JP7720339B2 - Water heater and communication device for water heater - Google Patents

Description

This disclosure relates to water heaters, etc.

A technology is known that equips a water heater remote control with a wireless module, allowing operations such as changing water heater settings and checking the status to be performed using a mobile device. For example, Patent Document 1 describes such technology, stating that "the antenna of the wireless LAN module is positioned so as not to face the flat surface of the control board."

Japanese Patent Application Laid-Open No. 2021-97395

The technology described in Patent Document 1 limits the layout when placing wireless LAN modules and control boards, so there is room for improvement.

The water heater according to the present disclosure includes a remote control board on which an intercom circuit having a bandpass filter is mounted, a wireless module having an antenna and performing wireless communication, and a water heater communication device having a metal plate disposed between the remote control board and the wireless module, with the bandpass filter disposed in a position overlapping the metal plate when viewed perpendicularly to the surface of the metal plate.

1 is an explanatory diagram of a hot water supply system including a hot water heater according to a first embodiment. FIG. 2 is an exploded perspective view of the communication device for the water heater according to the first embodiment. FIG. 2 is a diagram showing a circuit configuration related to communication of the water heater according to the first embodiment. 3 is a front view of the water heater according to the first embodiment with the lid of the case of the wireless module removed. FIG. 1 is a cross-sectional view of a state in which a communication device for a water heater including a kitchen remote control for a water heater according to a first embodiment is installed on a wall. 3 is an explanatory diagram showing the positional relationship between the wireless board, the metal plate, and the remote control board of the water heater according to the first embodiment. FIG. 10 is a cross-sectional view of a water heater communication device including a kitchen remote control for a water heater according to a second embodiment, installed on a wall. FIG. 10 is an explanatory diagram showing the positional relationship between a wireless board, a metal plate, and a remote control board of a water heater according to a second embodiment. FIG. 11 is a time chart including a call using an intercom circuit of a water heater according to a third embodiment and wireless communication via a wireless module. 11 is a flowchart showing the processing of a hot water supply system including a hot water heater according to a third embodiment. 10 is a flowchart showing the processing of a hot water supply system including a hot water heater according to a fourth embodiment.

First Embodiment
<Configuration of hot water supply system>
FIG. 1 is an explanatory diagram of a hot water supply system E1 including a hot water supply device 100 according to the first embodiment.
The thick solid lines in Fig. 1 indicate the pipes through which hot water flows. The dashed lines in Fig. 1 indicate communication paths (including wireless communication). The hot water supply system E1 is a system that performs heating operations, reheating operations, and hot water filling operations based on the operation of the bath remote control R1, the kitchen remote control R2, and the operation of the mobile terminal 2.

Note that "heating operation" refers to an operation in which the heat pump unit U1 heats the hot water in the hot water storage tank 21. Furthermore, "additional boiling operation" refers to an operation in which the heat pump unit U1 is operated when there is little high-temperature water (remaining hot water) in the hot water storage tank 21, thereby increasing the amount of high-temperature water in the hot water storage tank 21. "Bath filling operation" refers to an operation in which the bathtub B1 is filled with water. In the example of Figure 1, in addition to the bathtub B1 to which hot water is supplied from the water heater 100, a bath remote control R1, a kitchen remote control R2, and a router 1 are installed inside the building H1.

As shown in FIG. 1, the hot water supply system E1 includes a water heater 100, a router 1, a mobile terminal 2, and a server 3. The water heater 100 is a device that performs operations such as boiling water, reheating water, and filling the water tank. As shown in FIG. 1, the water heater 100 includes a heat pump unit U1, a hot water storage tank unit U2, a bath remote control R1, and a kitchen remote control R2.

The heat pump unit U1 is a device that heats low-temperature hot water that flows in through piping from the bottom of the hot water storage tank 21 during boiling operation or additional boiling operation. The hot water, whose temperature has increased through heat exchange with the refrigerant, is then guided from the heat pump unit U1 through piping to the top of the hot water storage tank 21.

The hot water storage tank unit U2 stores the hot water heated by the heat pump unit U1 in the hot water storage tank 21, and also adjusts the temperature of the hot water in the hot water storage tank 21 appropriately before supplying it to the bathtub B1 and a hot water supply terminal (such as a faucet: not shown).

The bath remote control R1 and kitchen remote control R2 are controls used for hot water supply. The bath remote control R1 is installed on the wall of the bathroom. The kitchen remote control R2 is installed on the wall of the kitchen, etc. The bath remote control R1 and kitchen remote control R2 each have an operation button, a button for adjusting the bath temperature, and a call button. The call button is pressed when users communicate with each other between the bath remote control R1 and the kitchen remote control R2.

Router 1 is a device that relays communications based on a specific communication protocol. That is, router 1 has the function of connecting a wireless module 11 (see Figure 2), described below, to network N1.

The mobile terminal 2 is a terminal device that performs predetermined communications with the server 3 via the network N1. Examples of such mobile terminals 2 include smartphones, mobile phones, tablets, and wearable devices. The mobile terminal 2 is associated with the water heater 100 by inputting an SSID (Service Set Identifier) or processing based on WPS (Wi-Fi Protected Setup). The user can then operate the mobile terminal 2 in a predetermined manner to check the status of the water heater 100, change settings, and start the water heater operation.

In addition to managing data related to the water heater 100, the server 3 also has the function of communicating with the mobile terminal 2 via the network N1, and with the wireless module 11 (see Figure 2) via the network N1 and the router 1 in turn.

FIG. 2 is an exploded perspective view of the communication device 10 for a water heater.
The water heater communication device 10 shown in Fig. 2 is a communication device used to control hot water supply, and is included in the water heater 100 (see Fig. 1). As shown in Fig. 2, the water heater communication device 10 includes a kitchen remote control R2, a wireless module 11, a connection cord 12, a switch box 13, a remote control cord 14, and a metal plate 15. When viewed from the front of a wall of a kitchen or the like, the kitchen remote control R2, metal plate 15, wireless module 11, and switch box 13 are arranged in this order toward the back.

The kitchen remote control R2 is an operating device that is installed on a wall in a kitchen or other location. The kitchen remote control R2 includes a remote control case 31, a display 32, and multiple buttons 33, as shown in Figure 2, as well as a remote control board 34 (see Figure 5). Note that the remote control board 34 (see Figure 5) is fixed to the rear side of the remote control case 31 (the wall side of the kitchen or other location), and therefore is not visible in Figure 2.

The wireless module 11 is a device that performs wireless communication. That is, the wireless module 11 has the function of performing predetermined wireless communication with the router 1 (see Figure 1) and is located on the rear side of the kitchen remote control R2. The wireless module 11 may be installed when the kitchen remote control R2 is installed, or the wireless module 11 may be installed later. The connection cord 12 shown in Figure 2 is a harness that electrically connects the wireless module 11 to the remote control board 34 (see Figure 5) of the kitchen remote control R2.

The switch box 13 is a metal or resin box that houses the wireless module 11. The switch box 13 is open at the front and is embedded in a wall of a kitchen or other space. The switch box 13 also has a pair of upper and lower fixing portions 13b, 13c. The upper fixing portion 13b extends horizontally along the upper edge of the rectangular opening 15a (similar to the lower fixing portion 13c). These fixing portions 13b, 13c are used to secure the metal plate 15. The remote control cord 14 is a power line that connects the remote control board 34 (see Figure 5) of the kitchen remote control R2 to a power source (not shown) and is drawn out through the switch box 13.

Metal plate 15 is a metal plate-shaped member used to secure kitchen remote control R2, etc. The metal plate 15 may be made of, for example, iron or copper, or a specific alloy. As shown in Figure 2, metal plate 15 has an opening 15a and multiple screw insertion holes 15b and 15c.

Opening 15a is a hole through which the connection cord 12 and remote control cord 14 are inserted. Radio waves emitted from the wireless module 11 are then emitted to the outside via opening 15a and the kitchen remote control R2. Note that radio waves are reflected by metal but have the property of penetrating resin components such as the remote control case 31.

The screw insertion holes 15b are holes through which metal screws C1 are inserted. In the example shown in Figure 2, one screw insertion hole 15b is provided at each of the four corners of the metal plate 15. A similarly shaped screw insertion hole 15c is provided between the two upper screw insertion holes 15b. A similarly shaped screw insertion hole 15c is also provided between the lower screw insertion holes 15b. These two screw insertion holes 15c are used when a specified sub-remote control (not shown) is directly fixed to the wall via the metal plate 15. In other words, the metal plate 15 can be shared when installing the kitchen remote control R2 and the sub-remote control.

With the wireless module 11 housed in the switch box 13, the metal plate 15 is fixed to the switch box 13 with multiple screws C1. That is, the screws C1 are inserted through the screw insertion holes 15b of the metal plate 15 and screwed into the fixing portions 13b and 13c of the switch box 13 as appropriate.

The metal plate 15 also has a plurality of locking claws 15d. Specifically, a pair of upper and lower locking claws 15d, 15d are provided near the right end of the metal plate 15, and a pair of upper and lower locking claws 15d, 15d are provided near the left end of the metal plate 15. These four locking claws 15d are engaged with the rear side of the remote control case 31, so that the kitchen remote control R2 is supported by the metal plate 15. Note that if a wireless module 11 is provided in the kitchen remote control R2, there is no particular need to provide a wireless module in the bath remote control R1 (see Figure 1).

FIG. 3 is a diagram showing a circuit configuration related to communication in the water heater 100. As shown in FIG.
The water heater 100 includes an intercom circuit 50 for the bath remote control R1, an intercom circuit 60 for the kitchen remote control R2, and a main body circuit board 40. The main body circuit board 40 is a board on which circuits for controlling the heat pump unit U1 (see FIG. 1) and the hot water tank unit U2 (see FIG. 1) are mounted.

The main body board 40 may be housed in the housing of the heat pump unit U1 (see Figure 1) or the housing of the hot water storage tank unit U2 (see Figure 1). The main body board 40 is connected to the bath remote control R1 via cable K1, and is also connected to the kitchen remote control R2. The bath remote control R1 and kitchen remote control R2 are also connected to each other via cable K1.

As shown in Figure 3, the main board 40 is equipped with a control unit 41 and a communication unit 42. The control unit 41 executes a predetermined program based on signals received from the bath remote control R1 and kitchen remote control R2 via the communication unit 42, and controls the hot water storage tank unit U2 and other components (see Figure 1). The communication unit 42 is a communication interface used by the control unit 41 when communicating with the bath remote control R1 and kitchen remote control R2. The communication unit 42 has the function of extracting control signals in a specific frequency band from signals received via cable K1 and outputting the extracted control signals to the control unit 41.

