JPH0639305Y2 - Water level detector in bathtub - Google Patents

Description

[Detailed Description of the Invention] [Field of Use] The present invention relates to a water level detection device in a bathtub for determining the water level of the filling water placed in a bathtub, and enables the water level detection operation to be performed quickly and accurately. It is the one.

[Prior Art and Problem] An automatic water filling device has come into widespread use, which automatically stops the water filling operation when the hot water supplied to the bathtub reaches the completion water level of the water filling. For example, the third
Some are shown in the figure.

In the water filling circuit (2) connected to the bathtub (1), a water pump (P), an opening / closing valve (3) and a water pressure gauge (4) are provided from the upstream side.
Are inserted in this order, and the operation of the water supply pump (P) and the on-off valve (3) is controlled by the control device (5) that monitors and judges the water pressure detected by the water pressure gauge (4). ing.

When a water filling switch (not shown) is turned on and a water filling operation is performed, a control signal from the control device (5) causes the open / close valve (3) to be opened and the water supply pump (P) to be driven. The filling water begins to be supplied into the bathtub (1) by P).

In this, the water supply operation to the bathtub (1) is performed intermittently, and the water supply pump (P) is stopped every time a predetermined fixed amount of water is supplied into the bathtub (1). At the same time, the on-off valve (3) is closed. That is, the filling operation is advanced by intermittently repeating water supply into the bathtub (1) and stopping.

When the water supply pump (P) is stopped and the on-off valve (3) is closed, the water pressure gauge (4) inserted in the water filling circuit (2) and the water filling placed in the bathtub (1). The water pressure (HB) corresponding to the difference in height from the water surface will be detected by the water pressure gauge (4), and the water in the bathtub (1) will reach the water level at which water filling is completed and the corresponding water pressure will be the above. When detected by the water pressure gauge (4), the water pump (P) is stopped and the on-off valve (3) is closed by the control device (5) which judges the output of the water pressure gauge (4). The tensioning operation is completed.

However, in the above-mentioned conventional one, the water pressure measuring operation of the water pressure gauge (4), which is repeatedly performed, is stopped after the water filling pump (P) is stopped and the opening / closing valve (3) is closed. Since it has to be executed, there is a problem that it takes a long time to fill water.

In order to solve this problem, the on-off valve (3) is removed from the water filling circuit (2) shown in FIG. 3 to form a circuit as shown in FIG. It is also conceivable to perform the water pressure detection operation by the water pressure gauge (4) while supplying the filling water with the pump (P).

However, in this case, there is a problem that the water level in the bathtub when the filling is completed is likely to deviate from the proper position and accurate filling cannot be performed.

In the improvement plan shown in FIG. 4, the pressure loss (hereinafter, referred to as “pressure loss” due to friction or the like generated between the filling water and the pipe inner wall (the pipe inner wall forming the filling circuit (2)) through which the filling water flows. This is because the PA loss (PA) changes with the rise of the water level in the bathtub.

The above cause will be described in more detail. In the case of the improvement plan shown in FIG. 4, when the water level in the bathtub rises as the water filling operation progresses, the water pressure in the water filling circuit (2) rises as the water level rises. Also rises, and this water pressure is transmitted to the water supply pump (P), so the amount (flow rate) of water sent out by the water supply pump (P)
Will decrease. Then, the conduit loss (PA) that changes in comparison with the flow rate of the filling water flowing through the water filling circuit (2) decreases as the flow rate decreases, and a conduit loss change Δ (PA) occurs. .

Then, the pipe loss change Δ (PA) is transmitted to the water filling circuit (2) as the water level in the bathtub rises, and the water pressure change Δ (H
B) and the water pressure gauge (4)
A) gets mixed in the water pressure change Δ (HB) due to the rise of the water level in the bathtub. That is, when the water level in the bathtub is detected as water pressure by the water pressure gauge (4), the above-mentioned pipe loss change Δ (PA) is applied to the water pressure gauge (4) as noise.

Therefore, the water in the bathtub (1) reaches the water level at which water filling is completed and the corresponding water pressure (the water pressure corresponding to the difference in height between the water level in the water bath in the water filling completed state and the water pressure gauge (4)) is Even if the water pressure is transmitted to the water pressure gauge (4) side, the water pressure indicating the completion of the filling is disturbed by the noise effect of the above-mentioned pipe line loss change Δ (PA),
The water pressure indicating the water filling completion state cannot be accurately detected by the water pressure gauge (4).

For this reason, when the filling operation is completed, the water level in the bathtub deviates from the proper position, and accurate filling cannot be performed.

As described above, the conventional one shown in FIG. 3 can perform accurate water filling in which the water level in the bathtub at the time of completion of the water filling is properly aligned with the proper position, but the disadvantage that the time required to fill the water is long occurs. On the other hand, on the other hand, in the improvement plan shown in FIG. 4 in which the water pressure detected by the water pressure gauge (4) is monitored while continuously supplying water with the water supply pump (P), in contrast to the one shown in FIG. Although it takes a short time, there is a problem that accurate filling cannot be done.

