JP3942350B2 - Liquid level display method of liquid storage tank in beverage dispenser - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  This inventionIn beverage dispensersThe present invention relates to a liquid level display method for a liquid storage tank, and more particularly to a liquid level display method for detecting the liquid level of a liquid stored in the tank based on the conductivity of the liquid and displaying it on display means. .
[0002]
[Prior art]
In beverage dispensers that pour beverages (liquids) such as coffee and juice, a liquid level gauge is used as a means to detect and display the beverage level (storage amount) in the storage tank where the beverage is stored. It has been. In other words, a liquid level gauge is provided in the beverage supply path from the liquid storage tank to the dispensing cock, and the operator directly looks at the scale attached to the liquid level gauge. In addition, a plurality of transmission type optical sensors are disposed adjacent to the liquid level gauge and spaced apart in the height direction, and the liquid level of the beverage is detected by the sensors.
[0003]
[Problems to be solved by the invention]
As described above, the method in which the operator looks directly at the scale attached to the liquid level gauge has a drawback that the liquid level is difficult to read. On the other hand, when using an optical sensor, the liquid level can be easily confirmed by displaying the detection result of each sensor on an appropriate display unit, but depending on the type of beverage, the optical sensor detects it. There are some that cannot be done, and there is a drawback that the drinks that can be applied are limited. Moreover, in any case, it is necessary to provide a portion (a liquid level gauge) for retaining the beverage in the beverage supply path, and it is pointed out that the piping system becomes complicated and the manufacturing cost increases. Moreover, since the liquid level gauge is difficult to clean, there is a problem that it tends to be unsanitary.
[0004]
In view of this, there has been proposed to detect the electrical conductivity (resistivity) of a beverage using an electrode and display the liquid level of the beverage on a display unit. In this method, the type of beverage is not limited, and the piping system is not complicated. However, since the conductivity varies depending on the type of beverage, it is complicated to change the setting of the conductivity threshold for determining the presence or absence of the beverage. In addition, even if it is the same beverage, the conductivity also changes due to temperature change. Therefore, when a beverage dispenser that cools or heats a beverage detects and displays the presence or absence of a beverage using a fixed threshold, the cooling or Even if there is a beverage in the heating process, the display may indicate no beverage.
[0005]
OBJECT OF THE INVENTION
   The present invention has been proposed to solve this problem in view of the above-described problems inherent in the conventional technology, and even if the type of liquid is changed or its temperature is changed,Change manually using a setting switch etc.An object of the present invention is to provide a liquid level display method for a liquid storage tank that can always detect and display the presence or absence of liquid accurately without performing complicated setting changes.
[0006]
[Means for Solving the Problems]
  In order to overcome the above-mentioned problems and achieve the desired purpose suitably, the liquid level of the liquid storage tank in the beverage dispenser according to the present inventiondisplayThe method is
  An earth electrode attached to a liquid storage tank of a beverage dispenser, a reference electrode disposed near the bottom of the liquid storage tank and having an exposed portion accessible to the liquid stored in the liquid storage tank, and an arrangement of the reference electrode A plurality of liquid level detection electrodes disposed above the installation position and spaced apart in the height direction of the liquid storage tank so that each exposed portion can contact the liquid stored in the liquid storage tank, and a plurality of liquid levels A method for displaying the liquid level of the liquid stored in the liquid storage tank by a liquid level detection circuit connected to a display means provided corresponding to the detection electrode,
  In the state where an AC high frequency voltage is applied between the ground electrode and the reference electrode, and the liquid is in contact with the reference electrode, the type of liquid and the temperature of the liquid change between the ground electrode and the reference electrode. The inter-electrode potential that changes in this way is determined, and this potential is set as a reference potential in the comparison / determination unit provided in the liquid level detection circuit.
  Subtract an appropriately set potential from the reference potential and set a value lower than the reference potential as a threshold in the comparison / determination unit. When the reference potential changes, a new threshold is automatically set for the changed reference potential. Change the settings automatically,
  An AC high-frequency voltage is applied between the ground electrode and the liquid level detection electrode to obtain an interelectrode potential between the ground electrode and each liquid level detection electrode, and the comparison / determination unit uses each potential as a measurement potential. In comparison with the threshold values, respectively,
  For the liquid level detection electrode in which the measurement potential is equal to or higher than the threshold value, display the presence of liquid by the corresponding display means,
  With respect to the liquid level detection electrode whose measured potential is lower than the threshold value, the display without liquid by the corresponding display means is performed.
