JPS62223523A - Abnormality detector for flame detecting circuit - Google Patents

Abstract

PURPOSE:To prevent malfunction such as abnormality detection because of the slow response of a flame sensor by providing a decision timer between an operation switch and a decision unit. CONSTITUTION:When an operation switch 15 is turned OFF by malfunction at a time (t1) under the condition of combustion, the level EF of an electric signal outputted from a flame signal converting unit 9 is higher than the decided level EC of a cut-off level unit 10. When the operation switch 15 is turned on again under this condition, a decision unit 12 detects an abnormal condition since there is a flame existing signal in spite of a condition that a sequence control unit 14 is stopping combustion, however, when a flame non-existing signal (t3) is inputted during the time T of a decision timer 13, the decision unit 12 decides that the combustion is normal and outputs a normal signal to the sequence control unit 14 to start combustion sequence. When the flame non-existing signal is not inputted during the time T, an abnormality signal is sent to the control unit 14 from the decision unit 12 simultaneously with the count-up of the time T whereby the control unit 14 holds the condition of stopping the combustion.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is a device for detecting an abnormality in a flame detection circuit of a combustion appliance that detects a flame, performs sequence control based on the flame signal, and automatically maintains combustion. It is related to.

Background of the Invention In recent years, abnormality detection devices for flame detection circuits have come to be used to automatically detect flames in various combustion appliances simply by operating a switch, and use the flame signal to maintain the combustion status. This is an essential device to prevent abnormalities such as detecting a flame signal even when there is no flame.

An example of the conventional abnormality detection device for the flame detection circuit described above will be described below with reference to the drawings.

FIGS. 3 and 4 are block diagrams of a conventional flame detection circuit abnormality detection device and its operation. In FIG. 3, reference numeral 1 denotes a flame sensor section that detects the presence or absence of flame. 2
tIi is a flame signal conversion section, which converts the signal from the flame sensor section 1 into an electrical signal. 3 is the cut-off level part,
Outputs a constant value electrical signal. Reference numeral 4 denotes a comparison section, which compares the electrical signals of the flame signal conversion section 2 and the cutoff level section 3, and outputs a signal indicating the presence or absence of a flame. 5 Haya j
Based on the signal from the comparison section 4, the flame sensor section 1,
It is determined whether the flame signal conversion section 2, cutoff level section 3, and comparison section 4 are normal. Reference numeral 6 denotes a sequence control section, which starts combustion if the signal from the determination section 5 is normal. If there is an abnormality, combustion is stopped and the state is maintained. 7
id is an operation switch, and provides an operation signal to the determination section 5 and the sequence control section 6.

The operation of the flame detection circuit abnormality detection device configured as described above will be described below.

First, the normal state will be explained using FIG. 4 (,).

When the operation switch 7 is turned on at a time t□ from the stopped state, the sequence control section 6 has stopped combustion, so the electric signal EF output from the flame signal conversion section 2 is almost 0 volts. , is lower than the flame determination level EC of the cut-off level section 3, so the comparison section 4 outputs a no-flame signal. At the same time as the operation switch 7 is pressed, this signal is determined to be normal in the I-determined section 5 since it is a flameless signal in the combustion stopped state, and a normal signal is output. Upon receiving the normal signal, the sequence control section 6 starts a combustion sequence.

Next, abnormal conditions will be explained using Figure 4. This time, when the operation switch 7 is turned on at the time t□, the electric signal EF output from the flame signal converter 2 has already been turned on.
is higher than the flame determination level EC of the cut-off level section 3, so a flame presence signal is output. This signal is processed by the determination unit 5.
At the same time that the operation switch 7 is turned on, since the combustion is stopped and the signal indicates that there is a flame, it is determined that there is an abnormality and an abnormal signal is output. Upon receiving the abnormality signal, the sequence control section 6 is held in a combustion stopped state and does not proceed with the sequence.

Problems to be Solved by the Invention However, in the above configuration, the determination section 5 determines whether the operation switch 7 is normal or abnormal at the same time as the operation switch 7 is turned on. , the response of the flame sensor section 1 is slow, and when the operation switch 7 is turned off from the combustion state and then turned on again, the comparison section 4 has a timing to output a flame presence signal, and the flame sensor section 1, There is a problem in that an abnormality may be detected even though the flame signal conversion section 2, cutoff level section 3, comparison section 4, etc. are normal.

