JP2010266128A - Fire power regulator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fire power regulator not requiring high torque in a motor, in the fire power regulator provided with a valve element valve-opened by a cam and for supplying and shutting off gas, and provided with a fire power regulating part for regulating a gas flow rate to a burner. <P>SOLUTION: This fire power regulator includes the fire power regulating part for regulating the gas flow rate to the burner, by rotating a movable plate 3 by a stepping motor 2, to increase and decrease an area where an opening 31 of the rotary disc 3 is overlapped an opening 41 of a fixed plate 4, the valve element 51 is provided as an opening and closing mechanism in series to the fire power regulating part, to shut off the gas by the valve element 51. The valve element 51 is opened by pressing a valve stem 5 by the cam 24. A shape of the cam 24 gets steep when fully opened from a weak fire state at the time of burner ignition, to require the high torque as an output of the motor 2, but the shape of the cam 24 is made mild to open fully the valve element 51 to a full opening degree at a time point when fire power reaches middle fire power or more, since the valve element 51 is not required to be opened fully under a low fire power state. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a thermal power adjusting device that is incorporated in a gas stove or the like and adjusts the thermal power of a burner by a motor.

  As a conventional thermal power control device of this type, openings are provided in both a movable plate that is moved by a motor and a fixed plate that is held in contact with the movable plate. There has been known one provided with a thermal power adjusting unit that adjusts the thermal power by adjusting the amount of gas passing through the overlapping portion of both openings by increasing / decreasing the overlapping area. In addition, an electromagnetic safety valve is provided on the upstream side of the thermal power control unit, and a cam that is rotated by a motor and a rod that is pushed and moved by the cam are arranged, and the cam rotates to move the load to force the electromagnetic safety valve. What is made to open automatically is known.

  When the holding current flows through the built-in electromagnet when the electromagnetic safety valve is forcibly opened to the fully open position by the rod, the force that was opened by returning the rod to the original position is released. Is also held open by the electromagnetic force of the electromagnet. And when there is an abnormality such as misfire, it is necessary to shut off the holding current and close the electromagnetic safety valve, so after the rod opens the electromagnetic safety valve, the rod is moved to a position that does not hinder the valve body of the electromagnetic safety valve from closing The shape of the cam is set so that can return.

JP 2006-189231 A (FIG. 5)

  In the conventional thermal power control device, the electromagnetic safety valve must be fully opened as soon as the ignition operation is performed. Therefore, it is necessary to open the electromagnetic safety valve fully open at once in a narrow rotation range. For this reason, the cam shape of the portion that pushes the rod must be very steep. However, in order to greatly move the rod at once with such a steep shape, a motor that generates high torque must be used as a motor for rotating the cam.

  A high-torque motor has a large shape and consumes a large amount of power, which causes problems such as difficulty in extending battery life when driven by dry batteries.

  Then, this invention makes it a subject to provide the thermal-power adjustment apparatus which does not produce the above-mentioned malfunction in view of said problem.

  In order to solve the above-described problem, the thermal power control apparatus according to the present invention provides openings in both a movable plate that is moved by a motor and a fixed plate that is held in contact with the movable plate, and moves the movable plate. In the thermal power control apparatus having a thermal power control unit that adjusts the thermal power by adjusting the amount of gas passing through the overlapping part of both apertures by increasing or decreasing the overlapping area of both apertures by the cam rotated by the motor An open / close mechanism that is opened and held open is provided in series with the thermal power control unit, and the opening degree of the open / close mechanism increases as the thermal power specified by the thermal power control unit increases from a low fire condition to a high fire condition. The shape of the cam is set such that the opening degree of the opening / closing mechanism is maximized when the heating power reaches the medium heat or higher.

  According to the above configuration, the opening / closing mechanism is not fully opened at once in a low fire state, but by gradually increasing the opening until reaching the heating power between medium and high fires, even a motor with a small torque can be ensured. The opening / closing mechanism is opened.

  In order to ensure that the opening / closing mechanism is closed when a problem occurs, a stopper is provided on the apparatus body side, and the stopper is rotated at the position where the opening / closing mechanism is closed by rotating with the rotating shaft of the motor. Stop means for forcibly stopping the rotation of the rotation shaft may be provided in contact with the portion.

  Alternatively, it includes a cam that rotates together with the rotating shaft of the motor, and a limit switch that is mounted so that the on / off state is reversed by the cam at the position where the opening / closing mechanism is closed, and rotates by reversing the on / off state of the limit switch. It is also possible to provide stop means that can forcibly stop the rotation of the shaft.

  As is apparent from the above description, the present invention can reliably open the opening / closing mechanism even with a small torque motor, and thus a small motor with low torque can be used.

The figure which shows the structure of one embodiment of this invention Diagram showing relationship between cam phase and gas passage area Diagram showing cam profile Diagram showing the structure of the phase detection sensor The figure which shows other embodiment.

  Referring to FIG. 1, reference numeral 1 denotes a thermal power control apparatus according to the present invention. A stepping motor 2 is attached to the lower part of the thermal power control apparatus 1. A phase detection sensor 22 for detecting the rotational phase of the rotary shaft 21 is attached to the rotary shaft 21 of the stepping motor 2. A cam member 23 is further attached to the rotating shaft 21 so as to rotate together with the rotating shaft 21. A cam portion 24 is provided on the outer periphery of the cam member 23. When the stepping motor 2 is operated to rotate the rotating shaft 21, the cam portion 24 pushes the valve shaft 5 to the right in the drawing. A valve body 51 as an opening / closing mechanism is attached to the valve shaft 5, and when the valve shaft 5 is pushed rightward, the valve body 51 is changed from the closed state to the opened state. When the valve body 51 is opened, the gas passes around the valve body 51 and flows toward the cam member 23.

  A circular movable plate 3 is engaged with the upper portion of the cam member 23, and the movable plate 3 is configured to rotate in conjunction with the cam member 23. The movable plate 3 is pressed against the lower surface of the fixed plate 4. The movable plate 3 has one opening 31, and the fixed plate 4 has five openings 41 in the present embodiment.

  When the opening 31 of the movable plate 3 overlaps any one of the openings 41 due to the phase of the movable plate 3, the gas flows further downstream through the overlapped portion and is supplied to the burner. When the movable plate 3 rotates in the forward direction, the area where the opening 31 and the opening 41 overlap is increased. And when this overlapping area increases, the amount of gas supplied to the burner increases and the thermal power increases.

  By the way, the movable plate 3 and the cam member 23 are rotated in the forward direction and the reverse direction within a predetermined angle range. That is, when the movable plate 3 and the cam member 23 are rotated in the forward direction and the valve body 51 is rotated from the closed state to a position where the maximum opening is exceeded and the valve is closed again, it is necessary to further rotate in the forward direction. Absent. However, a stopping means is provided so that the movable plate 3 and the cam member 23 do not rotate beyond the angular range due to some abnormality. Specifically, the stopper 11 is provided on the apparatus main body side, and an engaging portion 23a that contacts the stopper 11 is formed in the cam member 23 when the cam member 23 exceeds a predetermined angle range. Accordingly, if the stepping motor 2 continues to rotate in either the forward or reverse direction, the engaging portion 23a comes into contact with the stopper 11 and the rotation of the rotating shaft 21 is forcibly prevented so that the cam member 23 does not rotate any further. Stop.

  Referring to FIG. 2, in the above configuration, in the state shown in FIG. 2A, the cam portion 24 is not in contact with the valve shaft 5, that is, the valve body 51 is in a closed state. Therefore, even if the opening 31 overlaps with a part of the openings 41 as shown in the drawing, the gas is blocked by the valve body 51 and does not flow to the cam member 23 side. In this state, the opening 31 may be set so as not to overlap any of the openings 41 when the valve body 51 is in a closed state.

  In the figure, when the cam member 23 is rotated in the right direction (forward direction) by the stepping motor 2, the cam portion 24 pushes the valve shaft 5 to the right side and moves it, thereby opening the valve body 51 (FIG. 2B). )). However, the opening degree of the valve body 51 is small in this state. Further, since the opening 31 overlaps only with the two openings 41, the flow rate of the gas supplied to the burner is small. In other words, the burner's firepower is low.

  When the cam member 23 is further rotated in the right direction from the state shown in (b), the valve shaft 5 is moved to the right, and the opening degree of the valve body 51 is increased. Moreover, since the opening 41 which overlaps with the opening 31 increases and the diameter of the overlapping opening 41 increases, the amount of gas supplied to the burner increases. The state shown in (c) is the maximum flow rate, that is, a high fire state. In addition, in normal thermal power control, when the fire is extinguished from the strong fire state shown in (c), the rotating shaft 21 is reversed to return to the state shown in (a) through the state shown in (b). That is, the normal heating power adjustment range is the range shown in (a) to (c). However, for example, in the state shown in (c), if the burner extinguishes fire due to wind or spillage, it is necessary to immediately stop the ejection of gas from the burner. In such a case, the valve body 51 is closed by rotating the rotating shaft 21 forward from the state shown in (c) instead of rotating in the forward direction to the state shown in (d).

  Here, the profile of the cam part 24 is demonstrated with reference to FIG. The profile of the cam portion 24 shown in FIG. 2 is indicated by P1, and when the valve body 51 is gradually opened from the fully closed state and the heating power becomes 3 (medium fire), the opening degree of the valve body 51 is maximum. After that, the valve body 51 was set to be held at the maximum opening until the heating power 5 (high fire). In addition, as shown to P2, you may set to the profile which increases the opening degree of the valve body 51 with the increase in a thermal power until it becomes a thermal power 5 (strong fire). In any case, the profiles P1 and P2 are both gentler than the profile S in which the valve element 51 is fully opened at a stretch in the state of thermal power 1 (low heat).

  When the valve body 51 is suddenly opened to the fully open state as in the profile S, a stepping motor 2 having a high torque must be used, the stepping motor 2 becomes large, power consumption increases, and the stepping motor 2 The price of will be higher. On the other hand, when the heating power is small, the opening degree of the valve body 51 does not need to be fully opened. Therefore, the profiles P1 and P2 are more advantageous because the small stepping motor 2 can be used.

  The phase detection sensor 22 is a semi-fixed resistance type. As shown in FIG. 4, a C-shaped carbon film 22 b and an annular conductive portion 2 a are provided inside the phase detection sensor 22, and a slider 22 c that rotates together with the rotating shaft 21 is incorporated. Yes. When the slider 22c rotates, the short-circuit portion between the resistance coating 22b and the conductive portion 22a moves, so that the electric resistance continuously changes and the phase can be detected from the output partial pressure. In addition, a discontinuous non-detection range is always formed in the resistance coating 22b. Therefore, this non-detection range is set to a position where the cam member 23 does not normally rotate, that is, a position where the valve shaft 5 is detached from the cam portion 24 and the valve body 51 is closed. This position also coincides with the set position of the stopper 11.

  As described above, the rotational phase of the rotary shaft 21 is always detected by the phase detection sensor 22. Then, the rotation of the stepping motor 2 is controlled based on the detected phase data. Further, for example, when the burner is extinguished urgently during ignition or when a misfire occurs during ignition as described above, the stepping motor 2 is reversed, the opening 31 is moved to the low-fire side, and the valve body 51 is closed. It is determined from the phase signal output by the phase detection sensor 22 whether the valve is faster or it is faster to rotate forward and move the opening 31 to the high fire side to close the valve body 51.

  As described above, since the phase control of the stepping motor 2 is always performed based on the phase signal of the phase detection sensor 22, if the phase signal is not output due to disconnection or the like, the phase of the rotary shaft 21 of the stepping motor 2 is changed. It cannot be detected. In such a case, when the stepping motor 2 is rotated until the above-described engaging portion 23a comes into contact with the stopper 11, the rotation of the rotating shaft 21 causes gas to be supplied to the burner while the valve body 51 is closed. In such a state, the stopper 11 is forcibly stopped. The emergency rotation direction may be either forward or reverse.

  For example, as shown in FIG. 5, the cam 61 is further attached to the rotating shaft 21, and the limit switch 6 is provided so that the valve body 51 is turned on at the closed position as shown in FIG. Can be adopted. In this configuration, even if a disconnection failure occurs in the phase detection sensor 22, the operation of the stepping motor 2 may be stopped at a position where the limit switch 6 is turned on. However, when a microcomputer (not shown) that controls the operation of the stepping motor 2 runs away, a configuration in which the rotation of the rotary shaft 21 is mechanically stopped using the stopper 11 is effective.

  In addition, this invention is not limited to an above-described form, You may add a various change in the range which does not deviate from the summary of this invention.

DESCRIPTION OF SYMBOLS 1 Thermal power control apparatus 2 Stepping motor 3 Movable plate 4 Fixed plate 5 Valve shaft 11 Stopper 22 Phase detection sensor 24 Cam part 51 Valve body

Claims (3)

  An opening is provided in both the movable plate that is moved by the motor and the fixed plate that is held in contact with the movable plate. By moving the movable plate, the overlapping area of both openings is increased or decreased. In a thermal power control apparatus having a thermal power control unit that adjusts the thermal power by adjusting the amount of gas that passes through the overlapping portion, the thermal power control is performed on the opening and closing mechanism that is opened and held by the cam rotated by the motor. The opening degree of the opening / closing mechanism is increased as the thermal power specified by the thermal power control unit increases from a low heat state to a high fire state, and when the thermal power reaches or exceeds the medium fire, A thermal power control apparatus, wherein the shape of the cam is set so that the opening degree is maximized.   A stopper is provided on the apparatus main body side, and a stopping means for forcibly stopping the rotation of the rotating shaft by contacting the stopper at a position where the opening and closing mechanism rotates with the rotating shaft of the motor and closes the valve is provided. The thermal power control apparatus according to claim 1, wherein   A cam that rotates together with the rotating shaft of the motor, and a limit switch that is mounted so that the on / off state is reversed by the cam at a position where the opening / closing mechanism is in the valve-closed state. 2. The thermal power control apparatus according to claim 1, further comprising stop means capable of forcibly stopping rotation.

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