  In addition, in order to overcome the above-described problems and achieve the intended purpose suitably, the liquid level of the liquid storage tank in the beverage dispenser according to another invention of the present applicationdisplayThe method is
  A reference electrode disposed near the bottom of the liquid storage tank of the beverage dispenser and having an exposed portion accessible to the liquid stored in the liquid storage tank; and above the position where the reference electrode is disposed, A plurality of liquid level detection electrodes that are spaced apart from each other in the height direction and that allow each exposed portion to come into contact with the liquid stored in the liquid storage tank, and display means that correspond to the plurality of liquid level detection electrodes And a liquid level detection circuit connected to and displaying the liquid level of the liquid stored in the liquid storage tank,
  In the state where an AC high frequency voltage is applied between the reference electrode and the lowest first liquid level detection electrode, and the liquid is in contact with the reference electrode and the first liquid level detection electrode, An inter-electrode potential that changes with changes in the type of liquid and the temperature of the liquid between the electrode and the first liquid level detection electrode is obtained, and this potential is provided as a reference potential in the liquid level detection circuit. Set in the comparison / determination section
  Subtract an appropriately set potential from the reference potential and set a value lower than the reference potential as a threshold in the comparison / determination unit. When the reference potential changes, a new threshold is automatically set for the changed reference potential. Change the settings automatically,
  An alternating-current high-frequency voltage is applied between the reference electrode and the other liquid level detection electrode, an inter-electrode potential between the reference electrode and the other liquid level detection electrode is obtained, and each potential is used as a measurement potential. The comparison / determination unit compares the threshold value with each other,
  For the liquid level detection electrode in which the measurement potential is equal to or higher than the threshold value, display the presence of liquid by the corresponding display means,
  With respect to the liquid level detection electrode whose measured potential is lower than the threshold value, the display without liquid by the corresponding display means is performed.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
  Next, according to the present inventionIn beverage dispensersThe liquid level display method of the liquid storage tank will be described below with reference to the accompanying drawings by giving a preferred embodiment. In addition, an Example demonstrates the case where a liquid level display method is employ | adopted as the drink dispenser which pours cold drinks, such as ice coffee and juice.
[0008]
A beverage dispenser 10 shown in FIG. 1 includes a water tank 12 having a heat insulating structure disposed inside a housing 11, and a reservoir 13 a that internally defines a required amount of beverage (liquid) inside the water tank 12. A liquid storage tank 13 to be stored is stored at a predetermined interval from the inner surface of the water tank 12. In the storage space 12a defined by the inner side surface of the water tank 12 and the outer side surface of the liquid storage tank 13, tap water as cooling water is passed through a pipe or container extending from an external water system (not shown). Supplied and stored in a substantially full state. In the storage space 12 a, an evaporation pipe 15 led out from the refrigeration apparatus 14 disposed in the housing 11 is disposed in a winding state surrounding the liquid storage tank 13, and the storage space 12 a is cooled by the cooling operation of the refrigeration apparatus 14. The cooling water stored in is frozen around the evaporator tube 15.
[0009]
A circulation pump 16 communicating with the storage space 12 a of the water tank 12 is disposed inside the housing 11, and the thickness of ice blocks that freeze on the evaporation pipe 15 by circulating the cooling water by the pump 16. The liquid storage tank 13 is cooled by the cooling water, and the beverage in the storage part 13a is indirectly cooled.
[0010]
As shown in FIG. 3, the bottom of the liquid storage tank 13 is provided with a mounting opening 17 for pouring the beverage stored in the storage 13 a to the outside. A plurality of (two in the embodiment) O-rings 18 are fitted on the outer periphery of the outer ring so as to be spaced apart from each other in the height direction. In addition, one end of a pouring pipe 19 faces the water tank through the bottom at the bottom corresponding to the mounting opening 17 in the water tank 12 and opens upward in the water tank of the pouring pipe 19. The mounting opening 17 is inserted into the receiving opening 20 so as to be detachable from above. Then, the two O-rings 18 fitted on the attachment port portion 17 are in close contact with the inner peripheral surface of the receiving port portion 20 so that the liquid tightness between the members 17 and 20 is ensured. Composed. Further, a stepped portion 20a that extends inward with approximately the same thickness as the wall thickness of the mounting port portion 17 is provided inside the receiving portion 20, and a ring-shaped packing placed on the stepped portion 20a. 21 is in contact with the lower end surface of the mounting opening 17 so that more reliable liquid-tightness is ensured.
[0011]
A tank fixing member 22 is disposed at the upper end of the water tank 12, and a plurality of brackets 23 disposed on the outer peripheral surface of the liquid storage tank 13 are screwed to the fixing member 22 (FIG. 4), the liquid storage tank 13 is positioned and fixed in a state in which the attachment port portion 17 is inserted into the receiving port portion 20 of the extraction pipe 19. At this time, the lower end surface of the mounting opening 17 is brought into contact with the packing 21 with a predetermined pressure, and the liquid tightness by the packing 21 is set to be reliable.
[0012]
As shown in FIG. 1, the other end of the extraction pipe 19 extends to the outside of the housing 11, and an extraction cock 24 is attached to the extended end. That is, by opening the dispensing cock 24, the beverage stored in the liquid storage tank 13 is dispensed through the dispensing pipe 19.
[0013]
An upper panel 25 is detachably disposed at the upper end of the casing 11, and the upper opening of the casing 11 is closed by the upper panel 25. However, an opening for allowing the supply of beverage to the tank 13 is provided at a position corresponding to the liquid storage tank 13 of the upper panel 25, and this opening is an upper part of the liquid storage tank 13. The lid is closed together with the opening 13b so as to be opened and closed (see FIG. 2). That is, the beverage is supplied to the liquid storage tank 13 through the opened upper opening 13b in a state where the lid body 26 is removed or the lid body 26 is pivotally opened with respect to the upper panel 25. .
