Patent Application
20080076079
The present invention relates to a gas valve and to a method for electrically actuating a gas valve, and in particular to a gas valve and to a method for actuating a gas valve in which at least one valve position is detected by means of the actuation.
The prior art discloses a large number of gas valves, for example in DE 198 25 846 A1, in particular also such valves with devices for securing the gas burning position.
For a large number of applications it is desirable to make available an electrically operated gas valve which can also be operated with a remote control. DE 3787200 T2 discloses, for example, a control unit for a gas flow with a motor drive unit which drives a valve closing part in rotation and which also comprises a position-determining unit with a position-signal-generating device which is mounted on a stem of the closing part, and also a position-assessment circuit which receives a signal from the position-signal-generating device and has the purpose of assessing a rotational position of the closing part.
The known control unit also comprises a drive unit which receives a target position signal and a rotational position signal from the position-determining unit and has the purpose of applying a drive signal to the motor drive unit. However, the known control unit with the motor drive unit which drives in a rotating fashion and the position-determining unit and also the position-signal-generating device and the position-assessment circuit is complex and correspondingly expensive to manufacture.
The object of the present invention is therefore to make available a reliable, safe, cost-effective and electrically operated gas valve which can also be operated with remote control. At the same time, an object of the present invention is also to specify a simple and reliable method for electrically actuating a gas valve.
The object is achieved with the features of the claims. Advantageous embodiments of the invention are mentioned in the features of the subclaims and/or the following description.
In the drawings:
a shows a schematic section through a gas valve according to a first embodiment of the present invention, and
a shows a schematic section through a gas valve according to a second embodiment of the present invention, and
The present invention relates in particular to a method for controlling a gas valve having a valve inlet and a first valve outlet and a first valve which closes/opens the first valve outlet and having a linear drive which is actuated by an electronic controller, wherein the linear drive activates the first valve by means of a drive axle, and wherein the first valve and the linear drive are embodied and arranged in such a way that the electronic controller detects the open/closed position of the valve by measuring current/voltage during activation of the linear drive. The linear drive and the drive axle can be made available here in a suitable way by a linear motor with a motor axle, and the electronic controller can be suitably and advantageously made available by means of a microcontroller.
With the advantageous provision of the linear drive for actuating an actuator element in conjunction with the electronic controller and the inventive detection of the position of the actuator element by measuring the current/voltage of the linear drive, a reliable method for controlling a gas valve is easily made available, and at the same time the gas valve can be manufactured cost-effectively.
According to a further embodiment of the present invention, the method according to the invention also comprises a gas valve having a second valve which closes/opens the valve inlet, wherein, by means of its drive axle, the linear drive also opens the second valve when the first valve is closed, and the electronic controller also detects the open/closed position of the second valve by measuring current/voltage. The second valve can at the same time advantageously be a protective valve which protects a gas burning location arranged downstream of the valve against gas which flows out without being burnt.
A further advantageous embodiment of the present invention relates in addition to a gas valve having the valve inlet and the first valve outlet for supplying gas to a main flame and a second valve outlet for supplying gas to a secondary flame, wherein the second valve can advantageously be embodied as a solenoid valve, and wherein the linear drive controls, by means of its drive axle, the first valve when the second valve is opened, and when the second valve is closed said linear drive opens the second valve, in which case the first valve is closed, and wherein the electronic controller detects at least one position of the drive axle of the linear drive by measuring current/voltage, and thus detects the position of the first valve and second valve.
In this context, the first valve and second valve and the linear drive are advantageously embodied and arranged in such a way that by measuring current/voltage the electronic controller detects in particular the following positions of its drive axle: abutment of the drive axle against the second valve when the second valve is closed, and/or activation of the second valve and/or abutment of the drive axle against a stop of the completely opened second valve; and/or abutment of the drive axle against the closed first valve and/or activation of the first valve and/or abutment against a stop of the completely opened first valve.
In the method according to the invention, the first valve and second valve are advantageously embodied and arranged in such a way that they open/close in opposite directions to one another, wherein the drive axle activates the actuator element of the first valve and second valve counter to the pressure force of a spring which is arranged on each of the valves.
The present invention also relates in particular to a gas valve for the method according to the invention, wherein a valve closure of the first valve is embodied as a cone with a central, continuous bore, and is arranged together with a spring in a series arrangement with the spring on the drive axle, and is held via a locking means at the end of the drive axle, wherein the spring, the drive axle and the cone are embodied in such a way that the spring force of the spring closes the first valve outlet when the drive axle is arranged correspondingly, and the drive axle opens/closes the first valve by means of the locking means as a stop against the cone counter to the pressure force of the spring when corresponding actuation occurs.
The present invention is described in detail below with reference to the schematic drawings.
a shows a schematic section through a gas valve 1 according to the invention in accordance with a first embodiment of the present invention having a valve housing 10 with a valve inlet 11 and a valve outlet 12 and a valve 14 which closes/opens the valve outlet 12, and having a linear drive 2 which is actuated by an electronic controller S, wherein by means of its drive axle 21 the linear drive 2 activates the first valve 14. In this context, the first valve 14 and the linear drive 2 are embodied and arranged in such a way that the electronic controller S detects the open/closed position of the valve 14 by measuring current/voltage. At the same time, the linear drive 2 can in particular advantageously be made available by means of a linear motor, and the drive axle 21 can advantageously be made available by means of its motor axle, and the electronic controller S can be made available in particular by means of a microcontroller.
