining the opening of the proportional control valve 48 at the opening corresponding to F1 is started. If T2>D is not in step 124, the control unit 51 repeats the processing from step 121 to wait for the change determination time D to pass. When the change in the pedaling amount exceeds the change judgment threshold C in step 121, the control unit 51 restarts the timer T2 in step 122 in the same manner as in steps 112 to 113, substitutes the current pedaling amount F(t) into the variable F0 in step 123, and then repeats the processing from step 121.

[0036] In either case where the control of maintaining the opening of the proportional control valve 48 is started by the maximum opening fixing function in step 107 or the control of maintaining the opening of the proportional control valve 48 is started by the adjustable opening fixing function in step 126, the control unit 51 determines whether the stepping is released in step 131 and waits until the stepping is released in order to detect that the user has released his foot from the foot controller 52. When the stepping is detected to be released, the control unit 51 determines whether the user has stepped on the foot controller 52 again in step 132. The control unit 51 waits for processing until the user steps on the foot controller 52 again, and during this period, the opening of the proportional control valve 48 is kept at the opening set in step 107 or step 126, so that pure water continues to flow at the set flow rate. When the stepping is detected in step 132, the control unit 51 closes the proportional control valve 48, thereby ending a series of pure water discharge flow rate controls in the opening fixing mode including the maximum opening fixing function and the adjustable opening fixing function. If the user releases his foot from the foot controller 52 in this state, the state becomes the same as the initial state in the series of processes described here, so if the user operates the foot controller 52 again thereafter, the above-described processes are repeated.

[0037] In the opening fixed mode, four parameters are used, namely, the operation determination threshold value A, the operation determination time B, the change determination threshold value C, and the change determination time D. It is preferred that the user can set these four parameters, especially the change determination threshold value C and the change determination time D, using the touch panel 54. In addition, in the actual foot controller 52, in order to prevent the pedal 53 from being stepped on excessively, a stopper or the like that limits the movable range of the pedal 53 is sometimes provided. Sometimes, due to the stopper, even if the pedal 53 is stepped on to the maximum with the foot, the stepping amount does not reach 100%. Therefore, when the stepping amount is equal to or greater than the operation determination threshold value A, it is preferred to set the stepping amount to 100% to enter the process.

[0038] Below, use Figure 3 An example of controlling the opening degree of the proportional control valve 48 based on the opening degree fixing mode having the maximum opening degree fixing function and the adjustable opening degree fixing function will be described. Figure 3Indicates the time variation of the stepping amount in the foot controller 52 and the opening of the proportional control valve 46 when the operation determination threshold value A is 95% and the change determination threshold value C is ±5%. Here, if the stepping amount is above the operation determination threshold value A, it is considered that the stepping amount is 100%. In the figure, among the numbers representing the stepping amount, there are numbers surrounded by a dotted line quadrilateral, a solid line quadrilateral, and a hexagon. The numbers surrounded by the dotted line quadrilateral indicate the start or restart of the timing that becomes the change determination time D at this timing. The numbers surrounded by the solid line quadrilateral indicate that the opening of the proportional control valve 46 is fixed by the maximum opening fixing function or the adjustment opening fixing function at this timing. In the example shown here, the buzzer sounds at this timing. The numbers surrounded by the hexagon indicate that after the opening is fixed and the foot leaves the foot controller 52, the foot controller 52 is stepped on again at this timing.

[0039] exist Figure 3 In the example 1 shown, the start of stepping on the foot controller 52 is detected by the stepping amount changing from 0% to 75%, the operation determination time B and the change determination time D are started, and the control of the proportional control valve 48 such that the opening corresponds to the stepping amount is started. And, before the operation determination time B has passed since the stepping start, the stepping amount becomes 98%, which becomes equal to or greater than the operation determination threshold value A. As a result, based on the maximum opening fixing function, the valve opening is controlled to be maintained at 100% from the time point when the stepping amount becomes equal to or greater than the operation determination threshold value A, regardless of the stepping amount. In the example 1, the stepping amount is 0%, that is, even if the user releases his foot from the foot controller 52, the valve opening is always maintained at 100%. After the stepping amount becomes 0%, if it is detected again that the foot controller 52 is stepped on, the proportional control valve 48 is closed at that time point, that is, the opening becomes 0%, and the flow rate of pure water becomes 0.

[0040] exist Figure 3 In the example 2 shown, the start of stepping is detected in the same manner as in the example 1. Here, the stepping amount does not exceed the operation determination threshold value A within the operation determination time B, but the stepping amount is stable and the state in which the change amount is within the change determination threshold value C continues. As a result, at a time point after the change determination time D has passed since the start of stepping, control is performed based on the adjustment opening fixing function to maintain the opening corresponding to the stepping amount at that time, which is 75% in the example shown here. As a result, even if the stepping amount becomes 0% later, the valve opening is maintained at 75%. After the stepping amount becomes 0%, if further stepping is detected, the proportional control valve 48 is closed.

