ES2552698T3 - Safety device of a gas appliance comprising a safety solenoid valve - Google Patents

Abstract

Safety device (10) of a gas apparatus comprising a safety solenoid valve (1) and a first switching means (I1) suitable for ordering the opening of the safety solenoid valve (1) when it is in a closed state and the closing of the safety solenoid valve (1) when it is in an open state, depending on the positioning of said switching means (I1) in said open and closed states of a first command signal (A), the safety device comprising (10) in addition at least second (I2) and third (I3) switching means suitable for ordering the opening of the safety solenoid valve (1) when they are in a closed state and the closing of the safety solenoid valve (1) when they are in an open state, said at least second (I2) and third (I3) switching means being mounted in series with the first switching means (I1), and their positioning being dependent on less second (I2) and third (I3) switching means in said open and closed states, respectively, of at least a second (B) and a third (C) command signal, the safety device being characterized in that it further comprises means (5) suitable for generating said third command signal (C) as a function of a dynamic type signal (Cd), for detecting an anomaly in at least one parameter of said dynamic type signal (Cd), and for setting at a first predefined value said third command signal (C) generated, when an anomaly is detected in said at least one parameter.

Description

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Safety device of a gas apparatus comprising a safety solenoid valve.

The present invention relates to a safety device of a gas apparatus.

In particular, it has as its object a safety device of a gas apparatus comprising a safety solenoid valve.

It also refers to a gas cooking apparatus comprising a safety device of this type.

In general, gas appliances, for example gas cooking appliances, comprise a safety solenoid valve suitable for passing (open solenoid valve) or for interrupting the passage (closed solenoid valve) of a gas flow.

Thus, in general, when the gas apparatus is not in operation, the safety solenoid valve is closed, thus interrupting the passage of the gas flow, and when the gas apparatus is put into operation, the safety solenoid valve opens after verify the absence of a malfunction in the gas appliance that could impair the safety of the appliance.

In addition, when the gas appliance is in operation and a situation is detected that could jeopardize the safety of the appliance or users, the safety solenoid valve closes to ensure the safety of the gas appliance and the users.

For example, the safety solenoid valve could be arranged between a gas supply device and a gas burner of the apparatus. Thus, for example, in the event of a malfunction of the gas burner, the safety solenoid valve must be closed to interrupt the passage of the gas.

EP 0 441 364 describes a solenoid valve intended to close the gas inlet in the burners. The solenoid valve is controlled by an order from a microprocessor.

Figure 1 schematically represents a safety solenoid valve 1 of the state of the art that is controlled by a switch I1. This switch I1 is controlled by a control signal A.

Control means 3 generate the control signal A which controls the switch I1 which will in turn control the safety solenoid valve 1.

When the solenoid valve 1 must not pass gas (for example, when a malfunction is detected or when the gas apparatus is not in use), the control means 3 generates a control signal such that the switch I1 is positioned in a open state so that it does not feed the solenoid valve 1. Thus, the solenoid valve 1 closes and does not let the gas pass.

When the safety solenoid valve 1 must let the gas pass (for example, when the user makes use of the gas apparatus and a malfunction is not detected), the control means 3 generates a control signal such that the switch I1 is positioned in a closed state so that it feeds the safety solenoid valve 1. Thus, the safety solenoid valve 1 opens and lets the gas pass.

If there is a failure in the control of the safety solenoid valve 1 of such a device, whether at the level of the switching means, of the control means or another, the opening of the safety solenoid valve 1 could ordered by mistake when a malfunction is present, or the closure of safety solenoid valve 1 may not be ordered when a malfunction is present. These two situations impair the safety of the gas appliance and may endanger the safety of the users.

The present invention aims to solve the aforementioned drawbacks and propose a safety device of a gas appliance that presents a reduced risk of failure.

For this purpose, the present invention has as its object a safety device of a gas apparatus comprising a safety solenoid valve and a first switching means suitable for ordering the opening of the solenoid valve when it is in a closed state and the closing of the safety solenoid valve when it is in an open state, the positioning of said switching means in said open and closed states depending on a first command signal, the safety device also comprising at least second and third switching means suitable for ordering the opening of the safety solenoid valve when they are in a closed state and closing of the safety solenoid valve when they are in an open state, said second and third switching means being mounted in series with the first switching means, and the positioning of said at least second switching means being dependent and you rcero in those states open and

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closed, respectively, of at least a second and a third command signal.

According to the invention, the security device comprises suitable processing means for generating said third control signal in function of a dynamic type signal, to detect an anomaly in at least one parameter of said dynamic type signal, and to fix a a first predefined value said third generated control signal, when an anomaly is detected in said at least one parameter.

