JP5986181B2 - Combustion device - Google Patents

Description

  The present invention relates to a combustion apparatus such as a water heater in which at least two on-off valves are interposed in a gas supply path to a burner.

  2. Description of the Related Art Conventionally, in a water heater, a gas supply path to a burner that heats a heat exchanger includes an electromagnetic valve and a water pressure responsive valve that is opened when water is supplied to a water supply path that is connected to the heat exchanger. There is an on-off valve, and a water flow switch that is turned on at the same time that the water pressure responsive valve opens when water flows is provided, and when the water flow switch is turned on, the electromagnetic valve is opened and the burner is ignited. (For example, refer to Patent Document 1).

  Recently, in order to save power, a motor valve is used instead of the electromagnetic valve. The motor valve has an armature connected to a rubber valve body, an electromagnet facing the armature, and a motor for moving the electromagnet back and forth in the X-axis direction, which is the opening / closing direction of the valve body, and the valve body is seated on the valve seat In the state where the valve is in the closed position, the electromagnet is advanced toward the valve body in one direction in the X-axis direction and brought into contact with the armature and the electromagnet is excited to attract the armature to the electromagnet. In this state, the electromagnet is moved in the X-axis direction. The valve body is configured to open by retreating to the other side (see, for example, Patent Document 2). In this way, in the motor valve, the armature is attracted to the electromagnet in contact with the armature, so that the energization current of the electromagnet can be reduced as compared with the case where the armature is attracted to the electromagnet away from the armature.

  However, if a motor valve is used, the motor valve may not be opened when the ambient temperature becomes low. The cause is that compounding agents such as anti-aging agents in the rubber forming the valve body ooze out on the valve body surface by bloom phenomenon and bite into the minute irregularities of the valve seat, and when the compounding agent hardens due to a decrease in ambient temperature, This is considered to be because the valve body is fixed to the valve seat by the anchor effect. In the motor valve, in order to reduce the energization current of the electromagnet, when the armature attracting force by the electromagnet falls below the anchoring force of the valve body due to the anchor effect and the electromagnet is retracted to the other in the X-axis direction, the electromagnet The valve body cannot be opened.

JP 2013-204885 A JP 2006-322492 A

  In view of the above points, an object of the present invention is to provide a combustion apparatus that can prevent a motor valve from becoming unopenable at low temperatures.

  In order to solve the above problems, the present invention is a combustion apparatus in which at least two on-off valves are interposed in a gas supply path to a burner, and one of the on-off valves is connected to a rubber valve body. Armature, an electromagnet facing the armature, and a motor for moving the electromagnet back and forth in the X-axis direction, which is the opening / closing direction of the valve body, and with the valve body in the closed position, the electromagnet is directed toward the valve body. The valve body is opened by advancing in one axial direction to abut the armature and exciting the electromagnet to attract the armature to the electromagnet and retreating the electromagnet to the other in the X-axis direction in this state. The motor valve is provided with temperature detecting means for detecting the atmospheric temperature, and the control means of the combustion apparatus is configured so that the atmospheric temperature is predetermined during the operation stop when both the motor valve and the other on-off valve are closed. Standards of When it is below degrees, characterized in that it is configured to perform the sticking prevention control repeating be closed after temporarily opening the motor valve at predetermined time intervals.

  According to the present invention, the motor valve is opened before the valve body of the motor valve firmly adheres to the valve seat at a low temperature during operation stop, so that the adhering state can be eliminated. Therefore, the valve body of the motor valve is not firmly fixed to the valve seat, and it is possible to prevent the motor valve from becoming unopenable. Even if the motor valve is once opened by the sticking prevention control, the other on-off valves remain closed, so that no gas is supplied to the burner and it is safe.

  In the present invention, it is preferable that the control means is configured to end the sticking prevention control when the ambient temperature becomes higher than the reference temperature by a predetermined temperature or more. According to this, it is possible to prevent hunting that repeats execution and termination of the sticking prevention control.

