JP2017228483A - Control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform the abnormality determination processing of a common relay 31, which supplies power to a plurality of electric loads 18, 20, using monitoring circuits 32, 35 which monitors a power supply state to each electric load 18, 20 and a drive state.SOLUTION: A control device is configured to perform operation abnormality determination processing of a common relay 31 at the execution of neither burning operation control nor the closing operation control of the common relay 31. Through the operation abnormality determination processing, the control device determines that the operation of the common relay 31 is abnormal, if a change occurs in the outputs of monitoring circuits 32, 35, which relate to each electric load 18, 20, despite that a control unit 30 does not perform the closing operation control of the common relay 31. Also, the control unit determines that the operation of the common relay 31 is abnormal, if a change does not occur in the outputs of the monitoring circuits 32, 35, despite that the control unit 30 performs the closing operation control of the common relay 31.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a control device for driving and controlling an electric load in a combustion device or the like, and relates to a control device capable of determining by itself the occurrence of an abnormality in an electric load drive circuit.

  The applicant of the present application has conventionally developed a hot water supply device (combustion device) for supplying hot water to a hot water heating terminal, a hot water tap, etc. by burning a fuel gas generated by vaporizing liquid fuel or a mixed gas containing the fuel gas. For example, it is disclosed in Patent Document 1 below. Such a vaporization type combustion apparatus includes various high-voltage electric loads that are operated by an AC 100 V power source as electric loads for hot water supply operation, and a control device that controls these electric loads. In particular, the operation state of an electric load that needs to be determined for abnormality is also monitored.

JP 2007-78281 A

  In the control device for the above-described vaporization type combustion device, in particular, the vaporization heater (73), the sub-heater (90), the igniter (ignition plug) for performing the vaporization combustion operation of the liquid fuel, and the liquid fuel for pumping up the liquid fuel It is preferable to configure the circuit so that power is supplied to the electrical load for combustion operation such as an electromagnetic pump via a common common relay (switch).

  In this case, the sub-heater (second electric load) is configured to be always energized when the common relay is closed, while the vaporization heater, the igniter, and the liquid fuel electromagnetic pump are further energized by individual relays. The circuit can be configured so that it can be controlled. These common relays and individual relays are closed by supplying 15V power for relay drive control, and provided with a main switching circuit (first switching circuit) for collectively shutting off power supply to all the relays. It is preferable to provide an individual switching circuit (second switching circuit) for opening / closing the switch driving power supply path for each relay in order to individually control opening / closing of each relay.

  Further, in order to automatically stop the vaporization combustion operation safely in the case of emptying and prevent reignition, the igniter and the electromagnetic pump for liquid fuel (first electric load) are supplied with power at an abnormal temperature. The circuit is configured so that power is supplied also through the empty safety device (temperature switch) that opens the supply path.

  In addition, in order to detect the operation of the empty safety device, that is, to detect that the power supply to the igniter and the liquid fuel electromagnetic pump has been cut off due to abnormal temperature, It is preferable to provide a high limit monitoring circuit that monitors the operating state, and it is also preferable to provide a heater monitoring circuit that monitors the presence or absence of an open failure (disconnection) of the vaporizing heater or the sub heater.

  In addition to these high limit monitoring circuits and heater monitoring circuits, it is preferable to provide a common relay monitoring circuit that monitors whether the common relay normally opens and closes. However, from the viewpoint of reducing the number of components and board mounting area, etc. Therefore, it is required to use the above high limit monitoring circuit and heater monitoring circuit for common relay abnormality determination.

  However, even if the output signal of the high limit monitoring circuit or heater monitoring circuit is abnormal, whether it is due to a failure of the safety device or heater or a failure of the common relay or its drive circuit. I can't judge.

  Therefore, the present invention provides a temperature switch by using a monitoring circuit for a temperature switch such as an empty safety device or a monitoring circuit for an electric load such as a sub heater. The purpose is to enable it to be distinguished from the failure of an electric load.

  In order to achieve the above object, the present invention takes the following technical means.