The serial arrangement of said at least three switching means implies that said at least three control signals must control, respectively, the switching means at the same time, so that they are positioned in a closed state so that the safety solenoid valve is open

Indeed, if one of the three switching means does not order the opening of the safety solenoid valve, the safety solenoid valve remains closed.

In addition, when the safety solenoid valve is open, the positioning of at least one single switching means in the open state is sufficient to close the safety solenoid valve.

Thanks to this serial arrangement of the switching means and the implementation of the different control signals for the positioning of the switching means, said at least second and third switching means constitute a redundancy of the first switching means in the control of the opening and closing of the safety solenoid valve.

Therefore, it is possible to control the opening and closing of the safety solenoid valve, even though there is a malfunction in the control of two switching means.

Thus, this safety device complies with IEC 60335-1 which is the standard established by the European Committee for Standardization for appliances. This standard requires the existence of safety measures at least in duplicate, that is, at least two malfunctions may be present without damaging the safety of the appliance and the user.

In addition, it will be observed that the probability of existence at the same time of a malfunction in the control of three switching means is very low.

Obviously, the greater the number of serial switching means, the lower the probability of an incorrect opening control of the safety solenoid valve. On the other hand, the greater the number of serial switching means, the greater the probability of failure of the switching means. Thus, the number of three switching means is a good balance for obtaining a good security of the device and the user.

In addition, the first predefined value to which the third command signal is set is representative of the existence of an anomaly of the dynamic signal.

Advantageously, said processing means are suitable for comparing the value of said at least one parameter with a predetermined value and for setting said first predefined value to a suitable value for establishing the third switching means in the open state when the value of said at least a parameter and said default value are different.

Therefore, thanks to the detection of an anomaly in said at least one parameter, the value of the control signal is set in such a way that it orders the closing of the safety solenoid valve (if it was open) or avoids ordering by mistake the opening of The safety solenoid valve.

For example, said at least one parameter is the frequency of said dynamic type signal.

Thus, when said at least one parameter of the dynamic type signal is different from the predetermined value, there is an anomaly in the dynamic signal. Therefore, in order to avoid damaging the safety of the gas apparatus, the corresponding switching means is set to an open state, and the solenoid valve closes.

According to a preferred feature, said first, second and third command signals are of static type and said third command signal is generated by said processing means as a function of the dynamic type signal.

Accordingly, the assembly formed by the second command signal and the second switching means represents a redundancy of the assembly formed by the first command signal and the first switching means.

In addition, the set formed by the third command signal and the third switching means represents, not

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only a redundancy of the previous sets, but also a means to verify an anomaly in the dynamic type signal.

Advantageously, first control means are suitable for generating said first command signal, and second control means are suitable for generating said dynamic type signal and said second command signal.

Thanks to this configuration, it is possible to avoid incorrect control of the safety solenoid valve in the event of a malfunction of the two control means. Indeed, the malfunction of the second control means is discovered by detecting an anomaly in at least one parameter of the dynamic type signal.

If one of the control means fails and a command signal is defective (command signal other than those generated by the control means that fail), it is also possible to avoid incorrect control of the safety solenoid valve.

Consequently, the opening of the safety solenoid valve by mistake or the omission of the closing of the safety solenoid valve is avoided.

According to a preferred feature, the safety device further comprises first and second control means suitable for generating the control signals.

There is thus a redundancy in the control means generated by the control signals that control the opening or closing of the safety solenoid valve. Therefore, if there is a malfunction in one of the control means, there are at least a few second suitable control means to control the opening or closing of the safety solenoid valve.

According to a second aspect, the present invention relates to a gas apparatus comprising a safety device according to the invention.

This gas apparatus has advantages similar to those described above with reference to the safety device according to the invention.

The present invention finds particular application when the gas appliance is a gas boiler or a gas cooking appliance, such as a cooker, a gas hob or a gas oven.

Other particularities and advantages are further derived from the following description.

In the attached drawings, provided by way of non-limiting examples:

- Figure 1 represents a functional control scheme of a prior art solenoid valve;

- Figure 2 schematically represents a gas apparatus comprising a safety device according to the invention from above; Y

- Figure 3 represents a functional scheme of a safety device according to an embodiment of the invention.

First, a type of gas apparatus suitable for practicing the present invention will be described with reference to Figure 2.

A gas cooking plate is illustrated in Figure 2, in an exploded schematic view that allows understanding the context of the present invention.

Obviously, all these elements are integrated in a compact manner in the gas hob.