[0014]
Here, when the beverage is supplied to the liquid storage tank 13, since the tank 13 is deep, the beverage poured into the storage portion 13a from the upper opening 13b is stirred at the bottom, and further the beverage is poured from above. There is a risk that the supplied beverage will foam and damage the flavor. In addition, in the case of a beverage dispenser for iced coffee, hot coffee is supplied to the liquid storage tank 13, so that foamed foam is rapidly cooled during supply, and at this time, a part of the coffee component is solidified. In other words, the inner surface of the liquid storage tank 13 is stuck, causing a problem that it takes time for cleaning.
[0015]
Therefore, in the embodiment, a guide member 27 is detachably disposed in the upper part of the liquid storage tank 13 so that the beverage supplied from above by the guide member 27 flows down along the inner surface of the tank. . That is, as shown in FIGS. 2 and 5, the guide member 27 is hooked to the upper end portions of the pair of side plates 27 a and 27 a that are separated from each other in the radial direction of the liquid storage tank 13. 27b are bent, and the both side plates 27a, 27a hang down inside the liquid storage tank 13 by hooking the hooking portions 27b, 27b to the opening edge of the upper panel 25. Yes. A connecting plate 27c is installed between the lower ends of the side plates 27a and 27a, and a trapezoidal guide plate 27d that is inclined downward at a required angle is formed at both end edges in the short direction of the connecting plate 27c. It extends to the vicinity of the inner surface of the tank. Therefore, when the beverage is supplied, if the beverage is poured above the connecting plate 27c, the beverage is guided toward the inner surface of the tank by the guide plates 27d and 27d, and then flows smoothly through the inner surface to the bottom. Therefore, it is possible to prevent the beverage from foaming.
[0016]
The guide member 27 is configured not to obstruct the closing of the upper opening 13b of the liquid storage tank 13 by the lid body 26 in a state of being hooked on the upper panel 25. If the lid 26 is removed or pivoted open, the guide member 27 can be taken out from the liquid storage tank 13, and the guide member 27 can be easily washed outside.
[0017]
The liquid storage tank 13 is provided with a liquid level detection device 50 for detecting the liquid level (storage amount) of the beverage stored in the storage part 13a. That is, as shown in FIG. 4, the reference detector 28A is disposed near the bottom of the liquid storage tank 13, and the reference electrode 29A provided in the reference detector 28A is a liquid disposed at the front of the casing 11. It is electrically connected to a liquid level detection circuit 31 provided in the level display unit 30 (see FIG. 8). Further, four liquid level detectors 28B, 28C, 28D, and 28E for detecting the liquid level of the beverage stored in the reservoir 13a are high in the liquid storage tank 13 above the position where the reference detector 28A is disposed. The liquid level detection electrodes 29B, 29C, 29D, and 29E provided in all the liquid level detection bodies 28B, 28C, 28D, and 28E are arranged at predetermined intervals in the vertical direction. Is electrically connected. In the embodiment, the first liquid level detector 28B (first liquid level detection electrode 29B), the second liquid level detector 28C (second liquid level detection electrode 29C), and the third liquid are viewed from below. The level detection body 28D (third liquid level detection electrode 29D) and the fourth liquid level detection body 28E (fourth liquid level detection electrode 29E) are set. Since the basic configuration of the reference detector 28A and each of the liquid level detectors 28B, 28C, 28D, 28E is the same, the configuration of the reference detector 28A will be described, and the liquid level detectors 28B, 28C, 28D, The same reference numerals are given to the same members of 28E. Since the reference detector 28A and the liquid level detectors 28B, 28C, 28D, 28E have the same mounting structure with respect to the liquid storage tank 13, the mounting structure related to the reference detector 28A will be described, and the liquid level detectors 28B, 28C. , 28D, 28E, the same members are attached with the same reference numerals.
[0018]
As shown in FIG. 6 and FIG. 7, the reference detector 28A is formed of a synthetic resin molded body in which a protective body 32 having a concentric and small-diameter boss 32b projecting from one side surface in the axial direction of a mounting portion 32a formed in a substantially disc shape. The reference electrode 29A (liquid level detection electrodes 29B, 29C, 29D, 29E) protrudes from the center of the boss 32b toward the outside with a predetermined length. The reference electrode 29A is bent at a substantially right angle inside the protector 32, and a lead wire 33 connected to the liquid level detection circuit 31 is connected to the end of the reference electrode 29A. That is, the connecting portion between the lead wire 33 and the reference electrode 29A is enclosed in a protective body 32 made of synthetic resin, so that cooling water (liquid) or the like is prevented from entering the connecting portion. It has become. The bending direction of the reference electrode 29A inside the protection body 32 is set so as to coincide with the wiring direction of the lead wire 33 when the reference detection body 28A is disposed in the liquid storage tank 13. And the reference electrode 29 </ b> A are configured so that an excessive force is not applied to the connection portion. Further, as the synthetic resin constituting the protective body 32, a heat-resistant resin is preferably used, so that it can be used without any trouble in either a high-temperature beverage or a low-temperature beverage.
[0019]
Further, a heat-resistant heat-shrinkable tube 34 is commonly covered over the extended portion of the lead wire 33 in the protector 32 and a portion of the lead wire 33 having a predetermined length derived from the protector 32. The connecting portion between the protector 32 and the lead wire 33 is configured to be reinforced.
[0020]
A holder 35 is fitted on the boss 32 b of the protector 32. As shown in FIG. 7, the holder 35 includes a bottomed cylindrical main body 36 formed with a concave portion 36a that opens in one axial direction into which the boss 32b can be fitted, and a bottom portion (recess 36a in the main body portion 36). A substantially concentric boss portion 37 protruding in the axial direction is formed on the opposite side of the opening. Further, a central through hole 37a communicating with the recess 36a is formed in the bottom portion of the main body 36 and the boss portion 37, and protrudes from the boss 32b when the boss 32b of the protective body 32 is fitted into the recess 36a. The reference electrode 29A to be inserted is inserted into the center through hole 37a. The protruding dimension of the reference electrode 29A from the boss 32b is set longer than the center through hole 37a, and the open end of the reference electrode 29A protrudes outward from the center through hole 37a, so that the exposed portion of the reference electrode 29A is exposed. Is configured to come into contact with the beverage stored in the liquid storage tank 13.
[0021]
An inner first convex portion 36b protruding radially inward is formed on the inner peripheral surface of the concave portion 36a (the fitting surface with respect to the protector 32), and the inner peripheral surface of the central through hole 37a ( On the fitting surface with respect to the electrode, inner second convex portions 37b projecting radially inward are formed at positions spaced apart in the axial direction over the entire circumference. When the holder 35 is fitted to the protector 32, the inner first convex portion 36b is in close contact with the outer peripheral surface (fitted surface) of the boss 32b, and the inner second convex portion 37b is the reference electrode. The degree of adhesion of the holder 35 to the protective body 32 and the reference electrode 29A due to the expansion / contraction of the protective body 32 and the holder 35 due to the temperature effect of the beverage, in close contact with the outer peripheral surface (fitting surface) of 29A Is designed to prevent the decrease. The holder 35 is formed of an elastic material such as a soft synthetic resin or rubber and an insulating material.
[0022]
An attachment tool 38 is disposed at the attachment position of the reference detection body 28A in the liquid storage tank 13. As shown in FIG. 7, the attachment 38 has a bottomed cylindrical shape formed with a storage portion 39 a that opens to one axial direction (side away from the tank 13) in which the main body 36 of the holder 35 can be fitted. The cylindrical main body 39 is provided with a substantially concentric positioning protrusion 39b protruding in the axial direction at the bottom of the cylindrical main body 39 (on the side opposite to the opening of the storage portion 39a). Then, the fitting 38 is disposed in the liquid storage tank 13 by fitting the positioning protrusion 39 b into the through hole 13 c of the liquid storage tank 13. A through hole 39c communicating with the storage portion 39a is formed in the bottom portion of the cylindrical main body 39 and the positioning projection 39b. When the main body portion 36 of the holder 35 is fitted into the storage portion 39a, the main body portion A boss portion 37 protruding from 36 is fitted into the through hole 39c.
[0023]
On the outer peripheral surface of the main body portion 36 of the holder 35 (the fitting surface with respect to the fixture 38), outer first convex portions 36c projecting radially outward at positions spaced apart in the axial direction are formed over the entire circumference. In addition, an outer second convex portion 37c protruding outward in the radial direction is formed on the outer peripheral surface of the boss portion 37 (a fitting surface with respect to the fixture 38) over the entire circumference. When the holder 35 is fitted to the fixture 38, the outer first convex portion 36c comes into close contact with the inner peripheral surface (fitted surface) of the storage portion 39a, and the outer second convex portion 37c The contact degree of both the members 35 and 38 decreases due to the expansion and contraction of the holder 35 and the attachment tool 38 due to the temperature effect of the beverage, in close contact with the inner peripheral surface (surface to be fitted) of the through hole 39c. It is designed to prevent this.
[0024]
A flange 39d having the same outer diameter as the mounting portion 32a of the protective body 32 is formed on the outer peripheral portion of the cylindrical body 39 of the mounting body 38 on the opening side of the storage portion 39a. In a state where the holder 35 is fitted to the fixture 38, the reference detection body 28A is attached to the liquid storage tank 13 by elastically fitting the clip 40 to the attachment portion 32a and the flange 39d in common. It has become. The clip 40 is formed with a fitting hole 40a having a width dimension in which the attachment portion 32a and the flange 39d can be inserted, and the clip 40 can be inserted by inserting the attachment portion 32a and the flange 39d into the fitting hole 40a. On the other hand, the mounting portion 32a and the flange 39d are fixed to prevent them from coming off. Each of the inner and outer convex portions 36b, 37b, 36c, and 37c is formed in an R shape so that the protector 32 (reference detection body 28A) can be easily attached to and detached from the holder 35 and the holder 35 can be attached to and detached from the fixture 38. It is configured so that it can be performed.