The intercom circuit 50 of the kitchen remote control R2 shown in Figure 3 is equipped with a control unit 51 and a communication unit 52 as components related to the control of the hot water tank unit U2 and other components (see Figure 1). The control unit 51 performs predetermined processing based on the operation of the kitchen remote control R2 as well as control signals received from the main body board 40 via the communication unit 52 and other components. The communication unit 52 is a communication interface used when the control unit 51 communicates with the main body board 40. The communication unit 52 has the function of extracting control signals in a specific frequency band from signals received via cable K1 and outputting the extracted control signals to the control unit 51.

The intercom circuit 50 of the kitchen remote control R2 also includes components related to communication between users, such as a microphone 53, an amplifier 54, a receive/transmit switch 55, an audio output unit 56, a speaker 57, an FM modulation/demodulation unit 58, and a bandpass filter 59. The microphone 53 converts sound pressure into an audio signal (electrical signal). The amplifier 54 is a circuit that amplifies the audio signal input from the microphone 53.

The receive/transmit switch 55 is a circuit that switches between "receive," in which the user listens to audio based on the audio signal from the bath remote control R1 through the speaker 57, and "transmit," in which the audio signal from the microphone 53 is transmitted to the bath remote control R1. In the first embodiment, when one of the bath remote control R1 and the kitchen remote control R2 is in the "transmit" state, the other is configured to be in the "receive" state.

For example, if the audio signal from the bath remote control R1 has a larger amplitude than the audio signal (including environmental sounds other than human voices) in the kitchen remote control R2, the receive/transmit switch unit 55 sets the state of the kitchen remote control R2 to "receive." Also, if the audio signal in the kitchen remote control R2 has a larger amplitude than the audio signal from the bath remote control R1, the receive/transmit switch unit 55 sets the state of the kitchen remote control R2 to "transmit."

When the state of the kitchen remote control R2 is switched to "receive" by the receive/transmit switch 55, the audio output unit 56 outputs an audio signal to the speaker 57. The speaker 57 converts the audio signal (electrical signal) input from the audio output unit 56 into audio.

The FM modulation/demodulation unit 58 modulates or demodulates the audio signal. For example, when an audio signal amplified by the amplifier unit 54 is input via the receive/transmit switch unit 55 (i.e., in the case of "transmit"), the FM modulation/demodulation unit 58 performs frequency modulation on this audio signal to convert it into a specified FM signal. The FM signal from the FM modulation/demodulation unit 58 is transmitted via cable K1. The FM modulation/demodulation unit 58 also has the function of demodulating the FM signal received from cable K1 via bandpass filter 59 into a specified audio signal. The audio signal demodulated by the FM modulation/demodulation unit 58 is input to the speaker 57 via the receive/transmit switch unit 55 and audio output unit 56 in sequence.

Note that the control signal from the main board 40, the audio signal from the kitchen remote control R2 to the bath remote control R1, and the audio signal from the bath remote control R1 to the kitchen remote control R2 are all transmitted via the common cable K1, but the carrier frequencies of these signals are different. Therefore, in order to extract signals in specific frequency bands from the signals transmitted via cable K1, a bandpass filter 59, described below, is used.

The bandpass filter 59 shown in Figure 3 is a filter circuit that extracts signals in a specific frequency band. Specifically, the bandpass filter 59 extracts signals in a specific frequency band that includes the carrier frequency of the audio signal transmitted from the bath remote control R1 from the signals transmitted via cable K1. This allows the audio signal transmitted from the bath remote control R1 to be demodulated by the FM modulation/demodulation unit 58. Furthermore, even if a signal such as an FM radio signal is superimposed on the audio signal transmitted via cable K1, this signal is blocked by the bandpass filter 59. This prevents audio from the FM radio signal from being emitted from the speaker 57.

For example, a ceramic filter or other filter circuit may be used as this bandpass filter 59. Ceramic filters have excellent characteristics for extracting signals in specific frequency bands, but with changes in the global situation, it is becoming increasingly difficult to procure ceramic filter components. Taking this into consideration, other filter circuits may be used as the bandpass filter 59 instead of a ceramic filter.

Specifically, the band-pass filter 59 may be a circuit that combines a predetermined low-pass filter and a high-pass filter. In this case, the low-pass filter included in the band-pass filter 59 may be an L-shaped circuit in which a capacitor and an inductor are connected in an L shape, or a so-called T-shaped circuit or a π-shaped circuit. Furthermore, the high-pass filter included in the band-pass filter 59 may be an RC circuit in which a capacitor and a resistive element are connected in an L shape, or a circuit that includes an operational amplifier, as appropriate. Furthermore, the band-pass filter 59 may include an LC resonant circuit.

The intercom circuit 60 of the bath remote control R1 shown in Figure 3 is configured to control the hot water tank unit U2 (see Figure 1) and includes a control unit 61 and a communication unit 62. The control unit 61 and communication unit 62 are the same as those of the kitchen remote control R2, so a description of them will be omitted.
The intercom circuit 60 of the bath remote control R1 is equipped with components related to communication between users, including a microphone 63, an amplifier 64, a voice detector 65a, a switch 65b, a voice output unit 66, a speaker 67, an FM modulator/demodulator 68, and a bandpass filter 69. The components of the bath remote control R1 other than the voice detector 65a and the switch 65b are the same as those of the kitchen remote control R2, so a description thereof will be omitted.

The audio detection unit 65a is a circuit that detects audio signals transmitted from the kitchen remote control R2 via the cable K1. The switch 65b is a two-way switch that switches whether or not the audio signal demodulated by the FM modulation/demodulation unit 68 is output to the audio output unit 66. For example, if the audio detection unit 65a detects an audio signal from the kitchen remote control R2, the switch 65b is switched on and the amplifier unit 64 is controlled to attenuate the audio signal from the microphone 63. As a result, the audio signal from the kitchen remote control R2 is input to the speaker 67.

