METHOD FOR ADJUSTING AND CONTROLLING AN ACTUATING DRIVE FOR A BURNER

Abstract

Before start-up of a burner, minimum and maximum actuating positions of an actuating drive are set by setting elements. During control of the actuating drive, an automatic firing mechanism receives from a position transducer position signals dependent on the actuating position of the actuating drive reached during operation. The automatic firing mechanism assigns to the minimum actuating position the position signal measured during the feedback of the minimum actuating position of the actuating drive, and assigns to the maximum actuating position of the actuating drive the position signal measured during the feedback of the maximum actuating position of the actuating drive. Using the position signals assigned to the minimum and maximum actuating positions, corresponding control parameters are determined for activating the minimum and maximum actuating positions, and the control parameters are stored.

Description

BACKGROUND

Described below is a method for adjusting and controlling an actuating drive for a burner, wherein certain actuating positions of the actuating drive are activated by an automatic firing device and monitored.

A method of the type described in the introduction is known from EP 1 215 442 A1, for example. In the known method four control signals to control the on, off, ignition-load and low-load actuating position of an actuating drive by a diode matrix and two relays from the automatic firing device are conducted via a control circuit to the actuating drive, wherein corresponding feedback signals are conducted to the automatic firing devices to detect the position of the actuating drive. During start-up of the burner the automatic firing device controls the actuating drive. The automatic firing device generates a clearing signal for a capacity regulator which then controls or regulates the on/off position of the actuating drive.

In the known method the capacity regulator is set to the working range of the actuating drive before the start-up of the burner and in burner mode an analog signal assessment of the regulator signal takes place in the actuating drive. As a result the known method for actuating drives cannot be used without corresponding analog signal processing.

SUMMARY

Described below is a method which enables a simple adjustment of the working range of the actuating drive and an automatic determination of the control parameters for the working range, wherein the adjustment and control of the actuating drive should be possible with low expenditure. According to the method, before the start-up of the burner, a minimum and maximum actuating position of the actuating drive, which define the working range of the actuating drive, are set by setting elements, and in that the automatic firing device, during the control of the actuating drive, monitors the set minimum and maximum actuating position by corresponding feedback signals, and here, position signals from a position transducer are received which are dependent on the actuating position of the actuating drive reached during the control, and in that the automatic firing device assigns to the minimum actuating position the position signal measured during the feedback of the maximum actuating position of the actuating drive, and from the position signals assigned to the minimum and maximum actuating positions, determines corresponding control parameters for activating the minimum and maximum actuating positions, and stores the control parameters.

Standard position values from automatic firing devices may be used to activate the minimum and maximum actuating positions which are stored in the automatic firing device before the start-up of the burner. Then the control parameters determined from the position signals are used for the activation of the minimum and maximum actuating position from the automatic firing device.

If no corresponding feedback signals are received when controlling the actuating drive with the control parameters, the automatic firing device then determines new control parameters from the position signals. If no feedback signals are received with the new control parameters either, the automatic firing device generates an error message and/or arranges a safety shutdown of the burner. In burner mode the automatic firing device compares the current position signal received with a desired value signal.

Depending on the difference between position signal and desired value signal, the automatic firing device generates an actuating signal for the actuating drive. A capacity regulator may generate the desired value signal, which is correspondingly assessed by the automatic firing device for adjusting and controlling the actuating drive. The automatic firing device has a memory, for example, an EEPROM, for storage of the standard position values and control parameters and corresponding signal inputs for the desired value, feedback and position signals.

An advantage of the method is that a standard actuating drive can be used without analog signal processing. In that in burner mode the automatic firing device permanently monitors the minimum and maximum actuating position of the actuating drive, drifting of the position signal can be detected by the automatic firing device and corrected accordingly. Manual readjustment of the adjusted working range is therefore unnecessary.

Control elements already present in the automatic firing device equipment and already present for the control of the actuating drive in the automatic firing device, such as analog/digital converters, microprocessors, etc. may be used for the adjustment of the working range of the actuating drive. Thus the adjustment and control of the actuating drive can be realized with little expenditure.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects and advantages will become more apparent and more readily appreciated from the following description of the exemplary embodiments, taken in conjunction with the accompanying drawings of which:

The only FIGURE is a block diagram of an actuating drive, an automatic firing device and a capacity regulator.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Reference will now be made in detail to the preferred embodiments, examples of which are illustrated in the accompanying drawing.

An exemplary embodiment is explained in more detail with reference to the FIGURE which is a functional block diagram.

The FIGURE shows an actuating drive 1 in a schematic representation, an automatic firing device 5 and a capacity regulator 10. The actuating drive 1 includes an electric motor 2, setting elements 3 and a position transducer 7.

Before the start-up of the burner the working range of the actuating drive 1, i.e. the minimum and maximum actuating position is adjusted for example by switch cams not shown here. Preferably before the start-up of the burner, standard position values for activating the actuating drive are stored in the automatic firing device 5. On the basis of the standard position values the automatic firing device 5 for example generates corresponding setting signals 6 to activate the adjusted minimum and maximum actuating position of the actuating drive 1. On reaching the minimum or maximum actuating position, the switch cams activate the switches 3 assigned to the minimum or maximum actuating position, as a result of which corresponding feedback signals 4 are received. While controlling the actuating drive 1, the automatic firing device 5 records the position signals 8 received from the position transducer 7. The position transducer 7 is e.g. a potentiometer, which supplies a position signal 8 which changes in proportion to the actuating position of the actuating drive 1.

The automatic firing device 5 assigns to the minimum actuating position the position signal 8 measured during the feedback of the minimum actuating position of the actuating drive. Correspondingly, the position signal 8 measured during the feedback of the maximum actuating position is assigned to the maximum actuating position. From the position signals 8 assigned to the minimum and maximum actuating positions, the automatic firing device 5 determines corresponding control parameters for activating the minimum and maximum actuating positions, and stores the control parameters.

The determination of the control parameters by the automatic firing device can take place during the start-up of the burner and/or in burner mode, wherein the automatic firing device monitors the switches 3 or the feedback signals 4 correspondingly. During the start-up of the burner the automatic firing device 5 controls the actuating drive 1 independently from a capacity regulator 10. In burner mode the capacity regulator 10 generates a desired value signal 9, which is evaluated from the automatic firing device 5 to control or regulate the actuating drive 1.

The automatic firing device 5 compares the desired value signal 9 received from the capacity regulator 10 with the currently received position signal 8 and generates a corresponding setting signal 6 for actuating drive 1 according to the difference between the position signal 8 and the desired value signal 5.

In the exemplary embodiment the capacity regulator 10 is shown as an independent functional unit. However, the function of the capacity regulator can also be integrated into the automatic firing device 5.

If no corresponding feedback signal 4 is received during the activation of the actuating drive with the control parameters determined for the minimum or maximum actuating position, the automatic firing device 5 determines the corresponding control parameters again and stores them. If no feedback signal 4 is received with the corresponding newly determined control parameters either, the automatic firing device 5 generates a corresponding error message and/or arranges a safety shutdown of the burner.

A description has been provided with particular reference to preferred embodiments thereof and examples, but it will be understood that variations and modifications can be effected within the spirit and scope of the claims which may include the phrase “at least one of A, B and C” as an alternative expression that means one or more of A, B and C may be used, contrary to the holding in Superguide v. DIRECTV, 358 F3d 870, 69 USPQ2d 1865 (Fed. Cir. 2004).

Claims

1-7. (canceled)

8. A method for adjusting and controlling an actuating drive for a burner using an automatic firing device to activate and monitor actuating positions of the actuating drive, comprising: setting, by setting elements, minimum and maximum actuating positions of the actuating drive before start-up of the burner, to define a working range of the actuating drive;monitoring, by the automatic firing device during control of the actuating drive, the minimum and maximum actuating positions that have been previously set, using corresponding feedback signals, during which position signals from a position transducer are obtained that are dependent on actuating positions of the actuating drive reached during the control;assigning to the minimum actuating position, by the automatic firing device, a first measured position signal measured during feedback of the minimum actuating position of the actuating drive;assigning to the maximum actuating position of the actuating drive, by the automatic firing device, a second measured position signal measured during feedback of the maximum actuating position of the actuating drive;determining from the position signals assigned to the minimum and maximum actuating positions, first control parameters corresponding thereto, for activating the minimum and maximum actuating positions; andstoring the first control parameters.

9. A method according to claim 8, wherein said setting before the start-up of the burner includes storing standard position values for activating the minimum and maximum actuating positions in the automatic firing device.

10. A method according to claim 9, further comprising determining, by the automatic firing device, second control parameters if no corresponding feedback signals are received during activation of the actuation drive using the first control parameters.

11. A method according to claim 10, further comprising at least one of generating by the automatic firing device an error message and performing a safety shutdown of the burner if no corresponding feedback signals are received during the activation of the actuation drive with the second control parameters.

12. A method according to claim 11, further comprising: comparing, by the automatic firing device during burner operation, a currently received position signal with a desired value signal; andgenerating an actuating signal for the actuating drive according to a difference between the currently received position signal and the desired value signal.

13. A method according to claim 12, further comprising generating the desired value signal by a capacity regulator.

14. An automatic firing device, coupled to setting elements and a position transducer, for adjusting and controlling an actuating drive for a burner, comprising: signal inputs for feedback, position and desired value signals;a memory storing standard position values set by the setting elements before start-up of the burner to define a working range of the actuating drive, and storing control parameters; anda processor programmed to monitor, during control of the actuating drive, minimum and maximum actuating positions corresponding to the standard position values, using the feedback and position signals from the position transducer that are dependent on actuating positions of the actuating drive reached during the control;assign to the minimum actuating position a first measured position signal measured during feedback of the minimum actuating position of the actuating drive;assign to the maximum actuating position of the actuating drive a second measured position signal measured during feedback of the maximum actuating position of the actuating drive;determine from the position signals assigned to the minimum and maximum actuating positions, first control parameters corresponding thereto, for activating the minimum and maximum actuating positions;store the first control parameters in said memory;compare, by the automatic firing device during burner operation, a currently received position signal with a desired value signal; andgenerate an actuating signal for the actuating drive according to a difference between the currently received position signal and the desired value signal.

15. An automatic firing device according to claim 14, wherein the desired value signal is generated by a capacity regulator.

16. An automatic firing device according to claim 14, wherein said processor is further programmed to determine second control parameters and store the second control parameters in said memory, if no corresponding feedback signals are received during activation of the actuation drive using the first control parameters.

17. An automatic firing device according to claim 16, wherein said processor is further programmed to at least one of generate an error message and perform a safety shutdown of the burner, if no corresponding feedback signals are received during the activation of the actuation drive with the second control parameters.