  Furthermore, in the present invention, it is desirable that the control means is configured to shorten the time interval as the atmospheric temperature becomes lower. According to this, at a very low temperature at which the valve body of the motor valve is likely to stick to the valve seat, the opening and closing frequency of the motor valve can be increased to reliably prevent the valve body from sticking, and the valve body is relatively difficult to stick. At the temperature, the frequency of opening and closing the motor valve can be reduced to save power.

The front view of the water heater which is a combustion apparatus of embodiment of this invention. Explanatory drawing which shows the structure of the water heater of embodiment typically. The flowchart which shows the control during a driving | operation stop.

  Referring to FIG. 1, reference numeral 1 denotes a water heater that is a combustion apparatus according to an embodiment of the present invention. An operation button 2 and a capacity switching lever 3 are arranged on the front side of the body of the water heater 1. As shown in FIG. 2, a burner 4, a heat exchanger 5 heated by the burner 4, and a controller 6 as control means are arranged in the container.

  The operation button 2 is locked at the push-in position by the first push operation, and returns to the non-push-down position by the second push operation. An operation switch 2 a that is turned on at the push position of the operation button 2 is connected to the controller 6. It is connected. The operation button 2 is rotatable to a predetermined hot water temperature adjustment range between “low” and “high” and a “water” position outside the hot water temperature adjustment range. A selection switch 2 b that is turned off in the “water” position is connected to the controller 6.

  In the water supply path 5a to the heat exchanger 5, an electric water stop valve 7 that is opened and closed by a motor 7a via a mechanical interlocking mechanism such as a cam in order from the upstream side, and water for adjusting the water supply pressure to a constant level. A governor 8 and a water amount adjusting valve 9 whose opening degree changes in conjunction with the rotation of the operation button 2 are interposed. A hot water discharge head 5c is connected to the downstream side of the heat exchanger 5 via a hot water discharge pipe 5b.

  The gas supply passage 4a to the burner 4 is opened by the operation of the water governor 8 when the water is supplied to the water supply passage 5a by opening the stop valve 7 and the motor valve 10 which is an on-off valve in order from the upstream side. A water pressure responsive valve 11 serving as an on-off valve, a gas governor 12 for adjusting the gas pressure to a constant value, and a gas amount adjusting valve 13 whose opening degree changes in conjunction with the swing of the capacity switching lever 3 are provided. . A water flow switch 14 that is turned on when the water pressure responsive valve 11 is opened is connected to the controller 6.

  The motor valve 10 includes a rubber valve body 102 that can be seated on a valve seat 101 in the valve casing 100, an armature 103 connected to the valve body 102 via a shaft portion 102 a, and an electromagnet 104 that faces the armature 103. The motor 105 moves the electromagnet 104 back and forth in the X-axis direction, which is the opening / closing direction of the valve body 102. The electromagnet 104 is attached to a movable body 106 that moves forward and backward in the X-axis direction by a motor 105 via a feed screw mechanism (not shown). Further, a cover 107 extending so as to surround the electromagnet 104 is attached to the movable body 106. Then, a spring 108 is contracted between the tip of the cover 107 and the valve body 102 so that the valve body 102 is normally biased and held by the spring 108 at a valve closing position where the valve body 102 is seated on the valve seat 101. Yes.

  When the motor valve 10 is opened, the electromagnet 104 is moved forward in the X-axis direction (to the right in FIG. 2) toward the valve body 102 by the forward rotation of the motor 105 and brought into contact with the armature 103 and the electromagnet 104 is moved. Energized to attract the armature 103 to the electromagnet 104, and in this state, the electromagnet 104 is moved backward in the X-axis direction (to the left in FIG. 2) by the reverse rotation of the motor 105, thereby separating the valve body 102 from the valve seat 101. So that it opens. When closing the motor valve 10, the energization of the electromagnet 104 is stopped and the valve body 102 is returned to the valve closing position by the spring 108.