Furthermore, if the audio detection unit 65a does not detect an audio signal from the kitchen remote control R2, the switch 65b is maintained in the off state, and the amplifier unit 64 is controlled to amplify the audio signal from the microphone 63. As a result, the audio signal from the microphone 63 is amplified by the amplifier unit 64, and then converted into a specified FM signal by the FM modulation/demodulation unit 68 before being transmitted via the cable K1. Note that the circuit configuration shown in Figure 3 is an example and is not limited to this.

FIG. 4 is a front view of the wireless module 11 with the cover of the case 112 removed.
As described above, the wireless module 11 shown in Fig. 4 is a device that performs wireless communication with the router 1 (see Fig. 1) and is included in the water heater communication device 10 (see Fig. 2). As shown in Fig. 4, the wireless module 11 includes a wireless board 111 and a case 112. The wireless board 111 is a board on which an IC (Integrated Circuit) chip 111a and an antenna 111b are mounted. The wireless board 111 is connected to the remote control board 34 (see Fig. 5) of the kitchen remote control R2 (see Fig. 5) via a connection cord 12.

The IC chip 111a is an integrated circuit that includes a CPU (Central Processing Unit) and memory, and is housed in a metal case. The antenna 111b is an element for transmitting and receiving radio waves. The example in Figure 4 shows an inverted L-shaped antenna 111b, but the shape and type of antenna 111b are not particularly limited. The case 112 is a resin component that houses the wireless board 111. As mentioned above, radio waves can pass through resin, so a resin case 112 is used to avoid interfering with the radio waves.

FIG. 5 is a cross-sectional view of the water heater communication device 10 including the kitchen remote control R2 installed on the wall W1.
5, the IC chip 111a (see FIG. 4) and the like of the wireless board 111 are omitted as appropriate. As described above, the switch box 13 is fitted into a hole (a rectangular hole when viewed from the front) in a wall W1 of a kitchen or the like. In this state, the edge of the opening 13a of the switch box 13 is located near the surface of the wall. In the example of FIG. 5, the wireless module 11 is fixed to the bottom surface (inner wall surface at the back) of the switch box 13, which is open at the front. When fixing the wireless module 11 to the switch box 13, adhesive tape (not shown) or a resin support member (not shown) is used as appropriate.

The remote control case 31 is supported by multiple locking claws 15d (see also Figure 2) on the metal plate 15. The remote control board 34 housed in the remote control case 31 is a board on which the intercom circuit 50 (see Figure 3) of the kitchen remote control R2 is mounted. As shown in Figure 5, the remote control board 34, metal plate 15, and wireless board 111 are arranged so that their respective plate surfaces are approximately parallel. In addition, the metal plate 15 is arranged between the remote control board 34 and the wireless module 11.

As shown in Figure 5, antenna 111b is mounted on the front surface of wireless board 111 (the surface facing metal plate 15). Radio waves from antenna 111b are radiated to the outside through opening 15a in metal plate 15 (see the outlined arrow in Figure 5). Note that because remote control case 31 and remote control board 34 are made of resin, there is little risk of the propagation of radio waves radiated from antenna 111b being obstructed.

For example, if a directional antenna is used as antenna 111b, it is advisable to ensure that a predetermined angular range in which the radio wave intensity is relatively high in the solid angle with antenna 111b as the reference (origin) includes opening 15a in metal plate 15. This makes it possible to increase the proportion of radio waves radiated from antenna 111b that pass through opening 15a in metal plate 15.

As shown in Figure 5, the bandpass filter 59 is mounted on the front surface of the remote control board 34 (the surface opposite the metal plate 15). Although not shown in Figure 5, the intercom circuit 50 (see Figure 3), which includes the bandpass filter 59, is also mounted on the surface of the remote control board 34 opposite the metal plate 15.

As shown in Figure 5, it is preferable to make the imaginary line segment L1 connecting the antenna 111b and the bandpass filter 59 pass through the metal plate 15. This causes the radio waves traveling from the antenna 111b to the bandpass filter 59 to be reflected by the metal plate 15. Therefore, it is possible to prevent noise (noise caused by the radio waves from the antenna 111b) from being superimposed on the audio signal of a specific frequency band extracted by the bandpass filter 59.

Note that line segment L1 may be, for example, a line segment connecting the position of the center of gravity (center) of antenna 111b and the position of the center of gravity (center) of bandpass filter 59. Alternatively, line segment L1 may be, for example, a predetermined line segment connecting the upper end of antenna 111b and the lower end of bandpass filter 59, or a predetermined line segment connecting the lower end of antenna 111b and the upper end of bandpass filter 59.

FIG. 6 is an explanatory diagram showing the positional relationship between the wireless board 111, the metal plate 15, and the remote control board 34 (also see FIG. 5 as appropriate).
6 shows the wireless board 111, metal plate 15, and remote control board 34 projected onto a predetermined plane (not shown) perpendicular to the respective plate surfaces. As shown in FIG. 6, when viewed from a direction perpendicular to the plate surface of the metal plate 15, the area inside the edge of the opening 15a is included in the projection area of the wireless module 11. This makes it easier for radio waves emitted from the wireless module 11 to propagate outward through the opening 15a. In the example of FIG. 6, a portion of the projection area of the antenna 111b is located outside the opening 15a, but even with this configuration, there is little risk of radio wave propagation being hindered.

In addition, a bandpass filter 59 is provided at a position overlapping the metal plate 15 when viewed from a direction perpendicular to the surface of the metal plate 15. With this configuration, radio waves traveling from the antenna 111b of the wireless module 11 to the bandpass filter 59 are reflected by the metal plate 15, preventing the bandpass filter 59 from being exposed to radio waves. This prevents noise from being superimposed on the audio signal of a specific frequency band extracted by the bandpass filter 59.

In the example of Figure 6, when bandpass filter 59 is projected in a direction perpendicular to the surface of metal plate 15, screw insertion hole 15b of metal plate 15 is present in part of the projection area. As described above, metal screw C1 (see Figure 2) is inserted into screw insertion hole 15b, so screw insertion hole 15b is blocked by the head of screw C1. As a result, radio waves traveling from antenna 111b toward screw insertion hole 15b are reflected by metal screw C1 (see Figure 2), thereby suppressing radio waves from entering bandpass filter 59.

The metal plate 15 also has a protruding portion 15e. The protruding portion 15e is a portion that protrudes inward from an imaginary rectangle whose two sides (two of the four sides) are the upper and right edges of the opening 15a. In the example of Figure 6, the protruding portion 15e is provided on the lower left side of the opening 15a, extending upward from the portion of the metal plate 15 that includes the projection area of the bandpass filter 59. By providing the protruding portion 15e in this manner, even if the antenna 111b is located higher than the bandpass filter 59 (see also Figure 5), radio waves traveling from the antenna 111b toward the vicinity of the bandpass filter 59 are reflected by the protruding portion 15e. This effectively prevents noise from being superimposed on the audio signal at the output of the bandpass filter 59.

<Effects>
According to the first embodiment, the bandpass filter 59 is provided at a position overlapping the metal plate 15 or the metal screw C1 (see FIG. 2), which prevents the bandpass filter 59 from being exposed to radio waves from the antenna 111b. As a result, noise is prevented from being introduced into the audio from the speaker 57 (see FIG. 3) of the kitchen remote control R2. Thus, according to the first embodiment, the reliability of the intercom function of the water heater 100 can be improved.

Furthermore, according to the first embodiment, there are fewer layout constraints when designing the remote control board 34 and wireless module 11, allowing for greater design freedom compared to the technology of Patent Document 1 mentioned above. Furthermore, because the configuration of the water heater communication device 10 is relatively simple, increases in manufacturing costs can be suppressed.

Second Embodiment
The second embodiment differs from the first embodiment in that a metal film M1 (see FIG. 7) is provided on the back side of the band-pass filter 59 in the remote control board 34A (see FIG. 7), but is otherwise similar to the first embodiment. Therefore, only the parts that differ from the first embodiment will be described, and a description of the overlapping parts will be omitted.

FIG. 7 is a cross-sectional view of a water heater communication device 10A including a kitchen remote control R2 for a water heater according to the second embodiment, installed on a wall W1.
As shown in FIG. 7 , the remote control board 34A of the kitchen remote control R2 has a metal film M1. The metal film M1 is a shielding pattern for reflecting radio waves directed toward the bandpass filter 59. For example, copper foil or other types of metal foil may be used as the metal film M1. Furthermore, the metal film M1 may be a foil such as copper foil (metal foil), a coating film made of paint containing metal powder, a metal-plated film, a metal tape with adhesive, or a plate thicker than a foil. The metal film M1 is provided on the plate surface of the remote control board 34A opposite the bandpass filter 59 (the plate surface facing the metal plate 15).

FIG. 8 is an explanatory diagram showing the positional relationship between the wireless board 111, the metal plate 15, and the remote control board 34A (also see FIG. 7 as appropriate).
8, the metal film M1 is indicated by diagonal lines (hatching). As shown in FIG. 8, it is preferable that the bandpass filter 59 overlaps the metal film M1 when viewed from a direction perpendicular to the surface of the metal plate 15. In other words, it is preferable that the projection area of the bandpass filter 59 is included in the metal film M1. As described above, radio waves from the antenna 111b traveling toward the bandpass filter 59 are reflected by the metal plate 15. However, even if there are radio waves traveling toward the bandpass filter 59 after multiple reflections, most of these radio waves are blocked by the metal film M1. Therefore, it is possible to prevent noise from being superimposed on the audio signal on the output side of the bandpass filter 59.

<Effects>
According to the second embodiment, radio waves directed toward the band-pass filter 59 are blocked not only by the metal plate 15 but also by the metal film M1. Therefore, it is possible to more effectively suppress noise from being superimposed on the audio signal on the output side of the band-pass filter 59 than in the first embodiment.

Third Embodiment
The third embodiment differs from the first embodiment in that, as part of the processing of the hot water supply system E1 (see FIG. 1), wireless communication by the wireless module 11 (see FIG. 3) is stopped during a call using the intercom circuits 50, 60 (see FIG. 3). Note that other aspects (such as the configuration of the hot water supply system E1: see FIGS. 1 to 6) are the same as those of the first embodiment. Therefore, only the differences from the first embodiment will be described, and descriptions of overlapping parts will be omitted.

FIG. 9 is a time chart including a call using the intercom circuit and a wireless communication via the wireless module (see also FIG. 3 as appropriate).
Note that "call" in Fig. 9 indicates whether or not a call is being made using the intercom circuit 50 of the kitchen remote control R2 or the intercom circuit 60 of the bath remote control R1. That is, "ON" indicates a state in which a call is being made between the bath remote control R1 and the kitchen remote control R2 via the cable K1, and "OFF" indicates a state in which no call is being made. "Wireless communication" in Fig. 9 indicates whether wireless communication via the wireless module 11 is "ON" or "OFF."

In the example of Figure 9, during the time period (time t2 to t3) when a call is taking place between the bath remote control R1 and the kitchen remote control R2, wireless communication by the wireless module 11 is stopped. This prevents noise caused by radio waves from the wireless module 11 from being superimposed on the audio signal of the call.

In the example of Figure 9, the time when the call starts and the time when wireless communication is stopped both coincide at time t2, but these times do not necessarily have to coincide. For example, wireless communication may be stopped a predetermined time after the call starts. Or, wireless communication may be resumed a predetermined time after the call ends. In short, it is desirable to stop wireless communication by the wireless module 11 for at least part of the period during which a call is being made via the intercom circuit 50. This type of processing also achieves the same effect.

FIG. 10 is a flowchart showing the processing of the hot water supply system (see also FIG. 3 as appropriate).
It is assumed that a "controller" including a CPU (not shown) of each board, such as the main body board 40 or the remote control board 34, executes the series of processes shown in Fig. 10. Although omitted from Fig. 10, it is assumed that pairing (association) between the mobile terminal 2 (see Fig. 1) and the water heater 100 (see Fig. 1) has been performed in advance based on a user operation.

Also, at "START" in Figure 10, it is assumed that the power of the wireless module 11 is in an ON state. In step S101, the control unit determines whether the call button has been pressed by a user operation. That is, the control unit determines whether the call button on the bath remote control R1 or the kitchen remote control R2 has been pressed. If the call button has not been pressed in step S101 (S101: No), the control unit returns to "START" (RETURN). Also, if the call button has been pressed in step S101 (S101: Yes), the control unit proceeds to step S102.

In step S102, the control unit initiates a call. That is, the control unit supplies power to the intercom circuit 60 of the bath remote control R1 and also to the intercom circuit 50 of the kitchen remote control R2.

In step S103, the control unit turns off wireless communication (times t2 to t3 in Figure 9). This prevents radio waves from being emitted from the antenna 111b of the wireless module 11 (see Figure 5), preventing noise caused by radio waves from being superimposed on the audio signal.

Next, in step S104, the control unit determines whether the call termination condition has been met. Here, the call termination condition is a condition for determining whether to terminate the call, and is set in advance. For example, the control unit determines that the call termination condition has been met when the user presses the call stop button or a predetermined upper limit time (e.g., 60 seconds) has elapsed since the start of the call. If the call termination condition has been met in step S104 (S104: Yes), the control unit proceeds to step S105. If the call termination condition has not been met in step S104 (S104: No), the control unit returns to step S103.

In step S105, the control unit ends the call, i.e., stops the power supply to the intercom circuit 60 of the bath remote controller R1 and the power supply to the intercom circuit 50 of the kitchen remote controller R2.
In step S106, the control unit turns on wireless communication. That is, the control unit resumes wireless communication by the wireless module 11. After performing the process of step S106, the process of the control unit returns to "START" (RETURN).

It is preferable that the water heater communication device 10 not accept any operations other than setting the call volume or canceling the call while wireless communication by the wireless module 11 is stopped. Here, the operations to "set the call volume" and "cancel the call" are performed by operating specific buttons on the bath remote control R1 or kitchen remote control R2. Furthermore, "operations" other than setting the call volume or canceling the call may also be performed on the mobile terminal 2 (see Figure 1) in addition to the bath remote control R1 or kitchen remote control R2.

To give a specific example, if the bath temperature can be changed by operating the bath remote control R1 even when wireless communication is stopped, the following will occur. That is, while wireless communication is stopped, the changed bath temperature will not be reflected on the display of the mobile device 2 (see Figure 1), and therefore the content displayed on the mobile device 2 may differ from the actual state of the water heater 100. Furthermore, even if an operation to change the bath temperature is performed on the mobile device 2 while wireless communication is stopped, this operation will not be immediately reflected in the actual control of the water heater 100. Therefore, as described above, the water heater communication device 10 will not accept any operations other than setting the call volume and canceling the call while wireless communication is stopped, thereby ensuring consistency between the actual state of the water heater 100 and the display content of the mobile device 2.

Furthermore, if an operation other than setting the call volume or canceling a call is performed while wireless communication by the wireless module 11 is stopped, the water heater communication device 10 may emit a specified reception prohibition sound. This reception prohibition sound is emitted by the device on which the user performed the specified operation, among the bath remote control R1, kitchen remote control R2, and mobile terminal 2 (see Figure 1). This reduces the user's sense of discomfort that their operation is not being accepted. Note that a specified error message may be displayed along with (or instead of) the reception prohibition sound.

<Effects>
According to the third embodiment, wireless communication is stopped during a call between the bath remote control R1 and the kitchen remote control R2, preventing noise from being superimposed on the audio signal. Also, by preventing the water heater communication device 10 from accepting any operation other than setting the call volume or canceling the call during a call, the actual state of the water heater 100 and the display content of the mobile terminal 2 can be aligned.

Fourth Embodiment
The fourth embodiment differs from the first embodiment in that the processing of the hot water supply system E1 (see FIG. 1) is set so that the polling period from the main board 40 (see FIG. 3) is lengthened during a call using the intercom circuits 50, 60 (see FIG. 3). Note that other aspects (such as the configuration of the hot water supply system E1: see FIGS. 1 to 6) are the same as those of the first embodiment. Therefore, only the differences from the first embodiment will be described, and overlapping portions will not be described again.