[0025]
The ground electrode 41 attached to the liquid storage tank 13 is connected to the liquid level detection circuit 31 to which the reference electrode 29A and the liquid level detection electrodes 29B, 29C, 29D, 29E are connected. In the embodiment, in a state where the beverage is stored up to the position where the reference electrode 29A is disposed (a state where the reference electrode 29A is in contact with the beverage), a predetermined AC height is set between the reference electrode 29A and the ground electrode 41. The interelectrode potential (conductivity of the beverage) when the frequency voltage is applied is obtained and set as the reference potential XA. Then, when the same AC high frequency voltage is applied between the ground electrode 41 and each of the liquid level detection electrodes 29B, 29C, 29D, 29E, the interelectrode potential (conductivity of the beverage) is measured as potentials XB, XC, XD. , XE, and the measured potential XB, XC, XD, XE is compared with the reference potential XA by the comparison / determination unit (comparison / determination means) 42 provided in the liquid level detection circuit 31 to determine whether or not there is a beverage. It is configured to determine.
[0026]
In the embodiment, the difference between the measured potentials XB, XC, XD, and XE and the reference potential XA is within a preset setting range in consideration of the change in conductivity accompanying the temperature change of the beverage and the measurement error of the potential. If there is a beverage, it is determined that there is a beverage (liquid is present), and if the difference between the measured potential XB, XC, XD, XE and the reference potential XA is outside the set range, it is determined that there is no beverage (no liquid). . Specifically, a threshold value XAd that is lower than the reference potential XA by a predetermined potential (α) is set, and when the measured potentials XB, XC, XD, and XE are equal to or higher than the threshold value XAd, it is determined that there is a beverage, and the measured potential When XB, XC, XD, and XE are lower than the threshold value XAd, it is determined that there is no beverage. Note that the difference between the reference potential XA and the threshold value XAd can be arbitrarily set.
[0027]
For example, if the beverage is stored up to the position of the third liquid level detection electrode 29D, the third liquid level detection electrode 29D and the ground electrode 41 are in a conductive state via the beverage, so that The measured potential XD is equal to or higher than the threshold value XAd (XD ≧ XAd), and it is determined that there is a beverage. On the other hand, since no beverage is stored at the position of the fourth liquid level detection electrode 29E, the fourth liquid level detection electrode 29E and the ground electrode 41 are in a conductive state via the beverage. The measured potential XE during that time is lower than the threshold value XAd (XD <XAd), and it is determined that there is no beverage.
[0028]
Further, the threshold value XAd is based on the premise that there is a beverage at the first liquid level detection electrode 29B (XB ≧ XAd), at every predetermined time interval or when the reference potential XA changes, or after that change. A new threshold value XAd is automatically changed for the reference potential XA. Then, the measurement potentials XB, XC, XD, and XE are compared again with the newly set threshold value XAd to determine the presence or absence of a beverage.
[0029]
The liquid level detection circuit 31 is connected to display lamps 43B, 43C, 43D, and 43E as display means corresponding to the liquid level detection electrodes 29B, 29C, 29D, and 29E. As described above, the display lamps 43B, 29B, 29D, 29E corresponding to the liquid level detection electrodes 29B, 29C, 29D, 29E determined as having a beverage by comparing the measured potentials XB, XC, XD, XE with the threshold value XAd. 43C, 43D, and 43E are turned on, and the display lamps 43B, 43C, 43D, and 43E corresponding to the liquid level detection electrodes 29B, 29C, 29D, and 29E determined as having no beverage are turned off, so that the operator The liquid level can be made known (see FIG. 9). In the embodiment, the first display lamp 43B corresponding to the first liquid level detection electrode 29B, the second display lamp 43C corresponding to the second liquid level detection electrode 29C, and the third liquid level detection. A third display lamp 43D corresponding to the electrode 29D and a fourth display lamp 43E corresponding to the fourth liquid level detection electrode 29E are arranged in the vertical direction from bottom to top in this order, The liquid level confirmability (visibility) is improved (see FIG. 1).
[0030]
[Effect of the embodiment]
Next, the operation of the beverage dispenser according to the above-described embodiment will be described. In the beverage dispenser 10, the refrigerant is circulated and supplied to the evaporation pipe 15 when the refrigeration apparatus 14 starts a cooling operation. When the refrigerant is circulated and supplied, the evaporation pipe 15 is gradually cooled, and a part of the cooling water stored in the storage space 12 a of the water tank 12 starts to freeze from the surface of the evaporation pipe 15. The ice growing on the surface of the evaporation tube 15 is connected to each other to form a cylindrical ice block, and the latent heat causes the cooling water stored in the water tank 12 to be cooled over time. When the circulating pump 16 is operated at a predetermined timing from the start of the operation of the refrigeration apparatus 14, the cooling water stored in the storage space 12a circulates around the ice block and is efficiently cooled.
[0031]
When the beverage is supplied to the liquid storage tank 13, the lid 26 is removed or pivoted open, and the beverage is poured from the upper opening 13 b of the tank 13 onto the connecting plate 27 c of the guide member 27. The beverage is guided toward the inner surface of the tank by the guide plates 27d and 27d and then smoothly flows to the bottom along the inner surface, so that the beverage can be prevented from foaming. That is, when hot coffee is supplied to the liquid storage tank 13, the coffee foams and the flavor is impaired, or the foam is rapidly cooled, so that a part of the coffee component is solidified on the inner surface of the liquid storage tank 13. Cleaning is easy without sticking. Moreover, since the guide member 27 can also be easily taken out from the liquid storage tank 13, the guide member 27 can be easily cleaned outside and can always be kept hygienic.
