JP7365305B2 - water heater - Google Patents

Description

The present invention relates to a water heater, and more particularly to a water heater that mixes hot water and water to obtain mixed hot water at a set temperature.

Conventionally, this type of valve has a mixing valve that mixes hot water and water at a timing that corresponds to the temperature change in the heat exchanger to obtain mixed hot water at a set temperature in preparation for the next hot water tap while the hot water tap is stopped. There is one that adjusts the opening degree of the mixing valve body. (For example, see Patent Document 1)
In addition, some water heaters carry out a reference position initialization process after a predetermined period of time has elapsed from the stop of hot water dispensing to return the position of the mixing valve element of the mixing valve to the reference position. (For example, see Patent Document 2)

JP2003-287280A Patent No. 5502772

Generally, when the mixing valve is driven, a driving sound is generated when the mixing valve is driven, but with this conventional type, when hot water is being dispensed, the combustion sound of the burner part of the main water heater and the sound of the faucet when hot water is being dispensed are generated. Although the driving sound of the mixing valve does not make the user feel uncomfortable due to the sound of water coming out of the shower or shower, the driving sound of the mixing valve when the hot water supply is stopped is the driving sound of the mixing valve even though the hot water supply is stopped. , which causes discomfort to the user.

Therefore, as a countermeasure against the driving noise of the mixing valve, it is possible to reduce the driving noise of the mixing valve by increasing the driving frequency of the stepping motor that drives the mixing valve, but in general, when the driving frequency is increased, the driving torque As a result, due to changes in the equipment over time, foreign matter adheres to the mixing valve element of the mixing valve, making it impossible to adjust the mixing valve to the normal opening degree, making it impossible to adjust the water temperature to the set temperature, and causing the water temperature to become smaller. There was a possibility that the mixing valve reference position initialization process could not be performed.

The present invention has been made in view of this background, and an object of the present invention is to provide a hot water supply device that can maintain the mixing valve normally while reducing the driving noise of the equipment when the hot water supply is stopped.

The present invention has been made to achieve the above object, and in claim 1, hot water heated by a heating means and water supplied from a water supply pipe are mixed, and the opening degree of the mixing valve is controlled by a stepping motor. The hot water supply device adjusts the mixed hot water to a set hot water temperature by driving and changing the temperature, the mixing valve control circuit controlling the opening degree of the mixing valve using the stepping motor, and a hot water supply detection circuit that detects whether hot water is being stopped, and the mixing valve control circuit drives the stepping motor at a first drive frequency when the hot water supply detection circuit detects that hot water is being discharged. , the stepper motor is driven at a second drive frequency higher than the first drive frequency when the hot water supply detection circuit detects that the hot water supply is stopped.

In a second aspect of the present invention, the mixing valve control circuit is configured to output a detection signal to the mixing valve control circuit when the opening degree of the mixing valve reaches a predetermined reference opening degree, and the mixing valve control circuit is configured to output a detection signal to the mixing valve control circuit. , a reference position initialization process is performed in which the opening degree of the mixing valve is directed toward the reference opening degree and the mixing valve is continuously driven until the detection signal is received from the mixing valve, and the reference position initialization process is performed. starts while the hot water supply is stopped, drives the stepping motor at the second drive frequency, starts counting the timer, and if the timer receives the detection signal within a predetermined time, If the position initialization process is completed and the timer does not receive the detection signal within a predetermined time, the stepping motor is driven at the first drive frequency. did.

In claim 3, the stepping motor is driven with a first excitation method instead of being driven with the first drive frequency, and with a second excitation method different from the first excitation method instead of being driven with the second drive frequency. It is characterized by being driven by an excitation method.

According to claim 1, even if the mixing valve element of the mixing valve becomes difficult to move due to scaling caused by aging of the stepping motor, contamination of foreign matter, or sticking of the valve, the driving frequency of the stepping motor is maintained during tapping. Since it is driven at the first drive frequency that gives priority to torque, it is possible to remove the sticking failure of the mixing valve element, and avoid the risk that the mixing valve element will not move and hot water at the set temperature set by the user will not come out. . Furthermore, when the hot water is not being dispensed, the main source of driving noise is the mixing valve, and the stepping motor is driven at a second driving frequency that is higher than the first driving frequency, so that the stepping motor can be driven at a driving frequency that allows the stepping motor to be driven with low noise. Since the device is driven by the power source, the driving noise can be reduced and the user can use it comfortably without feeling uncomfortable.