FIG. 11 is a flowchart showing the processing of the hot water supply system (see FIG. 3 as appropriate).
In the following description, it is assumed that the main board 40 alternately polls (periodic inquiries about setting information, etc.) the bath remote control R1 and the kitchen remote control R2. In other words, it is assumed that the main board 40 alternately sends polling signals to the remote control board 34 of the kitchen remote control R2 and the remote control board (not shown) of the bath remote control R1.

In step S201, the control unit transmits polling to each of the bath remote controller R1 and the kitchen remote controller R2.
In step S202, the control unit receives response signals from the bath remote control R1 and the kitchen remote control R2.

In step S203, the control unit determines whether call start information is present. That is, the control unit determines whether the response signal received in step S202 includes call start information. For example, when the call button on the bath remote control R1 is pressed, the response signal from the bath remote control R1 in response to polling from the control unit includes predetermined call start information.

In step S204, the control unit transmits the call start information to the other of the bathroom remote controller R1 and the kitchen remote controller R2 that does not have the call start information. For example, the control unit transmits the call start information to the kitchen remote controller R2.
In step S205, the control unit receives a response signal from the other of the bathroom remote control R1 and the kitchen remote control R2. For example, the control unit receives a response signal to the polling from the kitchen remote control R2.

In step S206, the control unit initiates a call. That is, the control unit supplies power to the intercom circuit 60 of the bath remote control R1 and to the intercom circuit 50 of the kitchen remote control R2.

In step S207, the control unit lengthens the polling period. That is, the main board 40 sets the polling period to be longer when a call is being made via the intercom circuits 50, 60 than when a call is not being made via the intercom circuits 50, 60.

As a specific example, the main board 40 may poll at a cycle of 20 ms when no call is being made, and at a cycle of 2 seconds when a call is being made. By lengthening the polling cycle in this way, the frequency with which control signals (signals with high-frequency carrier frequencies) are transmitted via cable K1 (see Figure 3) decreases. Therefore, even if the performance of bandpass filter 59 (see Figure 3) is not particularly high, it is possible to prevent noise caused by control signals (so-called self-noise) from being superimposed on the audio signal at the output of bandpass filter 59.

Next, in step S208, the control unit determines whether a predetermined call termination condition has been met. Here, the call termination condition is a condition used to determine whether to terminate a call, and is set in advance. For example, the control unit determines that the call termination condition has been met when the user presses the call stop button or a predetermined upper limit time (e.g., 60 seconds) has elapsed since the start of the call. If the call termination condition has been met in step S208 (S208: Yes), the control unit proceeds to step S209. If the call termination condition has not been met in step S208 (S208: No), the control unit returns to step S207. In this case, the polling cycle remains relatively long.

In step S209, the control unit ends the call, i.e., stops the power supply to the intercom circuit 60 of the bathroom remote control R1 and the power supply to the intercom circuit 50 of the kitchen remote control R2.
In step S210, the control unit returns the polling period to the original period. That is, the control unit returns the polling period to a relatively short period (for example, 20 ms) when no call is being made. After performing the process of step S210, the control unit returns to the process of "START" (RETURN).

<Effects>
According to the fourth embodiment, during a call between the bath remote control R1 and the kitchen remote control R2, the polling period from the main circuit board 40 is set to be longer. This reduces the frequency with which control signals are transmitted via the cable K1 (see FIG. 3), making it possible to suppress self-noise from being superimposed on the audio signal even when the performance of the bandpass filter 59 is not particularly high.

<<Variations>>
The hot water supply system E1 according to the present disclosure has been described above in relation to the various embodiments, but is not limited to these descriptions and various modifications can be made.
For example, in the first embodiment, the wireless module 11 (see FIG. 2) is provided in the kitchen remote control R2 (see FIG. 2), but this is not limiting. That is, the wireless module may be provided in the bath remote control R1 (see FIG. 1).

In addition, in each embodiment, the band-pass filter 59 (see Figure 6) is mounted near the lower end of the remote control board 34 (see Figure 6), but the position of the band-pass filter 59 on the remote control board 34 can be changed as appropriate.
Furthermore, when the water heater communication device 10 is attached to the wall of a room, it is preferable to mount the intercom circuit 50 near the center of the remote control board 34 in the horizontal direction parallel to the board surface. This makes it possible to prevent radio waves from interfering with the audio signal of the intercom circuit 50, even if a door phone (not shown) is installed to the right or left of the kitchen remote control R2, for example.

Furthermore, in each embodiment, a case has been described in which, when viewed from a direction perpendicular to the surface of the metal plate 15 (see FIG. 6), a portion of the band-pass filter 59 overlaps the metal plate 15 and the remaining portion of the band-pass filter 59 overlaps the screw C1 (the metal screw C1 inserted into the screw insertion hole 15c). However, this is not limited to this. For example, when viewed from a direction perpendicular to the surface of the metal plate 15, the band-pass filter 59 may overlap only the metal plate 15, or the band-pass filter 59 may overlap only the screw C1. In short, it is preferable to position the band-pass filter 59 so that it overlaps at least one of the metal plate 15 and the screw C1 when viewed from a direction perpendicular to the surface of the metal plate 15. This configuration can suppress noise from being superimposed on the audio signal at the output side of the band-pass filter 59.

Also, when viewed from a direction perpendicular to the surface of the metal plate 15, at least a portion of the bandpass filter 59 may overlap the metal plate 15. Also, when viewed from a direction perpendicular to the surface of the metal plate 15, at least a portion of the bandpass filter 59 may overlap the screw C1. Even with this configuration, radio waves heading toward the bandpass filter 59 can be blocked by the metal plate 15 or the screw C1.

