Combustion equipment and hot water supply equipment

Abstract

To prevent unintended opening of a gas solenoid valve of a combustion apparatus.SOLUTION: A combustion apparatus includes: a memory that stores first and second software for controlling an operation; a microcomputer that executes the first or second software; a load operated by receiving electric power supply; a drive circuit that drives the load on the basis of output from the microcomputer; and a resistor. One end of the resistor is connected to between an input / output port of the microcomputer and a control terminal of the drive circuit. When a first voltage value corresponding to a first logical level output from the microcomputer is applied to the drive circuit, the drive circuit is driven. When a second voltage value corresponding to a second logical level output from the microcomputer is applied to the drive circuit, the drive circuit is stopped. During updating of the second software by using the first software, the input / output port is set to be an input port (S420). An electric potential of the other one end of the resistor is maintained at a second voltage value.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE The present disclosure relates to combustion devices, and more particularly to water heating devices that control software used in combustion devices. [Background technology]

[0002] The functionality of a water heater can be improved by updating its built-in software. Regarding software updates, for example, Japanese Patent Application Laid-Open Publication No. 2020-112303 (Patent Document 1) discloses a technology for a "combustion appliance with a software update function that can reliably prevent fuel from being supplied to the combustion unit during a software update." This technology describes a "combustion appliance (1) with a control device (20) that includes a first control unit (21) that executes control processing based on first software and a second control unit (22) that executes control processing based on second software. The second software is configured to cause the second control unit (22) to execute processing to update the first software with new software, and to cause the second control unit (22) to execute control processing to maintain a control valve (4) that opens and closes a fuel supply path (3) to the combustion unit (2) in a closed state during the first software update process" (see [Abstract]). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-112303 Summary of the Invention [Problem to be solved by the invention]

[0004] While updating the software, it is necessary to prevent the combustion device from operating. However, there is a risk that the water heater's microcomputer may output an unintended signal, causing the water heater to operate. For example, the water heater's solenoid valve, fan, igniter, or pump may suddenly operate. Therefore, technology is needed to prevent the combustion device from operating unintendedly.

[0005] The present disclosure has been made in light of the above-described background, and according to one embodiment, a technique for preventing unintended operation of a combustion device when updating software is disclosed. [Means for solving the problem]

[0006] A combustion device according to one embodiment includes a memory storing first software and second software for controlling the operation of the combustion device, a microcomputer executing the first software or the second software, a load that receives power supply and operates, a drive circuit that drives the load based on output from the microcomputer, and a resistor. One end of the resistor is connected between an input / output port of the microcomputer and a control terminal of the drive circuit. The drive circuit operates when a first voltage value corresponding to a first logic level output from the microcomputer is applied to the drive circuit. The drive circuit stops when a second voltage value corresponding to a second logic level output from the microcomputer is applied to the drive circuit. While the first software updates the second software, the input / output port is set to an input port. The potential of the other end of the resistor is maintained at a second voltage value.

[0007] In one aspect, the potential of the second voltage value is ground. In one aspect, the potential of the second voltage value is a power supply voltage.

[0008] In one aspect, the load further comprises a combustion section and a fuel valve for supplying fuel to the combustion section. The load includes the fuel valve.

[0009] According to another embodiment, there is provided a water heater including any one of the combustion devices described above. The above and other objects, features, aspects and advantages of the present invention will become apparent from the following detailed description of the invention taken in conjunction with the accompanying drawings. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic diagram showing an example of the configuration of a communication system to which a water heating apparatus 100 is applied. [Figure 2] 2 is a block diagram showing an example of the hardware configuration of a communication adapter 150. FIG. [Figure 3] 2 is a block diagram showing an example of a hardware configuration of a water heater 110. FIG. [Figure 4] 10 is a flowchart showing an example of processing performed when firmware of the main microcomputer 10 is rewritten while the gas electromagnetic valve 51 is maintained in a closed state. [Figure 5] FIG. 2 is a diagram schematically illustrating a part of a circuit block diagram that controls the opening and closing of a gas electromagnetic valve 51. [Figure 6] FIG. 2 is a diagram schematically illustrating a part of a circuit block diagram that controls the opening and closing of a gas electromagnetic valve 51. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the following description, the same components are denoted by the same reference numerals. The names and functions of the components are also the same. Therefore, detailed description thereof will not be repeated.

[0012] <Overall structure> A configuration for implementing a software update in water heating apparatus 100 according to the present embodiment will be described with reference to Fig. 1. Fig. 1 is a schematic diagram showing an example configuration of a communication system to which water heating apparatus 100 equipped with a combustion apparatus is applied.

[0013] Communication system 200 includes water heating apparatus 100, communication device 3, external communication network 4, server 5, router 6, base station 7, and mobile terminal device 8. In communication system 200, water heating apparatus 100 and server 5 are communicatively connected via communication device 3 and external communication network 4, for remote management and remote operation of water heating apparatus 100 by server 5.

[0014] Water heating apparatus 100 includes water heater 110, a remote controller (hereinafter also simply referred to as "remote control") 160 that receives instructions from a user, and communication adapter 150. Hot water from water heater 110 is delivered to a hot water supply destination via pipes connected to a plurality of hot water supply outlets 111. For example, the hot water supply destination includes a faucet and a bathtub (not shown). Alternatively, the hot water supply destination may include a heater (not shown) that uses high-temperature water as a heat source, thereby providing water heating apparatus 100 with a heating function.

[0015] A circuit board 115 is mounted inside water heater 110. A controller 140 for driving and controlling water heater 110 is mounted on circuit board 115. Controller 140 controls a solenoid valve for controlling the supply of fuel gas to water heater 110, an air supply fan for supplying air to be mixed with the fuel gas, and the like.

[0016] Water heater 110 and remote control 160 are connected to communication adapter 150 via communication line (e.g., two-core communication line) 170. Remote control 160 has display 161 and input interface 162. A user can set the water heater, the hot water supply temperature setting, etc. by operating input interface 162 according to the display screen of display 161. For example, remote control 160 is installed in the bathroom or kitchen. Note that multiple remote controls 160 may be used. In this way, a user can use remote control 160 to make various settings for each function of water heating apparatus 100.

[0017] The communication adapter 150 has a wireless communication function for communicating with the communication device 3 using a predetermined communication protocol. The communication adapter 150 may be configured to be built into the remote control 160.

[0018] The communication device 3 has a function of connecting devices within a certain range to a server 5 for communication via an external communication network 4. For example, the communication device 3 is configured by a wireless LAN (Local Area Network) router. The external communication network 4 is typically the Internet.

[0019] A wired LAN router may be used instead of a wireless LAN router as the communication device 3. In this case, the communication adapter 150 is configured to communicate with the wired LAN router using a predetermined communication protocol.

[0020] Server 5 has a function for managing remote control (e.g., remote operation and remote monitoring) of water heating apparatus 100 via external communication network 4. Communication adapter 150 is communicatively connected to communication device 3 via wireless communication, thereby enabling communication with server 5 via external communication network 4. As a result, water heating apparatus 100 is communicatively connected to server 5 via communication adapter 150 as a relay device, and thus two-way data communication is carried out between water heating apparatus 100 and server 5.

[0021] The server 5 can also be connected to and communicate with a mobile terminal device 8 such as a smartphone or a tablet terminal. When the mobile terminal device 8 is within a range where it can connect to the communication device 3, it can communicate with the server 5 by connecting to the communication device 3 via wireless communication. When the mobile terminal device 8 is outside the home, for example, it can communicate with the server 5 by connecting to the external communication network 4 via the router 6 or the base station 7.

[0022] In this way, in addition to operating the remote control 160, the user can use the mobile terminal device 8 to access the server 5 both inside and outside the range where the communication device 3 can be connected, thereby remotely controlling the water heating device 100.

[0023] An application program for water heating apparatus 100 can be installed in remote control 160 and mobile terminal device 8. For example, the application program is downloaded from server 5 and then installed.

[0024] In addition, each of water heater 110 (controller 140), remote control 160, and communication adapter 150 stores a program (hereinafter also referred to as "firmware (F / W)") for controlling the operation of the respective devices. When the device is shipped from the factory, the current version of the firmware is written to the device. Also, the firmware can be rewritten to a different version by distribution from server 5. In some aspects, multiple pieces of firmware can be stored in water heater 110, remote control 160, or communication adapter.

[0025] <Configuration of the hot water supply device> (Communication adapter) The configuration of communication adapter 150 will be described with reference to Fig. 2. Fig. 2 is a block diagram showing an example of the hardware configuration of communication adapter 150. Communication adapter 150 includes microcomputer (hereinafter also referred to as "microcomputer") 151, communication units 152 and 153, power supply circuit 154, memory 155, antenna 157, and connector 158. Connector 158 is connected to communication line 170 shown in Fig. 1.

[0026] Microcomputer 151 includes a CPU (Central Processing Unit) 151a and an interface (I / F) 151b. Communication unit 152 transmits and receives data bidirectionally to and from water heater 110 and remote control 160 via communication line 170 connected to connector 158. Communication unit 153 transmits and receives data bidirectionally to and from communication device 3 by wireless communication via antenna 157. Power supply circuit 154 receives power from communication line 170 connected to connector 158 and generates operating power supply voltages for each element in communication adapter 150.

[0027] The memory 155 includes a read-only memory (ROM) 155a and a random access memory (RAM) 155b. The ROM 155a is typically configured with an electrically erasable programmable read-only memory (EEPROM) and stores firmware for the communication adapter 150, as well as data and programs used for control. During startup processing, the microcomputer 151 reads the firmware stored in the ROM 155a and loads it into the RAM 155b. The microcomputer 151 executes the programs loaded into the RAM 155b to control the operation of the communication adapter 150. Note that while the memory 155 and the microcomputer 151 are depicted as separate elements in FIG. 2, part or all of the memory 155 may be built into the microcomputer 151.

[0028] Communication unit 153 transmits and receives data to and from server 5 via communication device 3 and external communication network 4. As a result, communication adapter 150 periodically transmits operation information of water heating apparatus 100 to server 5. As a result, server 5 collects and manages various information about water heating apparatus 100 that is communicatively connected via communication adapter 150 and installed in homes, accommodation facilities, and the like.

[0029] Meanwhile, server 5 transmits data to communication adapter 150. This makes it possible to provide a remote control service for water heating apparatus 100. For example, predetermined operations of water heating apparatus 100, such as switching the hot water operation switch on / off and changing the hot water temperature setting, can be performed from server 5 or mobile terminal device 8 via external communication network 4.

[0030] In communication system 200, firmware updates for each of the components of water heating apparatus 100 are automatically executed by distribution from server 5. For example, in the case of communication adapter 150, firmware downloaded from server 5 is stored in ROM 155a, thereby updating the firmware.

[0031] <Water heater> The configuration of a water heater 110 according to an embodiment will be described with reference to Fig. 3. Fig. 3 is a block diagram showing an example of the hardware configuration of water heater 110. Water heater 110 includes a circuit board 115, a gas solenoid valve 51, a burner 52, and a gas supply pipe 53. Circuit board 115 includes a controller 140, a display 31, a drive power supply 41, a power supply cutoff circuit 42, a voltage detection circuit 43, and a solenoid valve drive circuit 44.

[0032] The controller 140 includes a main microcomputer (hereinafter also referred to as a “main microcomputer”) 10 and a sub-microcomputer (hereinafter also referred to as a “sub-microcomputer”) 20.

[0033] The main microcomputer 10 is communicatively connected to external devices (e.g., a remote control 160, a server 5, etc.) that exist outside the water heater 110. For example, the main microcomputer 10 is communicatively connected to the remote control 160 via a communication line 170, and is communicatively connected to the server 5 via the communication line 170, a communication adapter 150, a communication device 3, and an external communication network 4. The main microcomputer 10, the solenoid valve drive circuit 44, the gas solenoid valve 51, and the burner 52 constitute a part of a combustion device. The combustion device further includes a combustion unit (not shown). The gas solenoid valve 51 corresponds to a fuel valve that adjusts the amount of fuel (gas) supplied to the combustion unit.

[0034] On the other hand, the sub-microcomputer 20 is not connected for communication with any external device, but is connected for communication with the main microcomputer 10. In other words, the sub-microcomputer 20 cannot communicate directly with the remote control 160, the server 5, etc., and is configured to be able to communicate only with the main microcomputer 10.

[0035] The main microcomputer 10 includes a CPU 11 , an interface circuit 12 , a reset circuit 13 , a ROM 14 , a RAM 15 , and a communication unit 16 .

[0036] CPU 11 controls the operation of main microcomputer 10 and executes arithmetic processing according to a program. ROM 14 is configured, for example, with an EEPROM, and stores software (i.e., firmware) for controlling the operation of water heater 110, as well as data and programs used for other control. CPU 11 reads the firmware stored in ROM 14, expands it into RAM 15, and executes the expanded program to control the hot water supply operation of water heater 110. Typically, the firmware is written with the current version at the time of shipping from the factory.

[0037] The communication unit 16 is a communication interface for communicating with external devices (e.g., a remote control 160 and a server 5). The main microcomputer 10 is configured to be able to communicate with external devices using the communication unit 16. Therefore, the firmware stored in the memory (e.g., the ROM 14 and the RAM 15) of the main microcomputer 10 is configured to be rewritable with a different version of firmware distributed from the server 5. For example, the firmware is updated by storing update firmware transmitted from the server 5 in the ROM 14. For example, the firmware can be upgraded from the initial version as needed to add functions or fix bugs, etc.

[0038] The interface circuit 12 communicates various data and signals with the sub-microcomputer 20, the power supply cutoff circuit 42, the voltage detection circuit 43, and the solenoid valve drive circuit 44 in accordance with instructions from the CPU 11. The reset circuit 13 stops the main microcomputer 10 upon receiving a reset signal output from the sub-microcomputer 20.

[0039] The sub-microcomputer 20 includes a CPU 21, an interface circuit 22, a reset circuit 23, a ROM 24, and a RAM 25. The CPU 21 controls the entire sub-microcomputer 20 and executes arithmetic processing according to a program. The ROM 24 stores various data, programs, etc. The CPU 21 reads out the program stored in the ROM 24, expands it in the RAM 25, and executes the expanded program.

[0040] The interface circuit 22 communicates various data and signals with the main microcomputer 10, the display 31, and the power supply cutoff circuit 42 in accordance with instructions from the CPU 21. The reset circuit 23 outputs a reset signal to the main microcomputer 10 in accordance with instructions from the CPU 21.

[0041] A power-off signal is output from the main microcomputer 10 and the sub-microcomputer 20 via the interface circuits 12 and 22, respectively. The power-off signal is input to a power-off circuit 42. The power-off circuit 42 is inserted in the circuit extending from the drive power supply 41 to the solenoid valve drive circuit 44, and cuts off the voltage supplied to the gas solenoid valve 51.

[0042] The solenoid valve drive circuit 44 is mainly composed of, for example, a relay contact (not shown) that opens and closes a power supply line (not shown) that supplies a drive voltage to the gas solenoid valve 51, a relay coil (not shown) for controlling the relay contact, and a switching element that switches between energizing and de-energizing the relay coil. The switching element may be, for example, a field effect transistor (FET), a bipolar transistor, or the like. A control signal from the main microcomputer 10 can be input to a control terminal of the switching element (for example, a gate in the case of an FET, or a base in the case of a bipolar transistor).

[0043] Since the gas solenoid valve 51 is of a normally closed type, when the power supply cutoff circuit 42 functions to cut off the voltage supplied to the gas solenoid valve 51, the gas solenoid valve 51 closes and the supply of gas from the gas supply pipe 53 to the burner 52 is stopped. A voltage detection circuit 43 is provided between the power supply cutoff circuit 42 and the solenoid valve drive circuit 44, and a signal from the voltage detection circuit 43 is input to the interface circuit 12 of the main microcomputer 10.

[0044] As described above, the power supply cutoff signals output from the main microcomputer 10 and the sub-microcomputer 20 are input to the power supply cutoff circuit 42. The power supply cutoff circuit 42 is configured to cut off the power supply from the drive power supply 41 when it receives the input of a power supply cutoff signal output from either the main microcomputer 10 or the sub-microcomputer 20. In this case, the voltage supplied to the gas solenoid valve 51 is cut off, and the supply of gas to the burner 52 is stopped.

[0045] Whether or not the power supply from the drive power supply 41 has been cut off can be determined by the main microcomputer 10 checking the signal from the voltage detection circuit 43. The voltage detection circuit 43 is a circuit that determines whether or not power is being supplied to the solenoid valve drive circuit 44, and is a circuit that indirectly determines whether or not fuel is being supplied to the burner 52.

[0046] As described above, the main microcontroller 10 includes a communication unit 16 for communicating with external devices, so the firmware for controlling the operation of the water heater 110, which is stored in the ROM 14, can be updated remotely.

[0047] <Control Structure> The control structure of water heater 110 according to this embodiment will be described with reference to Figure 4. Figure 4 is a flowchart showing an example of processing performed when rewriting the firmware of main microcomputer 10 while maintaining gas solenoid valve 51 in a closed state. The following example shows a case where two pieces of software (first software A and second software B) stored in the water heater control a combustion appliance. First software A performs a firmware update (rewrite) of second software B. First software A is an example of the first software recited in the claims. Second software B is an example of the second software recited in the claims.

[0048] For safety reasons, it is necessary to close (close) a control valve (for example, gas solenoid valve 51) that can open and close the fuel supply path while first software A is rewriting second software B. Therefore, the main microcomputer 10 executes the following process.

[0049] In step S410, the CPU 11 of the main microcomputer 10 starts the first software A stored in the ROM 14.

[0050] In step S420, the CPU 11 sets to input mode the port for controlling the opening and closing of the gas electromagnetic valve 51. The port becomes high impedance, and the output of a signal to open the gas electromagnetic valve 51 is prohibited.

[0051] In step S430, the CPU 11 executes a firmware update of the second software B using the first software A.

[0052] In step S440, when the CPU 11 detects that the update of the second software B has been completed, the CPU 11 starts up the updated second software B.

[0053] In step S450, the CPU 11 sets the port for controlling the opening and closing of the gas electromagnetic valve 51 to the output mode, and initializes it to low output.

[0054] In step S460, the CPU 11 executes normal control by executing the second software B. After that, when the CPU 11 detects a combustion request, it starts the combustion operation.

[0055] 5 and 6, the operation of controlling the opening and closing of the gas electromagnetic valve 51 will be described. Each of Fig. 5 and Fig. 6 is a schematic diagram of a part of a circuit block diagram that controls the opening and closing of the gas electromagnetic valve 51.

[0056] 5, a port (not shown) of the main microcomputer 10 is electrically connected to the gate of the solenoid valve drive circuit 44. A resistor 620 connected to ground 630 is connected between the port and the gate. Ground 630 is, for example, the circuit ground of the circuit board 115 and does not necessarily have to be at earth potential. At a certain stage, the main microcomputer 10 turns off the output (arrow 610) from the port (0 V), thereby turning off the FET and closing the open / close state of the gas solenoid valve 51.

[0057] Referring to FIG. 6, in another aspect, when the main microcomputer 10 sets the port in input mode (high impedance), the gate level falls to Low, the FET is turned off, and the gas electromagnetic valve 51 is closed.

[0058] In this way, by setting the port for controlling the opening and closing of the gas solenoid valve 51 to input mode instead of output mode, the signal for controlling the opening and closing of the gas solenoid valve 51 is not output from the main microcomputer 10, and the signal does not go high due to unintended disturbances, etc. This ensures that the gas solenoid valve 51 is closed, preventing the supply of fuel gas to the water heater 110 during firmware updates.

[0059] The scope of application of the disclosed technical concept is not limited to the gas electromagnetic valve 51. For example, the technical concept can also be applied to a flow rate adjustment valve that controls the supply of kerosene or other liquid fuels.

[0060] Although the circuit configuration illustrated in FIG. 6 has a pull-down resistor, a circuit configuration according to another aspect may have a pull-up resistor instead of a pull-down resistor, as long as the solenoid valve drive circuit 44 can maintain the closed state of the gas solenoid valve 51 when the corresponding port of the main microcomputer 10 is set to the input mode.

[0061] Furthermore, the technical concept can be applied to devices other than solenoid valves, such as air intake fans, igniters, pumps, etc.

[0062] As described above, the water heater according to this embodiment has a circuit configuration in which there is a resistor that connects the gate terminal of the FET for driving gas solenoid valve 51 to ground. In the water heater, the ports of main microcomputer 10 that are connected to gas solenoid valve 51 and other drive circuits are set to input mode until the software update is complete. The drive circuits become high impedance and signals are no longer output from the ports to the FET, so the FET does not drive gas solenoid valve 51. This prevents gas solenoid valve 51 from opening unintentionally.

[0063] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0064] 3 communication equipment, 4 external communication network, 5 server, 6 router, 7 base station, 8 mobile terminal device, 10 main microcomputer, 12, 22 interface circuit, 13, 23 reset circuit, 14, 24, 155a ROM, 15, 25, 155b RAM, 16, 152, 153 communication unit, 20 sub-microcomputer, 31 display, 41 drive power supply, 42 power cut-off circuit, 43 voltage detection circuit, 44 solenoid valve drive circuit, 51 gas solenoid valve, 52 burner, 53 gas supply pipe, 100 water heater, 110 water heater, 111 hot water outlet, 115 circuit board, 140 controller, 150 communication adapter, 151 microcomputer, 154 power supply circuit, 155 memory, 157 antenna, 158 connector, 160 remote control, 161 display, 162 Input interface, 170 communication line, 200 communication system, 610 arrow, 620,820,920,1020 resistor, 630,830,930,1030 ground, 810 drive circuit, 910,1010 control circuit.

Claims

1. A combustion device comprising: a memory for storing first software and second software for controlling the operation of the combustion device; a microcomputer that executes the first software or the second software; A load that operates by receiving power supply; a drive circuit that drives the load based on an output from the microcomputer; and a resistance. one end of the resistor is connected between an input / output port of the microcomputer and a control terminal of the drive circuit; the drive circuit is driven when a first voltage value corresponding to a first logic level output from the microcomputer is applied to the drive circuit; the drive circuit is stopped when a second voltage value corresponding to a second logic level output from the microcomputer is applied to the drive circuit; While the first software updates the second software, the input / output port is set to an input port; The potential of the other end of the resistor is maintained at the second voltage value.

2. The combustion device according to claim 1 , wherein the potential of the second voltage value is ground.

3. The combustion device according to claim 1 , wherein the potential of the second voltage value is a power supply voltage.

4. A combustion section; a fuel valve for supplying fuel to the combustion section; The combustion device of claim 1 , wherein the load includes the fuel valve.

5. A water heater comprising the combustion device according to any one of claims 1 to 4.

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