JPH05281037A - Lifetime detecting device for ultraviolet detecting device - Google Patents

Abstract

PURPOSE:To automatically detect the life of an ultraviolet detecting device consisting of an UV tube and a shutter. CONSTITUTION:Each time the power source of an ultraviolet detecting device is turned on, the number x0 of electric discharge pulses and the number s0 of opening and closing motions of a shutter within a fixed time after the power source is turned on, are counted and stored in a memory. Thereafter, the number (x) of electric discharge pulses and the number (s) of opening and opening motions of the shutter every a fixed time are counted, and whether x0 x and s0's is established or not is examined. When the above relationship is established, the addition of the number of treatments assuming the treatment in a fixed time as one time, and it is detected that the integrated value reaches a constant value. The lifetime can thus be accurately known, and thereby unnecessary exchange of the device can be eliminated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultraviolet detector used for monitoring the presence or absence of flames in combustion control systems for various combustion devices, boilers, etc., and more particularly to an ultraviolet detector comprising an ultraviolet discharge tube and a shutter. The present invention relates to a life detecting device.

[0002]

2. Description of the Related Art Conventionally, in order to monitor the presence or absence of flames in a burner in a combustion apparatus, an ultraviolet ray detecting device including an ultraviolet ray discharge tube (hereinafter referred to as a UV tube) and a shutter has been used. The UV tube is a discharge tube configured to generate a discharge between the electrodes when ultraviolet rays emitted from the flame are incident while a high voltage is applied between a pair of electrodes provided on the glass tube. When is detected, a discharge current is obtained from the UV tube. Further, the shutter is configured to control the incidence and blocking of light on the UV tube.

When such an ultraviolet ray detecting device is used for detecting a flame, the shutter is opened and closed with a constant period which is sufficiently longer than this pulse while a high voltage pulse having a constant period is applied to the UV tube. Therefore, when there is a flame, a discharge pulse is obtained from the UV tube if the shutter is opened, and no discharge pulse is obtained if the shutter is closed. If there is no flame, UV will be used regardless of whether the shutter is open or closed.
No discharge pulse is obtained from the tube.

When the UV tube deteriorates due to aging or the like, it causes a failure such that self-discharge occurs even if ultraviolet rays do not enter, or discharge does not occur even when ultraviolet rays enter due to a decrease in discharge capability. The shutter is provided for checking the failure of the UV tube. For example, when the shutter is closed with a flame and a discharge pulse is obtained from the UV tube, the discharge pulse disappears, or when the shutter is opened without a flame,
An abnormality of the UV tube can be known by performing chucking such as whether a discharge pulse can be obtained.

In the above-mentioned conventional ultraviolet ray detecting device comprising the UV tube and the shutter, the UV tube suffers the above-mentioned troubles when it reaches the end of its life, and the shutter also comes to the end of its life during repeated opening and closing, and the opening / closing mechanism is opened. It will not operate smoothly. Conventionally, the user individually judges whether or not the life of the ultraviolet ray detection device has expired, and if it is judged that the life has expired, the ultraviolet ray detection device is replaced.

[0006]

As described above, conventionally, there is no objective standard for easily determining the life of the ultraviolet ray detecting device, and the user makes his / her own judgment. In many cases, problems such as unnecessary replacements occurred even within the endurance time.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a life detecting device for an ultraviolet detecting device which can accurately determine the life of the ultraviolet detecting device. ..

[0008]

According to the present invention, the number of discharge pulses x ₀ and the number of shutter opens / closes s ₀ within a fixed time after the power is turned on are counted every time the power is turned on and the result is stored in a memory. Further, the discharge pulse number x and the shutter open / closed number s are counted at every constant time, and x
_It is checked whether or not ₀ ≈ x ₁ and s ₀ ≈ s ₁ are established, and when they are established, the processing for the certain time is integrated once, and it is detected that the integrated value has reached a certain value. It is a thing.

[0009]

[Function] It is possible to automatically detect that the usage time of the UV tube and the shutter has reached a predetermined life time,
You can easily know the proper replacement time.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows an embodiment in which the ultraviolet detector is used for flame detection of a combustion device. In FIG. 1, 1 is a UV tube, 2 is a shutter for entering and blocking light to the UV tube 1, and 3 is a flame arranged in front of the shutter 2.
Reference numeral 4 denotes a drive unit for applying a high-voltage pulse of a constant cycle to the UV tube 1 and opening / closing the shutter 2 at a cycle sufficiently longer than the cycle of the high-voltage pulse, and 5 a detection circuit for detecting a discharge pulse obtained from the UV tube 1, 6 is a combustion controller that detects the presence or absence of the flame 3 based on the detected discharge pulse and controls the combustion device. 7 is a micro controller that determines the life based on the detected discharge pulse and the signal from the drive unit 4. computer (microcomputer) 8 E ² PROM, 9 is a display unit for displaying that or abnormal came lifetime for storing data, 10 is a power supply for backing up the E ² PROM 8.

