JP2003130332A - Heating power controlling device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely correct pulse gap by power swing or the like in a heating power controlling device which controls the opening of a flow control valve 3 by pulse number supplied to a stepping motor 34 because the heating power controlling device, which always detects the opening of the flow control valve 3 opened by the stepping motor 34 by using a position sensor such as a rotary encoder and improves the accuracy of opening control, becomes complex. SOLUTION: When a microswitch 5 set to the fully closed side beyond the position where the amount of gas becomes of the volume necessary for ignition is turned on, the gap between the pulse number and an actual opening is corrected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal power control system for controlling the amount of gas supplied to a burner provided in a gas appliance to perform point extinction and thermal control of the burner.

[0002]

2. Description of the Related Art Japanese Patent No. 2 is a conventional thermal power control device.
No. 129580 discloses a motor-driven electric valve, which corresponds to a flow rate adjusting mechanism for adjusting heat power, attached to each burner. In this case, a normal motor is used, and therefore, it is necessary to provide a position sensor in a part of the drive system including the rotary shaft of the motor. The position sensor adjusts the opening while detecting the opening of the electric valve.

Therefore, in this thermal power control mechanism, a position sensor must be provided to detect the opening of the electric valve. Then, the opening degree of the electric valve must be adjusted while constantly searching the output signal of the position sensor.

In such a case, it is considered that a stepping motor is used as a motor for driving the flow rate adjusting mechanism and the opening degree is controlled by the number of pulses supplied to the stepping motor. By using the stepping motor as described above, the opening can be maintained at a predetermined opening position.

[0005]

However, when a stepping motor is used, there is a risk that a step-out error may occur in which the expected opening and the actual opening deviate from the number of pulses supplied.

Therefore, it is possible to control the opening by only the number of pulses supplied to the stepping motor without detecting the opening of the flow rate adjusting mechanism, but it is necessary to correct the step-out.

In view of the above-mentioned problems, the present invention does not need to constantly monitor the opening of the flow rate adjusting mechanism by the position sensor when the flow rate adjusting mechanism is driven by the stepping motor, and can reliably correct the error. An object of the present invention is to provide a thermal power control device capable of achieving the above.

[0008]

In order to solve the above-mentioned problems, a thermal power control device according to the present invention is controlled by a motor to increase / decrease the amount of gas supplied to a burner and stop the supply of gas at a valve closed position. In a thermal power control device provided with a flow rate control mechanism to the downstream side of an electromagnetic safety valve that opens and closes a gas supply path to the flow rate control mechanism, a stepping motor is used as the motor, and the number of pulses supplied to the stepping motor varies depending on the number of pulses. While controlling the opening of the flow rate control mechanism, set the switch operating position to the fully closed side from the position where the opening of the flow rate control mechanism becomes the amount of gas required for ignition,
When the operation position of the switch is reached, the operation of the switch corrects an error between the opening degree defined by the pulse number and the actual opening degree.

According to the above construction, when the flow control mechanism is opened from the fully closed state and when the valve is closed from the open state to the fully closed state, the switch is always operated, so that the correction is surely performed. .

A cam plate that rotates in conjunction with the rotation shaft of the stepping motor and a micro switch that operates by the cam plate are attached, and the micro switch is the above switch.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Referring to FIG. 1, GT is a gas table, which includes two stove burners BC and one grill burner BG. Each of these burners BC, B
Gas is supplied to G from a gas supply pipe GP. The burner BC, BG is connected in series with a valve unit 1 for controlling the thermal power.

This valve unit 1 includes burners BC and B.
It is composed of an electromagnetic safety valve 2 that opens and closes a gas supply path to G and a flow rate control valve 3 that adjusts the thermal power by increasing or decreasing the flow rate of the gas supplied to each burner BC, BG.