The valve 14 comprises as actuator element a cone 22 which is arranged together with a spring 23 and a sealing element 25 in series in this sequence on the drive axle 21, and is secured on the drive axle 21 by a suitable locking means 24.
b and 1c each show schematic illustrations of the linear drive 2 from
In this context, according to the invention in each case the abutment of the locking means 24 against the cone 22 and/or the closed position of the cone 22 and/or an abutment of the cone 22 in the open position of the valve 14 can be detected solely by measuring current/voltage of the linear drive 2 by means of the electronic controller S so that at least one defined position of the actuator element of the valve 14 can be detected by activating the linear drive 2.
a shows a schematic section through a gas valve 1 according to a second embodiment of the present invention with a valve inlet 11 and a first valve outlet 12 and a first valve 14 which closes/opens the first valve outlet 12, and with a linear drive 2 which is actuated by an electronic controller S, wherein by means of its drive axle 21 the linear drive 2 activates the first valve 14.
It is clear that here, as in the first embodiment described above and also the third embodiment of the present invention described below with reference to
The second embodiment of the present invention also comprises a second valve 15 which closes/opens the valve inlet 11, wherein, according to the invention, the linear drive 2 is arranged and embodied in such a way that when the first valve 14 is closed it also opens, by means of its drive axle 21, the second valve 15, wherein the electronic controller S detects the open/closed position of the first valve 14 and of the second valve 15 by measuring current/voltage. In this context, the second valve 15 is embodied in such a way that its actuator element 3 is also pressed into the closed position of the valve 15 by means of a spring.
The drive axle 21, the sealing element 25, the spring 23, the cone 22 and the locking means 24 in the second embodiment of the present invention are embodied and arranged as in the first embodiment of the present invention described above.
b to 2e show the linear drive 2 with the drive axle 21, the sealing element 25, the spring 23, the cone 22 and the locking means 24, in each case in the open/closed position of the first valve 14 and of the second valve 15.
The activation of the first valve 14 which is illustrated schematically in
d and 2e are schematic illustrations of the activation of the actuator element 3 of the second valve 15 by means of the drive axle 21, wherein the drive axle 21 is moved, with the locking means 24, into the closed position of the first valve 14 in the direction of the second valve 15, wherein the abutment of the drive axle 21 against the actuator element 3 of the closed and/or opened second valve 15 can also be detected according to the invention by measuring the current/voltage of the drive current. In this context it is particularly advantageous that in addition an increasing counter pressure of the spring 23 or of the second spring (not illustrated in the drawings) of the second valve 15 is also detected by the electronic controller S by measuring the current/voltage when the first and/or second valve 14 and 15 open.
It is clear that given a correspondingly inverted arrangement of the actuator element on the drive axle 21, a decreasing spring pressure of the spring is correspondingly detected by the electronic controller S of the linear drive 2.
In the second embodiment of the present invention, the second valve 15 is suitably embodied and arranged as a protection valve and suitably as a solenoid valve and is suitably actuated by means of a flame monitoring device and, for example, ionization or temperature measurement.
When the first valve 14 closes, the travel A indicates the decreasing pressure of the spring 23 to the line P which represents the abutment of the cone 22 against the closed position of the first valve 14, after which the travel B indicates the constant friction of the drive axle 21 which moves beyond the cone 22 in the direction of the closed second valve 15, and abuts against the actuator element 3 of the second valve 15 at the point P1. The travel C finally indicates the opening of the second valve 15 counter to the counter pressure from the spring of the second valve 15.
The second valve 15, which is suitably embodied as a protection valve as in the second embodiment of the present invention described above, suitably comprises a magnet which, in the open position, holds the second valve 15 open given a sufficient, for example, thermal current of a thermal element, but does not have enough power to open a closed second valve 15 counter to the pressure of its spring.
Alternatively, the second valve 15 can also be embodied as a self-priming solenoid valve, in which the spring constant of the second spring and the force effect of the magnet of the second valve 15 are predetermined in such a way that the magnet can hold the second valve 15 in the opened state and can also open it automatically, and the pressure force of the second spring closes the valve inlet 11 when the magnet is switched off and the drive axle 21 is arranged correspondingly.
The travel D from the abutment of the drive axle 21 against the completely opened second valve 15 as far as the abutment of the locking means 24 against the actuator element, specifically the cone 22, of the closed first valve 14 then proceeds again with constant friction and a correspondingly constant drive current.
It is clear that given a first and/or second valve which are correspondingly arranged in inverted fashion and/or an additional locking means for the spring on the axle in the vicinity of the drive abutment, the spring forces which respectively increase and decrease during the opening/closing of the valves are respectively reversed and their corresponding current/voltage values can also advantageously be used in the same way to determine the valve positions.
The advantageous provision of the linear drive 2 in combination with the electronic controller S easily permits automatic detection of at least one defined position of the drive axle 21 and of the position of the first and/or second valves 14 and 15.
It is also clear that the second valve outlet 13 of the embodiment according to the invention in
The method according to the invention and the valve 1 according to the invention are particularly suitable for safely controlling the gas supply to a gas burning point and in particular to a cooker or gas stove.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2006 036 294.2 | Aug 2006 | DE | national |
