JPH05149531A - Nozzle drive control device in nozzle movable type burner - Google Patents

Abstract

PURPOSE:To protect the coils of a stepping motor from burning by extending calculation time up to the next proper combustion volume when the difference between the previous proper combustion volume and the current proper combustion volume is small. CONSTITUTION:A proper combustion volume difference arithmetic operation means 22 calculates the difference between the current proper combustion volume calculated by a proper combustion volume arithmetic operation means 18 and the previous proper combustion volume stored in a storage device. When the difference is small between the current combustion volume and the previous proper combustion volume, the calculation time up to the next proper combustion volume is extended. Therefore, when the change in the proper combustion volume is small, the calculation cycle of proper combustion volume is extended. As a result, the drive time ratio to the stop time of a stepping motor is minimized, which makes it possible to protect the coils of the stepping motor from burning by excessive heating.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nozzle drive control device for a nozzle moving burner.

[0002]

2. Description of the Related Art Conventionally, in a nozzle moving type burner in which a nozzle for spraying fuel oil is moved by a stepping motor to change the amount of fuel oil passing through an opening of a diaphragm plate to adjust the combustion amount, a combustion operation is performed. At some times, the proper combustion amount was calculated every predetermined time, and the nozzle was moved by the stepping motor based on the calculation.

[0003]

Since [0008] However the amount of burn control is subtle, in the conventional configuration, as shown in FIG. 5, for each calculation period T ₁ of the proper combustion amount over time of the most This often results in the application of a drive pulse to the stepping motor, and the drive voltage V ₁ is applied to the stepping motor substantially at all times, and the coil of the stepping motor may overheat and burn. Actually, drive pulses are sequentially and cyclically applied to a plurality of coils of the stepping motor in a predetermined short cycle, but in FIG. 5, the number of drive pulses is expressed in a small number for easy understanding. There is. Further, in FIG. 5, V ₂ is a voltage applied to the coil of the stepping motor at the time of stop.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a nozzle drive control device for a nozzle moving type burner which can prevent a coil of a stepping motor from being burnt out.

[0005]

SUMMARY OF THE INVENTION The present invention is a nozzle moving type in which a nozzle for spraying fuel oil is moved by a stepping motor to change the amount of fuel oil passing through an opening of an aperture plate to adjust the combustion amount. In the burner, pulse number storage means for storing in advance the number of drive pulses per cycle to be supplied to the stepping motor according to the proper combustion amount, and proper combustion amount computing means for computing the proper combustion amount, Necessary movement amount calculation means for calculating the necessary movement amount of the nozzle based on the proper combustion amount calculated by the proper combustion amount calculation means, and the stepping motor according to the proper combustion amount calculated by the proper combustion amount calculation means Pulse number reading means for reading the number of drive pulses per cycle supplied to the Driving for supplying drive pulses to the stepping motor until the stepping motor is moved by the required amount of movement calculated by the required amount of movement calculating means or the stepping motor is supplied with the number of driving pulses read by the pulse number reading means. Pulse supply means, proper combustion amount difference calculation means for calculating the difference between the proper combustion amount of this time calculated by the proper combustion amount calculation means and the last proper combustion amount, and the calculation result by this proper combustion amount difference calculation means And a calculation interval control means for varying the time until the next calculation of the appropriate combustion amount by the appropriate combustion amount calculation means, and when the difference between the appropriate combustion amount of this time and the appropriate combustion amount of the previous time is small, The feature is that the time until the calculation of the proper combustion amount is lengthened.

[0006]