Referring to FIG. 2, the safety valve 2 has a solenoid portion 21 having a solenoid coil and a spring built therein. The valve body 20 is constantly urged in the valve closing direction by this spring,
When the solenoid is energized, the valve body 20 resists the biasing force of the spring.
Is driven in the valve opening direction, and the gas supply path is opened. On the contrary, when the energization of the solenoid coil is stopped, the magnetic force of the solenoid coil disappears, and the urging force of the spring causes the valve body 20 to move.
Is returned in the valve closing direction, and the gas supply path is closed.

The flow control valve 3 is mainly composed of a rotary plate 31 and a fixed plate 3.
2 and the orifice plate 33. Further, with reference to FIG. 3, the rotary plate 31 is rotated by a rotary shaft 35 connected to a drive shaft 34 a of the stepping motor 34.
On the other hand, the fixed plate 32 is fixed to the housing of the valve unit 1. The rotary plate 31 has a long hole 31a formed along the rotation direction, and the fixed plate 32 has a plurality of through holes 32a formed along the locus of the long hole 31a.

If the long hole 31a and the through hole 32a do not match, the gas cannot pass through the long hole 31a.
Gas is not supplied to each burner BC, BG. When the stepping motor 34 is driven and the rotary plate 31 is rotated, the elongated hole 31a is sequentially aligned with the through hole 32a. Slot 31
Gas passes through the through hole 32a corresponding to a. However,
Since the long hole 31a is formed to have a length corresponding to the two through holes 32a, when the rotating plate 31a is rotated, the long hole 3a
The combination of the through holes 32a corresponding to 2a is sequentially switched.

If the gas type is different, it is necessary to change the gas supply amount according to the gas type. Therefore, the orifice plate 33 having the orifice hole 33a having a flow rate corresponding to the gas type is superposed on the upper surface of the fixed plate 33 via the packing 32b. With this configuration, the rotary plate 3
When 1 is rotated, the orifice holes 33a through which the gas passes are sequentially selected, and the amount of gas adjusted by the orifice holes 33a is supplied to each burner BC, BG. In addition,
When the gas type is changed, only the orifice plate 33 may be replaced according to the changed gas type.

By the way, the stepping motor 34 is rotationally driven by a pulse signal supplied from a controller (not shown). The rotation angle of the drive shaft 34a is proportional to the number of pulses supplied. In the present invention, not the feedback control in which the actual rotation angle of the drive shaft 34a is continuously detected using an encoder or the like, but the open loop control in which the rotation angle is controlled only by the number of pulses supplied is performed. However, when the gas supply amount reaches a predetermined amount, it is necessary to operate an ignition device equipped with an igniter and an ignition electrode (not shown) to ignite the burners BC and BG. Therefore, the cam 4 is attached to the drive shaft 34a of the stepping motor 34. Attached, micro switch 5 attached near this cam 4
The ignition device is activated when is turned on by the cam 4.

Referring to FIG. 4, when the flow control valve 3 is closed and the stepping motor 34 is driven to rotate the rotary plate 31 from the state shown in (a), the flow control valve 3 is opened. . However, the amount of gas supplied at the opening degree at the initial stage of valve opening is an extremely small amount, which is a gas amount corresponding to low heat. Even if the ignition device is operated in such a state, each burner BC, B
G cannot be ignited. Therefore, the rotating plate 31
The igniter was activated at the time when was rotated about 110 °. When the rotary plate 31 rotates by 110 °, the cam 4 also rotates by 110 °, and as shown in FIG.
1 turns on the microswitch 5.

The position of 110 ° is set slightly to the low heat position side from the medium heat position. However, the rotating plate 31
In the state of being rotated by 0 °, an amount of gas that can be ignited is not yet supplied to each of the burners BC and BG. When the rotary plate 31 is further rotated in a state where the ignition device is operated in advance and the amount of gas supplied to each burner BC, BG is increased, the amount of gas supplied exceeds the amount of gas that can be ignited, and the burner has already been activated. Ignition is performed by the igniting device.