The cooking plate 11 comprises at least one gas burner 12, associated with an ignition means 13 located near the gas burner 12. This ignition means 13 is suitable for lighting the gas burner 12 when it is fed with gas.

The cooking plate 11 is fed with gas through a supply line 14 that is connected to a gas source 15.

The safety device 10 according to the invention is arranged in the supply line 14. In particular, the safety solenoid valve 1 is mounted in the supply line 14 in order to leave

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pass or interrupt the flow of gas.

The opening and closing of the safety solenoid valve 1 is controlled by means described below.

Referring to FIG. 3, a safety device 10 of a gas apparatus comprising a safety solenoid valve 1 will be described.

Safety solenoid valve 1 is controlled by means of switching means I1, I2, I3.

In this embodiment, the switching means I1, I2, I3 are transistors used in switching, ie used as switches. Thus, in Figure 2, transistors I1, I2, I3 are represented as switches to facilitate understanding.

However, the switching means I1, I2, I3 may be different from a transistor.

In this embodiment, the first switching means I1 and second I2 are, respectively, a bipolar transistor of the NPN type and the third switching means I3 is a bipolar transistor of the PNP type.

Obviously, these three transistors can be of a different type. Thus, for example, the three transistors I1, I2, I3 can be identical, of the PNP type or of the NPN type.

The switching means I1, I2, I3 are arranged in series with the safety solenoid valve 1. The set of the switching means I1, I2, I3 and the safety solenoid valve 1 are fed by a supply potential Vcc.

Thus, a first terminal I1a of a first switching means I1 is connected to a reference potential 4 (in this case the null potential), a second terminal I1b of the first switching means I1 is connected to a first terminal I2a of a second switching medium I2. A second terminal I2b of the second switching means I2 is connected to a first terminal 1a of the safety solenoid valve 1, a second terminal 1b of the safety solenoid valve 1 is connected to a first terminal I3a of a third switching means I3, and a second terminal I3b of the third switching means I3 is connected to a power supply potential Vcc.

Obviously the order of serial connection of switching means I1, I2, I3 and safety solenoid valve 1 could be different.

Indeed, this electrical scheme is a particular arrangement of the transistors with respect to the safety solenoid valve 1. In other embodiments, the three switching means I1, I2, I3 could be arranged upstream of the safety solenoid valve 1. Asf , the three switching means I1, I2, I3 would be connected to each other, one of the end switching means being connected to the supply potential Vcc and another of the end switching means being connected to the safety solenoid valve 1, being the safety solenoid valve 1 connected in turn to the reference potential 4.

The switching means I1, I2, I3 can be in an open state or in a closed state.

Thus, since the switching means I1, I2, I3 are arranged in series, when one of the switching means I1, I2, I3 is open, the safety solenoid valve 1 is not powered. Therefore, the safety solenoid valve 1 is closed and does not allow gas to pass the supply line 14 towards the burner 12.

On the contrary, the switching means I1, I2, I3 must be simultaneously in a closed state so that the safety solenoid valve 1 is powered and is open, thus allowing gas to pass the supply line 14 towards the burner 12.

Control signals first A, second B and third C respectively control the switching means I1, second I2 and third I3.

The first A, second B and third C command signals are static signals, that is, they have a continuous value. In this example, the control signals A, B, C can have two possible values, a first predefined value and a second predefined value. The first predefined value is a suitable value for setting the corresponding switching means in the open state and the second predefined value is a suitable value for establishing the corresponding switching means in the closed state.

In this example, the first and second predefined values of the control signals A, B, C can have a value of 0 V or 5 V.

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By way of example in no way limiting, the reference potential 4 has a value of 0 V, and the supply potential Vcc has a value of 5 V or 12 V, 24 V or 48 V, this value depending on the type of solenoid valve security 1.

Obviously, the values of the control signals A, B, C suitable for controlling the switching means I1, I2, I3 depend on the type of switching means. This is something that the expert in the art knows well.

Thus, in this example, the first I1 and second I2 switching means are bipolar transistors of the NPN type. Thus, the first predefined value is 0 V (NPN transistor in open state) and the second predefined value is 5 V (NPN transistor in closed state).

It will be noted that, in this example, the third switching means I3 is a bipolar transistor of the PNP type. Thus, the first predefined value is 5 V (PNP transistor in open state) and the second predefined value is 0 V (PNP transistor in closed state).

