JP6953829B2 - Combustion device - Google Patents

Description

The present invention relates to a combustion device including two control units that control energization of a valve for supplying fuel to the combustion unit.

Combustion devices including two control units for controlling energization of a valve for supplying fuel to the combustion unit are described in JP-A-2002-318003 (Patent Document 1) and WO 2006/08223 (Patent Document). It is disclosed in 2).

Patent Documents 1 and 2 describe a configuration in which each of the main control unit and the sub control unit independently controls the operation of the energization cutoff circuit for shutting off the energization of the solenoid valve for supplying fuel. Has been done. In these combustion devices, two control units are mounted in the device, and the control units are communicated with each other to monitor each other, thereby preventing the runaway of the microcomputers constituting each control unit.

JP-A-2002-318003 International Publication No. 2006/080223

In Patent Documents 1 and 2, the energization cutoff circuit is configured by using a switch whose continuity and cutoff are controlled by a main control unit and a switch whose continuity and cutoff are controlled by a sub-control unit. By shutting off one of the switches, the energization of the solenoid valve can be cut off. Each of the two switches is composed of a semiconductor switching element such as a transistor.

According to the above configuration, even if an abnormality occurs in one of the main control unit and the sub control unit and the control unit becomes uncontrollable, the other control unit shuts off the corresponding switch. , The solenoid valve can be forcibly closed.

However, in the above configuration, when the two switches are both fixed in the conductive state and a failure that does not cause the breaking state occurs, the energization of the solenoid valve may not be cut off. In such a case, the solenoid valve is opened unintentionally by the main control unit and the sub control unit, so that there is a concern that fuel leakage or the like may occur. Therefore, in order to improve the safety of the combustion device, it is necessary not only to prevent the runaway of each control unit but also to prevent the malfunction of the solenoid valve due to the failure of the two switches.

The present invention has been made to solve such a problem, and an object of the present invention is to energize a solenoid valve by controlling the continuity and disconnection of two switches by two control units, respectively. It is an object of the present invention to provide a configuration for surely shutting off the energization of the solenoid valve in the event of a failure of the two switches in a combustion device configured to be controlled.

The combustion apparatus according to the present invention energizes a combustion portion that generates heat by burning fuel, a first valve that is opened by energization to supply fuel to the combustion portion, and a first valve. It includes first and second control units for control, and first to third switches electrically connected in series with the first valve between the power supply wiring and the ground wiring. The continuity and disconnection of each of the first and second switches are controlled by the first control unit. The continuity and disconnection of the third switch are controlled by the second control unit. The first valve is energized when the first to third switches are in a conductive state.

According to the above-mentioned combustion device, since three switches are electrically connected in series to the first valve, two of the three switches are fixed in a conductive state and are in a cut-off state. Even if a failure occurs, the power supply to the first valve can be cut off by turning off the remaining one switch. As a result, since the first valve is closed, the supply of fuel to the combustion portion can be reliably cut off, and the safety of the combustion device can be improved.

In Patent Documents 1 and 2 described above, in order to guarantee safety when two switches fail and the solenoid valve is opened, a spare solenoid valve is provided in series with the solenoid valve. In some cases, the spare solenoid valve is closed to avoid fuel leakage. On the other hand, in the combustion apparatus according to the present invention, as described above, the solenoid valve can be closed even if the two switches fail, so that such redundancy of the solenoid valve is not required. It is possible to guarantee the safety of the combustion device.

Preferably, the combustion device further includes a notification unit for notifying an abnormality of the combustion device. Each of the first and second control units is configured to detect the energized state of the first valve. When any two of the first to third switches are in a conductive state and the energized state of the first valve is detected, the first or second control unit sends a combustion device to the notification unit. Notify the abnormality of.

In this way, it is possible to determine whether or not each switch has failed, so that when any one of the three switches fails, the user can be notified of the failure.

Preferably, when any two of the first to third switches are brought into a conductive state and the energized state of the first valve is detected, the first and second control units are subjected to any of the above. At least one of the two switches is shut off.

In this way, the energization of the first valve can be cut off when any one of the three switches fails.

Preferably, one of the first and second control units is a main control unit that controls the combustion apparatus in an integrated manner. The other of the first and second control units is a sub control unit that controls energization of the first valve independently of the main control unit. The main control unit and the sub control unit execute bidirectional communication.

In this way, the main control unit and the sub control unit monitor each other to realize a function of preventing malfunction due to an abnormality of the microcomputer, and malfunction due to a failure of two switches. It is possible to realize a function to prevent.

Preferably, the first series circuit of the first valve and the first switch is connected between the power supply wiring and the ground wiring. Each of the second and third switches is connected between the power supply wiring and the first series circuit, or between the first series circuit and the ground wiring.

In this way, even if two of the first to third switches fail, the remaining one switch is shut off to energize the first valve. Can be blocked.

Preferably, the combustion apparatus is electrically connected in series with the second valve between the power supply wiring and the grounding wiring, and the second valve configured to be opened by energization to supply fuel to the combustion part. A fourth switch is further provided. The fourth switch is controlled for continuity and interruption by either the first or second control unit. The second series circuit of the second valve and the fourth switch is connected in parallel with the first series circuit between the power supply wiring and the ground wiring. The second valve is energized when the second to fourth switches are in a conductive state.

In this way, the first to third switches are electrically connected in series with the first valve, and the second to fourth switches are electrically connected in series with the second valve. Be connected. Therefore, in each of the first valve and the second valve, the energization of the valve when two of the three switches fail can be reliably cut off. Further, since the second switch and the third switch can be shared between the first valve and the second valve, it is possible to prevent the device from becoming larger due to the increase in the number of switches.

According to the present invention, in a combustion device in which two control units are configured to control energization of a solenoid valve by controlling conduction and interruption of the two elements, respectively, electromagnetic waves occur when the two elements fail. The energization of the valve can be reliably cut off.

It is a schematic block diagram of the hot water supply device to which the combustion device according to the embodiment of this invention is applied. It is a circuit diagram for demonstrating the structure for controlling the energization to a gas solenoid valve. It is a figure which extracts and shows only the part which controls the energization to the solenoid valve from the control structure shown in FIG. It is a circuit diagram for demonstrating the configuration for controlling the energization to the gas solenoid valve in the hot water supply device which follows a comparative example. It is a flowchart for demonstrating the failure determination process of the switch in the hot water supply apparatus according to embodiment. It is a schematic block diagram for demonstrating the structural example of the hot water supply apparatus according to embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The same or corresponding parts in the figure are designated by the same reference numerals, and the description thereof shall not be repeated in principle.

FIG. 1 is a schematic configuration diagram of a hot water supply device 1 to which a combustion device according to an embodiment of the present invention is applied. With reference to FIG. 1, the hot water supply device 1 includes a water inlet pipe 2, a hot water outlet pipe 3, a heat exchanger 4, combustion burners 5a and 5b, a power supply circuit 20, a controller 30, and a remote controller 90. The hot water supply device 1 further includes gas supply pipes 6a, 6b, 8 and gas solenoid valves 7a, 7b for supplying fuel gas to the combustion burners 5a, 5b. The heat exchanger 4 and the combustion burners 5a and 5b are housed in a can body (not shown).

Non-heated water such as tap water is supplied to the water inlet pipe 2. The heat exchanger 4 heats the unheated water from the water inlet pipe 2 by heat exchange by the combustion heat of the fuel gas by the combustion burners 5a and 5b. The heated water from the heat exchanger 4 is discharged from the hot water discharge pipe 3.

The gas supply pipe 8 is branched into a gas supply pipe 6a to the combustion burner 5a and a gas supply pipe 6b to the combustion burner 5b. A gas solenoid valve 7a is inserted in the gas supply pipe 6a. A gas solenoid valve 7b is inserted in the gas supply pipe 6b. The fuel gas output from each of the combustion burners 5a and 5b is mixed with the combustion air introduced by a blower fan (not shown) and ignited by an ignition device (not shown). When the air-fuel mixture is ignited, a flame is generated in which the fuel gas is burned. The combustion heat generated by the flames from the combustion burners 5a and 5b is given to the heat exchanger 4.

In the example of FIG. 1, the combustion burners 5a and 5b are arranged in parallel with the heat exchanger 4. Therefore, it is also possible to switch the number of combustion burners to which the fuel gas is supplied among the combustion burners 5a and 5b.

The gas solenoid valves 7a and 7b are opened and closed in response to a control command from the controller 30. The gas solenoid valves 7a and 7b are solenoid valves that are normally closed, and transition from a closed state to an open state when the solenoid is energized. The gas solenoid valve 7a has a function of executing / shutting off the supply of fuel gas to the combustion burner 5a. The gas solenoid valve 7b has a function of executing / shutting off the supply of combustion gas to the combustion burner 5b.

Although not shown, a gas proportional valve for controlling the gas flow rate of the gas supply pipe 6a may be further provided in series with the gas solenoid valve 7a. Similarly, a gas proportional valve for controlling the gas flow rate of the gas supply pipe 6b may be further provided in series with the gas solenoid valve 7b. The amount of heat generated in the can body is proportional to the amount of heat supplied to the entire combustion burner, which is determined by the combination of the number of combustion burners and the gas flow rate.

In the configuration shown in FIG. 1, the combustion burners 5a, 5b, the gas supply pipes 6a, 6b, 8, the gas solenoid valves 7a, 7b, and the controller 30 constitute a "combustion device" according to the present embodiment. That is, each of the combustion burners 5a and 5b corresponds to one embodiment of the "combustion unit", the gas solenoid valve 7a corresponds to one embodiment of the "first valve", and the gas solenoid valve 7b corresponds to the "second valve". Corresponds to one embodiment of "valve". The configuration for controlling the opening and closing of the valve will be described in detail later.

The hot water supply device 1 further includes a high limit switch 9 as a configuration for detecting an abnormality in the hot water supply device 1. The high limit switch 9 is arranged on the can body. The high limit switch 9 is a detection element for monitoring an abnormally high temperature of the can body. When the temperature of the can body reaches a certain value or higher, the high limit switch 9 opens its contacts to electrically transition from the conductive state to the cutoff state. The high limit switch 9 is configured so that the contact point automatically returns when the temperature of the can body drops.

The remote controller 90 is a device for remotely operating the hot water supply device 1. The remote controller 90 is equipped with a display for displaying the operating state of the hot water supply device 1, various switches, a speaker, and the like.

The power supply circuit 20 converts the AC voltage from the external power supply 10 into the DC voltage Vs between the power supply wiring 80 and the ground wiring 84. The external power supply 10 is typically a 100 VAC or 200 VAC commercial system power supply. Hereinafter, the DC voltage Vs is also referred to as a power supply voltage Vs. The power supply voltage Vs is controlled to, for example, about 15V.

The controller 30 is connected between the power supply wiring 80 and the ground wiring 84. The controller 30 operates by receiving the supply of the power supply voltage Vs from the power supply wiring 80. Specifically, the controller 30 controls the operation of the hot water supply device 1 according to the user operation on the remote controller 90. For example, the user operation includes an on / off instruction for hot water supply operation and a set temperature instruction for hot water supply. As a typical function, the controller 30 generates a control command to the combustion burners 5a and 5b so that the hot water temperature is controlled according to the set temperature. By controlling the combustion heat by the combustion burners 5a and 5b according to the control command, the hot water discharge temperature in the hot water supply device 1 is controlled.

The controller 30 includes a drive circuit 40, a monitoring circuit 50, a main microcomputer (hereinafter referred to as a main microcomputer) 60, and a sub-microcomputer (hereinafter referred to as a sub-microcomputer) 70.

The main microcomputer 60 controls the operation of the hot water supply device 1 in an integrated manner. Specifically, the main microcomputer 60 ignites the combustion burners 5a and 5b, adjusts the hot water temperature, controls various solenoid valves including the gas solenoid valves 7a and 7b, and controls the blower fan. By communicating with the remote controller 90, the main microcomputer 60 receives various instructions from the remote controller 90 and transmits the operating state of the hot water supply device 1 to the remote controller 90.

The main microcomputer 60 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and an I / F (Interface) circuit. The CPU executes the program stored in the ROM using the RAM as a working memory. The program stored in the ROM includes a function of controlling the operation of the hot water supply device 1. A drive circuit 40, a monitoring circuit 50, and various sensors (not shown) are connected to the I / F circuit.

The sub-microcomputer 70 controls the interruption of the supply of fuel gas to the combustion burners 5a and 5b independently of the main microcomputer 60. That is, the sub-microcomputer 70 can control the closing of the gas solenoid valves 7a and 7b independently of the main microcomputer 60.

Like the main microcomputer 60, the sub-microcomputer 70 has a CPU, a ROM, a RAM, and an I / F circuit. A drive circuit 40, a monitoring circuit 50, and various sensors are connected to the I / F circuit. The I / F circuit of the sub-microcomputer 70 is electrically connected to the I / F circuit of the main microcomputer 60, and can transmit and receive data to and from each other.

The drive circuit 40 controls the opening and closing of the gas solenoid valves 7a and 7b according to the control commands from the main microcomputer 60 and the sub-microcomputer 70. As will be described later in FIG. 2, the drive circuit 40 controls energization of the gas solenoid valves 7a and 7b according to a control command.

The monitoring circuit 50 monitors the energized state of each of the gas solenoid valves 7a and 7b. The monitoring circuit 50 outputs signals indicating the energized states of the gas solenoid valves 7a and 7b to the main microcomputer 60 and the sub-microcomputer 70. In the main microcomputer 60 and the sub-microcomputer 70, each of the gas solenoid valves 7a and 7b is in an energized state or a non-energized state based on the signal from the monitoring circuit 50, that is, each of the gas solenoid valves 7a and 7b. It is possible to detect whether the valve is open or closed.

Next, a configuration for controlling energization of the gas solenoid valves 7a and 7b will be described with reference to FIG.

With reference to FIG. 2, the power supply wiring 80 is connected to the feeder line 82 via the high limit switch 9. The power supply wiring 80 supplies the power supply voltage Vs to the power supply line 82. The power supply voltage Vs is controlled by the power supply circuit 20 to, for example, 15V. Specifically, the power supply circuit 20 includes a diode bridge 21 and a DC / DC converter 22. The diode bridge 21 rectifies the AC voltage from the external power supply 10. The DC / DC converter 22 converts the voltage rectified by the diode bridge 21 into the power supply voltage Vs. Gas solenoid valves 7a and 7b are connected to the feeder line 82. Further, another load (not shown) may be connected to the feeder line 82.

In the high limit switch 9, when the hot water supply device 1 is operating normally and the temperature of the can body is less than a certain value, the contact of the high limit switch 9 is kept in the closed state, so that the path into which the high limit switch 9 is inserted can be established. Make it conductive. On the other hand, when the temperature of the can body becomes abnormally high and the temperature of the can body exceeds a certain value, the contact is opened and the path into which the high limit switch 9 is inserted is blocked.

The main microcomputer 60 and the sub-microcomputer 70 are connected between the power supply wiring 86 and the ground wiring 88. The main microcomputer 60 and the sub-microcomputer 70 operate by receiving the supply of the power supply voltage Vc from the power supply wiring 86. The power supply voltage Vc is controlled to, for example, 5V by a power supply (not shown).

The main microcomputer 60 generates control commands S1a, S1b, S2 for controlling energization of the gas solenoid valves 7a, 7b. The generated control commands S1a, S1b, and S2 are input to the drive circuit 40.

The sub-microcomputer 70 generates a control command S3 for controlling energization of the gas solenoid valves 7a and 7b. The generated control command S3 is input to the drive circuit 40.

The drive circuit 40 is electrically connected in series with the gas solenoid valve 7a between the feeder line 82 and the ground wiring 84. The drive circuit 40 is also electrically connected in series with the gas solenoid valve 7b between the feeder line 82 and the ground wire 84. In the following, the voltage of the ground wiring 84 will be referred to as the ground voltage GND.

The drive circuit 40 controls energization from the feeder line 82 to the gas solenoid valve 7a in accordance with the control command S1a from the main microcomputer 60. The gas solenoid valve 7a transitions from the closed state to the open state when energized. The drive circuit 40 also controls energization from the feeder line 82 to the gas solenoid valve 7b in accordance with the control command S1b from the main microcomputer 60. The gas solenoid valve 7b transitions from the closed state to the open state when it is energized. The drive circuit 40 further controls the power supply to the feeder line 82 in accordance with the control command S2 from the main microcomputer 60 and the control command S3 from the sub-microcomputer 70.

Specifically, the drive circuit 40 has switches Q1a and Q1b, a switch Q2, and a switch Q3. The switch Q1a is electrically connected in series with the gas solenoid valve 7a between the feeder line 82 and the ground wiring 84. The switch Q1a is composed of, for example, a FET (Field Effect Transistor). In the switch Q1a, the drain is connected to the gas solenoid valve 7a, the source is connected to the ground wiring 84, and the gate receives the control command S1a from the main microcomputer 60.

The switch Q1a becomes conductive when it receives the H (logical high) level control command S1a, and connects the gas solenoid valve 7a between the feeder line 82 and the ground wiring 84. On the other hand, the switch Q1a is shut off when it receives the L (logical low) level control command S1a, and the gas solenoid valve 7a is not connected between the feeder line 82 and the ground wiring 84.

The switch Q1b is electrically connected in series with the gas solenoid valve 7b between the feeder line 82 and the ground wiring 84. The switch Q1b is composed of, for example, an FET. In the switch Q1b, the drain is connected to the gas solenoid valve 7b, the source is connected to the ground wiring 84, and the gate receives the control command S1b from the main microcomputer 60.

The switch Q1b becomes conductive when it receives the H level control command S1b, and connects the gas solenoid valve 7b between the feeder line 82 and the ground wiring 84. On the other hand, the switch Q1b is shut off when it receives the L-level control command S1b, and the gas solenoid valve 7b is not connected between the feeder line 82 and the ground wiring 84.

The switch Q2 and the switch Q3 are electrically connected in series between the power supply wiring 80 and the feeding line 82. Each of the switches Q2 and Q3 is composed of, for example, an FET. The switch Q2 receives the control command S2 from the main microcomputer 60 at the gate. The switch Q3 receives the control command S3 from the sub-microcomputer 70 at the gate.

The switch Q2 is in a conductive state when it receives the H level control command S2, and is in a cutoff state when it receives the L level control command S2. The switch Q3 is in a conductive state when it receives the H level control command S3, and is in a cutoff state when it receives the L level control command S3. When both the switches Q2 and Q3 are in a conductive state, the power supply wiring 80 and the feeding line 82 are electrically connected. In other words, when either of the switches Q2 and Q3 is in the cutoff state, the power supply wiring 80 and the power supply line 82 are disconnected.

In this embodiment, a configuration in which an FET is used for each of the switches Q1a, Q1b, Q2, and Q3 is illustrated, but a semiconductor switching element other than the FET such as a bipolar transistor can be used for each switch. ..

The monitoring circuit 50 detects the voltage of the node Na connecting the gas solenoid valve 7a and the switch Q1a, and outputs a signal indicating the detected voltage to the main microcomputer 60 and the sub-microcomputer 70. The monitoring circuit 50 also detects the voltage of the node Nb connecting the gas solenoid valve 7b and the switch Q1b, and outputs a signal indicating the detected voltage to the main microcomputer 60 and the sub-microcomputer 70.

The monitoring circuit 50 has, for example, a voltage dividing circuit. The voltage divider circuit divides the voltages of the nodes Na and Nb at a predetermined voltage divider ratio to generate a voltage divider voltage. The predetermined voltage division ratio is set so that the voltage division voltage is equal to or lower than the power supply voltage Vc of the main microcomputer 60 and the sub microcomputer 70.

The voltage appearing at the node Na differs between the energized state and the non-energized state of the gas solenoid valve 7a. Therefore, the main microcomputer 60 and the sub-microcomputer 70 can detect whether the gas solenoid valve 7a is energized or de-energized based on the voltage of the node Na indicated by the signal input from the monitoring circuit 50. can.

Similarly, the voltage appearing at the node Nb differs between the energized state and the non-energized state of the gas solenoid valve 7b. Therefore, the main microcomputer 60 and the sub-microcomputer 70 can detect whether the gas solenoid valve 7b is energized or de-energized based on the voltage of the node Nb indicated by the signal input from the monitoring circuit 50. can.

The main microcomputer 60 has a function of detecting an abnormality based on a control command issued by itself, an operating state of the hot water supply device 1, and signals from a monitoring circuit 50 and various sensors. Abnormalities include, for example, leakage of unburned gas (unburned fuel) and empty burning of combustion burners 5a and 5b. When the main microcomputer 60 detects an abnormality, it generates L-level control commands S1a, S1b, and S2, and outputs the generated control commands S1a, S1b, and S2 to the drive circuit 40. The drive circuit 40 shuts off the switches Q1a, Q1b, and Q2 in accordance with the L-level control commands S1a, S1b, and S2, respectively, thereby deenergizing the gas solenoid valves 7a and 7b. As a result, the gas solenoid valves 7a and 7b are closed, and the supply of fuel gas to the combustion burners 5a and 5b is cut off. Therefore, if combustion is in progress, combustion is stopped, and if combustion is stopped, combustion is prevented from starting.

The sub-microcomputer 70 also has a function of detecting an abnormality based on the operating state of the hot water supply device 1 and signals from the monitoring circuit 50 and various sensors. When the sub-microcomputer 70 detects an abnormality, it generates an L-level control command S3 and outputs the generated control command S3 to the drive circuit 40.

The drive circuit 40 shuts off the switch Q3 in accordance with the L-level control command S3 to de-energize the gas solenoid valves 7a and 7b. As a result, the gas solenoid valves 7a and 7b are closed, and the supply of fuel gas to the combustion burners 5a and 5b is cut off.

As described above, the main microcomputer 60 and the sub-microcomputer 70 are configured to independently detect an abnormality and cut off the supply of fuel gas to the combustion burners 5a and 5b. However, the I / F circuit of the main microcomputer 60 and the I / F circuit of the sub-microcomputer 70 are electrically connected, and data can be transmitted and received from each other. As a result, the main microcomputer 60 and the sub-microcomputer 70 can detect their own abnormalities (such as runaway of the microcomputer) or other abnormalities by monitoring each other's operations through the transmission and reception of data.

Further, the main microcomputer 60 and the sub-microcomputer 70 can output a reset signal to each other. The microcomputer that receives the reset signal stops and restarts. That is, the controller 30 realizes the self-diagnosis function by including two microcomputers 60 and 70.

Further, according to the hot water supply device 1 according to the present embodiment, the energization of one gas solenoid valve is controlled by conduction / disconnection of three switches electrically connected in series with the gas solenoid valve. Is adopted. This makes it possible to prevent the gas solenoid valve from being energized due to an on-failure of two of the three switches. In the specification of the present application, the on failure means a failure in which the switch is fixed in the conductive state and does not enter the cutoff state.

Hereinafter, the action and effect of the hot water supply device 1 according to the present embodiment will be described in detail with reference to FIGS. 3 and 4.

FIG. 3 is a diagram showing only a portion of the control configuration shown in FIG. 2 that controls energization of the gas solenoid valve 7a. With reference to FIG. 3, a gas solenoid valve 7a and three switches Q1a, Q2, and Q3 are electrically connected in series between the power supply wiring 80 and the ground wiring 84. Therefore, when all of these three switches Q1a, Q2, and Q3 are in a conductive state, an energization path from the power supply wiring 80 to the gas solenoid valve 7a is formed as shown by the arrow k1 in the figure. Become.

Here, in the three switches Q1a, Q2 and Q3, the continuity and disconnection of the two switches Q1a and Q2 are controlled by the main microcomputer 60, and the continuity and interruption of the remaining one switch Q3 are controlled by the sub-microcomputer 70. It is configured in.

With such a configuration, the main microcomputer 60 and the sub-microcomputer 70 can de-energize the gas solenoid valve 7a independently of each other. Therefore, for example, when the main microcomputer 60 goes out of control and the hot water supply device 1 cannot be controlled normally, the sub-microcomputer 70 shuts off the switch Q3, so that the gas solenoid valve 7a is de-energized and the combustion burner 5a is turned off. The supply of fuel gas to the fuel gas can be cut off.

Further, when an on-failure occurs simultaneously in two of the three switches Q1a, Q2, and Q3, it is possible to prevent the gas solenoid valve 7a from being energized unintentionally by the controller 30. This point will be described in more detail with reference to the comparative example shown in FIG.

With reference to FIG. 4, the water heater 1A according to the comparative example has a different controller configuration than the water heater 1 according to the embodiment shown in FIG. Specifically, the controller 30A in the hot water supply device 1A according to the comparative example replaces the drive circuit 40 in the controller 30 shown in FIG. 2 with the drive circuit 40A.

The drive circuit 40A includes switches Q11a and Q11b, a switch Q12, and a switch Q13. The switch Q11a is the same as the switch Q1a of FIG. 2, and is electrically connected in series with the gas solenoid valve 7a between the feeder line 82 and the ground wiring 84. The switch Q11a becomes conductive when it receives the H-level control signal S11a from the main microcomputer 60, and connects the gas solenoid valve 7a between the feeder line 82 and the ground wiring 84. On the other hand, the switch Q11a is shut off when the L-level control command S11a is received, and the gas solenoid valve 7a is not connected between the feeder line 82 and the ground wiring 84.

The switch Q11b is the same as the switch Q1b of FIG. 2, and is electrically connected in series with the gas solenoid valve 7b between the feeder line 82 and the ground wiring 84. The switch Q11b becomes conductive when it receives the H level control signal S11b, and connects the gas solenoid valve 7b between the feeder line 82 and the ground wiring 84. On the other hand, the switch Q11b is shut off when it receives the L-level control command S11b, and the gas solenoid valve 7b is not connected between the feeder line 82 and the ground wiring 84. Each of the switches Q11a and Q11b is composed of, for example, an FET.

The switch Q12 is electrically connected between the power supply wiring 80 and the power supply line 82. The switch Q12 is composed of, for example, an FET. In the switch Q12, the drain is connected to the power supply wiring 80 and the source is connected to the feeding line 82.

The switch Q13 is electrically connected between the switch Q12 and the main microcomputer 60. The switch Q13 is composed of, for example, an NPN transistor. In the switch Q13, the collector is connected to the gate of the FET forming the switch Q12, the emitter is connected to the main microcomputer 60, and the base receives the control command S13 from the sub-microcomputer 70.

The switch Q13 becomes conductive when it receives the L-level control command S13, and electrically connects the gate of the switch Q12 and the main microcomputer 60. On the other hand, the switch Q13 is shut off when it receives an H-level control command, and the gate of the switch Q13 and the main microcomputer 60 are disconnected.

The switch Q12 is in a conductive state when the switch Q13 is in a conductive state and receives an H-level control command S12 from the main microcomputer 60, and is in a conductive state to connect the power supply wiring 80 and the feeder line 82. On the other hand, the switch Q12 is in the non-conducting state when the switch Q13 is in the non-conducting state, or when the switch Q13 is in the non-conducting state and receives the L-level control command S12 from the main microcomputer 60, and the switch Q12 is in the non-conducting state. The power supply line 82 is not connected. That is, when both the switches Q12 and Q13 are in a conductive state, the power supply wiring 80 and the feeding line 82 are electrically connected.

In the hot water supply device 1A according to the comparative example, the gas solenoid valve 7a and the two switches Q11a and Q12 are electrically connected in series between the power supply wiring 80 and the ground wiring 84. Then, one of the two switches Q11a and Q12, the switch Q12, can be electrically connected when the switch Q13 is in the conductive state.

With such a configuration, even in the hot water supply device 1A according to the comparative example, when all three switches Q11a, Q12, and Q13 are in a conductive state, an energization path from the power supply wiring 80 to the gas solenoid valve 7a is formed. The Rukoto.

In the comparative example, the switch Q11a is configured so that the continuity and interruption are controlled by the main microcomputer 60, and the switch Q12 is configured so that the continuity and interruption are controlled by the main microcomputer 60 and the sub-microcomputer 70. Therefore, the main microcomputer 60 and the sub-microcomputer are controlled. The 70 can de-energize the gas solenoid valve 7a independently of each other.

However, in the hot water supply device 1A according to the comparative example, when two of the three switches Q11a, Q12, and Q13 are turned on, the gas solenoid valve 7a may be energized.

For example, when an on-failure occurs in the switch Q11a and the switch Q12, an energization path from the power supply wiring 80 to the gas solenoid valve 7a is formed. In this case, even if the sub-microcomputer 70 shuts off the switch Q13, the switch Q12 cannot be shut off, so that the gas solenoid valve 7a is fixed in the energized state. In this way, if the two switches are turned on at the same time, the gas solenoid valve 7a may be opened unintentionally by the controller 30. Therefore, there is a concern that fuel gas may be supplied to the combustion burner 5a through the gas solenoid valve 7a even when the combustion is stopped.

Such a situation may occur even when the switch Q13 and the switch Q11a are simultaneously on-failed. In this way, in the hot water supply device 1A according to the comparative example, when two switches are turned on at the same time, the gas solenoid valve 7a is energized, so that the supply of fuel gas to the combustion burner 5a cannot be cut off. There are challenges.

On the other hand, in the hot water supply device 1 according to the present embodiment, as shown in FIG. 3, three switches Q1a, Q2, and Q3 are electrically connected in series to the gas solenoid valve 7a. Even if two of the three switches are turned on at the same time, the gas solenoid valve 7a can be de-energized by shutting off the remaining one switch.

For example, when the switches Q1a and Q2 are turned on at the same time, the sub-microcomputer 70 shuts off the switch Q3 to stop the energization of the gas solenoid valve 7a. Therefore, the supply of fuel gas to the combustion burner 5a can be cut off by closing the gas solenoid valve 7a. The energization of the gas solenoid valve 7a can be stopped even when the switches Q1a and Q3 are turned on at the same time and the switches Q2 and Q3 are turned on at the same time.

As described above, according to the hot water supply device 1 according to the present embodiment, it is possible to prevent the gas solenoid valve from being unintentionally energized due to the simultaneous on-failure of two switches in the controller 30. be able to. Therefore, the safety of the hot water supply device can be improved.

Although the configuration in which the switches Q2 and Q3 are connected in series between the power supply wiring 80 and the feeding line 82 is illustrated in FIG. 3, the switches Q2 and Q3 are connected in series between the switch Q1a and the ground wiring 84. You may connect to. Alternatively, one of the switches Q2 and Q3 may be connected between the power supply wiring 80 and the feeder line 82, and the other of the switches Q2 and Q3 may be connected between the switch Q1a and the ground wiring 84.

Further, although FIG. 3 illustrates a configuration in which the switch Q1a is connected between the gas solenoid valve 7a and the ground wiring 84, the switch Q1a may be connected between the feeder line 82 and the gas solenoid valve 7a. good.

That is, the switches Q1a, Q2, and Q3 need only be electrically connected in series with the gas solenoid valve 7a between the power supply wiring 80 and the ground wiring 84, and the positions of the switches are shown in FIG. It is not limited to the configuration.

In the above-described embodiment, the main microcomputer 60 constitutes one of the "first control unit" and the "second control unit", and the sub-microcomputer 70 constitutes the "first control unit" and the "second control unit". ”Consists of the other. Further, the switches Q1a, Q2 and Q3 correspond to one embodiment of the "first to third switches". In the water heater 1 according to the present embodiment, one of the main microcomputer 60 and the sub microcomputer 70 controls the continuity and disconnection of any two of the three switches Q1a, Q2, and Q3, and the remaining one switch is used. The other of the main microcomputer 60 and the sub microcomputer 70 may control the control.

(Switch failure judgment processing)
In the hot water supply device 1 according to the present embodiment, it is possible to determine whether or not each of the switches Q1a, Q1b, Q2, and Q3 is turned on. According to this, the controller 30 can notify the user of the abnormality when an on-failure occurs in any one of the switches.

Hereinafter, the failure determination process of the switches Q1a, Q1b, Q2, and Q3 will be described with reference to FIG. The flowchart shown in FIG. 5 can be executed by the main microcomputer 60 and the sub-microcomputer 70 in cooperation with each other when a predetermined condition is satisfied. The predetermined conditions include that the hot water supply device 1 has stopped burning and that the elapsed time from the previous failure determination process is equal to or longer than the predetermined time.

With reference to FIG. 5, the failure determination process includes a step of determining the failure of the switch Q2 (STEP1), a step of determining the failure of the switch Q3 (STEP2), and a step of determining the failure of the switches Q1a and Q1b (STEP3). It is composed.

In the step (STEP1) of determining the failure of the switch Q2, in step S01, the main microcomputer 60 gives an L-level control command S2 to the drive circuit 40 in order to put the switch Q2 in the cutoff state. The sub-microcomputer 70 gives an H-level control command S3 to the drive circuit 40 to bring the switch Q3 into a conductive state.

Next, the main microcomputer 60 gives an H-level control command S1a to the drive circuit 40 in step S02 to bring the switch Q1a into a conductive state. That is, two of the switches Q1a, Q2, and Q3 connected in series with the gas solenoid valve 7a are brought into a conductive state.

In step S03, the main microcomputer 60 detects whether the gas solenoid valve 7a is energized or de-energized based on the signal from the monitoring circuit 50. When it is detected that the gas solenoid valve 7a is energized, the main microcomputer 60 determines that the switch Q2 is on and failed. When it is determined that the switch Q2 is on-failed (when YES is determined in S04), the main microcomputer 60 proceeds to step S13 and notifies the on-failure of the switch Q2 by using the remote controller 90.

After notifying the on failure of the switch Q2, the sub-microcomputer 70 may give the L-level control command S3 to the drive circuit 40 to shut off the switch Q3. According to this, since the gas solenoid valves 7a and 7b are in a non-energized state, the start of supply of fuel gas to the combustion burners 5a and 5b is prevented.

On the other hand, when it is determined that the switch Q2 is normal (on failure has not occurred) (NO determination in S04), the step (STEP2) for determining the failure of the switch Q3 is subsequently executed. In the step (STEP2) of determining the failure of the switch Q3, the main microcomputer 60 gives the H level control command S2 to the drive circuit 40 in step S05 to make the switch Q2 conductive. The sub-microcomputer 70 gives an L-level control command S3 to the drive circuit 40 in order to shut off the switch Q3. In step S06, the main microcomputer 60 gives an H-level control command S1a to the drive circuit 40 to bring the switch Q1a into a conductive state. That is, the two switches Q1a and Q2 of the switches Q1a, Q2 and Q3 connected in series with the gas solenoid valve 7a are brought into a conductive state.

Next, in step S07, the main microcomputer 60 detects whether the gas solenoid valve 7a is energized or de-energized based on the signal from the monitoring circuit 50. When it is detected that the gas solenoid valve 7a is energized, the main microcomputer 60 determines that the switch Q3 is on and failed. When it is determined that the switch Q3 is on-failed (when YES is determined in S08), the main microcomputer 60 proceeds to step S13 and notifies the failure of the switch Q3 by using the remote controller 90.

After notifying the on failure of the switch Q3, the main microcomputer 60 may give the L-level control command S2 to the drive circuit 40 to shut off the switch Q2. According to this, since the gas solenoid valves 7a and 7b are in a non-energized state, the start of supply of fuel gas to the combustion burners 5a and 5b is prevented.

On the other hand, when it is determined that the switch Q3 is normal (NO determination in S08), the step (STEP3) of determining the on failure of the switches Q1a and Q1b is executed. In the step (STEP3) of determining the failure of the switches Q1a and Q1b, the main microcomputer 60 gives the H-level control command S2 to the drive circuit 40 in step S09 to make the switch Q2 conductive. The sub-microcomputer 70 gives an H-level control command S3 to the drive circuit 40 to bring the switch Q3 into a conductive state. In step S10, the main microcomputer 60 gives L-level control commands S1a and S1b to the drive circuit 40 in order to shut off the switches Q1a and Q1b. That is, two of the switches Q1a, Q2, and Q3 connected in series with the gas solenoid valve 7a are brought into a conductive state. Further, two of the switches Q1b, Q2 and Q3 connected in series with the gas solenoid valve 7b, Q2 and Q3, are brought into a conductive state.

In step S11, the main microcomputer 60 detects whether each of the gas solenoid valves 7a and 7b is energized or de-energized based on the signal from the monitoring circuit 50. When it is detected that the gas solenoid valve 7a is in the energized state, the main microcomputer 60 determines that the switch Q1a is on and failed. The main microcomputer 60 also determines that the switch Q1b is on-failed when it is detected that the gas solenoid valve 7b is in the energized state.

When it is determined that at least one of the switches Q1a and Q1b is on-failed (when YES is determined in S12), the main microcomputer 60 proceeds to step S13 and notifies the on-failure of the switches Q1a and Q1b by using the remote controller 90. do. The main microcomputer 60 and the sub-microcomputer 70 may have at least one of the switches Q2 and Q3 cut off. According to this, since the gas solenoid valves 7a and 7b are in a non-energized state, the start of supply of fuel gas to the combustion burners 5a and 5b is prevented.

On the other hand, when it is determined that both the switches Q1a and Q1b are normal (NO determination in S12), the main microcomputer 60 and the sub-microcomputer 70 end the failure determination process.

(Configuration example of hot water supply device)
Finally, a configuration example of the hot water supply device according to the present embodiment will be described.

In FIGS. 1 and 2, the configuration of the hot water supply device 1 having two gas solenoid valves 7a and 7b has been described. However, in the hot water supply device according to the present invention, the number of gas solenoid valves may be singular or plural. There may be. In any case, the first to third switches are electrically connected in series to each gas solenoid valve. Then, the first control unit controls the continuity and disconnection of the first and second switches, and the second control unit controls the continuity and disconnection of the third switch.

According to this, the first and second control units can independently de-energize the gas solenoid valve to cut off the supply of fuel gas to the combustion burner. Further, when an on-failure occurs in two of the first to third switches, it is possible to prevent the gas solenoid valve from being energized without the intention of the first and second control units. can do.

As shown in FIG. 2, when the hot water supply device 1 has two gas solenoid valves 7a and 7b, the drive circuit 40 of the controller 30 connects the gas solenoid valve 7a and the ground wiring 84 between the power supply line 82 and the ground wiring 84. It is preferable to connect the series circuit of the switch Q1a and the series circuit of the gas solenoid valve 7b and the switch Q1b in parallel. In this case, the gas solenoid valve 7a corresponds to the "first valve", the switch Q1a corresponds to the "first switch", and the series circuit of the gas solenoid valve 7a and the switch Q1a corresponds to the "first series circuit". Constitute. Further, the gas solenoid valve 7b corresponds to the "second valve", the switch Q1b corresponds to the "fourth switch", and the series circuit of the gas solenoid valve 7b and the switch Q1b constitutes the "second series circuit". do.

In this way, the switches Q2 and Q3 can be shared between the energization path of the gas solenoid valve 7a and the energization path of the gas solenoid valve 7b. Further, even when the number of gas solenoid valves is increased to 3 or more, the series circuits of the gas solenoid valve and the switch are connected in parallel to the first and second series circuits, so that the series circuits of 3 or more are connected. It becomes possible to share the switches Q2 and Q3 with.

In FIG. 2, the main microcomputer 60 controls the continuity and interruption of the switches Q1a and Q1b, but the sub-microcomputer 70 may control the continuity and interruption of the switches Q1a and Q1b. Alternatively, one of the main microcomputer 60 and the sub-microcomputer 70 may control the continuity and interruption of the switch Q1a, and the other of the main microcomputer 60 and the sub-microcomputer 70 may control the continuity and interruption of the switch Q1b.

Further, in FIG. 1, a configuration in which two gas solenoid valves 7a and 7b are interposed in separate gas supply pipes 6a and 6b has been described, but as shown in FIG. 6, two gas solenoid valves 7a and 7b are inserted in a single gas supply pipe. The gas solenoid valves 7a and 7b may be inserted in series. In this case, when any of the gas solenoid valves 7a and 7b is de-energized, the supply of fuel gas to the combustion burner is cut off.

Further, in the present embodiment, the control of energization of the valve for supplying fuel in the gas-fueled combustion device applied to the hot water supply device has been illustrated, but the application of the present invention has such a configuration. It is not limited. That is, in a combustion device having a valve for supplying other fuel such as petroleum, it is possible to control the energization of the valve in the same manner as in the present embodiment.

It should be considered that the embodiments disclosed this time are exemplary in all respects and not restrictive. The scope of the present invention is shown by the scope of claims rather than the above description, and it is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

1,1A hot water supply device, 2 water inlet pipe, 3 hot water outlet pipe, 4 heat exchanger, 5a, 5b combustion burner, 6a, 6b gas supply pipe, 7a, 7b gas solenoid valve, 9 high limit switch, 10 external power supply, 20 power supply Circuit, 21 diode bridge, 22 DC / DC converter, 30 controller, 40, 40A drive circuit, 50 monitoring circuit, 60 main microcomputer, 70 sub microcomputer, 80,86 power supply wiring, 82 power supply line, 84,88 ground wiring, 90 Remote control, Q1a, Q1b, Q2, Q3, Q11a, Q11b, Q12, Q13 switches.

Claims (6)

A combustion part that generates heat by burning fuel,
A first valve that is opened by energization to supply the fuel to the combustion unit, and
The first and second control units for controlling the energization of the first valve, and
A first to third switch electrically connected in series with the first valve is provided between the power supply wiring and the ground wiring.
Each of the first and second switches is controlled to conduct and shut off by the first control unit.
Continuity and disconnection of the third switch are controlled by the second control unit, and the third switch is controlled.
A combustion device in which the first valve is energized when the first to third switches are in a conductive state. A notification unit for notifying an abnormality of the combustion device is further provided.
Each of the first and second control units is configured to detect the energized state of the first valve.
When any two of the first to third switches are in a conductive state and the energized state of the first valve is detected, the first or second control unit notifies the notification. The combustion device according to claim 1, wherein an abnormality of the combustion device is notified to a unit. When any two of the first to third switches are in a conductive state and the energized state of the first valve is detected, the first and second control units are subjected to any of the above. The combustion apparatus according to claim 2, wherein at least one of the two switches is shut off. One of the first and second control units is a main control unit that controls the combustion apparatus in an integrated manner.
The other of the first and second control units is a sub control unit that controls energization of the first valve independently of the main control unit.
The combustion device according to any one of claims 1 to 3, wherein the main control unit and the sub control unit execute bidirectional communication. The first valve and the first series circuit of the first switch are connected between the power supply wiring and the grounding wiring.
From claim 1, each of the second and third switches is connected between the power supply wiring and the first series circuit, or between the first series circuit and the ground wiring. The combustion apparatus according to any one of 4. A second valve that is opened by energization to supply the fuel to the combustion unit, and
A fourth, which is electrically connected in series with the second valve between the power supply wiring and the grounding wiring, and whose continuity and interruption are controlled by either the first or second control unit. With more switches
The second series circuit of the second valve and the fourth switch is connected in parallel with the first series circuit between the power supply wiring and the ground wiring.
The combustion device according to claim 5, wherein the second valve is energized when the second to fourth switches are in a conductive state.

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