In more detail, referring to FIG.
When an ignition instruction is given to the control device, the control device first resets two parameters N and M to 0 (S
1). Then, the drive shaft 34a is rotated in the reverse direction until reaching the origin. The origin can be detected by turning off the micro switch 5. The drive shaft 34a is reversed for a predetermined time, and if the micro switch 5 is not turned off, the parameter N is checked (S3), and if it is a value smaller than 1, that is, 0, the drive shaft 34a is reversed again for a predetermined time. The origin is adjusted (S4) and 1 is added to the parameter N (S5).

If the micro switch 5 is not turned off even after the origin adjustment is performed twice, the steps S3 to S6 are performed.
Then, the operation is further stopped as an origin error (S6). When it is confirmed that the micro switch 5 is turned off, the control device supplies 224 pulses to the stepping motor 34 to rotate the rotary plate 31. The 224 pulses correspond to a rotation angle of 130 °, which is the medium heat position.

The microswitch 5 is 110 ° as described above.
It is set to turn on at the position. 110 ° corresponds to 190 pulses in this embodiment. Therefore, if there is no abnormality, the micro switch 5 is turned on before the control device outputs all 224 pulses. Therefore, when the micro switch 5 is not turned on even if 224 pulses are output, it is determined that a disk operation error such as sticking has occurred on the rotary plate 31, and the control thereafter is stopped (S8, S9).
On the other hand, when the micro switch 5 is turned on, the number of pulses already output at that time is stored, and if the number of pulses exceeds 200, the ignition operation is not stopped immediately but a slight desorption occurs during rotation. If a tone etc. occurs,
Parameter M is set to 1 (S10, S11, S1
2).

The fact that the micro switch 5 is turned on means that the rotary plate 31 has rotated at least 110 ° and the amount of gas that can pass through the flow rate control valve 3 is close to the amount of gas that can be ignited. Indicates that. However, since the safety valve 2 is not open at this time, the gas is not supplied to the burner. When the micro switch 5 is turned on, the ignition device is operated (S13), and the rotary plate 31 is further rotated. When the number of pulses output from the control device becomes 224 and the medium heat position is reached, the stepping motor 34 is stopped (S14). When the medium heat position is reached, ignition can be performed with the amount of gas supplied to the burner in that state, so the safety valve 2 is opened to supply gas to the burner and ignition is performed (S15).

If ignition is confirmed within 10 seconds after the safety valve 2 is opened and gas supply to the burner is started, the ignition device is stopped (S16, S17), but ignition cannot be confirmed within 10 seconds. Then, the process proceeds to step 18 (S18).
If the number of steps when the micro switch 5 is turned on exceeds 200, step 12 (S1
The parameter M was set to 1 in 2). Step M is 1
If the parameter M remains 0, it means that the ignition device is stopped and the safety valve 2 is closed, and it is determined that the ignition error has occurred. (S19, S20, S21). If the parameter M is set to 1, it is determined that the rotary plate 31 is not rotating sufficiently to the medium heat position, the ignition device is stopped, the safety valve 2 is closed, and then it is determined that a disk operation error has occurred ( S22, S23, S24).

Since the position where the micro switch 5 is turned on is set closer to the valve closing side than the ignition possible position in this way, the micro switch 5 is always turned on when the ignition operation is performed unless the valve unit 1 is abnormal. Turned on. Therefore, when the micro switch 5 is not turned on, it is possible to detect the occurrence of an abnormality. Also, the micro switch 5
The pulse number in the subsequent control can be corrected from the pulse number at the time when is actually turned on. That is, although the microswitch 5 should originally be turned on at the position of 190 pulses, the control after ignition completion can be corrected using the difference between the number of pulses at the time of actually turning on and 190 pulses as an error.

Since the micro switch 5 is always turned off after ignition and before extinguishing the hysteresis, the hysteresis can be calculated from the number of pulses in the on position and the number of pulses in the off position. The calculated hysteresis is stored in the control device, and the hysteresis is applied to the control at the time of reversal at the next control.