The present invention has been made in view of such a point, and "The water supply pump (P) is provided in the water filling circuit (2) connected to the bathtub (1)."
And a water pressure gauge (4) located downstream of the water pressure gauge (4) are inserted so that the water level in the bathtub when the water is filled is detected as pressure by the water pressure gauge (4). Even if the water pressure detection operation by the water pressure gauge (4) is performed while continuing the water supply operation by the pump (P), the above-mentioned conduit loss change Δ (PA) that acts as noise when the water pressure is detected.
Therefore, it is an object of the present invention to prevent water from rising due to an increase in the water level in the bathtub, and thereby to perform the filling operation quickly and accurately.

[Means] The technical means of the present invention for solving the above-mentioned problem is that "a flow meter (6) for measuring the flow rate of water flowing in the water filling circuit (2) and an output of the flow meter (6) are provided. The control device (5) to be applied is provided, and the control device (5) controls the output of the water supply pump (P) so that the output of the flow meter (6) becomes constant.

[Operation] The above technical means operates as follows.

When the water supply pump (P) is driven to start the filling operation, the flow rate of the filling water flowing in the filling circuit (2) begins to be continuously measured by the flow meter (6).

When the water filling operation progresses and the water level in the bathtub rises, and the water pressure that increases with the rise of the water level acts on the water supply pump (P) from the water filling circuit (2), the increased water pressure is increased by the water supply pump (P). To reduce the amount of water to be sent.

However, a flow meter (6) that measures the flow rate in the water filling circuit.
The control device (5) to which the output of (3) is applied controls the output of the water supply pump (P) so that the output of the flow meter (6) becomes constant, and thus the water supply pump (P) that is likely to decrease. The amount of water sent will be kept constant. That is,
When the water level in the bathtub rises and the water pressure acting on the water feed pump (P) increases, the water feed pressure of the water feed pump (P) is increased by increasing the water feed pressure of the water feed pump (P) in proportion to the increase in the pressure. It keeps the flow rate constant. As a result, the flow rate of the filling water flowing in the filling circuit (2) becomes constant.

Then, if the flow rate of the filling water flowing through the filling circuit (2) is kept constant, the loss of the pipe line that occurs when the filling water flows through the filling circuit (2) affects the change in the water level in the bathtub. Instead, it is kept constant at all times, and the above-mentioned change in pipe loss that acts as noise on the water pressure gauge (4) does not occur.

[Effect] The present invention has the following unique effects.

Even if the water pressure detecting operation is performed by the water pressure gauge (4) while maintaining the water feeding operation by the water feed pump (P), the change in the line loss Δ entering the water pressure gauge (4) for detecting the water pressure as noise.
Since (PA) does not occur, the water pressure gauge (4) changes its output depending only on the change of the water level in the bathtub. From this, the water level in the bathtub can be accurately determined, and a quick and accurate filling operation can be performed.

[Embodiment] Next, an embodiment of the present invention described above will be described in detail with reference to the drawings.

As shown in FIG. 1, in the water filling circuit (2) connected to the bathtub (1), the water filling valve (21), the backflow prevention device (22), the flow meter (6), A water supply pump (P) and a water pressure gauge (4) are sequentially arranged. As the motor (M) that is the drive source of the water pump (P), in this embodiment, a DC motor that is easier to control the rotation speed and the magnitude of generated torque than an AC motor is used, and will be described later. It is easy to control the equipment. In addition, as the motor (M), a brushless DC motor is most preferable for controlling the appliance.

The outputs of the flow meter (6) and the water pressure gauge (4) are input to a control device (5) in which a microcomputer (hereinafter abbreviated as a microcomputer) (51) is incorporated, and the control device (5) The water supply pump (P) and the water filling valve (21) are controlled by judging the outputs of the flow meter (6) and the water pressure gauge (4).

The microcomputer (51) incorporated in the control device (5) has a second
A control program as shown in the flowchart of the drawing is written, and the operation of each component will be described below according to the above flowchart.