Furthermore, in each embodiment, a portion of the inverted L-shaped antenna 111b extends outside the edge of the opening 15a in the metal plate 15 when viewed from a direction perpendicular to the plate surface of the metal plate 15 (see Figure 6), but the position, shape, and size of the antenna 111b can be changed as appropriate. For example, the antenna 111b may be located inside the opening 15a in the metal plate 15 when viewed from a direction perpendicular to the plate surface of the metal plate 15.

Furthermore, the respective embodiments can be combined as appropriate. For example, the second and third embodiments can be combined to provide a configuration in which the metal film M1 is provided on the back side of the bandpass filter 59 on the remote control board 34 (second embodiment), and wireless communication can be stopped during a call (third embodiment).
Furthermore, the third embodiment and the fourth embodiment may be combined, so that wireless communication is stopped during a call (third embodiment) and the polling period from the main body board 40 is set to be longer (fourth embodiment). Alternatively, for example, the second embodiment and the fourth embodiment may be combined. It is also possible to combine three of the first to fourth embodiments (for example, three of the second to fourth embodiments).

Furthermore, in the third embodiment, the process of suspending wireless communication during a call was described, assuming the configuration of the first embodiment (see Figures 1 to 6), but this is not limited to this. For example, even in a water heater communication device configured so that the metal plate 15 and the bandpass filter 59 do not overlap in a front view, suspending wireless communication during a call can prevent noise from being superimposed on the audio signal.

Furthermore, in the fourth embodiment, the configuration of the first embodiment (see Figures 1 to 6) was assumed, and a process was described in which the polling period from the main board 40 was set to be longer during a call. However, this is not limited to this. For example, even in a water heater communication device in which the metal plate 15 and the bandpass filter 59 do not overlap in a front view, it is possible to prevent noise from being superimposed on the audio signal by lengthening the polling period from the main board 40 during a call.

In addition, the program for causing a computer to execute the processing of the control unit described in each embodiment can be provided via a communication line, or can be stored on a recording medium such as memory, a hard disk, a recording device such as an SSD (Solid State Drive), an IC card, an SD card, or a DVD.

Furthermore, each embodiment has been described in detail to clearly explain this disclosure, and is not necessarily limited to having all of the configurations described. Furthermore, it is possible to add, delete, or replace part of the configuration of an embodiment with other configurations. Furthermore, the mechanisms and configurations described above are those considered necessary for the explanation, and do not necessarily represent all mechanisms and configurations in the product. Furthermore, the control lines and information lines are those considered necessary for the explanation, and do not necessarily represent all control lines and information lines in the product. In reality, it can be assumed that almost all components are interconnected.

1 Router 2 Mobile terminal 3 Server 10, 10A Communication device for water heater 11 Wireless module 12 Connection cord 13 Switch box 14 Remote control cord 15 Metal plate 15a Opening 15b Screw insertion hole 34, 34A Remote control board 40 Main body board 50 Intercom circuit 59 Bandpass filter 100 Water heater 111 Wireless board 111a IC chip 111b Antenna 112 Case C1 Screw E1 Water heating system K1 Cable L1 Line M1 Metal film R1 Bath remote control R2 Kitchen remote control U1 Heat pump unit U2 Hot water storage tank unit W1 Wall

Claims (9)

a remote control board on which an intercom circuit having a bandpass filter is mounted;
a wireless module having an antenna and performing wireless communication;
a communication device for a water heater including a metal plate disposed between the remote control board and the wireless module;
The water heater, wherein the bandpass filter is provided at a position overlapping the metal plate when viewed from a direction perpendicular to the plate surface of the metal plate. The water heater according to claim 1, wherein an imaginary line segment connecting the antenna and the bandpass filter passes through the metal plate. the remote control board has a metal film provided on a plate surface facing the metal plate,
the intercom circuit is mounted on the surface of the remote control board opposite to the metal plate,
The water heater according to claim 1 , wherein the bandpass filter overlaps the metal film when viewed in a direction perpendicular to a surface of the metal plate. The water heater according to claim 1 , wherein wireless communication by the wireless module is stopped during at least a part of a period during which a call is made via the intercom circuit. The water heater according to claim 4, wherein the communication device for the water heater does not accept any operation other than setting a call volume or canceling a call while the wireless communication by the wireless module is stopped. The water heater according to claim 5, wherein when an operation other than setting the call volume or canceling the call is performed while wireless communication by the wireless module is stopped, the communication device for the water heater emits a predetermined reception prohibition sound. The device further includes a main body board that alternately transmits polling signals to the remote control board and another remote control board corresponding to the other party of a call using the remote control board,
The water heater according to claim 1, characterized in that the main circuit board makes the polling period longer when a call is being made via the intercom circuit than when a call is not being made via the intercom circuit. The water heater according to claim 1, characterized in that, when the water heater communication device is attached to a wall of a room, the intercom circuit is mounted near the center of the remote control board in a horizontal direction parallel to the board surface. a remote control board on which an intercom circuit having a bandpass filter is mounted;
a wireless module having an antenna and performing wireless communication;
a metal plate disposed between the remote control board and the wireless module;
The metal plate is provided with a screw insertion hole through which a metal screw is inserted,
The communication device for a water heater, wherein the bandpass filter is provided at a position overlapping at least one of the metal plate and the screw when viewed from a direction perpendicular to the plate surface of the metal plate.