By the way, in the present embodiment, the flow control valve 3
Since the safety valve 2 is attached to each of the above, the stepping motor 34 can be rotated while the safety valve 2 is closed while the burner is stopped, and the correction value and the hysteresis value can be updated. If the stepping motor 34 is rotated while the burner is stopped, the O
It is possible to prevent sticking of the ring and other sliding parts.
When the ignition operation is performed in a state where the stepping motor 34 is not rotated for a long time, the frequency of the pulse signal supplied to the stepping motor 34 is lowered for a while from the start of rotation, and the torque is increased to take measures against sticking. You can go.

When the burner is ignited and cooking is started, cooking may be performed for a long time by the heat power between medium heat and high heat. In this case, the micro switch 5
Is not turned off while it is on, there is a possibility that errors due to step-out etc. may be accumulated. Therefore, when the total number of pulses supplied to the stepping motor 34 exceeds a predetermined value while the micro switch 5 is still on, the stepping motor 34 is automatically driven to the valve closing side, and the micro switch 5 is turned off to correct it. May be performed to restore the original position.

In the above embodiment, the control device detects that the stepping motor 34 is actually rotating during the rotation of 110 ° at which the microswitch 5 is turned on after the rotation of the stepping motor 34 is started. I can't. Therefore, as shown in FIG. 6, a step portion 42 may be formed so that the first contact of the micro switch 5 is turned on immediately after the stepping motor 34 starts rotating. The micro switch 5 has a first contact and a second contact, the step 42 turns on the first contact (b), and the cam 41 turns on the second contact.

By the way, in the above-mentioned embodiment, one micro switch 5 is used in which the cam 4 is in one stage, but two micro switches 5 are provided corresponding to each cam 4 while the cam 4 is in two stages. May be attached, and one of the microswitches is turned on in the medium heat position and the other microswitch is turned on in the high heat position. By providing two micro switches in this way, medium fire ignition and high fire ignition may be freely selected.

[0031]

As is apparent from the above description, the present invention uses the stepping motor to drive the flow rate adjusting mechanism,
When the opening of the flow rate control mechanism is adjusted by the number of pulses supplied to the stepping motor, the position to correct the deviation of the pulse number due to step-out etc. is set to the amount of gas required for ignition. Since the position is set to the fully closed side from the position, the opening is always passed between the valve opening and the valve closing, so that the correction can be surely performed.

[Brief description of drawings]

FIG. 1 is a block diagram showing the overall configuration of a gas appliance.

FIG. 2 is a sectional view showing the structure of a valve unit.

FIG. 3 is a diagram showing a configuration of a disc portion.

FIG. 4 is a diagram showing the operation of the cam.

FIG. 5 is a flow chart showing a control flow at the time of ignition.

FIG. 6 is a diagram showing an operation of a cam according to another embodiment.

[Explanation of symbols]

1 valve unit 2 safety valve 3 Flow control valve 31 rotating plate 32 fixed plate 33 Orifice plate 34 Stepping motor 4 cams 5 micro switch

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Keiichi Mizutani             2-26, Fukuzumi-cho, Nakagawa-ku, Nagoya, Aichi Prefecture             Inside Nanai Co., Ltd. F-term (reference) 3H062 AA07 AA15 BB30 CC02 DD01                       EE07 FF03 HH02                 3H065 AA03 BA01 BB15                 3K068 AA01 BB01 BB12

Claims (2)

[Claims] 1. A flow control mechanism for controlling the amount of gas that is driven by a motor to supply gas to a burner, and for stopping the gas supply at a valve closing position is an electromagnetic valve that opens and closes a gas supply path to the flow control mechanism. In a thermal power control device provided on the downstream side of a safety valve, a stepping motor is used as the motor, the opening of the flow rate control mechanism is controlled by the number of pulses supplied to the stepping motor, and the opening of the flow rate control mechanism is ignited. The operating position of the switch is set to the fully closed side from the position where the required gas amount becomes, and when the operating position of this switch is reached, the error between the opening specified by the above pulse number and the actual opening due to the operation of the switch A thermal power control device characterized by correcting the. 2. The thermal power control system according to claim 1, wherein a cam plate that rotates in conjunction with the rotation shaft of the stepping motor and a micro switch that operates by the cam plate are attached, and the micro switch is used as the switch. apparatus.