In this case, when the control signals A, B, C have the first predefined value (in this case 0 V for the first A and second B control signals and 5 V for the third control signal C), the corresponding switching means I1, I2, I3 are in the open state. On the contrary, when the control signals A, B, C have the second predefined value (in this case 5 V for the first A and second B control signals and 0 V for the third control signal C), the corresponding switching means I1, I2, I3 are in the closed state.

In this example, the first command signal A is generated by first control means 3 and the second control signal B is generated by a second control means 3A.

The third control signal C is generated by means of processing means 5 based on a dynamic type signal Cd that is generated by the second control means 3A (this will be described later).

Thus, with this architecture of the safety device 1, the second and third switching means I2 and I3, as well as the second control means 3A constitute a redundancy, respectively, of the first switching means I1 and the first control means 3 This redundancy makes it possible to avoid incorrect control of the safety solenoid valve 1 to guarantee the safety of a gas appliance containing a safety device 10 of this type, as well as of a user of this gas appliance.

Possible defects that could occur in the security device 10 are represented in a dotted line.

Thus, the three main defects that could arise are:

- defects d1, d2, d3 relating to switching means I1, I2, I3, for example a short circuit d1, d2, d3 of switching means I1, I2, I3,

- defects d4, d5, d6, d7 related to the control signals A, B, C or to the dynamic signal Cd, for example a short circuit d4, d5, d6, d7 of the control signals A, B, C, or of the dynamic signal Cd at a fixed potential, for example the power supply Vcc or the reference potential 4, or

- a malfunction (not shown in figure 3) of the control means 3, 3A.

The described safety device 10 allows an incorrect control of the safety solenoid valve 1 in the presence of two of these defects at the same time.

Thus, for example, when there is a defect d1, d2, d3 concerning the switching means I1, I2, I3 in two of them, a third party guarantees the opening or closing function of the safety solenoid valve 1. In the same way, when a defect d4, d5, d6 related to the control signals A, B, C in two of them is presented, the third command signal guarantees the control of the switching means I1, I2, I3 corresponding to the in order to control the safety solenoid valve 1.

When there is a defect d1, d2, d3 relative to the switching means I1, I2, I3 in one of them and at the same time there is a defect d4, d5, d6 relative to the control signals A, B, C in one of them, a switching means and a control signal guarantee the control of the safety solenoid valve 1.

Thus, for example, if the first switching means I1 has a defect d1, and the second control signal B has a defect d5, the third switching means I3 and the third control signal C guarantee the control of the safety solenoid valve one.

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The detection of a defect related to a malfunction in the second control means 3A is guaranteed by means of the processing means 5.

As described above, the processing means 5 generates the third control signal C as a function of a dynamic signal Cd.

In this embodiment, the first 3 and second 3A control means are, respectively, first 3 and second 3A microcontrollers, and the dynamic type signal Cd is a periodic square type signal, generated by the second control means 3A when the safety solenoid valve 1 must be opened, that is when the switching means I1, I2, I3 must be closed at the same time.

When the safety solenoid valve 1 must be closed, that is to say when at least one of the switching means I1, I2, I3 must be opened, the dynamic signal Cd has a constant value.

Obviously, in other embodiments, second control means 3A could generate other types of periodic signals, for example, sinusoidal or triangular.

In this example, when the dynamic signal Cd is generated by the second microcontroller 3A and when the second microcontroller 3A (control means responsible for generating the dynamic signal Cd) does not malfunction, the signal type Dynamic generated Cd, being a digital signal, is a square periodic signal, presenting the parameters of the signal default values.

In this example, the dynamic signal Cd has two levels, a first level or low level (in this case 0 V) and a second level or high level (in this case 5 V), the value of the signal frequency Dynamic Cd is substantially 8 kHz, being able to have a tolerance of +/- 1 kHz, and the duty cycle is 50% with a tolerance of +/- 20%.

The processing means 5 are suitable for detecting an anomaly in at least one of the parameters of the dynamic signal Cd. In this example, the parameters are the frequency and the duty cycle.

When there is a malfunction in the second control means 3A, the dynamic signal Cd has a constant value (zero frequency), or is defective (incorrect frequency and / or duty cycle).

In this case, this detection is implemented by comparing the value of said at least one parameter with a predetermined value for that parameter.

When the value of said at least one parameter for which the comparison is made is not substantially similar to the predetermined value for that at least one parameter, an anomaly is detected in said at least one parameter. Thus, the processing means 5 generates the third command signal C and sets its value to a first predefined value suitable for setting the third switching means I3 in the open state.

When during this comparison, the value of said at least one parameter is substantially similar to the predetermined value for that at least one parameter, the processing means 5 generates the third command signal C and sets its value to a second predefined value suitable for setting the third switching means i3 in closed state.