[0032]
The beverage stored in the liquid storage tank 13 is also efficiently cooled by the circulation of the cooling water, and the beverage is opened to the outside from the tank 13 through the dispensing pipe 19 by opening the dispensing cock 24. Be poured out. As shown in FIG. 3, the mounting port 17 of the liquid storage tank 13 is liquid-tightly connected to the receiving port 20 of the pouring pipe 19 by an O-ring 18 and a packing 21. It is prevented that the beverage permeates between 20 and becomes unsanitary. Further, the liquid storage tank 13 is positioned and fixed via a tank fixing member 22 disposed in the upper part of the water tank 12 with the mounting port portion 17 fitted into the receiving port portion 20 of the extraction pipe 19 from above. Thus, the liquid storage tank 13 can be easily attached and removed after the refrigeration system is completed, and the confirmation work when a problem occurs is facilitated.
[0033]
The beverage dispenser 10 measures a reference potential (beverage conductivity) XA in a state where the AC high frequency voltage is applied between the reference electrode 29A and the ground electrode 41, and corresponds to the reference potential XA. A threshold value XAd is set. The measured potentials XB, XC, XD, and XE between the liquid level detecting electrodes 29B, 29C, 29D, and 29E and the ground electrode 41 are compared with the threshold value XAd by the comparison / determination unit 42, and the measured potential is measured. If XB, XC, XD, and XE are equal to or greater than the threshold value XAd (XB, XC, XD, XE ≧ XAd), it is determined that there is a beverage, and there is a beverage by lighting the corresponding display lamps 43B, 43C, 43D, and 43E. Is displayed. When the measured potentials XB, XC, XD, XE are lower than the threshold value XAd (XB, XC, XD, XE <XAd), it is determined that there is no beverage, and the corresponding display lamps 43B, 43C, 43D, 43E are turned off. No beverage is displayed (see FIG. 9). That is, the operator can check the liquid level by displaying the display lamps 43B, 43C, 43D, and 43E by turning on / off, so that the confirmation (visibility) of the current liquid level in the liquid storage tank 13 is improved. To do. In addition, since a liquid level gauge made of an elongated glass tube is not used, the structure is simplified and cleaning of the liquid storage tank 13 and the dispensing pipe 19 is facilitated.
[0034]
In addition, since the presence or absence of the beverage is determined by the threshold value XAd set by the reference potential XA based on the conductivity of the beverage, the type of the beverage is not limited, and the conductivity of the beverage has changed due to a temperature change. In this case, since the reference potential XA and the threshold value XAd are correspondingly changed, the liquid level can always be reliably detected and displayed without being influenced by the beverage temperature. That is, it is not necessary for the operator to manually perform a complicated operation of changing the threshold value using a setting switch or the like every time the beverage type is changed. Furthermore, since the threshold value XAd for actually determining the presence or absence of a beverage is set to a value lower than the reference potential XA, the beverage temperature (conductivity) is different at the upper and lower positions in the liquid storage tank 13. Even if it exists, it is possible to reliably detect the presence or absence of a beverage.
[0035]
In the reference detector 28A and the liquid level detectors 28B, 28C, 28D, and 28E, the connection portions between the electrodes 29A, 29B, 29C, 29D, and 29E and the corresponding lead wires 33 are provided inside the protector 32. Since it is enclosed, even if the protection body 32 is immersed in the cooling water in the water tank 12, the cooling water does not penetrate to the connection portion, and the reliability is improved. Further, the protector 32 and the electrode and the holder 35 or the holder 35 and the fixture 38 are all fitted in a liquid tight contact with the plurality of convex portions 36b, 37b, 36c and 37c, and the temperature of the beverage The degree of adhesion does not decrease due to the expansion / contraction of each component due to the influence, and the beverage leaks from the attachment portion of the reference detection body 28A and the liquid level detection bodies 28B, 28C, 28D, 28E to the liquid storage tank 13, Alternatively, it is possible to reliably prevent the cooling water from entering the tank.
[0036]
[Example of change]
In the above-described embodiments, the interelectrode potential between the reference electrode and the ground electrode is set as the reference potential. However, the electric circuit is configured so that a predetermined AC high frequency voltage is applied between the reference electrode and each liquid level detection electrode. And the interelectrode potential in a state where the reference electrode and, for example, the lowest first liquid level detection electrode are in contact with the beverage is set as the reference potential. Then, by comparing the measured potential, which is the interelectrode potential between the reference electrode and the other liquid level detection electrode, with a threshold set based on the reference potential in the comparison / determination unit, the presence or absence of the liquid level is determined. You may make it detect and display.