The pulse number storage means stores in advance the number of drive pulses per cycle to be supplied to the stepping motor according to the proper combustion amount. The appropriate combustion amount calculation means calculates the appropriate combustion amount. The required movement amount calculation means calculates the required movement amount of the nozzle based on the proper combustion amount calculated by the proper combustion amount calculation means. The pulse number reading means reads, from the pulse number storage means, the number of drive pulses per cycle supplied to the stepping motor according to the proper combustion amount calculated by the proper combustion amount calculation means. The drive pulse supply means supplies the stepping motor until the nozzle moves by the necessary movement amount calculated by the necessary movement amount calculating means or the driving pulse is supplied to the stepping motor by the number of pulses read by the pulse number reading means. Supply drive pulse. The appropriate combustion amount difference calculating means calculates the difference between the current appropriate combustion amount calculated by the appropriate combustion amount calculating means and the previous appropriate combustion amount.
The calculation interval control means varies the time until the next calculation of the proper combustion quantity by the proper combustion quantity calculation means based on the calculation result by the proper combustion quantity difference calculation means.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on the embodiments shown in the drawings. FIG. 2 is a schematic cross-sectional view of a nozzle moving burner including a nozzle drive control device according to an embodiment of the present invention.
The burner 1 is composed of a nozzle 2 and a diaphragm plate 3. The nozzle 2 is driven back and forth (left and right direction in FIG. 2) by a stepping motor 4 to control the combustion amount. The nozzle 2 communicates with a closed oil sump 6 via an oil conduit 5, and a pump 7 is installed in the oil conduit 5. Fuel oil such as petroleum supplied to the nozzle 2 through the oil conduit 5 by the pump 7 is sprayed from the nozzle 2 and partly blocked by the diaphragm plate 3 and returned to the oil sump 6 through the return pipe 8. .. The oil sump 6 communicates with the space around the nozzle 2 via an air vent pipe 9. That is, since the amount of fuel oil blocked by the throttle plate 3 changes depending on the position of the nozzle 2, the amount of fuel oil passing through the opening 3a of the throttle plate 3 changes, and the combustion amount in the combustion chamber 10 changes. is there. Combustion air is supplied by a blower fan 11 to a combustion chamber 10 in which the fuel oil injected from the nozzle 2 and passed through the opening 3a of the diaphragm plate 3 is burned, and the supply amount of this combustion air is controlled by the air volume control damper 12. Controlled. The air volume control damper 12 is driven by a stepping motor 13. The stepping motors 4 and 13 are connected to a controller 14 equipped with a microcomputer and driven by the controller 14. That is, the controller 14 constitutes a nozzle drive control device for performing feedforward and feedback control of the stepping motor 4. Further, the oil conduit 5 is provided with an oil temperature sensor 15.

FIG. 1 is a block diagram of a nozzle drive control device according to an embodiment of the present invention. The nozzle drive control device supplies a stepping motor 4 according to an appropriate combustion amount.
A pulse number storage unit 17 that stores in advance the number of pulses per cycle, an appropriate combustion amount calculation unit 18 that calculates an appropriate combustion amount, and a nozzle based on the appropriate combustion amount calculated by this appropriate combustion amount calculation unit 18. The required movement amount calculation means 19 for calculating the required movement amount of 2 and the number of drive pulses per cycle to be supplied to the stepping motor 4 according to the proper combustion amount calculated by the proper combustion amount calculation means 18 The pulse number reading means 20 read from the storage means 17 and the nozzle 2 are moved by the required moving amount calculated by the necessary moving amount calculating means 19, or the number of pulses read by the pulse number reading means 20 is read by the stepping motor 4. Drive pulse supply means 21 for supplying drive pulses to the stepping motor 4 until the drive pulses are supplied, and A proper combustion amount difference calculating means 22 for calculating a difference between the proper combustion amount and the previous proper combustion amount of time calculated by the shrink amount calculating means 18, a proper combustion amount difference calculating means 2
The calculation interval control means 23 for varying the time until the next calculation of the proper combustion amount by the proper combustion amount calculation means 18 is provided based on the calculation result of 2. Among these means, the pulse number storage means 17 is constituted by a part of a storage device (not shown), and the other means are realized by software by the microcomputer of the controller 14.
The controller 14 controls not only the stepping motor 4 but also the nozzle moving burner or the entire water heater including the nozzle moving burner based on input signals from a remote controller (not shown) and various sensors. To do.