[0041] Figure 3The example 3 shown shows the adjustment opening fixing function in the same way as the example 2. In this example, the pedaling amount changes from the start of pedaling, and each time the change amount becomes greater than the change determination threshold C, the timing of the change determination time D is restarted. And, in the figure, after the pedaling amount becomes 52%, the pedaling amount stabilizes and remains stable for the change determination time D. At the time point after the pedaling amount stabilizes and the change determination time D has passed, the control of maintaining the opening corresponding to the pedaling amount at that time, which is 75% in the example shown here, is performed based on the adjustment opening fixing function. At the time point when the pedaling amount becomes 0% and there is further pedaling thereafter, the opening of the proportional control valve 48 becomes 0%.

[0042] Figure 3 Example 4 is similar to Example 3, but shows an example in which the adjustment opening fixing function is applied when the depression amount is 95% or more of the operation determination threshold value A. In this case, the opening of the proportional control valve 48 is maintained at 100%.

[0043] In the pure water supply machine of the present embodiment described above, by using a foot controller 52 that generates a signal indicating the amount of operation when operated by the user's foot, it is possible to perform a control in an opening fixed mode in which the opening of the proportional control valve 48 is fixed to a desired value. The signal indicating the amount of operation is, for example, an analog signal or a multi-valued digital signal. The same control can also be achieved using a foot switch that can only detect whether it is stepped on or not. The foot switch referred to here refers to a switch that outputs a binary signal, i.e., a signal of being turned on and off.

[0044] In the case of using a foot switch to control the fixed opening mode, if the foot switch is stepped on and turned on, the opening of the proportional control valve 48 is gradually increased during the period of being stepped on, and the discharge flow rate of pure water is increased. When the flow rate desired by the user is reached, the user releases his foot from the foot switch and turns off the switch, thereby controlling the opening at that time point. After the flow rate of pure water is maintained constant, if it is detected that the foot switch is stepped on again, the valve is closed to stop the discharge of pure water. In this way, when the user wants to control the fixed opening mode by using the foot switch, it takes time to reach the flow rate desired by the user, and in particular, the time required to make the flow rate constant at a large flow rate becomes longer. In this embodiment, by using a foot controller 52 that generates a signal indicating the operation amount, the time required to fix the flow rate to the flow rate desired by the user can be greatly shortened, thereby improving the convenience of use of the pure water supply machine for the user. In particular, according to this embodiment, the flow rate at the maximum flow rate that is considered to be the most frequently used can be fixed in the shortest time through simple operations.

[0045] Explanation of symbols

[0046] 10Pure water production equipment

[0047] 22TOC meter

[0048] 23 Constant flow valve

[0049] 40Pure water supply machine

[0050] 45 Microfiltration membrane (MF) device

[0051] 48 proportional control valve

[0052] 51 Control Department

[0053] 52 foot controller

[0054] 53 pedals

[0055] 54 Touch Panel

[0056] 55 Buzzer

[0057] 60 Ventilation Room

[0058] 62 tubes.

Claims

1. A pure water supply machine connected to a pure water production device and supplies pure water according to the user's requirements, The pure water supply machine comprises: a valve provided in a pure water flow path to a discharge portion that discharges the pure water; A foot controller that is operated by a user's foot to generate a signal representing an amount of operation; and A control unit receives the signal from the foot controller and controls the valve so that the opening degree of the valve becomes an opening degree corresponding to the operation amount.

2. The pure water supply machine according to claim 1, wherein: The control unit performs control to maintain the opening degree of the valve based on a given timing of the user's operation of the foot controller.

3. The pure water supply machine according to claim 2, wherein: The control unit performs the following control: when the operation amount becomes greater than the operation determination threshold within a given operation determination time from the start of the operation of the foot controller, the control unit makes the opening of the valve the maximum opening, and thereafter, even if the operation of the foot controller is released, the control unit maintains the opening of the valve at the maximum opening.

4. The pure water supply machine according to claim 3, wherein: The foot controller includes a switch, the switch detecting that the operation amount is equal to or greater than the operation determination threshold. The control unit performs control to maintain the maximum opening degree when receiving a signal indicating that the operation amount is equal to or greater than the operation determination threshold value from the switch within the operation determination time from the start of the operation of the foot controller.

5. The pure water supply machine according to claim 3 or 4, wherein: After the operation of the foot controller is released, when the foot controller is operated again, the control unit performs control to close the valve.

6. The pure water supply machine according to claim 2, wherein: The control unit performs the following control: when the change in the operation amount is within a given change judgment threshold across the entire given change judgment time, the control unit sets the opening of the valve to an opening corresponding to the operation amount within the change judgment time, and thereafter, even if the operation of the foot controller is released, the control unit maintains the opening of the valve to the set opening.

7. The pure water supply device according to claim 6, wherein: The pure water supply machine further includes a notification unit for notifying the user through sound or light. When the control unit sets the opening degree of the valve to the opening degree corresponding to the operation amount within the change determination time, the control unit notifies the user via the notification unit.

8. The pure water supply machine according to claim 6 or 7, wherein: After the operation on the foot controller is released, when the foot controller is stepped on again, the control unit performs control to close the valve.

9. The pure water supply machine according to claim 6 or 7, wherein: The pure water supply machine includes an operation panel, and settings of the change determination time and the change determination threshold value can be changed using the operation panel.

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