  The burner 4 is provided with an ignition electrode 15a that generates a spark by the operation of an igniter 15 that is controlled by a controller 6 and a flame rod 16 that is a flame detection element.

  When the operation switch 2a is turned on, the controller 6 performs hot water supply operation control if the selection switch 2b is turned on, and performs water supply operation control if the selection switch 2b is turned off. In the hot water supply operation control, first, the igniter 15 is operated simultaneously with the operation switch 2a being turned on, and the water stop valve 7 is opened to allow water to flow through the water supply passage 5a. At this time, the water pressure responsive valve 11 is opened by the operation of the water governor 8 and the water flow switch 14 is turned on. When the water flow switch 14 is turned on, the motor valve 10 is opened and the burner 4 is ignited. Thus, water is supplied to the heat exchanger 5 with the burner 4 burned, and a hot water supply operation for supplying hot water to the hot water discharge pipe 5b is performed. On the other hand, in the water supply operation control, when the operation switch 2a is turned on, the igniter 15 is not operated only by opening the water stop valve 7, and the motor valve 10 is not opened even when the water flow switch 14 is turned on. Therefore, a water supply operation is performed in which the burner 4 is not burned and supplied to the heat exchanger 5 and cold water is supplied to the hot water outlet pipe 5b.

  By the way, in the motor valve 10, since the armature 103 is attracted to the electromagnet 104 in contact with the armature 103, the energization current of the electromagnet 104 can be reduced as compared with the case where the armature 103 is attracted to the electromagnet 104 away from the armature 103. Although a dry battery is used as the power source of the water heater 1, if the motor valve 10 is used as the on-off valve, the energization current of the electromagnet 104 can be reduced, so that the power consumption can be reduced and the dry battery life can be extended.

  However, if the ambient temperature becomes low (for example, 0 ° C. or less) during the operation stop when both the motor valve 10 and the water pressure responsive valve 11 are closed, the surface of the valve body of the motor valve 10 oozes due to the Bloom phenomenon. The valve body 102 may adhere to the valve seat 101 due to an anchor effect caused by the compounding agent biting into the minute irregularities of the valve seat 101 and hardening. In the motor valve 10, in order to reduce the energization current of the electromagnet 104 as described above, the attracting force of the armature 103 by the electromagnet 104 is less than the fixing force of the valve body 102 by the anchor effect, and the electromagnet 104 is moved to the other side in the X-axis direction. When retracted, the electromagnet 104 moves away from the armature 103 and the valve body 102 cannot be opened.

  Therefore, in the present embodiment, the temperature detecting means for detecting the ambient temperature in the body of the water heater 1 is turned on when the ambient temperature is equal to or lower than a predetermined reference temperature YT (for example, 0 ° C.), and the ambient temperature is the standard. A bimetal switch 17 that is turned off when the temperature becomes higher than the temperature YT1 by a predetermined temperature ΔT (for example, 3 ° C.) or more is connected to the controller 6. And the controller 6 performs control shown in FIG. 3 based on ON / OFF of the bimetal switch 17 during the operation stop. Hereinafter, this control will be described in detail.

  While the operation is stopped, it is first determined in STEP 1 whether or not the ambient temperature T has become equal to or lower than the reference temperature YT, that is, whether or not the bimetal switch 17 is turned on. When the bimetal switch 17 is turned on, the process proceeds to STEP 2 to open the motor valve 10, and then proceeds to STEP 3 to close the motor valve 10 after a predetermined time (for example, 1 second) has elapsed.

