JP5469579B2 - Gas appliances - Google Patents

Description

  The present invention relates to a gas appliance such as a gas water heater provided with an on-off valve in a gas supply path to a burner.

  Conventionally, as a gas water heater, a water supply valve upstream of a heat exchanger heated by a burner is provided with a water stop valve and a water pressure responsive mechanism, and an on-off valve comprising an electromagnetic valve is provided in the gas supply path to the burner. And a water pressure responsive valve linked to the water pressure responsive mechanism, and by pressing the tapping button, the water stop valve is first opened to pass water through the heat exchanger, and this water flow causes the water pressure to pass through the water pressure responsive mechanism. It is known that when the opening of the water pressure responsive valve is detected by opening the responsive valve, sparking is started at the ignition electrode attached to the burner and the open / close valve is opened to ignite the burner. (For example, refer to Patent Document 1).

  Here, in the above conventional example, at the time of ignition, a large flow rate gas is suddenly supplied to the burner by opening the on-off valve, and the ignition sound generated when the burner is ignited becomes large.

  Conventionally, a valve body biased in the closing direction by a spring, a stepping motor, and an electromagnet attached and retracted in the X-axis direction, which is the opening and closing direction of the valve body, via a feed screw mechanism by forward and reverse rotation of the stepping motor By moving the movable body toward the valve body in the X-axis direction by forward rotation of the stepping motor, the electromagnet is brought into contact with the armature fixed to the valve body, and the armature is attracted to the electromagnet. Then, a motor valve is known in which the movable body is moved backward in the X-axis direction by reversing the stepping motor to move the valve body in the opening direction (see, for example, Patent Document 2).

  If the on-off valve provided in the gas supply path to the burner is configured with such a motor valve, the amount of gas supplied to the burner is reduced by opening the valve body of the motor valve at a predetermined small opening degree at the time of ignition. Thus, the ignition sound can be reduced. However, since the correlation between the rotation angle of the stepping motor and the position of the valve element is caused by the dimensional variation of the components of the motor valve and the backlash of the feed screw mechanism, the opening degree at the time of ignition is set to a small opening degree. In this case, the actual opening at the time of ignition may become too small, resulting in poor ignition.

JP 2009-250469 A JP 2005-30440 A

  This invention makes it the subject to provide the gas appliance which can reduce ignition sound and can also prevent generation | occurrence | production of ignition failure in view of the above point.

In order to solve the above-mentioned problems, the present invention is a gas appliance in which a gas supply path to a burner is provided with an opening / closing valve, the opening / closing valve being urged in a closing direction by a spring, and a stepping motor And a movable body attached with an electromagnet that is advanced and retracted in the X-axis direction, which is the opening and closing direction of the valve body through a feed screw mechanism by forward and reverse rotation of the stepping motor, and the movable body as a valve body by forward rotation of the stepping motor By moving forward in the X-axis direction, the electromagnet is brought into contact with the armature fixed to the valve body, the armature is attracted to the electromagnet, and then the movable body is moved backward in the X-axis direction by reverse rotation of the stepping motor. is moved in the opening direction the valve element, when the flame sensors attached to the burner does not detect the flame, so that by stopping the energization of the electromagnet coil to return the valve body to the closed position by the biasing force of the spring In When starting ignition with an ignition electrode attached to the burner, the stepping motor is reversely rotated intermittently to move the valve body stepwise from the closed position to the opening direction. It is characterized by.

  According to the present invention, at the time of ignition, the valve body of the motor valve, which is an on-off valve, is moved stepwise from the closed position in the opening direction by a predetermined stroke step by step, so that a large flow rate of gas is not suddenly supplied to the burner. Sound can be reduced. Furthermore, even if there is an error in the correlation between the rotation angle of the stepping motor and the position of the valve body due to dimensional variations of parts, backlash of the feed screw mechanism, etc., the amount of gas supplied to the burner gradually increases over time Therefore, no ignition failure occurs.

  It is also conceivable to move the valve body in the opening direction at low speed by continuously reversing the stepping motor at low speed during ignition. However, the stepping motor has a characteristic that power consumption increases when it is continuously rotated at a low speed, and when a dry battery is used as a power source, the life of the dry battery is shortened. On the other hand, if the stepping motor is intermittently rotated as in the present invention, power consumption can be reduced, which is advantageous when a dry battery is used as a power source.

  In the present invention, it is preferable that the stepping motor is continuously reversed until the valve body moves to a predetermined fully opened position after the ignition of the burner is detected by the flame sensor attached to the burner. According to this, it is possible to shorten the time required until the motor valve is fully opened and a required amount of gas is supplied to the burner.

Explanatory drawing which shows the whole structure of the gas appliance of embodiment of this invention. (A) Sectional drawing of the motor valve provided in the gas appliance of FIG. 1, (b) The graph which shows the position change of the valve body of the motor valve at the time of ignition.

  With reference to FIG. 1, A has shown the gas water heater which is the gas appliance of embodiment of this invention. The gas water heater A includes a trunk portion 1, a burner 2 disposed so as to face the lower end opening of the trunk portion 1, and a heat exchanger 3 that is disposed on the upper portion of the trunk portion 1 and is heated by the burner 2. Yes.

  The gas water heater A includes a hot water button S1, a temperature adjustment dial S2, and a capacity switching lever S3 as operation members, and further includes a controller C that is electrically connected to the hot water button S1. Yes. Further, the burner 2 is provided with an ignition electrode 21 connected to an igniter 21a controlled by the controller C, and a flame sensor 22 composed of a frame rod for detecting the flame of the burner 2, etc. A detection signal is input to the controller C.

  The heat exchanger 3 is connected to an upstream water supply passage 3a and a downstream hot water supply passage 3c connected to the hot water discharge head 3b.

  A water stop valve 31, a water pressure responsive mechanism 32, and a water amount adjusting valve 33 mechanically interlocked with the temperature control dial S2 are interposed in the water supply passage 3a in this order from the upstream side. The gas supply path 2a for the burner 2 is provided with a motor valve 4 as an on-off valve, a water pressure responsive valve 5 and a gas amount adjusting valve 6 mechanically interlocked with the capacity switching lever S3 in order from the upstream side. Has been. The water pressure responsive mechanism 32 has a built-in diaphragm (not shown) that is displaced when water flows, and the water pressure responsive valve 5 is opened mechanically in conjunction with the displacement of the diaphragm. Further, the water pressure responsive mechanism 32 includes a valve opening sensor (not shown) that detects whether or not the water pressure responsive valve 5 is opened, and a detection signal of the valve opening sensor is input to the controller C.

  The igniter 21a, the water stop valve 31 and the motor valve 4 are controlled by the controller C as follows. That is, when the hot water outlet button S1 is pressed, the water stop valve 31 is opened by the controller C, and water is passed through the water supply passage 3a. With this water flow, the water pressure responsive valve 5 is opened via the water pressure responsive mechanism 32. The When the opening of the water pressure responsive valve 5 is detected by the valve opening sensor, the controller C activates the igniter 21a to start sparking at the ignition electrode 21, and the controller C opens the motor valve 4. Then, gas is supplied to the burner 2 and ignited.

  When the burner 2 is ignited and detected by the flame sensor 22, the spark at the ignition electrode 21 is stopped. Thereafter, when the hot water button S1 is pressed again, the water stop valve 31 is closed by the controller C and water flow is stopped. In conjunction with this, the water pressure responsive valve 5 is closed, and the motor valve is closed by the controller C. 4 is closed. If the flame of the burner 2 is lifted or misfires due to incomplete combustion, the flame sensor 22 stops detecting the flame, and the controller C closes the motor valve 4. The gas water heater A includes a dry battery (not shown) as a power source, and power is supplied from the dry battery to the controller C and also supplied to the igniter 21a, the water stop valve 31 and the motor valve 4 via the controller C.

  Referring to FIG. 2A, the motor valve 4 includes a valve casing having an inlet 411, an outlet 412, a valve chamber 413 communicating with the inlet 411, and a valve seat 414 at one end of the valve chamber 413. 41, and a valve hole 414a communicating with the outflow port 412 is formed in the valve seat 414. A valve body 42 and a movable body 43 are accommodated in the valve chamber 413.

  The valve body 42 is urged in a closing direction by which the valve body 42 is seated on the valve seat 414 and closes the valve hole 414a by a spring 421 contracted with the movable body 43. Further, with the opening / closing direction of the valve body 42 as the X-axis direction, the valve body 42 includes a valve portion 422 at the front end in the X-axis direction seated on the valve seat 414 and a shaft portion 423 extending rearward from the valve portion 422 in the X-axis direction. The armature 424 is fixed to the rear end of the shaft portion 423. The shaft portion 423 is connected to the valve portion 422 so as to be freely movable by a predetermined stroke in the X-axis direction. A spring 425 for biasing the shaft portion 423 rearward in the X-axis direction is provided, and an impact when an electromagnet 432 (described later) contacts the armature 424 in a state where the valve body 42 is in a closed position where the valve body 42 is seated on the valve seat 414 is provided. It can be absorbed by the spring 425.

  The movable body 43 has a guide cylinder 431 in which the shaft portion 423 of the valve body 42 is slidably inserted. In addition, an electromagnet 432 facing the armature 424 is attached to the movable body 43. The electromagnet 432 includes a U-shaped iron core 432a and a coil 432c wound around one arm portion of the iron core 432a via a bobbin 432b, and is excited by energizing the coil 432c.

  The other end of the valve chamber 413 is closed by a lid member 415 fastened to the valve casing 41. A stepping motor 44 is attached to the outer surface of the lid member 415. Further, a feed screw mechanism 45 including a screw shaft 451 on the output side of the stepping motor 44 and a nut 452 that is screwed into the screw shaft 451 and advances and retracts in the X-axis direction is provided. The movable body 43 is connected to the nut 452 via a pin 453, and the movable body 43 is advanced and retracted in the X-axis direction via the feed screw mechanism 45 by forward and reverse rotation of the stepping motor 44. It is also possible to configure the feed screw mechanism such that the nut is rotated by the stepping motor 44 and the screw shaft screwed to the nut advances and retreats in the X-axis direction.

  When opening the motor valve 4, first, the stepping motor 44 is rotated forward, the movable body 43 is advanced toward the valve body 42 in the X-axis direction, and the electromagnet 432 is brought into contact with the armature 424. Next, the electromagnet 432 is excited by energizing the coil 432c, the armature 424 is attracted to the electromagnet 432, and in this state, the stepping motor 44 is reversed to move the movable body 43 backward in the X-axis direction. It is moved in the opening direction away from the valve seat 414. Further, when closing the motor valve 4, energization to the coil 432 c is stopped, and the valve body 42 is returned to the closed position where the valve body 42 is seated on the valve seat 414 by the biasing force of the spring 421.

  By the way, if the valve element 42 of the motor valve 4 is rapidly moved to the fully open position at the time of ignition to start the spark at the ignition electrode 21, the burner 2 is ignited in a state where a large amount of gas is supplied to the burner 2. The ignition sound generated at the time of ignition becomes loud. In this case, it is conceivable to reduce the ignition noise by opening the valve element 42 of the motor valve 4 at a predetermined small opening during ignition to reduce the amount of gas supplied to the burner 2. However, since an error occurs in the correlation between the rotation angle of the stepping motor 44 and the position of the valve body 42 due to dimensional variations of the components of the motor valve 4 and backlash of the feed screw mechanism 45, the opening at the time of ignition is slightly opened. If it is set to the degree, the actual opening degree at the time of ignition becomes too small, and an ignition failure may occur.

  Therefore, in this embodiment, at the time of ignition, after the armature 424 is attracted to the electromagnet 432, the stepping motor 44 is intermittently reversed to open the valve body 42 from the closed position to the opening direction as shown in FIG. Are moved stepwise by a predetermined stroke. In addition, intermittent reverse rotation of the stepping motor 44 is performed by continuously inputting a predetermined number (for example, 3 pulses) of drive pulses in the reverse direction to the stepping motor 44 and inputting the drive pulses for a predetermined time (for example, 1 msec). This is done by repeating the pause.

  According to the present embodiment, at the time of ignition, the valve body 42 of the motor valve 4 moves stepwise from the closed position in the opening direction by a predetermined stroke, so that a large flow rate gas is not suddenly supplied to the burner 2. Ignition noise can be reduced. Furthermore, even if an error occurs in the correlation between the rotation angle of the stepping motor 44 and the position of the valve body 42 due to dimensional variation of parts, backlash of the feed screw mechanism 45, etc., the amount of gas supplied to the burner 2 is increased over time. Since it increases step by step, no ignition failure occurs.

  It is also conceivable to move the valve element 42 in the opening direction at a low speed by continuously reversing the stepping motor 44 at a low speed at the time of ignition. However, the stepping motor 44 has a characteristic that power consumption increases when it is continuously rotated at a low speed. When a dry battery is used as a power source, the life of the dry battery is shortened. On the other hand, if the stepping motor 44 is intermittently rotated as in the present embodiment, the power consumption can be reduced and the life of the dry battery is extended.

  By the way, even after the ignition of the burner 2 is detected by the flame sensor 22, the stepping motor 44 is intermittently reversed so that the valve element 42 is predetermined up to a predetermined fully open position as indicated by a virtual line in FIG. It is conceivable to move the stroke step by step. However, in this case, it takes time for the amount of gas supplied to the burner 2 to reach the required amount necessary for heating the heat exchanger 3, and the temperature of the hot water discharged becomes low during that time, which is inconvenient for the user. multiply.

  Therefore, in this embodiment, after the ignition of the burner 2 is detected by the flame sensor 22, the stepping motor 44 is continuously reversed until the valve body 42 moves to the fully open position. According to this, as indicated by a solid line in FIG. 2B, the valve body 42 continuously moves at a high speed in the opening direction after ignition, and reaches the fully opened position in a short time. Accordingly, it is possible to reduce the time required until a required amount of gas is supplied to the burner 2 and not inconvenience the user.

  As mentioned above, although embodiment of this invention was described with reference to drawings, this invention is not limited to this. For example, in the above-described embodiment, the present invention is applied to a gas water heater, but the present invention can be similarly applied to gas appliances other than the gas water heater.

  A ... Gas water heater (gas appliance), 2 ... Burner, 21 ... Ignition electrode, 22 ... Flame sensor, 2a ... Gas supply path, 4 ... Motor valve, 42 ... Valve body, 421 ... Spring, 424 ... Armature, 43 ... Movable body, 432 ... electromagnet, 44 ... stepping motor, 45 ... feed screw mechanism.

Claims (2)

A gas appliance having an open / close valve in the gas supply path to the burner,
The open / close valve is mounted with an electromagnet that is advanced and retracted in the X-axis direction, which is the opening / closing direction of the valve body via the feed screw mechanism by forward / reverse rotation of the stepping motor and the stepping motor, which is biased in the closing direction by a spring By moving the movable body toward the valve body in the X-axis direction by forward rotation of the stepping motor, the electromagnet is brought into contact with the armature fixed to the valve body, and the armature is attracted to the electromagnet. After that, the valve body is moved in the opening direction by reversing the movable body in the X-axis direction by reversing the stepping motor. When the flame sensor attached to the burner no longer detects the flame, the electromagnet coil is energized. the constructed the stop valve body by a motor valve which is to so that is returned to the closed position by the biasing force of the spring,
A gas appliance comprising a stepping motor that reverses intermittently during ignition to start sparking at an ignition electrode attached to a burner, and moves a valve body stepwise from a closed position in an opening direction.   2. The stepping motor is continuously reversed until the valve body moves to a predetermined fully open position after the ignition of the burner is detected by a flame sensor attached to the burner. Gas appliances.