CN109114589B

CN109114589B - Combustion apparatus

Info

Publication number: CN109114589B
Application number: CN201810600410.8A
Authority: CN
Inventors: 森政宏; 高林晃
Original assignee: Noritz Corp
Current assignee: Noritz Corp
Priority date: 2017-06-23
Filing date: 2018-06-12
Publication date: 2021-12-28
Anticipated expiration: 2038-06-12
Also published as: JP6953829B2; JP2019007670A; CN109114589A

Abstract

The invention provides a combustion apparatus. The 1 st valve (7a) is configured such that the 1 st valve (7a) is opened by energizing the 1 st valve (7a) to supply fuel to the combustion section (5 a). A1 st control unit (60) and a 2 nd control unit (70) control the energization of the 1 st valve (7 a). The 1 st to 3 rd switches (Q1a, Q2, Q3) are electrically connected in series with the 1 st valve (7a) between the power supply wiring (80) and the ground wiring (84). The 1 st switch (Q1a) and the 2 nd switch (Q2) are controlled to be turned on and off by a 1 st control unit (60), respectively, and the 3 rd switch (Q3) is controlled to be turned on and off by a 2 nd control unit (70). When the 1 st to 3 rd switches (Q1a, Q2, Q3) are in an ON state, the 1 st valve (7a) is energized.

Description

Combustion apparatus

Technical Field

The present invention relates to a combustion apparatus having two control portions for controlling energization to valves for supplying fuel to a combustion portion.

Background

Japanese patent laid-open publication No. 2002-.

The above-mentioned document describes a configuration in which the main control unit and the sub-control unit control the operation of an energization shutoff circuit for shutting off energization to an electromagnetic valve for supplying fuel, independently of each other. The combustion apparatus described above is provided with two control units in the apparatus, and the control units communicate with each other to monitor each other, thereby preventing the microcomputer constituting each control unit from running away.

Disclosure of Invention

In the above document, an energization shutoff circuit is configured by using a switch on/off controlled by a main control unit and a switch on/off controlled by a sub control unit, and energization of the solenoid valve can be shut off by shutting off either of the switches. The two switches are each formed of a semiconductor switching element such as a transistor.

With this configuration, even when an abnormality occurs in one of the main control unit and the sub control unit and the control unit fails to perform control, the other control unit can be caused to close the corresponding switch forcibly.

However, in the above configuration, when a failure occurs in which both the switches are fixed in the on state and cannot be turned off, there is a possibility that the energization of the solenoid valve cannot be turned off. In such a case, the electromagnetic valve may be opened unless the main control unit and the sub control unit are intended, and therefore, there is a possibility of fuel leakage or the like. Therefore, in order to improve the safety of the combustion apparatus, it is necessary to prevent not only runaway of each control unit but also malfunction of the solenoid valve due to failure of both switches.

The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a structure for reliably cutting off the power supply to the electromagnetic valve when the two switches fail in a combustion apparatus in which the two control units are configured to control the on and off of the two switches, respectively, to control the power supply to the electromagnetic valve.

The combustion apparatus according to the present invention comprises: a combustion unit that generates heat by combustion of fuel; a 1 st valve configured to supply fuel to the combustion section by opening the 1 st valve by energizing the 1 st valve; a 1 st control unit and a 2 nd control unit for controlling energization to the 1 st valve; and 1 st to 3 rd switches electrically connected in series with the 1 st valve between the power supply wiring and the ground wiring. The 1 st switch and the 2 nd switch are controlled to be switched on and off by the 1 st control part respectively. The 3 rd switch is controlled to be turned on and off by the 2 nd control section. When the 1 st to 3 rd switches are in the on state, the 1 st valve is energized.

In the combustion apparatus, since the 3 switches are electrically connected in series to the 1 st valve, even when two of the 3 switches are fixed in the on state and cannot be turned off, the remaining 1 switch is turned off to cut off the current to the 1 st valve. Thus, the 1 st valve is in a closed state, so that the supply of fuel to the combustion portion can be reliably cut off, and the safety of the combustion apparatus can be improved.

In addition, in the above-mentioned

patent documents

1 and 2, in order to ensure safety when the electromagnetic valve is opened due to failure of both the switches, there is a case where a spare electromagnetic valve is provided in series with the electromagnetic valve in advance, and the spare electromagnetic valve is closed to prevent fuel leakage. In contrast, in the combustion apparatus of the present invention, as described above, even if both switches fail, the solenoid valve can be closed, and therefore, the safety of the combustion apparatus can be ensured without making the solenoid valve redundant as described above.

Preferably, the combustion apparatus further includes a notification unit for notifying an abnormality of the combustion apparatus. The 1 st control unit and the 2 nd control unit are configured to detect an energization state of the 1 st valve, respectively. When the energizing state of the 1 st valve is detected when any two of the 1 st to 3 rd switches are turned on, the 1 st control unit or the 2 nd control unit causes the notification unit to notify the combustion apparatus of an abnormality.

In this way, since it is possible to determine whether or not each switch has failed, it is possible to notify the user of the failure at the timing when any of the 3 switches has failed.

Preferably, the 1 st control unit and the 2 nd control unit set at least one of the 1 st to 3 rd switches to an off state when the energized state of the 1 st valve is detected while the two switches are set to the on state.

Thus, the current supply to the 1 st valve can be cut off at the timing when any one of the 3 switches fails.

Preferably, one of the 1 st control unit and the 2 nd control unit is a main control unit that collectively controls the combustion apparatus. The other of the 1 st control unit and the 2 nd control unit is a sub-control unit that controls energization to the 1 st valve independently of the main control unit. The main control unit and the sub control unit perform bidirectional communication.