  Next, in STEP 4, it is determined whether or not the ambient temperature T is higher than the reference temperature YT1 by a predetermined temperature ΔT or more, that is, whether or not the bimetal switch 17 is turned off. If the bimetal switch 17 is not turned off, the process proceeds to STEP 5 to determine whether or not a predetermined waiting time (for example, 1 hour) has elapsed since the motor valve 10 was closed. The process returns to STEP 4 until the waiting time elapses, and returns to STEP 2 when the waiting time elapses without the bimetal switch 17 being turned off. As a result, the sticking prevention control is executed in which the motor valve 10 is once opened and then closed at a time interval equal to the waiting time. When the bimetal switch 17 is turned off, the sticking prevention control is terminated and the process returns to STEP1.

  According to the above control, before the valve body 102 of the motor valve 10 is firmly fixed to the valve seat 101 at a low temperature during operation stop, the motor valve 10 is opened to eliminate the fixed state. Therefore, the valve body 102 of the motor valve 10 is not firmly fixed to the valve seat 101, and the motor valve 10 can be prevented from being unable to open. Even if the motor valve 10 is once opened by the sticking prevention control, the water pressure responsive valve 11 which is another on-off valve remains closed, so that no gas is supplied to the burner 4 and it is safe.

  Further, according to the above control, when the bimetal switch 17 is turned off, that is, when the ambient temperature T is higher than the reference temperature YT by a predetermined temperature ΔT or more, the anti-adhesion control is terminated, so that the anti-adhesion control is executed. Hunting that repeats and ends can be prevented.

  By the way, in the above control, the waiting time that is the time interval of opening and closing of the motor valve 10 by the sticking prevention control is made constant, but a temperature sensor such as a thermistor is used as a temperature detecting means for detecting the ambient temperature, and the ambient temperature is It is also possible to shorten the waiting time continuously or stepwise as the value decreases. According to this, at a very low temperature at which the valve body 102 of the motor valve 10 is likely to stick to the valve seat 101, the motor valve 10 can be frequently opened and closed to reliably prevent the valve body 102 from sticking and the valve body 102. However, at a temperature at which it is relatively difficult to adhere, the frequency of opening and closing the motor valve 10 can be reduced to save power.

  In the above embodiment, the present invention is applied to a water heater in which the motor valve 10 and the water pressure responsive valve 11 are provided as an on-off valve in the gas supply path 4a. However, the motor valve is provided in the gas supply path. The present invention can be similarly applied to a combustion apparatus other than a water heater in which at least two on-off valves are included.

  DESCRIPTION OF SYMBOLS 1 ... Water heater (combustion apparatus), 4 ... Burner, 4a ... Gas supply path, 6 ... Controller (control means), 10 ... Motor valve, 101 ... Valve seat, 102 ... Valve body, 103 ... Armature, 104 ... Electromagnet , 105 ... motor, 11 ... water pressure responsive valve (other on-off valve), 17 ... bimetal switch (temperature detection means).

Claims (3)

A combustion apparatus in which at least two on-off valves are provided in a gas supply path to a burner, and one of the on-off valves includes an armature connected to a rubber valve body, an electromagnet facing the armature, A motor that advances and retracts the electromagnet in the X-axis direction, which is the opening / closing direction of the valve body, and moves the electromagnet toward the valve body in one direction in the X-axis direction while the valve body is in the closed position where the valve body is seated on the valve seat Consists of a motor valve that opens the valve element by abutting the armature and exciting the electromagnet, attracting the armature to the electromagnet, and retreating the electromagnet to the other side in the X-axis direction in this state In
A temperature detecting means for detecting the atmospheric temperature, and the control means of the combustion device is configured such that when the atmospheric temperature becomes equal to or lower than a predetermined reference temperature during the operation stop when both the motor valve and the other on-off valve are closed. The combustion apparatus is configured to execute sticking prevention control in which the motor valve is opened once and then closed at predetermined time intervals.   2. The combustion apparatus according to claim 1, wherein the control unit is configured to end the sticking prevention control when an ambient temperature becomes a predetermined temperature or more higher than the reference temperature.   The combustion apparatus according to claim 1 or 2, wherein the control means is configured to shorten the time interval as the atmospheric temperature decreases.

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