In view of the above-mentioned problems, the present invention has been developed to quickly turn off the operation switch in the combustion state, and to prevent the flame sensor section, the flame signal conversion section, the cut-off level section, and the comparative An object of the present invention is to provide an abnormality detection device for a flame detection circuit that prevents abnormality detection even when parts etc. are normal.

Means for Solving the Problems In order to solve the above problems, the flame detection circuit abnormality detection device of the present invention includes a flame sensor section that detects the presence or absence of a flame, and a signal from the flame sensor section that converts the signal from the flame sensor section into an electrical signal. A flame signal converter converts a flame signal, a cutoff level unit outputs a level of an electric signal for determining the presence or absence of a flame, and compares the electric signals of the flame signal converter and the cutoff level unit, and calculates the result. The output comparison section receives the signal from the comparison section, and if the flame sensor section, electric signal conversion section, cut-off level section, and comparison section are normal, it outputs a normal signal, and if it is abnormal, it outputs a constant signal. a determination unit that continues to make a determination until the time becomes normal, and outputs a normal signal if it becomes normal within a certain time, and outputs an abnormal signal if it does not become normal; in the determination unit, the flame sensor unit;
When the electric signal converter, cut-off level section, and comparison section determines that there is an abnormality, the determination is continued for a certain period of time.A determination timer that determines the time length of the determination, and a determination timer that determines the time length of the determination, and a determination timer that receives a normal signal or an abnormal signal from the determination section. The apparatus includes a sequence control section that starts an operation, and an operation switch that resets the determination timer and the sequence control section to an initial state.

According to the present invention, after the operation switch is turned on with the above-described configuration, during the time of the judgment timer, the judgment section checks whether the flame sensor section, the electric signal conversion section, the cutoff level section, and the comparison section are normal. 'll continue to be determined.

Therefore, if a normal signal is obtained during the judgment timer, the combustion sequence will start, so if the operation switch is quickly turned off in the combustion state, it will operate normally without malfunction even if there is a person or the flame sensor part with slow response. That will happen.

Embodiment Hereinafter, an abnormality detection device for a flame detection circuit according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows a block diagram of an abnormality detection device for a flame detection circuit according to an embodiment of the present invention. In Figure 1, 8
is the flame sensor section, which detects the presence or absence of flame. Reference numeral 9 denotes a flame signal conversion section, which converts the signal from the flame sensor section 8 into an electrical signal. Reference numeral 10 denotes a force 7 off level section, which outputs an electric signal of a constant value. 11t/'i comparing section compares the electrical signals of the flame signal converting section 9 and the cut-off level section 10, and outputs a signal indicating the presence or absence of a flame. Reference numeral 12 denotes a determination section, which determines whether the flame sensor section 8, flame signal conversion section 9, cutoff level section 10, and comparison section 11 are normal. 1
Reference numeral 3 denotes a determination timer, which determines the length of time for determining whether or not the leg portion 12 is normal for a certain period of time. 14 is a sequence control section, and the determination section 1
If the signal from 2 is normal, combustion is started, and if abnormal, combustion is stopped and that state is maintained. Reference numeral 15 denotes an operation switch, which is provided to reset the determination timer 13 and the sequence control section 14 to initialize them.

The operation of the abnormality detection device for the flame detection circuit configured as described above will be explained below with reference to FIGS. 1 and 2.

First, FIG. 2 shows the operation of the abnormality detection device for a flame detection circuit according to the present invention.

First, the normal state will be explained using FIG. 2 (,). When the operation switch 15 is turned on at a time of "to" from the stop condition, a signal is sent to the determination section 12 via the determination timer 13, and the flame sensor section 8, flame signal conversion section 9, cut-off level section 10, comparison section 11 is made. In the above state, the sequence control section 14 stops combustion, so the electric signal EF output from the flame signal conversion section 9 is approximately O volts, and the flame judgment level EC of the cutoff level section 10
Since the flame is lower, the comparison section 11 outputs a no-flame signal.

The determining unit 12 determines that this signal is normal because it is a flameless signal in a combustion stopped state, and immediately outputs a normal signal. Upon receiving the normal signal, the sequence control section 14 starts a combustion sequence.