This comparison is made taking into account a certain tolerance for the parameter values. The values of the tolerances for these parameters have been previously provided by way of example in no way limiting.

In addition, when a defect d7 relative to the dynamic signal Cd is presented, for example, a short circuit to the power supply potential Vcc, the processing means 5 generates the third command signal C and sets its value to the first predefined value suitable for set the third switching means I3 in the open state.

Therefore, when a malfunction occurs in the second control means 3A, the closing of the safety solenoid valve 1 is ordered, without thereby endangering the safety of a gas apparatus containing a safety device 10 of this type and a user of a gas appliance of this type.

Thus, thanks to this architecture comprising two control means 3, 3A, the first control means 3 generating the first command signal A and generating the second control means 3A the second command signal B and the dynamic signal Cd, when a malfunction occurs in the first control means 3 and when a second defect occurs in the second B or third C command signal, or in the second I2 or third I3 switching means, either the second I2 or the second third I3 switching means guarantee the control of the safety solenoid valve 1.

Also, when a malfunction occurs at the same time in the first 3 and 3A seconds.

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The safety solenoid valve 1 is ordered to close, after detection of the malfunction of the second control means 3A thanks to the dynamic signal Cd and the processing means 5.

Therefore, the presence of two defects does not jeopardize the safety of a gas appliance containing a safety device 10 of this type and of a user of such a gas appliance.

In this example, the first 3 and second 3A control means are connected to each other by a communication link 7. This communication link 7 is used for communication between the control means 3, 3A, and can be used, for example, by the first control means 3 to communicate to the second control means 3A that they have a malfunction or that they have detected a malfunction in other elements of the gas apparatus, or vice versa.

Thus, thanks to the invention, it is possible to control the opening and closing of the safety solenoid valve, even when there are two defects related to the switching means, the command signals and the control means at the same time.

Thus, the opening of the safety solenoid valve by mistake or the omission of the closing of the safety solenoid valve is avoided, thus guaranteeing the safety of an apparatus containing a safety device according to the invention and of a user of such an apparatus. .

Thus, the security device may comprise a greater number of switching means and control means.

On the other hand, the safety device can be used in various gas appliances, for example in a gas oven, a gas hob or in a boiler.

Claims (7)

10 fifteen twenty 2. 25 3. 30 Four. 35 5. 40 6. 45 7. 8. fifty Safety device (10) of a gas apparatus comprising a safety solenoid valve (1) and a first switching means (I1) suitable for ordering the opening of the safety solenoid valve (1) when it is in a closed state and the closing of the safety solenoid valve (1) when it is in an open state, depending on the positioning of said switching means (I1) in said open and closed states of a first command signal (A), the safety device comprising (10) also at least second (l2) and third (I3) switching means suitable for ordering the opening of the safety solenoid valve (1) when they are in a closed state and the closing of the safety solenoid valve (1) when they are in an open state, said at least second (I2) and third (I3) switching means being mounted in series with the first switching means (I1), and the positioning of said at least means being dependent switching second (I2) and third (I3) in said open and closed states, respectively, of at least a second (B) and a third (C) command signal, the safety device being characterized in that it further comprises processing means (5) suitable for generating said third control signal (C) in function of a dynamic type signal (Cd), to detect an anomaly in at least one parameter of said dynamic type signal (Cd ), and to set said third generated control signal (C) to a first predefined value, when an anomaly is detected in said at least one parameter. Safety device (10) according to claim 1, characterized in that said processing means (5) are suitable for comparing the value of said at least one parameter with a predetermined value and for setting said first predefined value to a suitable value for establishing said third switching means (I3) in the open state when the value of said at least one parameter and said predetermined value are different. Safety device (10) according to one of claims 1 or 2, characterized in that said at least one parameter is the frequency of said dynamic type signal (Cd). Safety device (10) according to one of claims 1 to 3, characterized in that said first (A), second (B) and third (C) control signals are of static type and said third control signal (C) is generated by said processing means (5) as a function of the dynamic type signal (Cd). Safety device (10) according to one of claims 1 to 4, characterized in that first control means (3) are suitable for generating said first command signal (A), and second control means (3A) are suitable for generating said dynamic signal (Cd) and said second command signal (B). Safety device (10) according to claim 1, characterized in that it also comprises first (3) and second (3A) control means suitable for generating said control signals (A, B, C). Safety device (10) according to one of claims 5 or 6, characterized in that said first (3) and second control means (3A) are connected to each other by means of a communication link (7). Gas apparatus comprising a safety device (10) according to one of claims 1 to 7.