In claim 2, the stepping motor is driven at the second drive frequency, which is a low-noise drive frequency, in the reference position initialization process performed while the hot water supply is stopped, so that drive noise can be reduced, causing discomfort to the user. If the reference position initialization process is not completed at the second drive frequency, the stepping motor is driven at the first drive frequency with a large drive torque. It is possible to eliminate the problem of sticking of the mixing valve body, and as a result, the frequency of occurrence of errors is reduced, and the equipment can be used comfortably without becoming unusable.

In a third aspect of the present invention, the stepping motor is driven by a first excitation method in which the stepping motor is driven with torque priority, instead of being driven at the first drive frequency, which is a method that gives priority to torque, and Instead of driving the motor at the second driving frequency, which is a method of driving the motor with low noise, the second excitation method, which is also a method of driving with low noise, is used to prevent sticking of the stepping motor during tapping. This eliminates the risk of the mixing valve becoming stuck and not producing hot water at the temperature set by the user, and reduces drive noise while the hot water supply is stopped, providing comfort without causing discomfort to the user. Can be used.

A schematic configuration diagram explaining an embodiment of the present invention A block diagram of an electric circuit according to the embodiment of the present invention A sectional view of a mixing valve according to the embodiment of the present invention Control circuit block diagram of the mixing valve according to the embodiment of the present invention Control flow diagram of the embodiment of the present invention Control flow diagram of mixing valve reference position initialization processing according to the embodiment of the present invention Control circuit block diagram of a mixing valve according to a second embodiment of the present invention

A water heater according to an embodiment of the present invention will be described with reference to FIGS. 1 to 7.
Note that, in each figure, common components and components of the same type are denoted by the same reference numerals, and overlapping explanations thereof will be omitted as appropriate.

As shown in FIG. 1, reference numeral 1 denotes a water heater, which is roughly divided into a hot water supply circuit 2, a bath reheating circuit 3, and a bath water filling circuit 4.

First, to explain the hot water supply circuit 2, 5 is a water supply pipe, 6 is a water supply temperature sensor that detects the temperature of water supply, 7 is a water supply flow rate sensor that detects the amount of water supply, 8 is a heat exchanger for hot water supply, 9 is a hot water outlet pipe, 10 is a hot water temperature sensor that detects the hot water temperature on the outlet side of the hot water supply heat exchanger 8; 11 is a bypass pipe that connects the water supply pipe 5 to the hot water supply pipe 9 by bypassing the hot water supply heat exchanger 8; and 12 is a hot water discharge pipe. 13 is a hot water supply pipe; 14 is a hot water temperature sensor that detects the temperature of the mixed hot water; 15 is a water supply temperature sensor that detects the temperature of the mixed hot water; 16 is a faucet provided at the end of the hot water supply pipe 13; 17 is a burner section as a heating means for heating the hot water supply heat exchanger 8; 60 is the surface of the hot water supply heat exchanger 8; This is a heat exchanger temperature sensor that detects temperature.

Next, the bath reheating circuit 3 will be explained. 18 is a bathtub, 19 is a bath return pipe, 20 is a bath going pipe, 21 is a bath heat exchanger heated by the burner part 17, and 22 is a hot water in the bathtub 18. 23 is a bath temperature sensor that detects the temperature of circulating bath water, 24 is a water switch that detects whether or not the bath water is being circulated, and 25 is a pressure sensor that detects the water level in the bathtub 18 by pressure. The water level detector 26 is a three-way water filling valve that connects the bath water filling circuit 4 and the bath reheating circuit 3, which will be described later.

Next, to explain the bath water filling circuit 4, 27 is a bath water filling pipe branched from the downstream side of the hot water supply pipe 13 of the hot water supply circuit 2 and connected to the hot water filling three-way valve 26 of the bath reheating circuit 3; 28 is a hot water filling solenoid valve that opens and closes the bath water filling pipe 27; 29 is a hot water filling flow rate sensor that detects the flow rate passing through the bath hot water filling pipe 27; and 30 is a water filling solenoid valve for preventing bath water from flowing back into the hot water supply circuit 2. A double check valve is used to fill the bathtub 18 with a preset amount of hot water.

Next, reference numeral 31 denotes a control section which is composed of a microcomputer and controls the water heater 1.
Further, 32 is a remote controller that is connected to the control unit 31 and instructs the operation of the water heater 1, and includes various operation switches such as a bath automatic switch 33, a bath set temperature change switch 34, a hot water set temperature change switch 35, and a reheat switch 36. and a display 37 are provided.

Furthermore, as shown in FIG. 2, on the input side of the control unit 31, there are various sensor groups 38, such as a water supply temperature sensor 6, a water supply flow rate sensor 7, a hot water outlet temperature sensor 10, a heat exchanger temperature sensor 60, a water level detector 25, etc. Various operation switches such as the above-mentioned bath automatic switch 33, bath set temperature change switch 34, hot water supply set temperature change switch 35, reheating switch 36 are connected, and the output side is connected to control the combustion of the burner section 17. A burner drive circuit 39, a three-way valve control circuit 40 that controls the above-mentioned hot water filling three-way valve 26, an indicator 37, a circulation pump 22, and a stepping motor 46 that drives the mixing valve 12 are connected and controlled to be energized. .

The control unit 31 also includes a hot water supply detection circuit 52 that determines whether hot water is being discharged or hot water has been stopped based on a signal input from the water supply flow rate sensor 7, a mixing valve control circuit 53 that controls the mixing valve 12, and a mixing valve control circuit 53 that controls the mixing valve 12. A timer 54 is provided to count the time limit for the valve control circuit 53 to perform the reference position initialization process.

Next, the mixing valve 12 shown in FIG. 3 will be explained.
41 communicates with a hot water flow path 42 through which hot water from the outlet pipe 9 flows, and a water flow path 43 which has a slightly smaller diameter than the hot water flow path 42 and through which the water supply from the bypass pipe 11 flows, facing each other at 180 degrees opposite positions. The mixing portion is provided with a mixing valve body 45 having a hollow interior and an open port 44 extending over half of its peripheral wall.

A stepping motor 46 drives the mixing valve body 45 via a drive shaft 47, and is fixed above the mixing section 41 with a screw 48. Reference numeral 49 denotes a mixing flow path that communicates with the hollow part of the mixing valve body 45 at the bottom of the mixing part 41 and through which a mixture of hot water and water flows, and a hot water supply temperature sensor 14 that detects the temperature of the mixed water is provided in the middle. .

The control unit 31 controls the driving of the stepping motor 46 based on the deviation value between the set temperature set by the hot water setting temperature change switch 35 of the remote controller 32 and the actual mixed water temperature detected by the hot water temperature sensor 14, and performs mixing. By adjusting the opening degree of the mixing valve body 45 of the valve 12, the mixing ratio of hot water and water is adjusted.

The drive circuit for the mixing valve 12 will be explained with reference to FIG.
The mixing valve control circuit 53 includes a drive frequency switching circuit 50 that switches the drive frequency of the stepping motor 46 based on the signal input from the hot water detection circuit 52, and a drive pulse generation circuit 51 that generates pulses. , drives the stepping motor 46.

Next, the operation of this embodiment of the invention will be explained based on FIG.
If you open the faucet 16 now and start dispensing hot water, the mixing valve control circuit 53 detects this as a dispensing hot water by the dispensing water flow rate sensor 7 at the dispensing water detection circuit 52 in S001, and then proceeds to S002 to start the stepping motor 46. , the stepping motor 46 is driven at a first drive frequency (for example, 180 pps) that gives priority to drive torque.

To adjust the opening degree of the mixing valve body 45, the mixing valve control circuit 53 moves the mixing valve body 45 to a position where the mixing ratio of hot water and water reaches a predetermined value based on a signal from the hot water setting temperature change switch 35. , and adjust the opening degrees of the hot water flow path 42 and the water flow path 43 at the same time.
Hot water heated by the hot water supply heat exchanger 8 is supplied from the hot water flow path 42, and cold water is supplied from the water flow path 43, mixed in the mixing section 41, and supplied via the mixing flow path 49. The hot water supply temperature sensor 14 detects the actual mixed water temperature, and based on the deviation value from the set temperature, the stepping motor 46 is driven again, and the position of the mixing valve body 45 is finally finely adjusted and determined. After that, you can obtain mixed hot water at the set temperature.

As a result, even if the mixing valve body 45 becomes difficult to move due to clogging with scale over time, contamination of foreign matter, or sticking of the valve, the driving frequency is driven at the first driving frequency during tapping. Since the mixing valve body 45 is driven with torque priority, it is possible to eliminate the problem of sticking of the mixing valve body 45, and to avoid the risk of the mixing valve body 45 not moving and hot water at the set temperature set by the user not being dispensed.

Next, when the faucet 16 is closed, the mixing valve control circuit 53 detects that the hot water supply detection circuit 52 has stopped dispensing hot water by the water supply flow rate sensor 7 in S001, and transitions to S003, in which the stepping motor 46 is driven, and the mixing valve control circuit 53 starts the first drive. The stepping motor 46 is driven at a second drive frequency (for example, 500 pps) that is higher than the frequency.

As a result, when adjusting the opening of the mixing valve body 45 when the hot water tap is stopped, the mixing valve body 45 is driven at a second drive frequency that is higher than the first drive frequency, and the mixing valve body 45 is driven at a drive frequency that can be driven with low noise. It can be used comfortably without causing discomfort to the user.

Next, reference position initialization processing for the mixing valve 12 will be explained based on FIG. 6.
The mixing valve control circuit 53 performs a reference position initialization process for the mixing valve 12 after a predetermined period of time (for example, 10 minutes) has elapsed since hot water has stopped dispensing, and corrects the deviation in the reference opening position of the mixing valve body 45. I'm trying to prevent it from happening.

The mixing valve control circuit 53 resets the timer 54 that counts the time limit required for the reference position initialization process in S004, and starts counting in S005. If the timer 54 is within the predetermined time in S006, in S007 the stepping motor 46 is driven at a second drive frequency (for example, 500 pps) that can be driven with lower noise than the first drive frequency, and the rotation range angle of the mixing valve body 45 is changed. When the mixing valve body 45 comes to a predetermined position (i.e., the magnet provided on the rotation angle regulating member is set to the hole When a detection signal is received from the Hall element in step S008, it is determined that the opening is the reference opening degree, and the reference position initialization process is terminated. If the opening degree is not the standard opening degree, the process moves to S006.

When the timer 54 reaches a predetermined time in S006, the process moves to S009, the timer 54 is reset, and counting starts in S010. If the timer 54 is within the predetermined time in S011, the stepping motor 46 is driven at the first drive frequency (for example, 180 pps) that can be driven with torque priority in S012, and the rotation that regulates the rotation range angle of the mixing valve body 45 is performed. When the mixing valve body 45 comes to a predetermined position by the magnet and the Hall element provided in the corner regulating member, when a detection signal is received from the Hall element in S013, it is determined that the opening is at the reference opening and returns to the initial reference position. Terminate the conversion process. If the opening degree is not the standard opening degree, the process moves to S011.

When the timer 54 reaches a predetermined time in S011, the process moves to S014, an error is reported on the display 37 of the remote controller 32, and the process ends.

As a result, S007 was driven at the second drive frequency that allows for low-noise driving, so the drive noise can be reduced and the user can use it comfortably without causing discomfort. Even if the reference opening degree is not reached within the predetermined time, the mixture valve body 45 is driven at the first drive frequency with a larger drive torque than the second drive frequency in S012, so that the sticking of the mixing valve body 45 due to limescale can be released.

Next, a second embodiment will be described with reference to FIG.
The mixing valve control circuit 53 is driven by a drive pulse generation circuit 51 that generates pulses to the stepping motor 46 based on the signal input from the hot water output detection circuit 52, and a first excitation method that can be driven with torque priority. A first excitation method drive circuit 56a, a second excitation method drive circuit 56b that is driven by a second excitation method that can be driven with lower noise priority than the first excitation method, and a first excitation method drive circuit 56a that is connected to the stepping motor 46. The first excitation method priority switch 57a connects the first excitation method priority switch 57a, and the second excitation method priority switch 57b connects the second excitation method drive circuit 56b to the stepping motor 46, and drives the stepping motor 46.

The mixing valve control circuit 53 controls so that only one of the first excitation method priority switch 57a and the second excitation method priority switch 57b is turned on, and the first excitation method can be driven with torque priority during tapping. It is driven by the second excitation method, which allows driving with priority given to low noise while hot water is not being dispensed.

As a result, even if the mixing valve body 45 becomes difficult to move due to clogging with scale over time, contamination of foreign matter, or sticking of the valve, the mixing valve is driven by the first excitation method during tapping, and the mixture is mixed. Since the valve body 45 is driven with priority given to torque, it is possible to eliminate the problem of sticking of the mixing valve body 45, and to avoid the risk that the mixing valve body 45 will not move and hot water at the set temperature set by the user will not come out.
Furthermore, while the hot water supply is stopped, the second excitation method is used to drive the mixing valve body 45 with low noise, so the driving noise can be reduced and the user can use it comfortably without feeling uncomfortable.

Note that the first excitation method may be a two-phase excitation method, and the second excitation method may be a 1-2 phase excitation method, which is said to have lower drive noise and less vibration than the two-phase excitation method.
Furthermore, the (N+1) phase excitation method is used as the first excitation method, and the (N+1) phase excitation method is said to have lower drive noise and less vibration than the (N+1) phase excitation method as the second excitation method. You may also choose an N-(N+1) phase excitation method that repeats the following steps.

Furthermore, while the two-phase excitation method and the 1-2-phase excitation method rotate the mixing valve body 45 by a fixed angle by turning the excitation phase on and off according to the input pulse, the current value of one phase of the excitation phase By gradually increasing the current value of the other phase and gradually decreasing the current value of the other phase, a microstep drive is applied to rotate the mixing valve element 45 by a fixed angle. A control method with a large rotational step angle or a small control current value may be used as the first excitation method, and a control method with a small rotation step angle or a small control current value may be used as the second excitation method.

Although this embodiment has been described using a direct pressure type water heater that directly heats the supplied water by combustion in the burner section 17, the present invention is not limited to this, and for example, a hot water storage type that constantly stores hot water at a constant temperature may be used. A water heater is also fine.

Note that the other configurations used in this embodiment are presented as examples, and are not intended to limit the scope of the invention, and may be implemented in various other forms. Various omissions, substitutions, and changes can be made without departing from the gist of the invention. These embodiments and their modifications are included within the scope and gist of the invention, as well as within the scope of the invention described in the claims and its equivalents.

1 Hot water supply device 12 Mixing valve 45 Mixing valve body 46 Stepping motor 52 Hot water output detection circuit 53 Mixing valve control circuit 54 Timer

Claims (3)

Mixing hot water heated by a heating means and water supplied from a water supply pipe,
A water heater that adjusts mixed hot water to a set water temperature by driving a stepping motor to change the opening degree of a mixing valve,
a mixing valve control circuit that controls the opening degree of the mixing valve using the stepping motor;
Equipped with a hot water supply detection circuit that detects whether hot water is being discharged or hot water is being stopped,
The mixing valve control circuit, when the hot water tapping detection circuit detects that hot water is being tapped,
driving the stepping motor at a first driving frequency;
When the hot water supply detection circuit detects that the hot water supply is stopped,
A water heater characterized in that the stepping motor is driven at a second drive frequency that is higher than the first drive frequency. configured to output a detection signal to the mixing valve control circuit when the opening degree of the mixing valve reaches a predetermined reference opening degree;
The mixing valve control circuit performs a reference position initialization process of causing the stepping motor to continuously drive the opening of the mixing valve toward the reference opening until the detection signal is received from the mixing valve. Run
The reference position initialization process starts while the hot water supply is stopped,
driving the stepping motor at the second driving frequency to start counting a timer;
If the timer receives the detection signal within a predetermined time, the reference position initialization process is terminated;
If the timer does not receive the detection signal within a predetermined time,
The water heater according to claim 1, wherein the stepping motor is driven at the first drive frequency. the stepping motor is driven with a first excitation method instead of being driven with the first drive frequency;
The water heater according to claim 1 or 2, characterized in that instead of being driven at the second drive frequency, it is driven by a second excitation method different from the first excitation method.

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