Next, Figure 2 (b) shows an example of malfunction in the past.
Explain using. In the combustion state, the operating switch 15 is turned off at a time tl. The sequence control section 14 stops combustion in response to the signal from the operation switch 15, but since the response of the flame sensor section 8 is slow, the electric signal EF output from the flame signal conversion section 9 is '
lJ is higher than the constant level EC. If the operation switch 15 is turned on again in this state, the determination section 12 will be activated by the sequence control section 14.
Although combustion is stopped, there is a flame presence signal, so an abnormality is detected, but as seen at the timing t3 where no output is output after the judgment timer time 2T, there is no flame within the judgment timer time = T. As soon as the no signal is received, it is determined to be normal, and a normal signal is output to the sequence control section 14 to start the combustion sequence. In addition, if the no-flame signal is not received during the determination timer time T, as shown in FIG. 2(c), the determination unit 12
An abnormality signal is sent to the sequence control section 14, and the sequence control section 14 is maintained in a combustion stopped state, and the sequence is not allowed to proceed.

As described above, according to this embodiment, by providing the determination timer section 13 between the operation switch 15 and the determination section 12, the flame sensor section 8, the flame signal conversion section 9, the cutoff level section 10,
Although the comparison unit 11 is normal, the flame sensor unit 8
It is possible to prevent malfunctions such as detection of abnormality due to slow response, which not only increases the user's sense of security but also improves usability.

Effects of the Invention As described above, the present invention includes a flame sensor section, a flame signal conversion section and a cutoff level section that convert signals from the flame sensor section into electrical signals, and an electric signal from the flame signal conversion section and cutoff level section. A comparison section that compares signals, and a signal from the comparison section to judge the status of the flame sensor section, flame signal conversion section, cut-off level section, and comparison section, and if it is normal, the judgment is made immediately, and if it is abnormal, it continues for a certain period of time. During the process, there is a determination section that outputs a normal signal if the condition becomes normal, and an abnormal signal if the abnormality continues beyond a certain period of time, a determination timer that determines the determination time in the determination section, and a combustion state based on the output from the determination section. By providing a sequence control section that determines the timing, and an operation switch that resets the judgment timer and sequence control section and makes the initial state abrupt, it is possible to ensure that the flame sensor section, flame signal conversion section, cut-off level section, and comparison section are normal. Despite this, it is possible to prevent malfunctions such as detection of an abnormality due to slow alignment of the flame sensor section, which not only increases the user's sense of security but also improves usability.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an abnormality detection device for a flame detection circuit according to the present invention, FIG. 2 is an explanatory diagram of the operation of FIG. 1, FIG. 3 is a block diagram of a conventional abnormality detection device for a flame detection circuit, and FIG. is an explanatory diagram of the operation of FIG. 3. 8...Flame sensor section, 9...Flame signal conversion section, 10...Cutoff level section, 11...
... Comparison section, 12 ... Judgment section, 13 ...
... Judgment timer section, 14 ... Sequence control section, 15 ... Operation switch. Name of agent: Patent attorney Toshio Nakao and 1 other person 2nd
Figure Time Figure 3

Claims (1)

[Claims] a flame sensor section that detects the presence or absence of a flame; a flame signal conversion section that converts a signal from the flame sensor section into an electrical signal; and a cutoff level section that outputs a level of the electrical signal for determining the presence or absence of a flame; a comparison unit that compares the electrical signals of the flame signal conversion unit and the cut-off level unit and outputs the result; the flame sensor unit that receives the signal from the comparison unit;
If the cut-off level section and the comparison section are normal, a normal signal is output, and if they are abnormal, the judgment continues for a certain period of time until it becomes normal, and if it becomes normal within a certain period of time, a normal signal is output. For example, there is a determination unit that outputs an abnormality signal, and the determination unit continues determination for a certain period of time when the flame sensor, electrical signal conversion unit, cut-off level unit, and comparison unit determines that the flame sensor, electrical signal conversion unit, cutoff level unit, and comparison unit are abnormal. the determination timer, a sequence control unit that starts operation upon receiving a normal signal or an abnormal signal from the determination unit, and an operation switch that resets the determination timer and the sequence control unit to an initial state. An abnormality detection device for a flame detection circuit, characterized in that: