JPH04353343A - Bath circulation device - Google Patents

Abstract

PURPOSE:To provide a bath tub hot water circulation device for use in circulat ing hot water in a bath tub under an operation of a pump, a circulating flow rate of the hot water is adjusted accurately, stably and within a wide range in response to a disturbance in the pump or a phase control circuit or a varia tion in voltage of power supply or a length of a circulation passage or a setting condition such as a set height of equipment and the like. CONSTITUTION:A pressure sensor 10 and a flow switch 8 are disposed in a circulation passage having a pump 3 therein. A bath hot water circulation device is comprised of a reference pressure memory 17 for storing a signal of the pressure sensor 10 when a state of the flow switch 8 is varied, and a flow rate control circuit 16 for feed-back controlling a phase control circuit 15 of the pump with a value of the reference pressure memory 17 and a signal of the pressure sensor 10. A capability of the pump is controlled in such a way that the value of the pressure signal is kept at a value determined according to the ratio between a target flow rate and an on-off flow rate of the flow switch 8, resulting in that the circulating flow rate can be adjusted accurately, stably and within a wide range.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bath circulation device for circulating hot water in a bathtub for reheating, generating bubbles, etc.

0002

2. Description of the Related Art In a conventional bath circulation system, as shown in FIG. 4, a bathtub 1 is connected to a pump 3 and a heating device 4 through a return pipe 2, and is further connected to a bubble generating nozzle 6 through a return pipe 5 to return to the bathtub. It consists of a circulation path and a phase control circuit 7 that further adjusts the capacity of the pump 3. As a means for adjusting the capacity of the pump 3, a phase control circuit with a simple configuration is often used.

[0003] With the above configuration, the strength of the bubble bath can be switched,
The circulating flow rate is adjusted depending on the heating of the bathtub water.

0004

However, in the conventional configuration described above, the relationship between the ignition phase angle of the phase control circuit 7 and the circulation flow rate is as shown in FIG. 5, and the flow rate at low flow rates cannot be stably controlled. I can't do that. In other words, a in the same figure shows the change in the circulating flow rate when the ignition phase angle is changed when the power supply voltage is standard.In the low flow range, the pump is used at a location far outside of its rating, so the change in the circulating flow rate with respect to the phase angle is The change in the flow rate becomes large, and even if control is performed using the phase angle c to adjust the flow rate to the target flow rate b, the flow rate will change greatly due to variations in the pump and variations in the phase control circuit. Furthermore, d and e in the same figure are the characteristics when the power supply voltage changes up and down, respectively, and when the control is performed at the same phase angle c, the flow rate is f
In the case of characteristic e, the pump stops.

FIG. 5 shows a case where the lengths of the return pipe 2 and the outgoing pipe 5 of the circulation path are constant, but in reality, these lengths change depending on the installation state, so the change in flow rate becomes even larger.

As described above, the conventional bath circulation device has the problem that the flow rate cannot be stably adjusted and the flow rate adjustment range cannot be widened.

The present invention solves the above-mentioned problems by stably and widely adjusting the circulation flow rate against variations in pumps and control circuits and fluctuations in power supply voltage, as well as adjusting the circulation flow rate depending on the length of the circulation path and the height of the bathtub and equipment. The object of the present invention is to provide a bath circulation device that can accurately adjust the circulation flow rate without being affected by installation conditions such as differences.

[0008]

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a pressure sensor and a flow switch in a circulation path having a pump, and stores the signal of the pressure sensor when the state of the flow switch changes. The configuration includes a reference pressure memory and a flow rate control circuit that performs feedback control of the pump capacity according to the value of the reference pressure memory and the signal from the pressure sensor.

[0009]

[Operation] With the above configuration, the present invention uses a pressure sensor to detect changes in pressure determined by the piping resistance and circulation flow rate in the circulation path from the bathtub to the pressure sensor, and also changes the state of the flow switch that turns on and off at a constant flow rate. The signal of the pressure sensor at the time is stored in the reference pressure memory, the set value of the pressure signal for the target flow rate is calculated from the value of the reference pressure memory, and the flow rate control circuit is configured so that the signal of the pressure sensor is constant with respect to the set value. Since the pump capacity control means is driven while performing feedback control, the circulating flow rate is kept constant with respect to the target flow rate.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be described below with reference to the accompanying drawings.

