ES2322330T3 - BURNER CONTROL WITH PULSE SEQUENCE WITH VALVE. - Google Patents

Abstract

A cooking appliance with a cooktop including at least one gas burner includes a control for sequentially delivering gas and igniting the gas to burner ports. The control comprises a valve with a responsive element for controlling gas flow to the burner ports, an ignition module for generating a drive signal to an ignitor, an electronic controller interfacing with the ignition module and coupled to a driver for actuating a responsive element in the valve. The driver that causes displacement of the responsive element includes a pick up actuator enabling the responsive element to initiate a status that opens the passageway. The valve also includes a holding actuator that enables the responsive element to maintain the status of the passageway as open when flame is detected at the burner. <IMAGE>

Description

Burner control with pulse sequence with valve

The present invention relates to apparatus for cook that have a plate with gas burners to which it flows Gas and gas flow ignition is adjustable and assisted by a controller that has a microprocessor to control the actuators to activate the elements that control the flow as well  as the timing of the flow.

Prior art

In most gas burner systems of conventional surface, used in the opposite part to the plate or in the plate part of the intervals, the flame can be adjusted manually from a high output ratio to a proportion of minimum output The minimum output protection is the flow rate at which a small flame can be kept in the burner holes without interfering extinction. For most burner systems existing, the minimum output ratio is in the range of 234 to 440 watts (800 to 1,500 BTU / h).

An earlier known attempt to obtain a output ratio less than that of most systems existing burners was to segregate gas flows using double burner heads. A small head is put on to simmering in the center of a burner ring more big. This burner system is used together with a valve manual that has two internal valves. In cooking mode a Slow fire, the outer ring is not used. The central burner provides the low output required for simmering. A major drawback of this system is the complexity of the system. of gas pipes. There are two supply pipes from the valve manual to the burner head. The burner head, as has been analyzed above, it really has two heads and the valve Manual is really two valves in one. Another disadvantage is that the central simmer cooking head has a deficiency of performance in which the heat of a maintained flame is concentrated in A very small area. As a result, hot spots are created that may be hot enough to scorch a Food item that is simmering.

Another improvement that provides a lower output energy, for example a Thermador XLO burner system, provides sustainable flame control by cycling with the ignition and flame off to get an output ratio of heat less than what was normally achieved using only a limited range with conventional burner systems controlled. This avoids complicated pipes and can be incorporated with a plate construction with a head conventional size burner. The heat dissipates more evenly and the intensity of hot spots is eliminates

The previous system uses a manual valve which rotates 280º in the counterclockwise direction. The valve is HIGH at the 90º mark that provides a flow maximum through the valve. Additional rotation reduces the gas flow to the burner as the valve is turned towards a minimum opening that allows a low flow rate at which the flame can Stay in the burner. The unmodulated gas flow outlet is it keeps constant as the valve is rotated from 210º to 280º. Between 210º and 280º, the microcontroller generates a valve control signal opening and closing sequentially a solenoid operated valve. For example, in a system that uses a period of 60 seconds as the base time, at 210 ° C, the flame is turn on for a predetermined time, for example 54, every 60 seconds. At 280º, the flame ignites 7 seconds out of every 60 seconds. The times it turns on vary linearly between the 210º mark and 280º mark. The signal is supplied to a solenoid operated valve connected between the gas valve manual and burner head. The controller determines when Open the solenoid. The position of the manual valve is indicated by controller using a potentiometer located on the manual valve and that works by a variation in the response as the user rotates the manual valve stem. Valve solenoid is powered by the electric controller which in turn It is activated by the network supply. Therefore, the previous system is not operational during a power outage because the solenoid valve is closed when it is not activated

In addition, multi-valve bodies require additional path and gas couplings that They must be sealed and maintained for the lifetime. In addition, the automatic operation of the previous supply valve it would require a driving force so high that the coils or similar would be too large to pack conveniently or from Build a product for consumption at a reasonable cost.