In this way, the main control unit and the sub control unit can realize a function for preventing malfunction due to abnormality of the microcomputer by monitoring each other, and can realize a function for preventing malfunction due to failure of both switches.

Preferably, the 1 st series circuit of the 1 st valve and the 1 st switch is connected between the power supply wiring and the ground wiring. The 2 nd switch and the 3 rd switch are connected between the power supply wiring and the 1 st series circuit or between the 1 st series circuit and the ground wiring, respectively.

In this way, even when two switches among the 1 st to 3 rd switches fail, the current supply to the 1 st valve can be shut off by turning the remaining 1 switch off.

Preferably, the combustion apparatus further comprises: a 2 nd valve configured to supply fuel to the combustion portion by opening the 2 nd valve by supplying current to the 2 nd valve; and a 4 th switch electrically connected in series with the 2 nd valve between the power supply wiring and the ground wiring. The 4 th switch is controlled to be turned on and off by either one of the 1 st control unit and the 2 nd control unit. A2 nd series circuit of a 2 nd valve and a 4 th switch is connected in parallel with the 1 st series circuit between a power supply wiring and a ground wiring. When the 2 nd to 4 th switches are in the on state, the 2 nd valve is energized.

Thus, the 1 st to 3 rd switches are electrically connected in series with the 1 st valve, and the 2 nd to 4 th switches are electrically connected in series with the 2 nd valve. Therefore, when the 1 st valve and the 2 nd valve fail to operate in two of the 3 switches, the energization of the valves can be reliably cut off. Further, since the 2 nd and 3 rd switches can be shared between the 1 st and 2 nd valves, it is possible to prevent the apparatus from being increased in size due to an increase in the number of switches.

The foregoing and other objects, features, aspects and advantages of the present invention will become apparent from the following detailed description of the present invention, which is to be read in connection with the accompanying drawings.

Drawings

Fig. 1 is a schematic configuration diagram of a hot water supply device to which a combustion device according to an embodiment of the present invention is applied.

Fig. 2 is a circuit diagram for explaining a configuration for controlling energization to the pneumatic solenoid valve.

Fig. 3 is a diagram showing only a portion for controlling energization to the solenoid valve in the control structure shown in fig. 2.

Fig. 4 is a circuit diagram illustrating a configuration for controlling energization to a pneumatic solenoid valve in the hot water supply device of the comparative example.

Fig. 5 is a flowchart for explaining a failure determination process of the switch in the hot water supply device according to the embodiment.

Fig. 6 is a schematic configuration diagram for explaining a configuration example of the hot water supply device according to the embodiment.

Detailed Description

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or equivalent portions are denoted by the same reference numerals, and description thereof will not be repeated in principle.

Fig. 1 is a schematic configuration diagram of a hot water supply apparatus 1 to which a combustion apparatus according to an embodiment of the present invention is applied. Referring to fig. 1, the hot water supply apparatus 1 includes a water inlet pipe 2, an output hot water pipe 3, a heat exchanger 4,

burners

5a, 5b, a power circuit 20, a controller 30, and a remote controller 90. The hot water supply device 1 further includes

gas supply pipes

6a, 6b, 8 for supplying fuel gas to the

burners

5a, 5b, and

pneumatic solenoid valves

7a, 7 b. The heat exchanger 4 and the

burners

5a and 5b are housed in a tank body not shown.

Unheated water such as tap water is supplied to the water inlet pipe 2. The heat exchanger 4 heats the unheated water from the water intake pipe 2 by heat exchange using combustion heat of the fuel gas generated by the

burners

5a, 5 b. The heating water generated by the heat exchanger 4 is output from the output hot water pipe 3.

The gas supply pipe 8 is branched into a gas supply pipe 6a to the burner 5a and a gas supply pipe 6b to the burner 5 b. The pneumatic solenoid valve 7a is inserted into the gas supply pipe 6 a. The pneumatic solenoid valve 7b is inserted into the gas supply pipe 6 b. The fuel gas output from each of the

burners

5a and 5b is mixed with combustion air introduced by an unillustrated blower fan, and ignited by an unillustrated ignition device. By igniting the mixed gas, a flame formed by combustion of the fuel gas is generated. Combustion heat generated by flames from the

burners

5a, 5b is applied to the heat exchanger 4.

In the example of fig. 1, the

burners

5a and 5b are arranged in parallel with the heat exchanger 4. Therefore, the number of burners to be supplied with the fuel gas can be switched among the

burners

5a and 5 b.

The

pneumatic solenoid valves

7a and 7b are opened and closed in accordance with a control command from the controller 30. The

pneumatic solenoid valves

7a, 7b are normally closed solenoid valves, and the

pneumatic solenoid valves

7a, 7b are changed from a closed state to an open state by energizing the solenoid valves. The pneumatic solenoid valve 7a has a function of executing/shutting off the supply of the fuel gas to the burner 5 a. The pneumatic solenoid valve 7b has a function of performing/cutting off supply of the combustion gas to the burner 5 b.

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 pneumatic solenoid valve 7 a. 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 pneumatic solenoid valve 7 b. The amount of heat generated in the tank is proportional to the amount of heat supplied to the entire burner, which is determined by the number of burners and the combination of the gas flow rate.

In the configuration shown in fig. 1, the

burners

5a and 5b, the

gas supply pipes

6a, 6b, and 8, the

pneumatic solenoid valves

7a and 7b, and the controller 30 constitute a "combustion apparatus" according to the present embodiment. That is, the

burners

5a and 5b correspond to an embodiment of the "combustion section", the pneumatic solenoid valve 7a corresponds to an embodiment of the "1 st valve", and the pneumatic solenoid valve 7b corresponds to an embodiment of the "2 nd valve", respectively. The structure for controlling the opening and closing of the valve will be described in detail later.

The hot water supply apparatus 1 further includes a high-precision limit switch 9 as a structure for checking for an abnormality in the hot water supply apparatus 1. The high-precision limit switch 9 is arranged on the tank body. The high-precision limit switch 9 is an inspection element for monitoring an abnormal high temperature of the can body. When the can body reaches a temperature of a certain value or more, the contact of the high-precision limit switch 9 is opened, and the electrical connection is switched from the on state to the off state. In addition, when the temperature of the can body decreases, the contact of the high-precision limit switch 9 automatically resets.

The remote controller 90 is a device for operating the hot water supply apparatus 1 from a remote place. The remote controller 90 includes various switches, a speaker, a display for displaying the operating state of the hot water supply apparatus 1, and the like.

The power supply circuit 20 converts an ac voltage from the external power supply 10 into a dc voltage Vs between the power supply wiring 80 and the ground wiring 84. The external power supply 10 is typically a commercial system power supply of 100VAC or 200 VAC. In the following description, the dc voltage Vs is also referred to as a power supply voltage Vs. The power supply voltage Vs is controlled to be about 15V, for example.

The controller 30 is connected between the power wiring 80 and the ground wiring 84. The controller 30 operates upon 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 apparatus 1 according to a user operation on the remote controller 90. For example, the user operation includes an instruction to start and stop the hot water supply operation and an instruction to set the temperature of the hot water supply. As a representative function, the controller 30 generates a control command to the

burners

5a, 5b so as to control the output hot water temperature in accordance with the set temperature. The temperature of the hot water output from the hot water supply apparatus 1 is controlled by controlling the combustion heat generated by the

burners

5a, 5b in accordance with a control command.

The controller 30 has a drive circuit 40, a monitor circuit 50, a main microcomputer 60, and a sub-microcomputer 70.

The main microcomputer 60 controls the operation of the hot water supply device 1 in a lump. Specifically, the main microcomputer 60 performs ignition of the

burners

5a and 5b, adjustment of the temperature of the output hot water, control of various solenoid valves including the

pneumatic solenoid valves

7a and 7b, control of the blower fan, and the like. The main microcomputer 60 receives various instructions from the remote controller 90 by communicating with the remote controller 90, and transmits the operation state of the hot water supply apparatus 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 work memory. The program stored in the ROM includes a function for controlling the operation of the hot water supply apparatus 1 and the like. The drive circuit 40, the monitor circuit 50, and various sensors (not shown) are connected to the I/F circuit.

The sub-microcomputer 70 controls the cutoff of the supply of the fuel gas to the

burners

5a, 5b independently of the main microcomputer 60. That is, the sub-microcomputer 70 can control the closing of the

pneumatic solenoid valves

7a and 7b independently of the main microcomputer 60.

The sub-microcomputer 70 has a CPU, a ROM, a RAM, and an I/F circuit, as in the main microcomputer 60. The drive circuit 40, the monitor 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 or receive data to or from each other.

The drive circuit 40 controls the opening and closing of the

pneumatic solenoid valves

7a and 7b in accordance with control commands from the main microcomputer 60 and the sub-microcomputer 70. As described later with reference to fig. 2, the drive circuit 40 controls energization to the

pneumatic solenoid valves

7a and 7b in accordance with a control command.

The monitoring circuit 50 monitors the respective energization states of the

pneumatic solenoid valves

7a, 7 b. The monitoring circuit 50 outputs signals indicating the respective energization states of the

pneumatic solenoid valves

7a and 7b to the main microcomputer 60 and the sub-microcomputer 70. The main microcomputer 60 and the sub-microcomputer 70 can detect which of the energized and de-energized states the

pneumatic solenoid valves

7a and 7b are respectively, that is, which of the open and closed states the

pneumatic solenoid valves

7a and 7b are respectively, based on a signal from the monitoring circuit 50.

Next, a configuration for controlling energization to the

pneumatic solenoid valves

7a and 7b will be described with reference to fig. 2.

Referring to fig. 2, the power supply line 80 is connected to a power supply line 82 via the high-precision limit switch 9. The power supply wiring 80 supplies a 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 has a diode bridge 21 and a DC/DC converter 22. The diode bridge 21 rectifies the alternating-current 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.

Pneumatic solenoid valves

7a and 7b are connected to the power supply line 82. Further, another load not shown may be connected to the power feeding line 82.

In a state where the hot water supply device 1 normally operates and the temperature of the tank body is lower than a certain value, the contact of the high-precision limit switch 9 is kept in a closed state, and the path into which the high-precision limit switch 9 is inserted is turned on. When the can body reaches an abnormally high temperature and the temperature of the can body reaches a certain value or more, the contact of the high-precision limit switch 9 is opened, and the path into which the high-precision limit switch 9 is inserted is cut off.

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

The main microcomputer 60 generates control commands S1a, S1b, S2 for controlling energization to the

pneumatic solenoid valves

7a, 7 b. 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 the energization to the

pneumatic solenoid valves

7a, 7 b. The generated control command S3 is input to the drive circuit 40.