Next, the operation will be described. Pulse number storage means 1
In FIG. 7, the number of drive pulses per cycle supplied to the stepping motor 4 according to the appropriate combustion amount is stored in advance as a table. During the combustion operation, first, the proper combustion amount calculation means 18 calculates the proper combustion amount based on the input signals from the remote controller, various sensors and the like. As a result, the required movement amount calculation means 19 calculates the required movement amount of the nozzle 2 based on the proper combustion amount calculated by the proper combustion amount calculation means 18 and the current position of the nozzle 2, and determines the movement direction. .. Further, the pulse number reading means 20 uses the proper combustion amount calculated by the proper combustion amount calculating means 18 to determine the stepping motor 4
The pulse number of the drive pulse per one cycle supplied to is read from the pulse number storage means 17. As a result, the drive pulse supply means 21 supplies a drive pulse to the stepping motor 4 in accordance with the moving direction calculated by the required movement amount calculation means 19. This allows stepping motor 4
Is driven, the nozzle 2 moves, and the amount of combustion changes.
Then, when the nozzle 2 moves by the required movement amount calculated by the required movement amount calculating means 19 or when the driving pulse is supplied to the stepping motor 4 by the number of pulses read by the pulse number reading means 20, the driving is performed. The pulse supply means 21 stops the supply of the drive pulse to the stepping motor 4. On the other hand, the appropriate combustion amount difference calculation means 22
Calculates the difference between the current proper combustion amount calculated by the proper combustion amount calculation means 18 and the previous proper combustion amount stored in the storage device (not shown). As a result, the calculation interval control means 23 varies the time until the next calculation of the proper combustion amount by the proper combustion amount calculation means 18, based on the calculation result by the proper combustion amount difference calculation means 22. That is, when the difference between the proper combustion amount of this time and the proper combustion amount of the previous time is small, the time until the calculation of the proper combustion amount of the next time is lengthened. Therefore, when the change in the proper combustion amount is small, the calculation cycle of the proper combustion amount becomes long, and as a result, the stepping motor 4
Since the ratio of the drive time to the stop time is reduced, it is possible to prevent the coil of the stepping motor 4 from burning due to overheating.

Regarding the operation of the nozzle drive control device,
A more specific description will be given with reference to the flowchart of FIG. First, the proper combustion amount calculation means 18 calculates the proper combustion amount (step S1). Next, the appropriate combustion amount difference calculation means 2
2 calculates the difference between the proper combustion amount calculated by the proper combustion amount calculation means 18 in step S1 and the previous proper combustion amount stored in the storage device, and whether or not the difference is less than or equal to a predetermined value A. It is determined (step S2). If the difference is less than or equal to the predetermined value A, the calculation interval control means 23 starts the timer t ₂ corresponding to the calculation cycle T ₂ in FIG. 4 (step S3). Next, the required movement amount calculation means 19 performs step S
Based on the proper combustion amount calculated by the proper combustion amount calculating means 18 in 1 and the current position of the nozzle 2, the required movement amount and direction of the nozzle 2 are calculated (step S4). Next, the pulse number reading means 20 calculates the pulse number of the driving pulse per one cycle to be supplied to the stepping motor 4 based on the proper combustion amount calculated by the proper combustion amount calculating means 18 in step S1. Are read out from (step S5). Next, the drive pulse supply means 19 applies a drive pulse of a predetermined pulse width to each coil of the stepping motor 4 in a predetermined cycle based on the moving direction of the nozzle 2 calculated by the required movement amount calculation means 18 in step S4. Supply cyclically (step S6), step S
It is determined whether or not the supply of the drive pulses of the number of pulses read in 5 is completed (step S7), and if the supply is not completed, it is determined whether or not the nozzle 2 has moved by the required movement amount calculated in step S4. It is determined (step S8), and if it is moving, the stop voltage V ₂ of FIG. 4 is applied to the coil of the stepping motor 4 (step S9). As a result, the position of the nozzle 2 changes, the amount of fuel oil passing through the opening 3a of the diaphragm plate 3 changes, and the amount of combustion changes. The drive pulse has a voltage V _{1 as shown} in FIG. In addition, in practice, drive pulses are sequentially and cyclically applied to a plurality of coils of the stepping motor 4 in a predetermined short cycle, but in FIG. 4, the number of drive pulses is expressed in a small number for easy understanding. ing. Next, the calculation interval control means 23 performs step S
It is determined whether or not the timer t ₂ started in step 3 has timed out (step S10). If the time has expired, the proper combustion amount calculated by the proper combustion amount calculation means 18 in step S1 is stored in the storage device. Store (step S11) and return to step S1. Incidentally it is judged that the timer t ₂ has not timed in step S10, the flow returns to step S10. If it is determined in step S8 that the nozzle 2 has not moved by the required movement amount calculated in step S4, the process returns to step S7. If it is determined in step S7 that the supply of the drive pulses of the number of pulses read in step S5 has been completed, the process proceeds to step S9. If it is determined in step S2 that the difference between the current proper combustion amount and the last proper combustion amount is not equal to or less than the predetermined value A, the calculation interval control means 23 causes the calculation cycle T _{1 in} FIG.
The timer t ₁ corresponding to is started (step S1
2), go to step S4. When the timer t ₁ is started in step S12, it is determined in step S10 whether or not the timer t ₁ is up.

As described above, when the change in the proper combustion amount is small, the calculation cycle of the proper combustion amount is lengthened from T ₁ to T ₂ , so that the ratio of the drive time to the stop time of the stepping motor 4 is as shown in FIG. The size of the coil is reduced, and the burnout due to overheating of the coil of the stepping motor 4 can be effectively prevented.

In the above embodiment, the calculation cycle of the proper combustion amount is switched between two stages of T ₁ and T ₂ , but it may be switched to three stages or more, or the proper combustion amount of this time and the proper combustion amount of the previous time. It may be changed steplessly in proportion to the difference from the amount.

[0013]

According to the present invention, which has the above-described structure, the nozzle for spraying fuel oil is moved by a stepping motor to change the amount of fuel oil passing through the aperture of the diaphragm plate to adjust the amount of combustion. In the burner, a pulse number storage means for storing in advance the number of drive pulses per cycle to be supplied to the stepping motor in accordance with the proper combustion amount, and a proper combustion amount computing means for computing the proper combustion amount, A required movement amount calculation means for calculating the required movement amount of the nozzle based on the appropriate combustion amount calculated by the appropriate combustion amount calculation means, and a stepping motor according to the appropriate combustion amount calculated by the appropriate combustion amount calculation means 1
A pulse number reading means for reading the number of drive pulses per cycle from the pulse number storage means, and the nozzle is moved by the required movement amount calculated by the required movement amount calculation means or is read by the pulse number reading means on the stepping motor. The difference between the proper combustion amount of this time calculated by the drive pulse supply means that supplies the drive pulse to the stepping motor until the drive pulse is supplied by the specified number of pulses, and the proper combustion amount of the previous time calculated by the proper combustion amount calculation means. An appropriate combustion amount difference calculating means for calculating and an operation interval control means for varying the time until the next calculation of the appropriate combustion amount by the appropriate combustion amount calculating means based on the calculation result by the appropriate combustion amount difference calculating means, If the difference between the proper combustion amount of this time and the proper combustion amount of the previous time is small, increase the time until the calculation of the proper combustion amount of the next time. Because, when the degree of deviation from the combustion amount is small since the ratio of the driving time to the stop time of the stepping motor is reduced, it can be favorably prevented burnout due to overheating of the stepping motor coil.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a nozzle drive control device according to an embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view of a nozzle moving burner including a nozzle drive control device according to an embodiment of the present invention.

FIG. 3 is a flowchart illustrating an operation of the nozzle drive control device in the embodiment of the present invention.

FIG. 4 is a timing chart of a drive pulse that is an output of the nozzle drive control device in the embodiment of the present invention.

FIG. 5 is a timing chart of drive pulses output from a conventional nozzle drive control device.

[Explanation of symbols]

 2 nozzle 3 diaphragm plate 3a opening 4 stepping motor 17 pulse number storage means 18 proper combustion amount calculation means 19 necessary movement amount calculation means 20 pulse number reading means 21 drive pulse supply means 22 proper combustion amount difference calculation means 23 calculation interval control means

Claims (1)

[Claims] 1. A nozzle moving burner that adjusts the combustion amount by changing the amount of fuel oil passing through the opening of a diaphragm plate by moving a nozzle for spraying fuel oil with a stepping motor, according to an appropriate combustion amount. Pulse number storage means for storing in advance the number of drive pulses per cycle to be supplied to the stepping motor, an appropriate combustion amount operation means for calculating an appropriate combustion amount, and an operation performed by the appropriate combustion amount operation means. Required movement amount calculation means for calculating the required movement amount of the nozzle based on the appropriate combustion amount, and drive per cycle for supplying to the stepping motor according to the appropriate combustion amount calculated by the appropriate combustion amount calculation means The pulse number reading means for reading the pulse number of the pulses from the pulse number storage means, and the nozzle by the required movement amount calculation means. Drive pulse supply means for supplying drive pulses to the stepping motor until the stepping motor is moved by the required amount of movement or the drive pulses are supplied to the stepping motor by the number of pulses read by the pulse number reading means; A proper combustion amount difference calculating means for calculating the difference between the proper combustion amount of this time calculated by the proper combustion amount calculating means and the last proper combustion amount, and the proper combustion based on the calculation result by the proper combustion amount difference calculating means. With the calculation interval control means for varying the time until the calculation of the next proper combustion amount by the amount calculation means, until the calculation of the next proper combustion amount when the difference between the current proper combustion amount and the last proper combustion amount is small. Nozzle drive control device for a nozzle moving type burner, characterized in that it is configured to extend the time.