Another type of valve control known, for example the plate controls of certain European manufacturers, use an integrated isolation solenoid valve. The solenoid valve is composed of a magnetic coil and a piston with a rubber seal on one end that moves to allow or prevent gas flow. The solenoid is used together with a thermocouple mounted near the burner head that generates the energy to activate the solenoid.

During operation, the stem of the valve or button is pressed down and turned in the direction counter clockwise. The push action pushes the solenoid plunger to open and against the force of a spring deviation that pushes the plunger to close. Piston opening It allows gas to flow to the burner head. The gas is then burn by an independent ignition system. The resulting flame heats the thermocouple that generates an output to Activate the coil and keep the plunger open. At this point, the user can stop the push on the valve button and the Flame must be maintained. In the event that the flame in the head of the burner extinguishes, the thermocouple cools and the generated output falls until it releases the plunger to close, stopping the flow of gas. This is a closing element that prevents the escape of gas that It has not burned. However, such control is not a control for reduce energy output during cooking and does not address Hot spot problems or low energy flame control. In addition, said valves are physically designed to handle substantially less operating cycles (opening and closing) than that would be required in a sequential operation over a life of reasonable appliance service, for example ten thousand cycles during many years, where the valve closing and opening cycle is Repeat every minute during operation.

EP 0 837 283 B1 describes a system Automatic control with double safety protection to make operate gas burners intermittently comprising a first safety solenoid valve with at least one first and second excitation windings; a second solenoid valve of cascade regulation with the first valve that has a third winding a medium connected to a gas pipe between the first and second valves to supply a light pilot, a medium to light the pilot light and a thermocouple, heated with the pilot light and connected to the first winding to keep open The first solenoid valve. The automatic control system It is characterized by additionally comprising a detector means to recognize if the voltage generated by the thermocouple is by above or below a predetermined threshold value, and a medium of control that has a state of ignition of the pilot light, a burner operating status and alarm status, in the status of ignition, the control means provides a first signal of control to open the first solenoid valve and activate the ignition medium with the exclusion of a second control signal to open the second solenoid valve and in which the state operating burner, the control means provides the second signal excluding the first signal, in the alarm state, disconnecting the first and second signals both with the change of control means from the ignition state to the state of burner operation when the voltage generated by the thermocouple and detected by the detector means exceeds the threshold value default, and the control medium changes to alarm status after the appearance of one of the following events: (a) the tension generated by the thermocouple and detected by the falling detector means below a predetermined threshold value with the control medium in the operating state of the burner, (b) the voltage generated by the thermocouple and detected by the detector means not exceeds the predetermined threshold value within a range of default time with the control medium in the state of ignition.

The document DE-A-197 52 472 shows a control device for a gas burner with a valve control and a safety valve. An electronic unit drives the control valve according to a position detector associated with an operating element and according to the signal of a flame detector The right pressure allows the ignition of the gas.

Description of the present invention

The present invention overcomes the disadvantages mentioned above providing an electronic controller and a valve with an actuator to control both the timing as the flow of gas supplied through the burner valve. The control actuator on the board includes a actuator for a valve that opens and closes the gas flow to the burner and an actuator that provides a control interval for the flow of gas to the burner, preferably within a single valve housing container.

The known isolation solenoid valve previously it can be modified for example to respond to a external electronic controller to pull the plunger and control the closing and opening of the gas flow. To reduce the size and energy required to operate the valve structures known above, material characteristics may be added such as wear resistance, physical coatings and surface hardness characteristics to reduce resistance that create electrical losses and thus minimize the coil size and packaging requirements. In addition, a thermocouple provides high electrical energy to the coil to use in keeping the plunger open once the plunger opens and a flame is established. In addition, the valve is coupled with so that the electronic controller can interrupt the output of the thermocouple to release the plunger and stop the flow of gas.

The present invention provides the advantages of the existing isolation solenoid valve and also the advantage of using the valve as the cycle valve for operational characteristic of the pulse sequence burner. The preferred embodiment of the present invention eliminates the need of a different external solenoid valve and at the same time, improves the previously known sequencing feature adding an extra level of flame control, as well as a control Feedback from the burner. Unlike the system of single isolation solenoid valve analyzed in section Previous, the user does not need to keep the button down while that the thermocouple is heated when a flame is established by first time, since the electronic controller directs the actuator to open the valve and keep the plunger open to allow the gas flow during the initial heating of the thermocouple.

Additionally, the present invention allows use of the burner in the case of an electrical cut, while the Existing XLO system does not. In the preferred embodiment, if the Burner flame has already been generated when an interruption occurs of power, the burner will remain on. On the other hand, if the flame goes out, for example because it is in the off part of a sequencing cycle, then the burner will remain without turn on. If the burner has no flame when the current, the button can be pressed down while the flame It is manually lit with a match. After ignition, the button can be pressed down for a while, for example a couple of seconds, until the thermocouple generates enough energy to keep the safety valve open. At this point, the user can release the button and the burner should work normally, except without the sequencing element being pressed. Regardless of the presence of the main network, the system prevents gas releases after a flame shutdown involuntary.

In a preferred embodiment, a valve solenoid of the previously known type is modified by the addition of a pickup coil. The pickup coil is will activate by electronic control. Once the plunger is open, the actuator signal of the microcontroller for the coil of uptake can be reduced to a maintenance value. Also so soon as the thermocouple output reaches a sufficiently high level high to activate the existing maintenance coil, the energy for the pickup coil it disconnects. To release the plunger, the controller can shorten the thermocouple output, deactivating this way the maintenance coil and releasing the plunger to close the valve Alternatively, the controller can provide a trigger signal to the pickup coil with a power whose magnitude is at least equivalent to that produced by the thermocouple but of opposite polarity. The opposite energy will generate a magnetic field that will cancel out the magnetic field produced by the thermocouple, thus releasing the plunger. In any case, the controller allows pulse sequencing of the gas flow when electric power is available and incorporates a flame shutdown capability without requiring electrical power to operate the gas burner.

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Brief description of the drawing

The present invention will be understood more clearly with reference to the following detailed description of the  preferred embodiment when read together with the accompanying drawing in which similar reference characters refer to parts similar in all views and in which:

Figure 1 is a schematic diagram of the plate control system in accordance with the present invention.

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Detailed description of the embodiment

Referring first to the Figure 1, a plate comprising a burner system of plate 10 in which the panel of plate 12 includes at least one gas burner 14. Burner 14 is connected in communication fluid with a gas manifold 16 and a control 18 to supply gas to the collector as described in detail below. He control 18 includes valve actuator 22 and a module electronic control such as the controller based on the microprocessor 24. In addition control 18 includes a module of ignition control 26 to operate the lighter 28 which is placed adjacent the burner 14 in the role of the plate 12.

The electronic controller 24 is adapted to control the sensitive elements in a valve 30 that includes also manual inputs as they are well known in the burner sequential prior to U.S. Patent No. 5,765,542. Preferably, the electronic controller 24 and the module ignition 26 are housed in a single control package 32 by convenience of disposition and interconnect with the other parties of control 18. In addition, valve 30 can be of various types of construction, although as schematically represented in the Figure 1 includes at least one element sensitive to an actuator 34. The valve is preferably maintained in a single housing body 31, for example, as achieved in a Sourdillon Model valve 099, which includes an isolation valve and an adjuster flow. The sensitive element 36 in the preferred embodiment is a pickup coil 58, although others could also be used electronically operated devices. The sensitive element 36 controls at least one valve actuator, for example, the shaft of piston 38, to control the connection between the supply of gas 20 and gas manifold 16.

In the preferred embodiment shown in the Figure 1, the sensitive member 36 includes the plunger shaft 38 which actuates a valve stem that carries a valve head 40 to move it to contact and move away from the seat of the valve 42. The closure of the valve head 40 against the seat of valve 42 obstructs the flow of gas entering between the supply 20 and gas manifold 16. In addition, the construction of valve shown in Figure 1 includes a flow adapter that varies the amount of gas that can be passed from the supply 20 to the gas manifold 16 and to the burner 14. By example, actuator 22 may include a valve stem tapered with a flow control channel that controls the amount of blockage of the flow passage through valve 30 from its inlet 72 at its outlet 74. Both valve head 40 and the valve stem control chamber are inside the flow passage through the valve body from its inlet 72 at its exit 74. The piston shaft 38, the maintenance coil 52 and pickup coil 58 are located in a sealed chamber by the cover 70. Preferably, these parts are located in a 76 cartridge for easy installation inside the chamber. By For example, cartridge 76 can be constructed to replace valve components provided with the Sourdillon valve Model 099, without changing the valve body on the other hand, although replacing the original coil actuator with both coil actuators of the preferred embodiment.

The position of the valve stem 44 is transmits by means of a position encoder 46, preferably a potentiometer when a simple electrical circuit is desired that incorporates previous controls, coupled to an electronic controller 24, although other counters or devices may be used. In the preferred embodiment, the rod is operated by a button 48. Regardless, other types of controls such as touch sensitive switches or the like can be used as a actuator 22 without departing from the present invention. In any In this case, the return of the actuator 22 to the controller 24 alerts the gas flow controller 24 to be supplied to the burner as will analyze in detail below.

Plate 12 also includes a thermocouple 50 adjacent to the peripheral holes of the burner 14. The thermocouple 50 generates a current in response to the presence of a flame in the thermocouple that is supplied to a maintenance coil 52 that acts on the valve shaft 38. As long as the flame is hold to generate heat in burner 14, thermocouple 50 generates enough current to maintain the solenoid core of the piston shaft 38 in a retracted position from the seat of the valve 42. Of course, the valve head 40, can move elastically, for example by means of spring 54, towards seat 42 to close the gas flow in the event that electric power is not available for lighter 28 or controller 18 for the gas valve. The maintenance coil 52 is large enough to activate so that it exceeds deflection force, for example, the force of spring 54 for move tree 38 to its stowed position.

The position encoder 46 may be a analog device such as a potentiometer or device digital such as a binary encoder counter, without moving away from the present invention The position of the valve stem 44 determine the amount of gas within the range default flow rates for gas supplied to manifold 16 to control the amount of heat released to the burner 14 in the preferred embodiment In the preferred embodiment, button 48 is turn to open the valve to a very open position to facilitate ignition by burner 28. For example, the position encoder 46 may indicate that the drive of the button 48 is to start a flame generation shaped almond in the holes using burner 28, for example, a spark burner, as the rod 44 movement opens the passage between the valve seat 42 and the gas manifold 16. At the same time, the actuator 34 generates a drive signal to pickup coil 58 and releases the valve head 40 from the valve seat 42. Accordingly, the inlet of gas from supply 20 can be supplied through the valve and manifold to burner holes in burner 14.

Preferably, the controller 24 directs the lighter 28 to repeatedly generate a charge until a flame detector, for example, thermocouple 50 as shown in 60, or a specific ignition detector incorporated in the lighter designated with the number 62, determines that it has been generated a flame in the adjacent holes of the burner 14. In addition, a Once the thermocouple 50 has been heated to continuously generate a signal to the maintenance coil 52, the actuator 34 of the controller 24 is disconnected while the valve head 40 remains folded from the valve seat 42 by means of the force on the maintenance coil 52. Alternatively, the lighter 28 can be an electronic spark module for ignition, for example, a hot surface lighter that may or may not create a cycle with the flame when using the element of pulse sequence.

As indicated in Figures 1 to 60, the flame detector element of the lighter 28 can be directed to the electronic controller 24 so that if the burner fails to generate a flame after a number has been supplied default loads to lighter 28, controller 24 can generate a response, for example, to activate the coil of pickup 58 or activate maintenance coil 52. For example, if the output of thermocouple 50 achieves a sufficiently high level to activate the existing maintenance coil 52, the energy for pickup coil 58 it can be disconnected. To release the piston, controller 24 shortens the output of thermocouple 50, deactivating the maintenance coil 52 and allowing the valve head 40 is closed against the valve seat 42 when electronic controller 24 determines that it is required a sequence operation by pulses.

Alternatively, controller 24 can provide a trigger signal for pickup coil 58 with an energy whose magnitude is equivalent to that produced by the maintenance coil 52 but of opposite polarity so that an opposite magnetic field force will cancel out the magnetic field produced in the coil by the thermocouple current 50. In In any case, controller 24 allows sequencing by gas flow pulses in a well known way when it is Electric power available. In addition, the system provides a flame-extinguishing capacity in the event that gas ignition in burner 14 it cannot be maintained with a continuous flame. In addition, the burner 14 can be operated even without power electric if thermocouple 50 detects the existence of a flame, of so that the maintenance coil 52 maintains the head of the valve 50 in a retracted position relative to the seat of the valve 42.

In addition, the control of the flow sequence as well as the flow can be further automated. For example, a valve as used in the preferred embodiment can be modified incorporating an actuator 66 to supply an energy signal to a displacer 68 in the rod 44 in a manner that varies the flow rate, for example, by turning the valve body 45 for a variable pitch capability when a user interface is desired modern such as a panel with touch sensitive switches. How alternatively and preferably, an automated flow control could be more conveniently produced as a response to a electronic controller using a proportional gas valve that the gas flow varies in proportion to an electric current or voltage applied to an actuator by the controller.

Having described the present invention, many modifications will be apparent to specialists in the technique to which it belongs without departing from the scope of this invention as defined in the appended claims.

Claims (8)

1. A plate control (18) for an apparatus for cook (10) that includes a plate that has at least one burner (14) having a plurality of holes, at least one lighter (28) adjacent to at least one hole in the burner (14); and a control (32) to supply gas to the burner holes and burn the gas in the burner holes, said said control: a valve (30) and a sensitive element (36) in said valve (30) to control the flow of gas through a passage coupled in fluid communication with said plurality of holes; an ignition module (26) to generate a trigger signal for the at least one lighter (28); an electronic controller (24) that makes interface with said ignition module (26) and is coupled to a actuator (34) for actuating said sensitive element; wherein said actuator (34) allows said sensitive element (36) is by default in a state that closes said passage, whereby said actuator (34) comprises a pickup actuator (58) that allows said element sensitive (36) initiate an open position state that opens said passage (16), and a maintenance actuator (52) that allows said sensitive element (36) maintain a positional state open a detector (50) to detect the presence of called in said burner hole and coupled to said actuator of maintenance (52) and said electronic controller (24); Y wherein said actuator (34) is sensitive to each of said controller (24) and said detector (50) for moving said sensitive element (36) from said defective state to said open position state, in which the control (32) supplies sequentially gas to the burner holes. 2. Control of the plate for an apparatus for cooking (10) according to claim 1 wherein said open position state comprises a period of pulses timed in a sequence of timed pulses. 3. The plate control (18) for an apparatus for cooking (10) according to claim 1 wherein said sensitive element (36) controls a displacement of a head of the valve (40) with respect to a valve seat (42) in fluid communication with said passage (16). 4. The plate control (18) for an apparatus for cooking (10) according to claim 3 wherein said sensitive member (36) comprises a plunger shaft (38) that acts like a valve stem that carries the valve head (40) to move it to contact and move away from the seat of the valve (42). 5. The plate control (18) for an apparatus for cooking (10) according to claim 3 wherein a tree of the piston (38), a maintenance coil (52) and a coil of uptake (58) are placed in a chamber sealed by a layer (70). 6. The plate control (18) for an apparatus for cooking (10) according to claim 3 wherein the tree of the piston (38), a maintenance coil (52) and a coil of pickup (58) are carried in a cartridge (76). 7. The plate control (18) for an apparatus for cooking (10) according to claim 3 wherein the detector (50) to detect the presence of the flame is also for generate an indication; and in which a signal of feedback to drive said actuator in response to said indication, and in which the electronic controller (24) additionally comprises a pulse sequence control for said actuator (34). 8. The plate control (18) for an apparatus for cooking (10) according to claim 7 wherein said pulse sequence control selectively applies said signal from feedback to said actuator.