． When a water filling switch (not shown) is turned on, the water filling valve (21) is opened and the water supply pump (P) is driven, whereby the water filling operation is started. (Refer to the step of drawing code (90)). When the filling operation is started, the filling water is sent to the downstream end portion of the filling circuit (2) (the water discharge port (29) portion where the filling circuit (2) opens to the bathtub (1)). Wait for the waiting time (T1) required for the circuit (2) to fill with water. (Refer to the step of drawing code (91)). After the waiting time (T1) has elapsed and the water is filled up to the downstream end of the water filling circuit (2), the water filling water in the bathtub (1) is discharged for a while (the water discharge port (29) at the downstream end of the water filling circuit. Until the water level rises to a certain portion), a constant water pressure is applied to the water pressure gauge (4). This water pressure corresponds to the line loss (PA) that occurs when the filling water flows in the filling circuit, and the height difference between the water pressure gauge (4) and the outlet (29) at the downstream end of the filling circuit. It is the sum of water pressure (PC). The microcomputer (51) uses the output of the water pressure gauge (4), which detects the sum of the two water pressures (PA) and (PC), as the reference water pressure (P0).
It is stored in the second memory (M2). At this time, the output of the flow meter (6) measuring the flow rate of water flowing in the water filling circuit (2) per unit time is used as the reference flow rate (Q0), and the first memory (M1) of the microcomputer (51) is used. To memorize. (Refer to the step of drawing code (92)). When the water filling operation progresses and the water level in the bathtub rises, the water level becomes higher than the water discharge port (29) portion where the water filling circuit opens inside the bathtub. Then, the water pressure applied to the water pressure gauge (4) is as follows. That is, the water pressure gauge (4) has a water pressure (hereinafter, referred to as a monitoring water pressure (PB)) corresponding to the height difference between the water discharge port (29) on the wall surface of the bathtub and the water surface of the water in the bathtub, and the second memory (M).
The water pressure added with the reference water pressure (P0) stored in 2) will be applied. Then, the microcomputer (51) outputs the output of the water pressure gauge (4), which detects the sum of the above-mentioned monitored water pressure (PB) and reference water pressure (P0), to the water filling completion water pressure (reference stored in the second memory (M2)). It is judged whether the water pressure (P0) and the monitor water pressure (PB) that is expected to be reached at the time of completion of filling are reached, and the water pressure detected by the water pressure gauge (4) becomes the completion water filling pressure. When it has reached, the water supply pump (P) is stopped and the water filling valve (21) is closed to stop the water filling operation. (Refer to the steps of the drawing symbols (93), (94)) On the other hand, the water pressure detected by the water pressure gauge (4) is smaller than the water filling completion water pressure, and it is determined that the water level in the bathtub (1) has not reached the water filling completion level. If it does, the program control shifts to the step “” described below.

． When the water level in the bathtub rises and the increased water pressure corresponding to the water level rise is applied to the water feed pump (P), the water pressure acts to reduce the water feed amount of the water feed pump (P), and the water filling circuit (2). The flow rate inside is likely to decrease. Then, when the flow rate in the water filling circuit (2) decreases, the pipe loss (PA) that is going to be maintained at a constant value decreases, so is there a decrease in the water supply amount of the water supply pump (P)? Whether or not it is determined by the output of the flow meter (6). That is, the flow meter (6)
It is determined whether or not the detected flow rate is less than the reference flow rate (Q0) stored in the first memory (M1). (Refer to the step of the drawing code (95)) And when it is judged that the output of the flow meter (6) is smaller than the reference flow rate (Q0) and the flow rate of water flowing in the water filling circuit (2) is low. Controls the electric power supplied to the motor (M) so that the rotation speed of the motor (M) that drives the water supply pump (P) does not drop, thereby keeping the rotation speed of the motor (M) constant. That is, water pump (P)
The amount of water supplied is kept constant and the flow rate of the filling water flowing in the filling circuit (2) is stabilized. As a result, the flow rate of the filling water flowing in the filling circuit (2) is kept constant until the filling operation is completed, and thus the pipe line loss (PA) is also kept constant, and the water pressure gauge ( The measured water pressure of 4) changes depending only on the change of the water level in the bathtub (1). That is, when the water level in the bathtub is detected by the water pressure gauge (4) as pressure, the water pressure detected by the water pressure gauge (4) has a pipe loss change Δ (PA) which acts as noise on the detected water pressure.
Will no longer be included.

When the flow rate of the filling water flowing in the filling circuit (2) reaches the standard flow rate (Q0), the control program
Again, the process is returned to the above step "" for judging whether the water level in the bathtub has reached the hot water completion level, and by judging the output of the water pressure gauge (4) as described above, the bathtub (1)
When it is found that the inside of the tank has reached the level of boiling water, the water supply pump (P) is stopped and the water filling valve (21) is closed.
Stop the filling operation.

As described above, in the case of the above, the line loss (PA) is always constant until the filling is completed, and the line loss change Δ
Since (PA) does not occur, the above Δ (PA) does not act as noise on the water pressure gauge (4) that determines when the filling of water is completed. Therefore, the water pressure gauge (4) can accurately detect the water level in the bathtub, and the water level in the bathtub in the water-filled state is hardly displaced from the proper position.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an embodiment of the present invention, FIG. 2 is a flow chart explaining a control program written in a microcomputer (51) for a control device (5), and FIG. 3 is an explanatory diagram of a conventional example. FIG. 4 is an explanatory view showing an improvement plan of the conventional example. In the figure, (1) ... tub (2) ... water filling circuit (4) ... water pressure gauge (5) ... control device (6) ... … Flowmeter (P) …… Water pump

Claims (2)

[Scope of utility model registration request] 1. A water filling circuit (2) connected to a bathtub (1),
Water pump (P) and water pressure gauge (4) located downstream of it
In the bathtub water level detection device in which the water level in the bathtub when the water is filled is detected by the water pressure gauge (4) as a pressure, the flow rate of water flowing in the water filling circuit (2) is measured. A flowmeter (6) for controlling the flowmeter and a control device (5) to which the output of the flowmeter (6) is applied are provided, and water is supplied by the control device (5) so that the output of the flowmeter (6) becomes constant. A water level detection device in a bathtub configured to control the output of a pump (P). 2. A water level detecting device in a bathtub according to claim 1, wherein a direct current motor is used as a drive source of the water supply pump (P).