[0037]
In the embodiment, the presence or absence of a beverage is determined by comparing a threshold value that is lower than the reference potential by a predetermined potential and the measured potential, but the reference potential itself is compared with the measured potential. Is possible. That is, when a hot beverage is supplied to the liquid storage tank and the beverage gradually cools, the lower portion is colder and the upper portion is hotter. At this time, the potential between the electrodes of the ground electrode, the reference electrode, and each liquid level detection electrode is smaller at the lower beverage temperature and larger at the higher beverage temperature, so the reference potential itself is used as a threshold value. However, the presence or absence of a drink can be determined reliably. However, when the beverage stored in the liquid storage tank is hot, if a new cold beverage is replenished, the lower one is hot and the upper one is cold. The potential between the electrodes at this time is larger when the beverage temperature is higher and lower, and lower when the beverage temperature is lower, and the reference potential has the largest value. Therefore, if the reference potential itself is used as a threshold value, the upper measured potential is smaller than the reference potential, so that the display lamp is turned off even though there is a beverage on the upper side of the liquid storage tank. Therefore, when handling such a beverage, it is recommended to use a threshold value lower than the reference potential as in the embodiment.
[0038]
It is also possible to store the threshold value once set in an appropriate storage means and determine whether or not there is a beverage based on the threshold value. In this case, when changing a drink, you may set so that it may reset by operating an appropriate switch, or may be reset automatically by turning on the power again.
[0039]
The number of electrodes for detecting the liquid level in the liquid storage tank and the display lamps corresponding thereto is not limited to the four units described above, and an arbitrary number may be arranged. Only the liquid level can be detected finely and displayed. Further, in the embodiment, the dispenser configured to cool the beverage stored in the liquid storage tank has been described as an example, but the liquid level display method of the present application is also applied to a dispenser that heats the beverage with hot water or air. Can do. Furthermore, the present invention can also be applied to a beverage dispenser of a type that dispenses a beverage at room temperature using only a liquid storage tank. In the embodiment, the earth electrode has been described as being disposed in the liquid storage tank. However, as long as it is electrically connected, the mounting location is not limited.
[0040]
【The invention's effect】
  As described above, according to the present invention.In beverage dispensersIn the liquid level display method for the liquid storage tank, the potentials of the plurality of liquid level detection electrodes disposed apart from each other in the height direction of the tank with reference to the potential of the reference electrode disposed in the liquid storage tank and the reference By comparing the potential with the liquid level, the liquid level in the liquid storage tank is detected and displayed on the display means, so the liquid level can be displayed more easily and accurately than when using a liquid level gauge as in the past. can do. Further, the configuration of the liquid storage tank, the liquid supply path, etc. is simple, cleaning becomes easy, and it can be kept hygienic. Furthermore, the type of liquid is not limited, and the reference potential is changed according to the temperature change of the liquid, so that accurate liquid level display is always achieved.
[0041]
  According to the first aspect of the present invention, since the presence or absence of the liquid is determined based on the threshold set by the reference potential based on the conductivity of the beverage, the type of the liquid is not limited, and the liquid is changed according to the temperature change. When the electrical conductivity of the liquid crystal changes, the reference potential and the threshold value are correspondingly changed, so that the liquid level can always be detected and displayed reliably without being affected by the liquid temperature. That is, every time the type of liquid is changed, it is not necessary for the operator to manually perform a complicated operation of changing the threshold value using a setting switch or the like. Furthermore, since the threshold value for determining the presence or absence of liquid is set to a value lower than the reference potential, the temperature of the liquid at the upper and lower positions in the liquid storage tank. ( conductivity ) Even if they are different, the presence or absence of liquid can be reliably detected and displayed on the corresponding display means.
  Further, according to the invention according to claim 2, since the presence or absence of the liquid is determined based on the threshold set by the reference potential based on the conductivity of the beverage, the type of the liquid is not limited, and the temperature change When the electrical conductivity of the liquid changes, the reference potential and the threshold value are correspondingly changed, so that the liquid level can always be reliably detected and displayed without being affected by the liquid temperature. That is, every time the type of liquid is changed, it is not necessary for the operator to manually perform a complicated operation of changing the threshold value using a setting switch or the like. Furthermore, since the threshold value for determining the presence or absence of liquid is set to a value lower than the reference potential, the temperature of the liquid at the upper and lower positions in the liquid storage tank. ( conductivity ) Even if they are different, the presence or absence of liquid can be reliably detected and displayed on the corresponding display means.
[Brief description of the drawings]
FIG. 1 is a side view of a beverage dispenser according to a preferred embodiment of the present invention, partially broken away.
FIG. 2 is a cross-sectional view showing a main part of a beverage dispenser according to an embodiment.
FIG. 3 is a cross-sectional view of a main part showing a connection portion between a liquid storage tank and a dispensing pipe according to an embodiment.
FIG. 4 is a side view showing a liquid storage tank according to an embodiment.
FIG. 5 is a plan view showing a guide member according to the embodiment.
FIG. 6 is a cross-sectional view showing a reference detector according to an embodiment.
FIG. 7 is an exploded view showing a mounting structure of the reference detector according to the embodiment with respect to the liquid storage tank.
FIG. 8 is a control block diagram of the liquid level detection device according to the embodiment.
FIG. 9 is a flowchart for determining the presence or absence of a beverage according to an embodiment.
[Explanation of symbols]
13 Liquid storage tank, 29A Reference electrode, 29B First liquid level detection electrode
29C Second liquid level detection electrode, 29D Third liquid level detection electrode
29E 4th liquid level detection electrode, 43B 1st display lamp (display means)
43C Second display lamp (display means), 43D Third display lamp (display means)
43E Fourth display lamp (display means)
43B, 43C, 43D, 43E Display lamp (display means), XA Reference potential
XAd threshold, XB, XC, XD, XE Measurement potential

Claims (2)

Ground electrode (41) mounted in the liquid storage tank (13) of the beverage dispenser (10), is disposed near the bottom of the liquid storage tank (13) and reservoir and the exposed portion in the liquid storage tank (13) a reference electrode which enables contact with the liquid (29A), above the arrangement position of the reference electrode (29A), a plurality of arranged spaced in the height direction of the liquid storage tank (13), each exposure unit Compatible with liquid level detection electrodes (29B, 29C, 29D, 29E) and multiple liquid level detection electrodes (29B, 29C, 29D, 29E) that can contact the liquid stored in the liquid storage tank (13) display means provided in (43B, 43C, 43D, 43E) by the are connected liquid level detection circuit (31), a method of displaying the liquid level of the liquid that has accumulated in the liquid storage tank (13) ,
Wherein an AC high frequency voltage is applied between the ground electrode (41) and the reference electrode (29A), in a state where the liquid is in contact with the reference electrode (29A), the ground electrode (41) and the reference electrode (29A) A comparison / determination unit provided in the liquid level detection circuit (31) with the potential between the electrodes as a reference potential (XA) obtained as a reference potential (XA). Set to (42)
Subtracting appropriately set the potential (alpha) from the reference potential (XA), said reference potential and sets the comparison and judgment unit lower than (XA) value as the threshold (XAd) (42), said reference potential (XA) When is changed , the threshold (XAd) is automatically set and changed with respect to the changed reference potential (XA) ,
The earth electrode (41) and the liquid level sensing electrode (29B, 29C, 29D, 29E) by applying an AC high frequency voltage between the grounding electrode (41) and the liquid level detection electrode (29B, 29C, 29D , 29E), and the respective potentials as measured potentials (XB, XC, XD, XE) are compared with the threshold value (XAd) in the comparison / determination unit (42) ,
For the liquid level detection electrodes (29B, 29C, 29D, 29E) in which the measured potential (XB, XC, XD, XE) is equal to or higher than the threshold (XAd) , the corresponding display means (43B, 43C, 43D) performs the display of the presence of liquid by 43E),
For the liquid level detection electrodes (29B, 29C, 29D, 29E) in which the measured potential (XB, XC, XD, XE) is lower than the threshold value (XAd) , the corresponding display means (43B, 43C, 43D) , 43E) liquid level display method of the liquid storage tank in a beverage dispenser according to claim <br/> it has to perform display without liquid by. Beverage dispenser (Ten) Liquid storage tank (13) In the vicinity of the bottom of the liquid storage tank (13) Reference electrode that can contact the liquid stored in (29A) And the reference electrode (29A) On the upper side of the arrangement position of the liquid storage tank (13) A plurality of tanks are arranged apart from each other in the height direction, and each exposed portion is stored in a liquid storage tank (13) Electrode for liquid level detection that enables contact with liquid stored in (29B, 29C, 29D, 29E) And multiple liquid level detection electrodes (29B, 29C, 29D, 29E) Display means provided for each (43B, 43C, 43D, 43E) Level detection circuit connected to (31) By the storage tank (13) A method of displaying the liquid level of the liquid stored in
  Reference electrode (29A) And lowest first liquid level detection electrode (28B) AC high frequency voltage is applied between the reference electrode and the reference electrode (29A) And first liquid level detection electrode (28B) When the liquid is in contact with the reference electrode (29A) And first liquid level detection electrode (28B) Find the interelectrode potential that changes with the change in the type of liquid and the temperature of the liquid, and use this potential as the reference potential. (XA) As said liquid level detection circuit (31) Comparison / determination unit (42) Set to
  Potential set appropriately ( α ) The reference potential (XA) Subtract from the reference potential (XA) Lower value is threshold (XAd) As comparison / determination part (42) And the reference potential (XA) Changes, the reference potential after the change (XA) New threshold for (XAd) Automatically change settings,
  Reference electrode (29A) And other liquid level detection electrodes (29C, 29D, 29E) AC high frequency voltage is applied between the reference electrode and the reference electrode (29A) And other liquid level detection electrodes (29C, 29D, 29E) And determine the potential between the electrodes and measure each potential. (XC, XD, XE) As the comparison / determination unit (42) In the threshold (XAd) Compared to
  Measurement potential (XC, XD, XE) Is the threshold (XAd) Liquid level detection electrode (29C, 29D, 29E) For the corresponding display means (43B, 43C, 43D, 43E) Display the presence of liquid by
  Measurement potential (XC, XD, XE) Is the threshold value (XAd) Lower liquid level detection electrode (29B, 29C, 29D, 29E) For the corresponding display means (43B, 43C, 43D, 43E) Display no liquid by
A liquid level display method for a liquid storage tank in a beverage dispenser.

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