  That is, the control device of the present invention includes first and second electric loads connected in parallel to a load driving power source, a switch for opening and closing a power supply path to the first and second electric loads, A temperature switch connected in series to the first electric load and in parallel to the second electric load to open a power supply path to the first electric load at an abnormal temperature; and an open / close for driving the switch When a load driving power supply voltage is applied to the first switching circuit that opens and closes the power supply path for driving the device and the power supply path between the temperature switch and the first electrical load, a predetermined temperature switch conduction signal is output. A temperature switch monitoring circuit, a second electric load monitoring circuit that outputs a predetermined second electric load driving state signal when power is supplied from the load driving power source to the second electric load, and a first switching circuit Control the opening and closing of And a control unit to which the temperature switch conduction signal and the second electric load driving state signal are input, and the control unit performs the first operation when the closing operation control of the first switching circuit is not performed. The first operation abnormality determination process is configured to perform an operation of the switch when at least one of the temperature switch conduction signal and the second electric load drive state signal is output. It is determined that it is abnormal (claim 1).

  According to the control device of the present invention, when the first and second electric loads are driven, the first switching circuit is controlled to be closed so that the switch is turned on (closed). When the temperature switch does not detect an abnormal temperature, the first electrical load is also fed. At this time, if the temperature switch monitoring circuit outputs a temperature switch conduction signal, the control unit can determine that the temperature switch is conducting (closed), and the second electric load monitoring circuit is the second one. If the electric load driving state signal is output, the control unit can determine that the second electric load is operating normally without an open failure such as disconnection.

  On the other hand, while the operation is stopped, the first switching circuit is controlled to open to shut off the switch (opening operation) in order to stop the power supply to the first and second electric loads. In the present invention, the first operation abnormality determination process is performed during the operation stop, so that a short circuit failure (closed fixing) of the switch or the first switching circuit can be obtained without providing a circuit configuration for determining the abnormality of the switch. It is possible to determine the abnormal operation of the switch due to short circuit failure.

  Further, in the first operation abnormality determination process, at least one of the temperature switch conduction signal and the second electric load drive state signal is output even though the closing operation control of the first switching circuit is not performed. If the temperature switch is opened due to an abnormal temperature or the second electrical load is short-circuited, both of these are determined. Since it does not occur at the same time, it is possible to accurately determine that the operation of the switch is abnormal. If the operation of the switch is not determined to be normal by the operation abnormality determination of the switch, the temperature by the temperature switch conduction signal By configuring so as not to determine the open / close state of the switch or the failure determination of the second electric load by the second electric load driving state signal, Determination of the electrical loads is also so performed accurately.

  In the control device of the present invention, a second switching circuit whose switching operation is controlled by the control unit is provided in the switch driving power supply path in series with the first switching circuit, and the control unit includes the first switching circuit. The second operation abnormality determination process is performed after the first operation abnormality determination process is performed, and the second operation abnormality determination process is performed when both the first and second switching circuits are controlled to be closed. When neither the temperature switch conduction signal nor the second electric load drive state signal is output, it can be determined that the operation of the switch is abnormal (Claim 2).

  According to this, since both the first and second switching circuits are controlled to be closed, a control power supply voltage is applied to the switch via the switch driving power supply path. It is further prevented that the switch is accidentally closed. The first switching circuit can be configured as a common main switching circuit for supplying control power supply voltage to other switches and other control electrical components, and the second switching circuit opens and closes the switch. It may be a separate switching circuit for controlling. When the first operation abnormality determination process is performed, it is preferable that the second switching circuit is controlled to be closed.

  Then, after it is determined that the first operation abnormality determination process is normal, the second operation abnormality determination process is performed, so that one of the first and second switching circuits has an open failure or is opened / closed. It can be determined that an abnormal operation of the switch occurs due to an open failure (open fixation) of the switch. Also in this case, since it is determined that there is an abnormality when both the temperature switch conduction signal and the second electric load drive state signal are not output, the temperature switch is closed due to the abnormal temperature, or the disconnection of the second electric load occurs. Even when the other signal is output, it is possible to accurately determine that the operation of the switch is normal because the other signal is output, and then perform an abnormality determination individually for the temperature switch and the second electric load. Thus, it is possible to accurately distinguish and determine which part is abnormal.

  As described above, it is preferable to determine the abnormal operation of the switch based on the output signals of the two monitoring circuits of the temperature switch monitoring circuit and the second electric load monitoring circuit, but the output of one of the monitoring circuits It is also possible to determine the abnormal operation of the switch based only on the signal.

  That is, the control device according to the present invention provides a first electric load connected to a load driving power source, a switch for opening and closing a power supply path to the first electric load, and the first electric load. A temperature switch that is connected in series and opens a power supply path to the first electric load at an abnormal temperature; a first switching circuit that opens and closes a switch drive power supply path for driving the switch; and the temperature switch A temperature switch monitoring circuit that outputs a predetermined temperature switch conduction signal when a load driving power supply voltage is applied to a power supply path between the first electric load and the first electric load, and controls an opening / closing operation of the first switching circuit And a control unit to which the temperature switch conduction signal is input. The control unit is configured to perform a first operation abnormality determination process when the first switching circuit is not closed. Operational abnormality determination process 1, the operation of the switch when the temperature switch conduction signal is output may be one determined to be abnormal (claim 3).

  Even in such a configuration, the temperature switch conduction signal can be obtained without providing a separate circuit configuration for switch abnormality determination by the first operation abnormality determination processing executed when the closing operation control of the first switching circuit is not performed. Based on the above, it is possible to determine the malfunction of the switch due to a short circuit failure (closed fixing) or a short circuit failure of the first switching circuit.

  If the first operation abnormality determination process is executed when the temperature switch is open due to an abnormal temperature, it may be determined that the switch is normal even if the switch is short-circuited. When the abnormality determination process is to be executed, the first abnormality determination process is preferably performed after a necessary and sufficient standby time until the temperature switch changes from the abnormal temperature to the normal temperature.

  The control device of the present invention includes first and second electric loads connected in parallel to a load driving power source, a switch for opening and closing a power supply path to the first and second electric loads, A first switching circuit for opening and closing a switch driving power supply path for driving the switch, and a predetermined second electric load driving state when power is supplied from the load driving power source to the second electric load A second electrical load monitoring circuit that outputs a signal; and a control unit that controls the opening and closing operation of the first switching circuit and that receives the second electrical load drive state signal, the control unit comprising: The first operation abnormality determination process is performed when the switching circuit closing operation control is not performed, and the first operation abnormality determination process is performed when the second electric load driving state signal is output. The operation of the switch is abnormal May be those determined (Claim 4).

  Even in such a configuration, the second electric load can be obtained without providing a separate circuit configuration for determining a switch abnormality by the first operation abnormality determining process executed when the closing operation control of the first switching circuit is not performed. Based on the driving state signal, it is possible to determine the malfunction of the switch due to a short circuit failure (closed fixing) or a short circuit failure of the first switching circuit.

  When the second electric load has an open failure due to disconnection or the like, power is not supplied from the load driving power source to the second electric load, and the second electric load driving state signal is not output. The first operation abnormality determination process cannot detect that the switch is short-circuited. Therefore, in the case of the above configuration, first, the second electric load driving state signal is output depending on whether or not the first switching circuit provided in series with the switch driving power supply path is controlled to be closed. It is determined whether or not the electrical load has a short circuit failure, and when it is determined that the second electrical load has not a short circuit failure, the operation abnormality determination of the switch is performed by the first operation abnormality determination process. It is preferable to do.

  In the control device of the present invention, the control unit may be configured to execute a first operation abnormality determination process at the time of activation (claim 5). According to this, the operation abnormality determination of the switch is performed before the start of the predetermined operation control such as the combustion operation, so that the temperature switch based on the temperature switch conduction signal and the second electric load drive state signal after the operation start and the second The electrical load of 2 can be accurately monitored.

  Further, the present invention may be a combustion device provided with the above-described control device for combustion operation control. In this case, the first electric load and / or the second electric load is for performing a combustion operation. It may be an electrical load (claim 6). According to this, it is possible to monitor a plurality of electrical loads responsible for the combustion operation and monitor the drive circuit of these electrical loads using a common circuit configuration, simplifying the circuit configuration, reducing the number of parts, By reducing the board mounting area, it is possible to reduce the size and cost of the apparatus.

  According to the present invention, a failure check of a switch such as a common relay or a drive circuit thereof is performed using a monitoring circuit for a temperature switch such as an empty safety device or a monitoring circuit for an electric load such as a sub heater. It can be performed separately from the failure of the electric load.

It is a schematic block diagram of the hot-water supply apparatus for heating terminals as a combustion equipment provided with the control apparatus which concerns on one Embodiment of this invention. It is a circuit diagram of the principal part of the control device.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the drawings.

  FIG. 1 shows a vaporization combustion type hot water supply apparatus for a heating terminal according to an embodiment of the present invention. The hot water supply apparatus vaporizes a liquid fuel such as kerosene to burn, and the combustion section. A primary heat exchanger 2 that heats and heats hot water with a high-temperature combustion gas generated by 1 is disposed in the combustion can body 3. In the illustrated example, the combustion unit 1 is disposed above the combustion can body 3, the primary heat exchanger 2 is disposed below the combustion unit 1, and combustion gas is supplied downward from the combustion unit 1. However, when passing through the primary heat exchanger 2 downward, the hot water flowing through the primary heat exchanger 2 is heat exchange heated. An exhaust cylinder 4 is connected to the lower part of the combustion can body 3, and the exhaust gas after heat exchange is exhausted through the exhaust cylinder 4.

  A secondary heat exchanger 5 for recovering the latent heat of the combustion gas that has passed through the primary heat exchanger 2 is provided in the exhaust pipe 4 at a position higher in the vertical direction than the primary heat exchanger 2. The condensed water generated in the secondary heat exchanger 5 is collected in the neutralizer 6 and is drained after being neutralized with a neutralizer.

  The hot water supply apparatus of the present embodiment includes a hot water supply circuit for circulating hot water supply to the heating terminal T, and the hot water supply circuit is discharged from the primary heat exchanger 2 and the primary heat exchanger 2. Outward piping 7 for guiding hot water to the heating terminal T, a heating tank 8 (expansion tank), a return piping 9 for guiding the hot water returned from the heating terminal T to the heating tank 8, and the secondary heat exchanger 5, a first connection pipe 10 for guiding hot water from the heating tank 8 to the secondary heat exchanger 5, and a second connection pipe 11 for guiding hot water from the secondary heat exchanger 5 to the primary heat exchanger 2, The bypass pipe 12 returns a part of hot water discharged from the primary heat exchanger 2 to the heating tank 8. A circulation pump 13 is provided in the middle of the first connection pipe 10. A bypass thermal valve 14 for adjusting the bypass flow rate is provided in the middle of the bypass pipe 12.

  The combustor 1 includes a cup-shaped vaporizer 15, a vaporization heater 16 for heating the vaporizer 15, a flame hole base 17, a sub-heater 18 for preheating the flame hole base 17, and an igniter (ignition device). 19). In the present embodiment, liquid fuel such as kerosene is pumped up by the fuel pump 20 and can be supplied into the vaporizer 15 via the fuel pipe 21. The vaporizer 15 is heated to a predetermined temperature by an electric vaporization heater 16, and the liquid fuel is supplied into the heated vaporizer 15 so that the vaporization of the liquid fuel is promoted.

  A diffusion member 22 (diffusion blade) is disposed in the vaporizer 15 so as to be rotationally driven by a motor M, and the liquid fuel is diffused by the diffusion member 22 to a wide area on the inner surface of the vaporizer 15 before contacting the vaporizer 15. As a result, vaporization of fuel is further promoted. The vaporized fuel gas flows toward the upper side of the flame hole base 17 and is mixed with combustion air. The combustion air is taken into the combustion can body 3 by the fan 23 that is rotationally driven by the motor M from the air supply port 3 a above the combustion can body 3. A mixed gas of vaporized fuel and combustion air is ejected downward from a plurality of flame holes (not shown) penetrating the flame hole base 17 and burned by being ignited by an igniter 19.

  The hot water supply apparatus of the present embodiment further includes an ignition transformer 24 for applying a high voltage to the igniter 19, a frame rod (flame detection device) 25, a temperature switch 26 as an empty safety device, and a control unit 30. The temperature switch 26 is attached to the combustion can 3 near the outlet of the primary heat exchanger 2, and the contact is closed within a normal temperature range, but the contact opens when the temperature becomes abnormally high, for example, 100 ° C or higher. It is configured as follows.

  The control unit 30 is mainly composed of a microcomputer, and constitutes a control device for the hot water supply device together with the above-described various electric loads and other electric components provided in the hot water supply device. The fuel pump 20 (first electric load), the sub heater 18 (second electric load), the vaporization heater 16, the ignition transformer 24, the circulation pump 13, the bypass thermal valve 14, the motor M, and the like serve as electric loads. The temperature switch 26, the frame rod 25, and various sensors (not shown) (atmosphere temperature sensor, can body temperature sensor, flame hole base temperature sensor, combustion air temperature sensor, liquid fuel sensor, neutralizer water level sensor, etc.) Other electrical parts. When a hot water supply operation start command is issued from a remote controller (not shown), the control unit 30 performs the hot water supply operation for the heating terminal T by controlling the operation of the electric load based on the set temperature and detection signals of various sensors.

  FIG. 2 shows a main part of the control device according to the present embodiment. A high-voltage circuit unit to which a commercial 100V AC power supply voltage as a load driving power source A is supplied is shown by a bold line, and a relay driving 15V DC is shown. The low-voltage circuit unit to which the power supply voltage and the control unit operation 5V DC power supply voltage are supplied are illustrated by thin lines.

  A fuel pump 20 (first electric load) and a sub-heater 18 (second electric load) are connected in parallel to the load driving power source A, and the power supply path to the fuel pump 20 and the sub-heater 18 is in the middle. The part is provided with a normally open contact type common relay 31 (switch), and the control unit 30 controls opening and closing of the common relay 31 so that the power supply path to the fuel pump 20 and the sub heater 18 can be opened and closed. Has been. It should be noted that an electric load related to the vaporizing and burning operation in the combustion section 1 such as the ignition transformer 24 and the vaporizing heater 16 is also connected in parallel with the fuel pump 20 and the sub-heater 18 so as to be able to cut off the power supply collectively by the common relay 31. A can be connected. Other electrical loads such as the circulation pump 13 and the bypass thermal valve 14 can be directly connected to the load driving power source A on the load driving power source A side than the common relay 31.

  The temperature switch 26 is connected to the fuel pump 20 in series. When the temperature switch 26 reaches an abnormal temperature, such as when there is a vacancy, the power supply to the fuel pump 20 is automatically cut off. Yes. The temperature switch 26 is connected in parallel to the sub-heater 18. Therefore, even if the temperature switch 26 is opened, the power supply to the sub-heater 18 is continued if the common relay 31 is closed. .

  A sub-heater monitoring circuit 32 (second electric load monitoring circuit) is connected in series to the sub-heater 18. When power is supplied from the load driving power source A to the sub-heater 18 and a voltage is applied to the ground side of the sub-heater 18. A predetermined sub heater driving state signal (second electric load driving state signal) indicating that the sub heater 18 is driven is output to the control unit 30. Although the configuration of the monitoring circuit 32 may be appropriate, in the illustrated embodiment, the AC power supply voltage is half-wave rectified and energized to the photocoupler P1, so that a pulse signal is supplied while power is supplied to the sub-heater 18. Is output to the sub-heater monitoring input port of the control unit 30. On the other hand, when the sub-heater 18 is disconnected or when the common relay 31 is opened, the sub-heater 18 is not supplied with power. 5V voltage signal) is output to the sub heater monitoring input port of the control unit 30.

  The fuel pump 20 is connected in series with a normally-open contact type fuel pump relay 33 for individually shutting off energization of the fuel pump 20, and the fuel pump relay 33 is opened and closed by the control unit 30. Be controlled.

  The open / closed state of the fuel pump relay 33 can be monitored by a fuel pump monitoring circuit 34 connected in parallel to the fuel pump 20 and in series to the fuel pump relay 33. The fuel pump monitoring circuit 34 has the same configuration as the sub heater monitoring circuit 32, and a fuel pump driving state signal consisting of a pulse signal is output to the fuel pump monitoring input port of the control unit 30 when the fuel pump relay 33 is closed. On the other hand, when the fuel pump relay 33 is opened, a steady voltage signal is output to the fuel pump monitoring input port of the control unit 30.

  Further, a temperature switch monitoring circuit 35 is provided for monitoring the open / closed state of the temperature switch 26 based on whether or not a load driving power supply voltage is applied to the power supply path between the temperature switch 26 and the fuel pump 20. It has been. The temperature switch monitoring circuit 35 has the same configuration as the sub heater monitoring circuit 32. If the common relay 31 and the temperature switch 26 are closed, a temperature switch conduction signal composed of a pulse signal is applied to the high limit monitoring input port of the control unit 30. On the other hand, if either the common relay 31 or the temperature switch 26 is open, a steady voltage signal is output to the high limit monitoring input port of the control unit 30.

  The load driving power source A is connected to an AC / DC converter 28 that generates and outputs a 15V DC power source voltage for driving various relays including the common relay 31 and the fuel pump relay 33. The regulator 29 is connected to the regulator 37, and the regulator 37 generates and outputs a 5V DC power supply voltage that becomes a control power supply voltage for the control unit 30 and the like.

  The control device according to the present embodiment includes a common switching circuit 36 (first switch) for collectively opening and closing relay drive power supply paths (switch drive power supply paths) to various relays including the common relay 31 and the fuel pump relay 33. Switching circuit). The common switching circuit 36 is configured to switch whether or not the 15V DC power is supplied to the relay driving voltage line Vr in accordance with a command signal from the relay power control output port of the control unit 30. In the illustrated example, when a high signal is output from the relay power control output port of the control unit 30, the relay drive power line Vr is energized to the 15V DC power supply, and when a low signal is output from the relay power control output port, the relay drive power supply line Vr is energized. The power supply line Vr is cut off from the 15V DC power supply.

  The positive terminal of the electromagnetic coil 31a of the common relay 31 is connected to the relay driving power line Vr, and the negative terminal is connected to the ground via the common relay driving switching circuit 37 (second switching circuit). . A back electromotive force prevention diode D1 is connected in parallel to the electromagnetic coil 31a. The common relay driving switching circuit 37 may have an appropriate configuration, but in the illustrated example, the switching circuit 37 is mainly configured by an FET. When a high signal (closing operation command signal) is output from the common relay control output port of the control unit 30 in a state where the common switching circuit 36 is closed, the switching circuit 37 is closed and the common relay 31 is closed. When the signal (open operation command signal) is output, the switching circuit 37 is opened and the common relay 31 is opened. As a whole, the common relay driving power supply path from the 15V DC power supply to the ground is connected in series with the common switching circuit 36, and one of the switching circuits 36, 37 is opened. Then, the power supply to the common relay 31 is cut off, the common relay 31 is opened, and both the switching circuits 36 and 37 are closed so that the power is supplied to the common relay 31 and the common relay 31 is closed. In the illustrated example, the common relay driving switching circuit 37 is connected to the ground side of the common relay 31, but may be connected to the relay driving power line Vr.

  Similarly, the positive terminal of the electromagnetic coil 33a of the fuel pump relay 33 is connected to the relay driving power line Vr, and the negative terminal is connected to the ground via the fuel pump relay driving switching circuit 38 (third switching circuit). It is connected. A back electromotive force prevention diode D2 is connected in parallel to the electromagnetic coil 33a. The fuel pump relay driving switching circuit 38 may have an appropriate configuration, but in the illustrated example, it is mainly configured by a bipolar transistor. When a high signal (a closing operation command signal) is output from the fuel pump control output port of the control unit 30 with the common switching circuit 36 closed, the switching circuit 38 is closed and the fuel pump relay 33 is closed. When the Low signal (open operation command signal) is output, the switching circuit 38 is opened and the fuel pump relay 33 is opened. The fuel pump relay driving switching circuit 38 is connected in series with the common switching circuit 36 when viewed as a whole fuel pump relay driving power supply path from the 15V DC power source to the ground, and any one of the switching circuits 36, 38 is connected. When the opening operation is performed, the power supply to the fuel pump relay 33 is cut off, the fuel pump relay 33 is opened, and both the switching circuits 36 and 38 are closed so that the fuel pump relay 33 is supplied with power and the fuel pump relay 33 is operated. Closes. In the illustrated example, the fuel pump relay drive switching circuit 38 is connected to the ground side of the fuel pump relay 33, but may be connected to the relay drive power supply line Vr.

  In this embodiment, the control unit 30 is activated at the time of power-on, at the start of the hot water supply operation, or at a predetermined timing during the stop of the hot water supply operation (for example, immediately after the stop of the hot water supply operation or after a predetermined time has elapsed since the stop of the hot water supply operation). The common relay abnormality determination process for determining whether the operation of the common relay 31 is normal or abnormal is performed later or every predetermined time during which the hot water supply operation is stopped.

  The common relay abnormality determination process can include a first operation abnormality determination process for mainly detecting an abnormality due to a short failure and a second operation abnormality determination process for mainly detecting an abnormality due to an open failure. First, the first operation abnormality determination process is performed, and when no abnormality is detected by the first operation abnormality determination process, the second operation abnormality determination process can be performed.

  The first operation abnormality determination process will be described. First, while maintaining the output of the relay power control output port at Low (that is, while maintaining the open operation control of the common switching circuit 36), the output of the common relay control port is changed. Switching to High (that is, the common relay driving switching circuit 37 is controlled to be closed). At this time, if any of the input signals to the sub heater monitoring input port and the high limit monitoring input port is a pulse signal (that is, a temperature switch conduction signal or a sub heater driving state signal), the common switching circuit 36 is controlled to open. However, since the power supply voltage for load driving is applied to the temperature switch monitoring circuit 35 or the sub heater monitoring circuit 32, the common relay 31 is closed due to the common relay 31 being closed and the common switching circuit 36 being short-circuited. It is determined that there is an operation abnormality that does not open, and an error notification that the operation is abnormal is issued, the abnormality determination process is terminated, and the hot water supply operation is prohibited. The error notification method may be any appropriate method. For example, an error code such as E021 can be displayed on the remote control display screen.

  If it is not determined to be abnormal in the first operation abnormality determination process, the output of the relay power control output port is switched to High while maintaining the output of the common relay control port at High (that is, the common switching circuit 36 is switched). Close operation is controlled). At this time, if any of the input signals to the sub heater monitoring input port and the high limit monitoring input port is a pulse signal (that is, a temperature switch conduction signal or a sub heater driving state signal), the operation of the common relay 31 is normal. The common relay abnormality determination process is completed, and if a hot water supply operation start command is issued, the process proceeds to hot water supply operation control. On the other hand, if neither of the input signals to the sub-heater monitoring input port and the high limit monitoring input port becomes a pulse signal, the common relay 31 is stuck open or the common switching circuit 36 or the common relay drive switching circuit 37 is open. It is determined that there is an operation abnormality that the common relay 31 does not close, an error notification that the operation is abnormal is performed, the abnormality determination process is terminated, and the hot water supply operation is prohibited.

  Note that when the first and second operation abnormality determination processes are executed, the fuel pump relay 33 is kept open to prevent the liquid fuel from being accidentally supplied into the vaporizer 15.

  As described above, according to the present embodiment, the operation abnormality of the common relay 31 is determined, the temperature switch monitoring circuit 35 for monitoring the open / closed state of the temperature switch 26, and the driving state of the sub heater 18 are monitored. Based on the output signal of the sub heater monitoring circuit 32, it can be performed when the hot water supply operation is stopped. Then, by starting the hot water supply operation including the combustion operation only when no abnormality is detected by the operation abnormality determination of the common relay 31, the open / close state determination of the temperature switch 26 during the hot water supply operation (combustion operation), When determining the driving state of the sub-heater 18, it is possible to reduce the notification that the temperature switch 26 or the sub-heater 18 has failed even though the operation of the common relay 31 is actually abnormal. Will be able to do.