Next, a method of determining the life will be described with reference to the flowchart of FIG. In FIG. 2, when the power is turned on in step ST1, first, in step ST2, the opening / closing number s ₀ of the shutter 2 and the discharge pulse number x ₀ obtained during the period from the power ON to t are counted. , Using this as a reference value, E ² PR in step ST3
Store in OM8. Further, the first t time after the power is turned on is set to t ₀ , which is also stored in the E ² PROM 8.

Next, at step ST4, the number s of opening / closing operations of the shutter 2 and the number x of discharge pulses during the next time t after the time t are counted. Next, in step ST5, E ²
The above s ₀ and x ₀ are read out from the PROM 8 to obtain s ₀ and s
And x ₀ are compared with x. The result of this comparison is x ₀ ≈x (where x is within the allowable range of x ₀ ),
If s ₀ ≅s (s is within the allowable range of s ₀ ), it is regarded as normal and the process proceeds to step ST5. In this step ST5, the fact that the second time t has elapsed since the power was turned on is counter-counted, and the count value n = 2 is written to the E ² PROM 8. If the comparison result is s ₀ ≠ s or x ₀ ≠ x, it is determined that there is an abnormality and an alarm is generated in step ST 6 and displayed on the display unit 9.

Thereafter, steps ST4 to ST6 are performed every t hours.
Is repeated, the shutter opening / closing number s and the discharge pulse number x are detected and compared with s ₀ and x ₀ , respectively, and if normal, n
The value of is counted up by 1 and written in the E ² PROM 8, and if it is abnormal, an alarm is generated and displayed.

During this time, in step ST7, E ² P
The value of n in the ROM 8 is checked. When n reaches a constant value K, it is determined that the life has expired or is approaching, and the life is displayed to that effect in step ST8.

By the way, since the E ² PROM 8 generally has a small memory capacity, when processing is performed with t = 1 second in FIG. 2, for example, data such as the value of n is written every second, so the memory becomes full immediately. turn into. For this reason,
It is necessary to lengthen t, but if t is lengthened, the following problems occur.

In FIG. 3, for example, when t = 30 days, if normal operation is performed as shown in FIG.
The value of n is incremented every 30 days, such as 30 days, 60 days, 90 days, and so on, and is incremented by 1 such as n = 1, 2, 3 ,. However, if the power is turned off midway as shown in FIG. 6B, for example, if the power is turned off on the 59th day, the counter will be reset, so that the count is not incremented and the counter is actually used at that time. Approximately once (29 days) will not be accumulated in the E ² PROM 8 as the usage time.

In order to solve this problem, in this embodiment, the backup time is set longer than the time t as shown in FIG. Thus, if the power is turned on again within the backup time, the number of times can be counted up.

[0018]

According to the present invention, after the power is turned on, the shutter opening / closing number and the discharge pulse number in the first fixed time are counted and stored as a reference value. The number of pulses is counted and compared with the reference value, and the processing in the normal case is integrated once, and it is detected that the integrated value has reached a certain value, so that the life of the UV tube and shutter is optimized. It is possible to obtain the effect of being able to surely know and eliminating unnecessary replacement and reducing extra costs.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a life detecting device of an ultraviolet ray detecting device according to an embodiment of the present invention.

FIG. 2 is a flowchart showing the operation of the same device.

FIG. 3 is an explanatory diagram for explaining memory backup.

[Explanation of symbols]

1 UV tube 2 Shutter 7 Microcomputer 8 E ² PROM

Claims (2)

[Claims] 1. The number of discharge pulses x ₀ of the UV tube 1 and the opening / closing number s _{0 of the} shutter 2 within a fixed time after power-on of the ultraviolet detector are counted and stored in the memory 8, and then further stored. The discharge pulse number x and the shutter opening / closing number s are counted at the above-mentioned constant time intervals, and x ₀ ≈x
And s ₀ ≈s are established, the processing for the certain time when they are established is integrated once, and it is detected that the integrated value reaches a certain value. Lifetime detector. 2. A life detecting device for an ultraviolet detecting device, wherein a power source backup time of a memory for storing the integrated value is set longer than the fixed time.