The drive circuit 40 is electrically connected in series with the pneumatic solenoid valve 7a between the power supply line 82 and the ground wiring 84. The drive circuit 40 is electrically connected in series to the pneumatic solenoid valve 7b between the power supply line 82 and the ground wiring 84. In the following description, the voltage of the ground wiring 84 is referred to as ground voltage GND.

The drive circuit 40 controls the energization of the pneumatic solenoid valve 7a from the power supply line 82 in accordance with a control command S1a from the main microcomputer 60. By energizing the pneumatic solenoid valve 7a, the pneumatic solenoid valve 7a is changed from the closed state to the open state. The drive circuit 40 controls the energization of the pneumatic solenoid valve 7b from the power supply line 82 in accordance with a control command S1b from the main microcomputer 60. By energizing the pneumatic solenoid valve 7b, the pneumatic solenoid valve 7b is changed from the closed state to the open state. The drive circuit 40 controls the power supply to the power supply line 82 in accordance with a control command S2 from the main microcomputer 60 and a control command S3 from the sub-microcomputer 70.

Specifically, the drive circuit 40 includes switches Q1a, Q1b, a switch Q2, and a switch Q3. The switch Q1a is electrically connected in series with the pneumatic solenoid valve 7a between the power supply line 82 and the ground wiring 84. The switch Q1a is constituted by, for example, a FET (Field Effect Transistor). The switch Q1a has a drain connected to the pneumatic solenoid valve 7a, a source connected to the ground wiring 84, and a gate receiving a control command S1a from the main microcomputer 60.

The switch Q1a is turned on when receiving the control command S1a at the H (logic high) level, and the pneumatic solenoid valve 7a is connected between the power supply line 82 and the ground wiring 84. On the other hand, the switch Q1a is turned off when receiving the L (logic low) level control command S1a, and the pneumatic solenoid valve 7a is not connected between the power supply line 82 and the ground wiring 84.

The switch Q1b is electrically connected in series with the pneumatic solenoid valve 7b between the power supply line 82 and the ground wiring 84. The switch Q1b is formed of, for example, an FET. The switch Q1b has a drain connected to the pneumatic solenoid valve 7b, a source connected to the ground wiring 84, and a gate receiving a control command S1b from the main microcomputer 60.

The switch Q1b is turned on when receiving the H-level control command S1b, and the pneumatic solenoid valve 7b is connected between the power supply line 82 and the ground wiring 84. On the other hand, the switch Q1b is turned off when receiving the L-level control command S1b, and the pneumatic solenoid valve 7b is not connected between the power supply 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 power supply line 82. The switches Q2 and Q3 are each constituted by an FET, for example. The switch Q2 receives a control command S2 from the main microcomputer 60 at its gate. The switch Q3 receives a control command S3 from the sub-microcomputer 70 at its gate.

The switch Q2 is turned on when receiving the H-level control command S2 and turned off when receiving the L-level control command S2. The switch Q3 is turned on when receiving the H-level control command S3 and turned off when receiving the L-level control command S3. When both the switches Q2 and Q3 are in the on state, the power supply line 80 is electrically connected to the power supply line 82. In other words, when either of the switches Q2 and Q3 is in the off state, the power supply line 80 is not connected to the power supply line 82.

In the present embodiment, the switches Q1a, Q1b, Q2, and Q3 are configured using FETs, respectively, but each switch may use a semiconductor switching element other than an FET, such as a bipolar transistor.

The monitoring circuit 50 detects a voltage at a node Na connecting the pneumatic 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. Further, the monitoring circuit 50 detects the voltage at the node Nb connecting the pneumatic 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 divider circuit. The voltage divider circuit divides the voltages at the nodes Na and Nb at a predetermined division ratio to generate divided voltages. The predetermined voltage division ratio is set so that the divided voltage becomes 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 pneumatic solenoid valve 7 a. Thus, the main microcomputer 60 and the sub-microcomputer 70 can detect whether the pneumatic solenoid valve 7a is in the energized state or the non-energized state based on the voltage of the node Na indicated by the signal input from the monitoring circuit 50.

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

The main microcomputer 60 has a function of checking for an abnormality based on a control command issued by itself, an operating state of the hot water supply device 1, and signals from the monitoring circuit 50 and various sensors. The abnormality includes, for example, leakage of unburned gas (unburned fuel), dry combustion of the

burners

5a, 5b, and the like. When an abnormality is detected, the main microcomputer 60 generates the control commands S1a, S1b, and S2 at the L level, and outputs the generated control commands S1a, S1b, and S2 to the drive circuit 40. The drive circuit 40 turns off the switches Q1a, Q1b, and Q2 in accordance with the L-level control commands S1a, S1b, and S2, respectively, to put the

pneumatic solenoid valves

7a and 7b in a non-energized state. Thereby, the

pneumatic solenoid valves

7a and 7b are closed, and the supply of the fuel gas to the

burners

5a and 5b is shut off. Therefore, if the

burners

5a and 5b are burning, the combustion is stopped, and if the

burners

5a and 5b are burning, the start of the combustion is stopped.

The sub-microcomputer 70 also has a function of checking for 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 an abnormality is detected, the sub-microcomputer 70 generates the control command S3 at the L level and outputs the generated control command S3 to the drive circuit 40.

The drive circuit 40 turns off the switch Q3 in accordance with the control command S3 at the L level, thereby rendering the

pneumatic solenoid valves

7a, 7b in a non-energized state. Thereby, the

pneumatic solenoid valves

7a and 7b are closed, and the supply of the fuel gas to the

burners

5a and 5b is shut off.

In this way, the main microcomputer 60 and the sub-microcomputer 70 are configured to check for abnormality independently of each other and shut off the supply of the fuel gas to the

burners

5a, 5 b. However, the I/F circuit of the main microcomputer 60 and the I/F circuit of the sub-microcomputer 70 are electrically connected to each other, and can transmit or receive data to or from each other. Thus, the main microcomputer 60 and the sub-microcomputer 70 can check their own abnormality (such as runaway of the microcomputer) or other abnormality by monitoring the mutual operations through transmission or reception of data.

In addition, the main microcomputer 60 and the sub-microcomputer 70 can output a reset signal to each other. The microcomputer that has received the reset signal performs the stop and restart. That is, the controller 30 realizes the self-diagnosis function by having the two

microcomputers

60, 70.

In addition, the hot water supply apparatus 1 according to the present embodiment is configured to control energization to 1 pneumatic solenoid valve by turning on/off 3 switches electrically connected in series to the pneumatic solenoid valve. This prevents the pneumatic solenoid valve from being energized due to an activation failure of two of the 3 switches. In the present specification, the start-up failure refers to a failure in which the switch is fixed in the on state and cannot be in the off state.

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

Fig. 3 is a diagram showing only a portion of the control structure shown in fig. 2, in which control is applied to the pneumatic solenoid valve 7 a. Referring to fig. 3, the pneumatic solenoid valve 7a and the 3 switches Q1a, Q2, Q3 are electrically connected in series between the power supply wiring 80 and the ground wiring 84. Therefore, when all of the 3 switches Q1a, Q2, and Q3 are in the on state, a current-carrying path from the power supply line 80 to the pneumatic solenoid valve 7a is formed as indicated by an arrow k1 in the figure.

Here, two switches Q1a, Q2 of the 3 switches Q1a, Q2, Q3 are controlled to be turned on and off by the main microcomputer 60, and the remaining 1 switch Q3 is controlled to be turned on and off by the sub-microcomputer 70.

By forming such a configuration, the main microcomputer 60 and the sub-microcomputer 70 can set the pneumatic solenoid valve 7a to a non-energized state independently of each other. Therefore, for example, in the case where the main microcomputer 60 is out of control and the hot water supply device 1 cannot be normally controlled, the sub-microcomputer 70 turns off the switch Q3, whereby the pneumatic solenoid valve 7a can be set to the non-energized state and the supply of the fuel gas to the burner 5a can be shut off.

Further, in the case where the activation failure occurs simultaneously in two of the 3 switches Q1a, Q2, Q3, the pneumatic solenoid valve 7a can be prevented from being energized outside the intention of the controller 30. This will be described in further detail with reference to a comparative example shown in fig. 4.

Referring to fig. 4, the configuration of the controller of the hot water supply device 1A of the comparative example is different from the hot water supply device 1 of the embodiment shown in fig. 2. Specifically, the controller 30A in the hot water supply device 1A of 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 has switches Q11a, Q11b, a switch Q12, and a switch Q13. The switch Q11a is electrically connected in series with the pneumatic solenoid valve 7a between the power supply line 82 and the ground wiring 84, similarly to the switch Q1a of fig. 2. The switch Q11a is turned on when receiving the H-level control signal S11a from the main microcomputer 60, and the pneumatic solenoid valve 7a is connected between the power supply line 82 and the ground wiring 84. On the other hand, the switch Q11a is turned off when receiving the L-level control command S11a, and the pneumatic solenoid valve 7a is not connected between the power feeding line 82 and the ground wiring 84.

The switch Q11b is electrically connected in series with the pneumatic solenoid valve 7b between the power supply line 82 and the ground wiring 84, similarly to the switch Q1b of fig. 2. The switch Q11b is turned on when receiving the H-level control signal S11b, and the pneumatic solenoid valve 7b is connected between the power supply line 82 and the ground wiring 84. On the other hand, the switch Q11b is turned off when receiving the L-level control command S11b, and the pneumatic solenoid valve 7b is not connected between the power feeding line 82 and the ground wiring 84. The switches Q11a and Q11b are each formed of, for example, an FET.

Switch Q12 is electrically connected between power supply line 80 and power supply line 82. The switch Q12 is formed of, for example, an FET. Switch Q12 has a drain connected to power supply line 80 and a source connected to power supply line 82.

The switch Q13 is electrically connected between the switch Q12 and the main microcomputer 60. The switch Q13 is formed of an NPN transistor, for example. The switch Q13 has a collector connected to the gate of the FET constituting the switch Q12, an emitter connected to the main microcomputer 60, and a base receiving a control command S13 from the sub-microcomputer 70.

The switch Q13 is turned on when receiving the L-level control command S13, and the gate of the switch Q12 is electrically connected to the main microcomputer 60. On the other hand, the switch Q13 is turned off when receiving the H-level control command, and the gate of the switch Q13 is not connected to the main microcomputer 60.

The switch Q12 is turned on when the switch Q13 is turned on and the H-level control command S12 is received from the main microcomputer 60, and connects the power supply line 80 to the power supply line 82. On the other hand, the switch Q12 is turned off when the switch Q13 is turned off or when the switch Q13 is turned on and the control command S12 at the L level is received from the main microcomputer 60, and the power supply line 80 is not connected to the power supply line 82. That is, when both the switches Q12 and Q13 are in the on state, the power supply line 80 is electrically connected to the power supply line 82.

In the hot water supply device 1A of the comparative example, the pneumatic solenoid valve 7a and the two switches Q11A, Q12 are electrically connected in series between the power supply wiring 80 and the ground wiring 84. One of the two switches Q11a, Q12, i.e., the switch Q12, is turned on when the switch Q13 is turned on.

With such a configuration, in the hot water supply device 1A of the comparative example, when all of the 3 switches Q11A, Q12, and Q13 are in the on state, an energization path from the power supply wiring 80 to the pneumatic solenoid valve 7a is formed.

In the comparative example, the switch Q11a is controlled to be turned on and off by the main microcomputer 60, and the switch Q12 is controlled to be turned on and off by the main microcomputer 60 and the sub-microcomputer 70, so the main microcomputer 60 and the sub-microcomputer 70 can put the pneumatic solenoid valve 7a in a non-energized state independently of each other.

However, in the hot water supply device 1A of the comparative example, when the activation failure occurs in two of the 3 switches Q11A, Q12, and Q13, there is a possibility that the pneumatic solenoid valve 7a is energized.

For example, when the switch Q11a and the switch Q12 fail to operate, an energization path is formed from the power supply line 80 to the pneumatic solenoid valve 7 a. In this case, even if the sub-microcomputer 70 turns off the switch Q13, the switch Q12 cannot be turned off, and therefore the pneumatic solenoid valve 7a is fixed in the energized state. Thus, when the two switches simultaneously fail to be activated, the pneumatic solenoid valve 7a may be opened by the intention of the controller 30. Therefore, even if the combustion of the burner is stopped, the fuel gas may be supplied to the burner 5a via the pneumatic solenoid valve 7 a.

Even when the switch Q13 and the switch Q11a have failed to start at the same time, such a situation may occur. As described above, the hot water supply device 1A according to the comparative example has a problem in that, when the two switches simultaneously fail to be activated, the pneumatic solenoid valve 7a is energized, and therefore the supply of the fuel gas to the burner 5a cannot be shut off.

In contrast, in the hot water supply device 1 of the present embodiment, as shown in fig. 3, since the 3 switches Q1a, Q2, and Q3 are electrically connected in series to the pneumatic solenoid valve 7a, even when the activation failure occurs simultaneously in two of the 3 switches, the remaining 1 switch is turned off, and the pneumatic solenoid valve 7a is turned off.

For example, when the switches Q1a and Q2 simultaneously cause a startup failure, the sub-microcomputer 70 can stop the energization of the pneumatic solenoid valve 7a by turning off the switch Q3. Therefore, the pneumatic solenoid valve 7a can be closed, and the supply of the fuel gas to the burner 5a can be shut off. Even when the start failure occurs simultaneously in the switches Q1a and Q3, and when the start failure occurs simultaneously in the switches Q2 and Q3, the energization of the pneumatic solenoid valve 7a can be stopped.

Thus, according to the hot water supply device 1 of the present embodiment, it is possible to prevent the pneumatic solenoid valve from being accidentally energized due to the simultaneous occurrence of the actuation failure of the two switches in the controller 30. Therefore, the safety of the hot water supply device can be improved.

In fig. 3, the switches Q2 and Q3 are connected in series between the power supply line 80 and the power supply line 82, but the switches Q2 and Q3 may be connected in series between the switch Q1a and the ground line 84. Alternatively, one of the switches Q2, Q3 may be connected between the power supply wiring 80 and the power supply line 82, and the other of the switches Q2, Q3 may be connected between the switch Q1a and the ground wiring 84.

In fig. 3, the switch Q1a is connected between the pneumatic solenoid valve 7a and the ground wiring 84 as an example, but the switch Q1a may be connected between the power supply line 82 and the pneumatic solenoid valve 7 a.

That is, the switches Q1a, Q2, and Q3 may be electrically connected in series with the pneumatic solenoid valve 7a between the power supply wiring 80 and the ground wiring 84, and the positions of the switches are not limited to the configuration of fig. 3.

In the above-described embodiment, the main microcomputer 60 constitutes one of the "1 st control unit" and the "2 nd control unit", and the sub-microcomputer 70 constitutes the other of the "1 st control unit" and the "2 nd control unit". The switches Q1a, Q2, and Q3 correspond to an example of "1 st to 3 rd switches". In the hot water supply device 1 of the present embodiment, one of the main microcomputer 60 and the sub-microcomputer 70 may control on and off of any two of the 3 switches Q1a, Q2, and Q3, and the other of the main microcomputer 60 and the sub-microcomputer 70 may control the remaining 1 switch.

(failure determination processing of switch)

In the hot water supply device 1 of the present embodiment, it is possible to determine whether or not the switches Q1a, Q1b, Q2, and Q3 have failed to be activated. Thus, the controller 30 can notify the user of the abnormality at the timing when the start failure occurs in any of the switches.

The failure determination processing of the switches Q1a, Q1b, Q2, Q3 will be described below with reference to fig. 5. For example, when a predetermined condition is satisfied, main microcomputer 60 and sub-microcomputer 70 can cooperate with each other to execute the flowchart shown in fig. 5. The predetermined condition includes that the hot water supply device 1 is in a combustion stop state, that the time elapsed since the previous failure determination process is a predetermined time or more, and the like.

Referring to fig. 5, the failure determination process includes a STEP of determining a failure of the switch Q2 (STEP1), a STEP of determining a failure of the switch Q3 (STEP2), and a STEP of determining a failure of the switches Q1a and Q1b (STEP 3).

In the STEP of determining the failure of the switch Q2 (STEP1), in STEP S01, the main microcomputer 60 gives the drive circuit 40 an L-level control command S2 to turn off the switch Q2. The sub-microcomputer 70 gives a control command S3 of H level to the drive circuit 40, and turns on the switch Q3.

Next, in step S02, the main microcomputer 60 gives the H-level control command S1a to the drive circuit 40, and turns on the switch Q1 a. That is, of the switches Q1a, Q2, and Q3 connected in series to the pneumatic solenoid valve 7a, two switches Q1a and Q3 are turned on.

In step S03, the main microcomputer 60 detects which of the energized state and the non-energized state the pneumatic solenoid valve 7a is in based on the signal from the monitoring circuit 50. When the pneumatic solenoid valve 7a is detected to be in the energized state, the main microcomputer 60 determines that the switch Q2 has an activation failure. When it is determined that the start failure of the switch Q2 has occurred (YES at S04), the main microcomputer 60 proceeds to step S13 and notifies the start failure of the switch Q2 using the remote controller 90.

After the start failure of the switch Q2 is notified, the sub-microcomputer 70 may give the L-level control command S3 to the drive circuit 40 to turn off the switch Q3. Accordingly, the

pneumatic solenoid valves

7a and 7b are in a non-energized state, and therefore the start of supply of the fuel gas to the

burners

5a and 5b is prevented.

On the other hand, when the determination switch Q2 is normal (NO start failure occurs) (when it is determined NO at S04), a STEP for determining the failure of the switch Q3 is performed next (STEP 2). In the STEP of determining the failure of the switch Q3 (STEP2), in STEP S05, the main microcomputer 60 gives the H-level control command S2 to the drive circuit 40, and turns on the switch Q2. The sub-microcomputer 70 gives a control command S3 of the L level to the drive circuit 40 so that the switch Q3 is turned off. In step S06, the main microcomputer 60 gives an H-level control command S1a to the drive circuit 40, and turns on the switch Q1 a. That is, of the switches Q1a, Q2, and Q3 connected in series to the pneumatic solenoid valve 7a, two switches Q1a and Q2 are turned on.

Next, in step S07, the main microcomputer 60 detects which of the energized state and the non-energized state the pneumatic solenoid valve 7a is in based on the signal from the monitoring circuit 50. When the pneumatic solenoid valve 7a is detected to be in the energized state, the main microcomputer 60 determines that the switch Q3 has an activation failure. When it is determined that the start failure of the switch Q3 has occurred (YES in S08), the main microcomputer 60 proceeds to step S13 and notifies the failure of the switch Q3 using the remote controller 90.

After the start failure of the switch Q3 is notified, the main microcomputer 60 may give the L-level control command S2 to the drive circuit 40 to turn off the switch Q2. Accordingly, the

pneumatic solenoid valves

burners

5a and 5b is prevented.

On the other hand, when the determination switch Q3 is normal (when NO is determined in S08), a STEP for determining the activation failure of the switches Q1a and Q1b is executed (STEP 3). In the STEP of determining the failure of the switches Q1a, Q1b (STEP3), in STEP S09, the main microcomputer 60 gives the control command S2 of the H level to the drive circuit 40, and turns on the switch Q2. The sub-microcomputer 70 gives a control command S3 of H level to the drive circuit 40, and turns on the switch Q3. The main microcomputer 60 gives the L-level control commands S1a and S1b to the drive circuit 40 in step S10 to turn off the switches Q1a and Q1 b. That is, of the switches Q1a, Q2, and Q3 connected in series to the pneumatic solenoid valve 7a, two switches Q2 and Q3 are turned on. Further, of the switches Q1b, Q2, and Q3 connected in series to the pneumatic solenoid valve 7b, two switches Q2 and Q3 are turned on.

In step S11, the main microcomputer 60 detects which of the energized state and the non-energized state the

pneumatic solenoid valves

7a and 7b are in, based on the signal from the monitoring circuit 50. When the pneumatic solenoid valve 7a is detected to be in the energized state, the main microcomputer 60 determines that the switch Q1a has failed to be activated. When detecting that the pneumatic solenoid valve 7b is in the energized state, the main microcomputer 60 determines that the switch Q1b has failed to start.

When it is determined that the start failure has occurred in at least one of the switches Q1a and Q1b (YES at S12), the main microcomputer 60 proceeds to step S13 and notifies the remote controller 90 of the start failure of the switches Q1a and Q1 b. In addition, main microcomputer 60 and sub-microcomputer 70 may set at least one of switches Q2 and Q3 to the off state. Accordingly, the

pneumatic solenoid valves

burners

5a and 5b is prevented.

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

(structural example of Hot Water supply device)

Finally, a configuration example of the hot water supply device of the present embodiment will be described.

In fig. 1 and 2, the configuration of the hot water supply device 1 having two

pneumatic solenoid valves

7a and 7b is described, but in the hot water supply device of the present invention, the number of the pneumatic solenoid valves may be 1 or more. In either case, the 1 st to 3 rd switches are electrically connected in series with the pneumatic solenoid valves. The 1 st switch and the 2 nd switch are turned on and off by the 1 st control unit, and the 3 rd switch is turned on and off by the 2 nd control unit.

Thus, the 1 st control unit and the 2 nd control unit can set the pneumatic solenoid valve to a non-energized state independently of each other, and can shut off the supply of the fuel gas to the combustor. Further, when the activation failure occurs in two of the 1 st to 3 rd switches, it is possible to prevent the energization of the pneumatic solenoid valve from being performed beyond the intention of the 1 st control unit and the 2 nd control unit.

As shown in fig. 2, when the hot water supply device 1 includes two

pneumatic solenoid valves

7a and 7b, the drive circuit 40 of the controller 30 preferably connects a series circuit of the pneumatic solenoid valve 7a and the switch Q1a and a series circuit of the pneumatic solenoid valve 7b and the switch Q1b in parallel between the power supply line 82 and the ground wiring 84. In this case, the pneumatic solenoid valve 7a corresponds to the "1 st valve", the switch Q1a corresponds to the "1 st switch", and the series circuit of the pneumatic solenoid valve 7a and the switch Q1a constitutes the "1 st series circuit". The pneumatic solenoid valve 7b corresponds to the "2 nd valve", the switch Q1b corresponds to the "4 th switch", and the series circuit of the pneumatic solenoid valve 7b and the switch Q1b forms the "2 nd series circuit".

In this way, the switches Q2 and Q3 can be shared between the energization path of the pneumatic solenoid valve 7a and the energization path of the pneumatic solenoid valve 7 b. In addition, when the number of the pneumatic solenoid valves is increased to 3 or more, the switches Q2 and Q3 can be shared between 3 or more series circuits by connecting the series circuit of the pneumatic solenoid valves and the switches in parallel with the 1 st series circuit and the 2 nd series circuit.

In fig. 2, the on and off of the switches Q1a and Q1b are controlled by the main microcomputer 60, but the on and off of the switches Q1a and Q1b may be controlled by the sub-microcomputer 70. Alternatively, one of the main microcomputer 60 and the sub-microcomputer 70 may control the on/off of the switch Q1a, and the other of the main microcomputer 60 and the sub-microcomputer 70 may control the on/off of the switch Q1 b.

In addition, although fig. 1 illustrates a configuration in which the pneumatic solenoid valve 7a is inserted into the gas supply pipe 6a and the pneumatic solenoid valve 7b is inserted into the gas supply pipe 6b, two

pneumatic solenoid valves

7a and 7b may be inserted in series into 1 gas supply pipe, as illustrated in fig. 6. In this case, the supply of the fuel gas to the burner is shut off by both the

pneumatic solenoid valves

7a and 7b being in the non-energized state.

In the present embodiment, the energization control of the valve for supplying fuel in the combustion device using gas as fuel, which is used in the hot water supply device, is exemplified, but the application of the present invention is not limited to this configuration. That is, in a combustion apparatus having a valve for supplying other fuel such as petroleum, the energization of the valve can be controlled in the same manner as in the present embodiment.

While the embodiments of the present invention have been described above, the embodiments disclosed herein are illustrative in all respects and should not be considered as restrictive descriptions. The scope of the present invention is indicated by the claims, and all changes that come within the meaning and range of equivalency of the claims are intended to be embraced therein.

Claims

1. A combustion apparatus, wherein,

the combustion apparatus includes:

a combustion unit that generates heat by combustion of fuel;

a 1 st valve configured to supply the fuel to the combustion portion by opening the 1 st valve by applying current to the 1 st valve;

a 1 st control unit and a 2 nd control unit for controlling energization to the 1 st valve; and

the 1 st switch to the 3 rd switch,

the 1 st valve and the 1 st to 3 rd switches are electrically connected in series between a power supply wiring and a ground wiring,

the 1 st switch and the 2 nd switch are controlled to be switched on and switched off by the 1 st control part respectively,

the 3 rd switch is controlled to be turned on and off by the 2 nd control part, and,

when the 1 st to 3 rd switches are in the on state, the 1 st valve is energized.

2. The combustion apparatus of claim 1,

the combustion apparatus further includes a notification portion for notifying an abnormality of the combustion apparatus,

the 1 st control portion and the 2 nd control portion are respectively configured to detect an energized state of the 1 st valve,

the 1 st control unit or the 2 nd control unit causes the notification unit to notify the abnormality of the combustion apparatus when the energization state of the 1 st valve is detected when any two of the 1 st to 3 rd switches are turned on.

3. The combustion apparatus of claim 2,

the 1 st control unit and the 2 nd control unit set at least one of the 1 st to 3 rd switches to an off state when the energization state of the 1 st valve is detected while the two arbitrary switches are set to the on state.

4. The combustion apparatus according to any one of claims 1 to 3,

one of the 1 st control unit and the 2 nd control unit is a main control unit that collectively controls the combustion apparatus,

the other of the 1 st control unit and the 2 nd control unit is a sub-control unit that controls energization to the 1 st valve independently of the main control unit,

the main control unit and the sub control unit perform bidirectional communication.

5. The combustion apparatus according to any one of claims 1 to 3,

a 1 st series circuit of the 1 st valve and the 1 st switch is connected between the power supply wiring and the ground wiring,

the 2 nd switch and the 3 rd switch are connected between the power supply wiring and the 1 st series circuit or between the 1 st series circuit and the ground wiring, respectively.

6. The combustion apparatus of claim 4,

7. The combustion apparatus of claim 5,

the combustion apparatus further comprises:

a 2 nd valve configured to supply the fuel to the combustion portion by opening the 2 nd valve by supplying current to the 2 nd valve; and

a 4 th switch electrically connected in series with the 2 nd valve between the power supply wiring and the ground wiring and controlled to be turned on and off by any one of the 1 st control portion and the 2 nd control portion,

a 2 nd series circuit of the 2 nd valve and the 4 th switch is connected in parallel with the 1 st series circuit between the power supply wiring and the ground wiring,

when the 2 nd to 4 th switches are in the on state, the 2 nd valve is energized.

8. The combustion apparatus of claim 6,

the combustion apparatus further comprises: