JPH01247942A - Water level detection device - Google Patents

Abstract

PURPOSE:To surely supply water at a set water level regardless of whether there is residual water or not by judging whether or not there is residual water in a water reservoir and setting up a new water level value when there is no residual water, by detecting the pressure at a point of inflexion of pressure when the water level passes an adapter and determining the water level of the water storage section, and when there is residual water, by using the previous water level standard value for the control of the water level. CONSTITUTION:There is no change in the pressure until the supply water to a water reservoir 1 reaches an adapter 2. As soon as the water level in the reservoir 1 goes across the adapter 2 the pressure starts rising. The detection of the residual water is, therefore, carried out before starting water supply operation. When there is no residual water the point of inflection is detected to renew the water level standard value, and water is supplied according to that value. If there is residual water, a stored value is read out and water replenishing operation is carried out by that value. The judgement whether or not there is residual water is made by the circulation mode operation and it is judged by a water flow switch 9. This switch 9 is turned OFF if there is no residual water because air comes in from the water reservoir 1 and it is possible to judge. The period to make the judgement is the elasped time tB. If the water flow switch 9 is ON at this time, the value Px in the store and used in the previous judgement is used and water is replenished to the value of PA added to the value Px.

Description

[Detailed description of the invention] Industrial applications The present invention supplies a set amount of water or hot water to a bathtub.

This relates to an automatic bath water level detection device that circulates and maintains the water at a set temperature.

BACKGROUND OF THE INVENTION A system diagram of a conventional water level detection device of this type is shown in FIG. 1 is a bathtub which is a water storage part, 2 is an adapter 13 provided on the side of the bathtub 1 is a water heater, and the adapter 2 and the water heater 3 are connected by an outgoing pipe 4 and a return pipe 5. . 6
is the external piping of the return pipe 5. Connected to the outgoing pipe 4 are a pump 7 for circulating water in the water storage section 1 and supplying water into the water storage section 1, and a heating means 8 for raising the temperature of the circulating water. In addition, the return pipe 5 includes a residual water detection means 9 (water flow switch) that detects whether there is water in the water storage tank 1, a pressure sensor 10 that detects the water level in the water storage tank 1, and a pressure sensor 10 that detects the temperature of the circulating water. A temperature sensor 11 for detection is connected thereto. Further, a water supply source 12 is connected to a switching means 14 via a water supply pipe 13.

The switching means 14 switches the connection of the outgoing pipe 4 to the return pipe 5 or the water supply pipe 13. Further, 15 is a control means, which receives signals from the pressure sensor 10 and temperature sensor 11 as input and determines each set value as shown in FIG. Working together, the pump 7 is connected to a heating means 8, a water supply source 12. It controls the switching means 14. In the above configuration, the water level in the water storage section 1 is detected by the pressure sensor 1o on the water heater 3 side, and water is supplied to the set water level, and the pressure detected by the pressure sensor 1o is p A + p X in FIG. 3. Of these, the water level above adapter 2 is determined by the dimensions of the human body, and since there is little difference, it does not change much even if the bathtub is different.
Therefore, the pressure PA also does not change much, but the pressure PX between the adapter 2 and the pressure sensor 10 changes greatly depending on the relative installation status of the water storage part 1 and the water heater 3, and therefore cannot be determined uniformly. This is inconvenient because it requires adjustment of each item on site. Furthermore, even if one item is adjusted as described above, the pressure sensor, controller, etc. will change over time. However, as shown in the pressure characteristic diagram in Figure 5, there is no change in pressure, as represented by Px, from when water starts to be supplied to the water storage section and water enters and leaves the water storage section 1 until it reaches the adapter 2. .

Since the pressure exhibits the characteristic of increasing when the water level crosses adapter 2, by detecting that pressure inflection point and using it as a reference value, it becomes possible to supply water to a constant water level regardless of installation conditions. . A flow diagram of the water supply operation using this principle is shown in FIG.

The period up to the elapsed time to is the reference value water supply shown in 81 to S4, which is the state until the adapter 2 is reached.

At the elapsed time to, the water level crosses the adapter 2, and the pressure inflection point shown in S5 is detected. The new water level standard value obtained this time is memorized in S6, and S7 is continued until the PA is raised from there.
Perform set value water supply. When the set value is reached at the elapsed time tA, the water supply is stopped as shown in 88 to 5101.

Problems to be Solved by the Invention However, in some areas, there is a bathing system in which all the water used for bathing is drained and water is refilled into the empty water storage area the next time the bath is taken.
Since it has AT-, it is possible to detect the pressure inflection point every time water is supplied, update the memory of the water level standard value, and supply water at the set value. There is a bathing style in which the water is boiled before taking a bath, and in this case, the pressure only increases due to the water supply, and the inflection point does not appear no matter how long it takes, so there is a problem that the water may overflow beyond the set water level. Was.

The present invention is intended to solve such conventional problems, and aims to determine whether or not it is boiling back, and when it is boiling back, to supply water at a set value without relying on the inflection point.

Means for Solving the Problems In order to solve the above-mentioned problems, the water level detection device of the present invention includes a residual water detection means for detecting the presence or absence of residual water in the water storage section, and a water level detection means for detecting the presence or absence of residual water in the water storage section, and a method for detecting the presence of residual water from the residual water detection means prior to operation in the water supply mode. It determines whether there is residual water based on the input, and if there is no residual water, it operates in water supply mode to detect pressure changes and white spots, and updates the memory as a new water level reference value.

