Gas flow rate controller and gas appliance using the same

• US 6,619,613 B1
• Filed: 05/23/2001
• Issued: 09/16/2003
• Est. Priority Date: 11/24/1998
• Status: Expired due to Fees

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Yokohata, Mitsuo, Naganuma, Naoto, Murakami, Kouichi, Yanagisawa, Tadashi, Senda, Hiroyuki, Kagomoto, Yoshiteru, Matsumura, Mitsumasa, Hatano, Kazuyoshi, Akamatsu, Yoshio
• Primary Examiner(s): Mancene, Gene
• Assistant Examiner(s): Bastianelli, John
• Application Number:
  US09/831,889
• Time in Patent Office: 846 Days
• Field of Search: 251/129.04, 251/129.05, 137/625.13, 126/39.E
• US Class Current: 251/129.04
• CPC Class Codes: F16K 31/04 using a motor
• CPC Class Codes: F23N 1/005 using electrical or electromechanical means F23N1/04 - F23N1/10 take precedence
• CPC Class Codes: F23N 2223/08 Microprocessor; Microcomputer
• CPC Class Codes: F23N 2235/16 variable flow or proportional valves
• CPC Class Codes: F23N 2237/02 two or more burners
• CPC Class Codes: F23N 2241/08 Household apparatus
• CPC Class Codes: F24C 3/126 on ranges
• CPC Class Codes: Y10T 137/86517 With subsequent closing of first port

Abstract

Gas flow control apparatus that includes a gas flow control unit having a gas flow adjusting capability and a gas closing capability of selectively opening and closing a gas. A stepping motor is used for driving the gas flow control unit. A drive control unit is provided for controlling the stepping motor. The gas flow control unit is capable of adjusting the gas flow in multiple stages by selectively opening and closing one of a plurality of gas flow adjusting holes and also capable of varying the gas flow in multiple stages by selectively opening and closing one of the plural gas flow adjusting holes according to a number of pulses of the stepping motor.

Claims

1. A gas flow control apparatus which comprises:

a gas flow control unit having a gas flow adjusting capability and a gas closing capability of selectively opening and closing a gas flow;

a stepping motor for driving the gas flow control unit; and

a drive control unit for controlling the stepping motor;

wherein said gas flow control unit is configured to adjust the gas flow in multiple stages by selectively opening and closing a variable number of a plurality of gas flow adjusting holes and also configured to vary the gas flow in multiple stages by selectively opening and closing said one of the plurality of gas flow adjusting holes according to a number of pulses of the stepping motor.

2. The gas flow control apparatus as claimed in claim 1, wherein the gas flow control apparatus is configured to have a variable flow control capability in which the flow of gas is varied stepwise according to the number of pulses applied to the stepping motor, a constant flow control capability in which the flow of gas is not varied and a gas interrupting control capability.

3. The gas flow control apparatus as claimed in claim 1, wherein the gas flow control unit comprises:

a slide shutter having an adjusting portion for adjusting the gas flow;

a cock body accommodating the slide shutter;

a flow control plate having a gas flow adjusting portion which includes the plural gas flow adjusting holes;

a drive connection that connects the slide shutter to the stepping motor; and

a spring for applying a load on the slide shutter and the flow control plate in a direction perpendicular to a direction of sliding of the slide shutter to thereby urge the slide shutter and the flow control plate to contact the cock body,

whereby a relative position between the adjusting portion of the slide shutter and the gas flow adjusting portion of the flow control plate is varied in accordance with the pulses of the stepping motor to thereby accomplish a gas flow adjustment and interruption.

4. A gas appliance utilizing a gas flow control apparatus as defined in claim 1, which comprises:

a control panel for issuing an instruction to the drive control unit of the flow control apparatus;

said control panel including a gas control key and a gas power adjusting key,

wherein the drive unit of the flow control unit has a plurality of stepwise variable flow characteristics each having a linearly variable flow portion, in which the gas flow does not vary, and

wherein the drive control unit is configured such that depending on a signal input from the gas power adjusting key a decision is made to determine whether a stepwise gas power change or a linear gas power change is desired, whereby a selection instruction of one of the linear gas power change and the stepwise gas power change is issued.

5. The gas appliance as claimed in claim 4, wherein the drive control unit further includes a motor speed controller for changing a drive-speed,

wherein depending on the signal input from the gas power adjusting key a decision is made to determine whether the stepwise gas power change or the linear gas power change is desired and the selection instruction of one of the linear gas power change and the stepwise gas power change is issued, and

wherein when the linear gas power change is selected, a gas power adjusting speed is slower than when the stepwise gas power change is selected.

6. The gas appliance as claimed in claim 4, wherein when a period during which the gas power adjusting key is depressed is shorter than a predetermined value, a gas power is switched stepwise, but when the period during which the gas power adjusting key is depressed is longer than the predetermined value, the gas power is changed linearly.

7. The gas appliance as claimed in claim 6, wherein the drive control unit further includes a key input trouble determiner and wherein a length of time during which a trouble of the gas power adjusting key is determined is set to be longer than a length of time during which a gas power switching selection is carried out.

8. The gas appliance as claimed in claim 4, wherein the drive control unit further includes a position detector for detecting a position of a flow control unit, and

wherein when a gas power is changed linearly, a maximum gas power and a minimum gas power causes a display device to be switched on according to the position of the position detector, and a display position is changed when there is a medium gas power according to a number of pulses.

9. The gas appliance as claimed in claim 4, wherein the drive control unit further includes a position detector for detecting a position of a flow control unit, and

wherein when a gas power is changed linearly, a maximum gas power and a minimum gas power causes a display device to be switched on according to the position of the position detector, and when the gas power is changed stepwise, a specified display is switched on and displays at higher and lower positions are switched on or blink on and off, when there is a medium gas power according to a number of pulses.

10. A gas appliance employing a flow control apparatus as defined in claim 1, which comprises a plurality of gas burners,

wherein the stepping motor comprises a plurality of stepping motors, and

wherein when some of the plurality of gas burners are activated, the drive control unit drives in succession the plurality of stepping motors associated with some of the plurality of gas burners, whereby some of the plurality of gas burners are not activated simultaneously.

11. The gas appliance as claimed in claim 10, wherein the drive control unit drives the stepping motors in a manner wherein highest priority is given to a gas extinguishing function, second highest priority is given to a gas igniting function, third priority is given to a manual gas power adjusting function and fourth priority is given to an automatic gas power adjusting function.

12. A gas flow control apparatus comprising;

a gas flow control unit having a gas flow adjusting function and a gas closing function for selective opening and closing of the gas flow;

a stepping motor for driving the gas flow control unit;

a drive control unit for controlling a drive of the stepping motor; and

a position detector that detects a gas flow control position,

wherein the drive control unit includes a position determiner that determines the gas flow control position based on at least a signal from the position detector, and

wherein the position detector is configured such that when no closing stop signal is obtained, at least during a closing state, combustion of the gas is disabled.

13. The gas flow control apparatus as claimed in claim 12, wherein the drive control unit is configured to provide a predetermined number of pulses to the stepping motor to drive the stepping motor to a position detectable by the position detector whereby a predetermined gas power position is defined.

14. A gas flow control apparatus comprising:

a gas flow control unit having a gas flow adjusting function and a gas closing function for performing selective opening and closing of the gas flow;

a stepping motor for driving the gas flow control unit;

a drive control unit for controlling a drive of the stepping motor; and

a position detector that detects a gas flow control position,

wherein the drive control unit has a plurality of specified stop positions determined according to the number of available gas power switching positions, and

wherein at least one of the specified stop positions that is not detected by the position detector is ascertained based at least on a number of pulses for driving the stepping motor.

15. A gas flow control apparatus which comprises:

a gas flow control unit having a gas flow adjusting capability and a gas closing capability of selectively opening and closing a gas flow;

a stepping motor for driving the gas flow control unit;

a drive control unit for controlling the stepping motor; and

said drive control unit including a burner drive determining unit for adjusting a speed of a drive unit from a flow control position of the flow control unit.

16. The gas flow control apparatus as claimed in claim 15, wherein the burner drive determining unit is configured to reduce the drive speed when the drive control unit is moved to at least a position adjacent a minimum flow position of the flow control unit.

17. The gas flow control apparatus as claimed in claim 15, wherein the burner drive determining unit is configured to reduce the speed during an extinguishing operation at a position other than the position adjacent the minimum flow position of the flow control unit.

18. A gas flow control l apparatus which comprises:

a gas flow control unit having a gas flow adjusting capability and a gas closing capability of selectively opening and closing a gas flow;

a stepping motor for driving the gas flow control unit;

a drive control unit for controlling the stepping motor; and

said drive control unit being configured for variable speed control by determining a correlation with a flow control position of the gas flow control unit,

wherein the drive control unit outputs pulses to the stepper motor through an electricity saver to vary a drive speed of the stepping motor.

19. The gas flow control apparatus as claimed in claim 18, wherein the drive control unit is configured to selectively supply no electric power for speed control.

20. A gas flow control apparatus which comprises:

a gas flow control unit having a gas flow adjusting capability and a gas closing capability of selectively opening and closing a gas flow;

a stepping motor for driving the gas flow control unit;

a drive control unit for controlling the stepping motor; and

said drive control unit including a voltage determiner, an electricity saver for performing a duty control according to a level of voltage by fixing a frequency of pulses to be applied to the drive control unit according to a level of a power source voltage, a position determiner for determining a correlation with a flow control position of the gas flow control unit, and a motor speed controller for supplying no electric power for a predetermined cycle by fixing the frequency of the power supply pulses,

whereby an electric power supplied to the drive control unit can be leveled by converting the level of the power source voltage into a level of a duty ratio.

21. A gas flow control apparatus which comprises:

a gas flow control unit having a gas flow adjusting capability and a gas closing capability of selectively opening and closing a gas flow;

a stepping motor for driving the gas flow control unit;

a drive control unit for controlling the stepping motor;

said drive control unit including a voltage determiner for a drive control battery power source and an electricity saver for leveling an electric supply power; and

said electricity saver being configured to level the electric supply power of pulses based upon a variation in power source voltage.

22. The gas flow control apparatus as claimed in claim 21, wherein the electricity saver is configured to perform a duty control according to a level of voltage by fixing a frequency of the pulses to be applied to the drive control unit based on the power source voltage and is configured to level the electric supply power by converting the level of the power source voltage into a level of a duty ratio.

23. A gas flow control apparatus which comprises:

a gas flow control unit having a gas flow adjusting capability and a gas closing capability of selectively opening and closing a gas flow;

a stepping motor for driving the gas flow control unit;

a drive control unit for controlling the stepping motor; and

said gas flow control unit being configured to adjust the gas flow in multiple stages by selectively opening and closing a variable number of a plurality of gas flow adjusting holes and varying the gas flow in multiple stages by selectively opening and closing said one of the plurality of gas flow adjusting holes according to a number of pulses of the stepping motor.

24. The gas flow control apparatus as claimed in claim 23, wherein the drive control unit controls an electric power supply by at least one of increasing the electric supply power, increasing the duty ratio and lowering a frequency to increase torque of the stepping motor when the frequency of drive is measured for the first time.

25. A gas flow control apparatus which comprises:

a gas flow control unit having a gas flow adjusting capability and a gas closing capability of selectively opening and closing a gas flow;

a stepping motor for driving the gas flow control unit;

a position detector for detecting a flow control position of the gas flow control unit and a gas interrupted condition;

a drive control unit for driving the stepping motor and for determining a position with reference to a signal from the position detector;

wherein the drive control unit has a plurality of specified stop positions determined according to the number of available gas power switching positions, and

wherein at least one of the specified stop positions is a stop position at which position detection is carried out and one of the specified stop positions is a stop position at which no position detection occurs, whereby the stop position at which no position detection occurs is ascertained based on both the number of pulses for driving the stepping motor and a position determining signal from the position detector;

a position determiner for correcting a movement of the stepping motor; and

the drive control unit being configured to store at least one of the specified stop positions,

wherein the gas flow control unit is controlled by the number of pulses applied to the stepping motor.

26. The gas flow control apparatus as claimed in claim 25, wherein the position determiner is configured to increase an accuracy of a gas flow adjustment by counting the number of pulses necessary for the position detector to return to a predetermined position by accomplishing a reverse rotation after a predetermined number of pulses has been supplied to the stepping motor, and is configured to determine an error peculiar to the apparatus by determining a difference between the numbers of pulses during forward and reverse rotation motions, whereby the peculiar error of the apparatus is added or subtracted to or from the number of pulses at a desired position in the event that a direction of rotation differs from the forward rotation direction.

27. The gas flow control apparatus as claimed in claim 26, wherein the drive control unit detects the error peculiar to the apparatus at the time of ignition.

28. The gas flow control apparatus as claimed in claim 25, wherein the position determiner is configured to increase an accuracy of a gas flow adjustment by counting the number of pulses necessary for the position detector to return from the predetermined position and whereby a reverse rotation is accomplished after a predetermined number of pulses have been supplied to the stepping motor, an error peculiar to the apparatus being determined by determining a difference between the numbers of pulses during forward and reverse rotations, the error peculiar to the apparatus being stored in the drive control unit, and the peculiar error of the apparatus being added or subtracted to or from the number of pulses at a desired position in the event that a direction of rotation differs from the forward rotation direction.

29. A gas flow control apparatus which comprises:

a gas flow control unit having a gas flow adjusting capability and a gas closing capability of selectively opening and closing a gas flow;

a stepping motor for driving the gas flow control unit;

a position detector for detecting a flow control position of the gas flow control unit and a gas interrupted condition;

a drive control unit for driving the stepping motor and for determining a position based on a signal from the position detector; and

said drive control unit being configured to supply an electric power by increasing an electric supply power to increase a torque of the stepping motor in the event that the position detector fails to reach a predetermined position even though a predetermined number of pulses is supplied to the stepping motor during gas flow adjustment subsequent to opening of the gas flow control unit.

30. The gas flow control apparatus as claimed in claim 29, wherein the drive control unit is configured to increase torque of the stepping motor in the event that the position detector fails to reach the predetermined position by movement in a predetermined direction even though the predetermined number of pulses is supplied to the stepping motor, whereby the position determiner is caused to reach the predetermined position by effecting a movement that is reverse to the predetermined direction and then by reversing the movement in the predetermined direction in the event that the position detector fails to reach the predetermined position.

31. The gas control apparatus as claimed in claim 29, wherein the drive control unit is configured to control the supply of electric power under a duty control by fixing a frequency of applied pulses and is configured to increase the supply of electric power by increasing a duty ratio whereby a torque of the stepping motor is increased.

32. The gas control apparatus as claimed in claim 29, wherein the drive control unit is configured to control the supply of electric power so a frequency of the applied pulses can be varied and whereby the supply of electric power can be increased by lowering the frequency in order to increase the torque of the stepping motor.