  The present invention is not limited to the above-described embodiment, and the design can be changed as appropriate. For example, in the above embodiment, a hot water supply device for a heating terminal is shown, but the present invention can be adopted for an appropriate combustion type heat source machine such as a hot water heater for supplying hot water to a hot water tap and a fan heater, and other appropriate electric appliances. It can also be used in equipment.

  In the above-described embodiment, an example in which the operation abnormality of the common relay 31 is determined based on the output signals of the two monitoring circuits of the temperature switch monitoring circuit 35 and the sub heater monitoring circuit 32 has been described. , 35 can be used to determine whether the common relay 31 is operating abnormally.

A Load drive power supply 18 Second electric load (sub heater)
20 First electrical load (fuel pump)
26 Temperature switch 30 Control unit 31 Switch (common relay)
32 Second electrical load monitoring circuit (sub-heater monitoring circuit)
35 Temperature switch monitoring circuit 36 First switching circuit (common switching circuit)
37 Second switching circuit (switching circuit for common relay drive)

Claims (6)

  First and second electric loads connected in parallel to the load driving power source, a switch for opening and closing a power supply path to the first and second electric loads, and a series with respect to the first electric load And a temperature switch that is connected in parallel to the second electric load and opens the power supply path to the first electric load at an abnormal temperature, and a switch driving power path for driving the switch. A switching circuit, a temperature switch monitoring circuit that outputs a predetermined temperature switch conduction signal when a load driving power supply voltage is applied to a power supply path between the temperature switch and the first electric load; A second electric load monitoring circuit that outputs a predetermined second electric load driving state signal when electric power is supplied to the electric load from the load driving power source, and controls the opening / closing operation of the first switching circuit and the temperature. switch A control unit to which a communication number and the second electric load driving state signal are input, and the control unit performs a first operation abnormality determination process when the first switching circuit is not closed. The first operation abnormality determination process determines that the operation of the switch is abnormal when at least one of the temperature switch conduction signal and the second electric load drive state signal is output. A control device.   2. The control device according to claim 1, wherein a second switching circuit whose switching operation is controlled by the control unit is provided in the switch driving power supply path in series with the first switching circuit, and the control unit includes: The second operation abnormality determination process is performed after the first operation abnormality determination process, and the second operation abnormality determination process controls the first and second switching circuits to be closed. A control device that determines that the operation of the switch is abnormal when neither the temperature switch conduction signal nor the second electric load driving state signal is output.   A first electric load connected to the load driving power source, a switch for opening and closing a power supply path to the first electric load, and a first electric load connected in series to the first electric load and at the time of abnormal temperature A temperature switch that opens a power supply path for one electrical load; a first switching circuit that opens and closes a power supply path for driving the switch for driving the switch; and between the temperature switch and the first electrical load When a load driving power supply voltage is applied to the power supply path, a temperature switch monitoring circuit that outputs a predetermined temperature switch conduction signal, and controls the opening / closing operation of the first switching circuit, and the temperature switch conduction signal is input. And a control unit configured to perform a first operation abnormality determination process when the closing operation control of the first switching circuit is not performed. The first operation abnormality determination process includes: Said The switch operation when the time switch conduction signal is output is to determined to be abnormal, the control unit.   First and second electric loads connected in parallel to the load driving power source, a switch for opening and closing a power supply path to the first and second electric loads, and an opening and closing for driving the switch A first switching circuit that opens and closes the power supply path for driving the power supply, and a second electric load monitor that outputs a predetermined second electric load driving state signal when power is supplied from the load driving power source to the second electric load. And a control unit for controlling the opening / closing operation of the first switching circuit and receiving the second electric load driving state signal, and the control unit controls the closing operation of the first switching circuit. The first operation abnormality determination process is performed when there is not, and the first operation abnormality determination process is abnormal in the operation of the switch when the second electric load driving state signal is output. Control Location.   5. The control device according to claim 1, wherein the control unit is configured to execute a first operation abnormality determination process when activated.   A combustion apparatus comprising the control device according to any one of claims 1 to 5 for combustion operation control, wherein the first electric load is an electric load for performing a combustion operation. Combustion equipment.

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