If there is residual water, the system is equipped with a control means that determines the water level in the water storage section using the memory of the previous water level reference value.

Effects of the present invention With the above-described configuration, it is possible to supply water at a set value even in the case of reheating, and since the water level standard value memory used at that time uses the updated value from the previous time when water was newly supplied, it is possible to prevent changes over time due to aging. This allows stable water level control by absorbing all changing error factors.

Embodiment 1 The water supply mode operation in an embodiment of the present invention will be explained based on the flow diagram of FIG. 1 and the pressure characteristic diagram of FIG. 2. The same steps as in FIG. 6 are given the same numbers in FIG. 1, and when the pressure and time are the same as in FIG. 5, the same numbers are also given in FIG. The difference from the conventional method is that prior to the water supply mode operation that starts from S2, residual water is detected as shown in S11 to 813, and if it is determined that there is no residual water, the same steps as the conventional method shown from S2 onwards are performed. Detects the inflection point, updates the memory of water level and level, and supplies water to the set value. However, if it is determined that there is residual water, it is determined that boiling is occurring, and the previously stored value is restored in S14. Water replenishment operation is performed in take-out S15 to S16 to supply water at a set value. The presence or absence of residual water is determined by performing circulation mode operation in steps 811 to 812 and determining whether or not the water flow switch 9, which is a residual water detection means, is turned on. If there is no remaining water, air will enter from the water storage section 1 and the device will be turned off, making it possible to make a determination. This determination period is the elapsed time tB shown in Fig. 2, and if the water flow switch 9 is on at this time, the previous stored value Px is used, water is added to the value obtained by adding the value K P A, and the set water level is reached. It supplies water. Previous memory value Px used at this time
If it is extremely old, there is a high possibility that it has lost its optimal value due to changes over time in the pressure sensor 10, control means 15, etc., but fortunately, even if you use boiling water as a form of bathing, you do not have to do this every time. Since the water storage tank 1 is emptied and fresh water is supplied several times, the previous stored value Px is always updated to a relatively new state and no problem occurs. 5 Although it is omitted in Figure 1, when it is determined that there is abundant water and water is replenished, most of the stored water remains cold, so the circulation mode operation is started after the SIO water supply end. Then, the heating means 8 is energized to heat the water stored in the water tank 1 to the set temperature,
FIG. 1 shows only the flow for supplying water to the set water level. Another method for detecting residual water is to first start water supply and, when the water level (pressure) starts to rise immediately, determine that there is residual water and replenish water, as shown in the dashed line in Figure 2. However, this method has the drawback that even if the water level is at the set level from the beginning, water is supplied to the tank for determining the remaining water, and the water level rises above the set water level. In comparison, the configuration in which discrimination is performed using a water flow switch does not have the above-mentioned drawbacks because the water level does not rise for discrimination.

Effects of the Invention As described above, the water level detection device of the present invention includes a residual water detection means for detecting the presence or absence of residual water in the water storage section, and a residual water detection means that detects the presence or absence of residual water by input from the residual water detection means prior to operation in the l&water mode. determine,
If there is no remaining water, the pressure at the pressure inflection point is detected in water supply mode operation and the memory is updated as a new water level reference value, and if there is remaining water, the memory of the previous water level reference value is used to update the water storage area. Since it has a control means for determining the water level, it has the following characteristics.

(1) A new water level standard value is memorized and used each time the water in the water tank is replaced, making it less susceptible to aging of the pressure sensor and control means, and ensuring that the set water level is reached even when supplementing with water during boiling. Water can be supplied.

■ Prior to water supply mode operation, it is determined whether there is any remaining water, so the water level will not rise above the set level.

[Brief explanation of the drawing]

Fig. 1 is a flow diagram of the control means of a water level detection device in an embodiment of the present invention, Fig. 2 is a pressure characteristic diagram of the same device when there is residual water, and Fig. 3 is a water level detection to which the same device is applied. The system diagram of the device, Fig. 4 is a block diagram of the control means in the same device, and Fig. 6 is a 70% diagram of the water supply mode operation of the conventional control means.
- Figure and Figure 5 are pressure characteristic diagrams. 1...Water storage section, 4...Outgoing pipe, 5...
...Return pipe, 7...Pump, 9...
Remaining water detection means (water flow switch), 10... Pressure detection means, 12... Water supply source. 14...Switching means, 15. Old control means. Name of agent: Patent attorney Toshio Nakao
Figure 2 Figure 5 Figure 6

Claims (1)

[Claims] a water storage section, an outflow pipe and a return pipe connected to the side of the water storage section, a pump connected to the outflow pipe, and a pressure detection means connected to the return pipe that detects the water level of the water storage section as a pressure signal. a water supply source, a water supply pipe connected to the water supply source, a residual water detection means for detecting the presence or absence of residual water in the water storage section, and a water supply pipe connected to the return pipe or the water supply pipe for circulation. mode or water supply mode, and the pressure value from the pressure detection means are input, and the pump, the water supply source, and the switching means are energized to perform the circulation mode operation and the water supply mode operation, and the water supply mode is activated. Prior to mode operation, the presence or absence of residual water is determined based on the input from the residual water detection means, and if there is no residual water, the pressure at the pressure inflection point is detected in water supply mode operation and the memory is updated as a new water level reference value. and a control means for determining the water level in the water storage section using a memory of a previous water level reference value when there is residual water.