In FIG. 1, a bathtub 1 is connected to a pump 3 through a return pipe 2, a flow switch 8 and a reheating heater 9 are connected in order to the outlet side of the pump 3, and a return pipe 5 is connected to a flow switch 8 and a reheating heater 9 in this order.
A circulation path that returns to the bathtub 1 connected to the bubble nozzle 6 is constructed. A pressure sensor 10 is connected to the return pipe 2 near the pump 3. A pouring section 12 is connected to the circulation path via a check valve 11.
is connected. An air valve 14 is connected from the bubble nozzle 6 via an air pipe 13. Pump 3 is connected to AC power supply 21 through phase control circuit 15 . A signal from the pressure sensor 10 is connected to a reference pressure memory 17 and a stop pressure memory 18 via a pressure detection circuit 16, and is also connected to a flow rate control circuit 19. The values of the reference pressure memory 17 and the stop pressure memory 18 are connected to the target pressure calculation section 20, respectively, and the output of the target pressure calculation section 20 is connected to the flow rate control circuit 19. Furthermore, the output of the flow rate control circuit 19 is configured to be connected to the phase control circuit 15.

In the above configuration, the pressure sensor 10 detects the pressure at the connection point of the pressure sensor 10 of the return pipe 2. Figure 2
is a characteristic diagram showing the relationship between the circulating flow rate and the signal of the pressure sensor. g in the same figure is the characteristic in the case of the piping example in FIG. It changes depending on the relationship. In this case, pressure sensor 10
is connected to the suction side of the pump 3, so the pressure signal changes in the negative direction. Once the length of the return pipe 2 is determined in this manner, the relationship between the circulation flow rate and the pressure signal becomes constant.

FIG. 3 is a control flowchart of the above embodiment. The pump 3 is stopped in step S1, and the pump 3 is stopped in step S2.
Then, the pressure signal at that time is stored in the stop pressure memory 18. Since the flow rate of the return pipe 2 is zero, the pressure signal at this time is a static pressure determined by the water level of the bathtub 1 and the installation height of the pressure sensor 10, and becomes h in FIG. After that, in step S3, the phase control circuit 15 gradually increases the capacity of the pump 3 from the minimum capacity, and in step S4, it detects that the signal of the flow switch 8 changes from off to on, and converts the pressure signal at that time to the reference pressure. It is stored in the memory 17. The pressure signal at this time becomes i in FIG. This ON flow rate of the flow switch 8 will be referred to as a reference flow rate hereinafter. In step S5, the target pressure calculation section 2
At 0, the value of stop pressure memory 18 and reference pressure memory 1
Find j in FIG. 2, which is the difference between the values of 7 and 7. In step S6, a set pressure signal for the target circulation flow rate is determined. For example, when the target flow rate is k, which is twice the reference flow rate, the pressure changes as the square of the flow rate with a coefficient due to piping resistance, so m, which is the difference between the pressure at the target flow rate k and the pressure at the time of stop, is It is determined as the square of the ratio to the reference flow rate (in this case, 4 times j). Once m is determined, the set pressure is determined as n, which is lower than the stop pressure h by m. Thereafter, in step S7, the flow rate control circuit 19 changes the firing phase angle of the phase control circuit 15 so that the pressure signal becomes equal to n, and the flow rate is controlled to be constant. If the target flow rate has been changed, step S6 in FIG.
Start over.

P in FIG. 2 shows the characteristic when the lengths of the return pipe 2 and the outgoing pipe 5 become longer, and the change in pressure becomes larger for the same flow rate change as the piping resistance becomes larger. In this case, similarly to the above, the pressure signal when the flow switch 8 is turned on is stored, the pressure difference q is determined from the signals of the stop memory 17 and the reference pressure memory 18, and the pressure difference r for twice the flow rate is calculated. , the set pressure s is determined, and the flow rate is controlled to be twice the reference flow rate. Therefore, even if the piping resistance changes depending on the installation conditions, the flow rate can be controlled to any desired value based on the maximum flow rate.

[0015] Also, depending on the installation conditions, the bathtub 1 and the pressure sensor 1 may be
When a height difference of 0 is created, the absolute value of the stop pressure h in FIG. 2 changes up and down. In this case as well, since the difference is determined using the stop pressure memory 18 and the reference pressure memory 17, the vertical difference in installation is canceled and has no effect.

When the bubble valve 14 is opened and the pump 3 is operated, air is sucked in by the suction effect of the bubble nozzle 6, resulting in bubble jet operation. At this time, the strength of the bubble jet can be changed arbitrarily by adjusting the circulation flow rate using the above-mentioned action. Further, during heat retention and reheating, the bubble valve 14 is closed and the pump 3 is operated while the reheating heater 9 is energized. At this time, the circulating flow rate is controlled to a low flow rate to prevent hot water from hitting the bather with force. Further, by confirming that the flow switch 8 is turned on and energizing the reheating heater 9, dry heating can be prevented.

The hot water pouring section 12 automatically fills hot water into the bathtub 1, and has a function of mixing hot water from the hot water inlet and water from the water inlet at an appropriate temperature, and an opening/closing function, and has an opening/closing function. Fill the bathtub with hot water. At this time, the pump 3 is stopped, and a change in pressure corresponding to the water level in the bathtub 1 is applied to the pressure sensor 10 via the return pipe 2. Stop pouring at the set water level.

As described above, according to the configuration of this embodiment, after the signal of the pressure sensor 10 when the flow switch 8 is turned on is stored in the reference pressure memory 17, the value of the reference pressure memory 17 and the signal of the pressure sensor 10 are stored. This allows the flow rate control circuit 19 to drive the phase control circuit 15 to perform feedback control of the circulating flow rate, and eliminates pump variations, power supply voltage fluctuations,
Furthermore, the circulation flow rate can be accurately and stably adjusted over a wide range without being affected by installation conditions such as the length of the circulation path or the set height of the equipment. Furthermore, the pressure sensor 10 can also be used as a water level sensor for automatic hot water filling, and the flow switch 8 can also be used to prevent dry heating of the reheating heater 9, so that the equipment can be realized at low cost.

In the above embodiments, an AC motor phase control circuit was used as the pump capacity control means, but it goes without saying that other control means can have similar effects. Further, although the storage timing of the reference pressure memory 17 is set when the flow switch 8 is turned on, the same holds true when the flow switch 8 is turned off when the pump is stopped.

[0020]

As explained above, according to the bath circulation device of the present invention, a pressure sensor and a flow switch are provided in a circulation path having a pump, and a signal from the pressure sensor is stored when the state of the flow switch changes. Since the system is equipped with a reference pressure memory to control the pressure, and a flow rate control circuit that drives the pump capacity control means based on the value of the reference pressure memory and the signal from the pressure sensor, the pressure signal does not match the set pressure determined from the value of the reference pressure memory. (1) The circulation flow rate can be stably adjusted over a wide range without being affected by variations in the pump or power supply voltage. (2) Even if the installation conditions such as the length of the circulation path or the installation height of the equipment change, the flow rate can be controlled accurately because it is controlled based on the ratio of the on/off flow rate of the flow switch.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of a bathtub circulation device in an embodiment of the present invention.

[Figure 2] Characteristic diagram of flow rate versus pressure of the device

[Figure 3] Control flowchart of the device

[Figure 4] Configuration diagram of a conventional bathtub circulation device

[Fig. 5] Flow control characteristic diagram of a conventional bathtub circulation device

[Explanation of symbols] 1 Bathtub 2 Return pipe 3 Pump 5 Outgoing pipe 8 Flow chart 10 Pressure sensor 15 Phase control circuit (capacity control means) 17 Reference pressure memory 19 Flow rate control circuit

Claims (1)

[Claims] 1. A bath circulation path having a bathtub and a pump, a pressure sensor and a flow switch connected to the circulation path, a capacity control means for the pump, and a control means for adjusting the capacity control means and controlling the state of the flow switch. a reference pressure memory that stores a signal from the pressure sensor when the pressure changes; and a flow rate control circuit that performs feedback control of the pump capacity control means based on the value of the reference pressure memory and the signal from the pressure sensor. Circulation device.