JP3185310B2 - Smoke detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a smoke detector,
In particular, the present invention relates to a device for detecting (measuring) smoke discharged by a laser sensor when the vehicle is running.

[0002]

2. Description of the Related Art At present, exhaust gas regulations are becoming stricter in diesel vehicles and the like. Smoke generated in exhaust gas at the time of starting and smoke such as high altitude smoke during traveling of a vehicle are detected and countermeasures are taken. Need to be taken.

[0003] As a conventional smoke detector, a method of adsorbing smoke particles to filter paper by a suction negative pressure method and measuring the smoke concentration by the light reflectance (BOSCH method).
And a method of measuring the density based on the light transmittance (Hartridge type, PHS meter type).

However, since the former method cannot measure in real time, it is difficult to measure the smoke that frequently occurs when the vehicle in which the fuel injection amount increases is transiently driven (starting, overtaking, climbing uphill, traveling at high altitude). It is not possible, and the latter method measures by transmission of light, so it is possible to measure in real time, but if the device is mounted on a vehicle, there is a difficulty that a power supply and an air compressor for operating the measuring device are required .

Therefore, as a device for realizing smoke detection in real time and eliminating the need for an auxiliary device such as a power supply and a compressor, a laser emitting portion and a laser receiving portion are provided as shown in Japanese Patent Publication No. 3-61020. A smoke detector that measures smoke density based on light transmittance has been proposed, and a smoke detector that is inexpensive and easy to handle without being affected by light beams such as sunlight due to laser light has been realized.

[0006]

[Problems to be Solved by the Invention]
In the conventional smoke detector disclosed in Japanese Patent Publication No. 020, the smoke to be detected is identified as black smoke, but in actuality, smoke in exhaust gas is generated in addition to black smoke in addition to black smoke. Since there is easy-to-use white smoke, and either one is generated alternately, there is a problem that white smoke is detected as black smoke.

That is, since the conventional smoke detector cannot discriminate between black smoke and white smoke, control is performed to reduce the fuel injection amount for all black smoke in accordance with the detection of black smoke.
If this is originally white smoke, the control has been reversed despite the necessity of increasing the fuel injection amount and controlling the injection timing and the like in order to warm up.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a smoke detector for detecting (measuring) smoke discharged by a laser sensor when the vehicle is running so that black smoke and white smoke can be distinguished from each other.

[0009]

In order to solve the above-mentioned problems, in a smoke detector according to the present invention, a first laser emitting section directed to an exhaust pipe of a vehicle, and a first laser emitting section of the first laser emitting section are provided. First and second laser light receiving portions for receiving output light as transmitted light and reflected light from the exhaust gas through the opening of the exhaust pipe, respectively, and a second laser receiving portion directed to the outside of the outlet of the exhaust pipe.
A third laser light receiving section that receives output light of the second laser light emitting section as reflected light from the exhaust gas, black smoke, white smoke, A data calculation unit for determining the mixed state of the steam white smoke or the both white smokes and measuring the concentration thereof.

Further, according to the present invention, between the first laser light emitting portion and the first and second laser light receiving portions and the exhaust pipe,
Further, a shielding plate having an opening aligned with the opening of the exhaust pipe may be provided between the second laser emitting section and the third laser receiving section and the exhaust pipe.

Further, in the present invention, instead of providing the shielding plate, a rectifying plate may be provided inside the exhaust pipe on the exhaust upstream side of the opening of the exhaust pipe.

Further, in the present invention, plates on which the respective laser light emitting portions and the laser light receiving portions are mounted may be provided on both sides of the exhaust pipe.

[0013]

In the present invention, a first exhaust pipe provided on one side of the exhaust pipe of the vehicle, preferably on a plate, is provided on one side in the diameter direction.
The laser light output from the laser light emitting unit is preferably passed through an opening of the shielding plate, and is emitted from the opening of the exhaust pipe to the exhaust gas in the exhaust pipe.

At this time, when the smoke of the exhaust gas is white smoke (particles), the laser light is reflected, and when the smoke is black smoke, the laser light is absorbed. Furthermore, there is non-smoke white smoke, which is transparent water vapor in the exhaust pipe, but becomes white smoke when it goes out of the exhaust pipe. Preferably, the light is received by the first laser light receiving unit via the opening of the shielding plate.

The laser light reflected in the exhaust pipe when the smoke is white smoke is preferably received by the second laser light receiving portion via the opening of the shielding plate.

Further, the exhaust gas emitted from the exhaust pipe is preferably similarly irradiated with a laser beam from a second laser emitting section provided on the same plate.

At this time, when the smoke is white smoke, the laser light is reflected and is preferably received by the third laser light receiving portion via the opening of the shielding plate, and when the smoke is black smoke, it is absorbed. You.

However, the water vapor transmitted through the exhaust pipe is
Once out of the exhaust pipe, it is cooled and becomes white smoke (water vapor white smoke), which is also reflected by the laser beam and received by the third laser light receiving unit.

Accordingly, there are two types of white smoke coming out of the exhaust pipe: harmful white smoke regarded as original smoke and steam white smoke not regarded as smoke. The light receiving results of the first to third laser light receiving units are evaluated by the data calculation unit, so that these two types of white smoke (the presence of each white smoke or a mixed state of both white smokes) and the black smoke are discriminated. The fuel injection amount can be controlled based on the determination result.

[0020]

FIG. 1 is a view showing an embodiment of a smoke detector according to the present invention. In this embodiment, reference numeral 1 denotes an exhaust pipe through which exhaust gas of a vehicle flows in the direction of the arrow shown in the figure, Having apertures 10A and 10B with a diameter of about 6 mm, 2
A and 2B are openings 10A and 10B of the exhaust pipe 1, respectively.
The plates 3A-1 and 3A-2 attached near B are both provided on the plate 2A with the first laser light emitting portion and the second laser light receiving portion, respectively, and the plate 3B is provided on the plate 2B with the first laser light emitting portion. Laser receiver, 3C-1 and 3C-
Reference numeral 2 denotes a second laser emitting unit and a third laser receiving unit both provided on the plate 2A. In FIG. 1, for simplicity, the laser emitting section 3A-1 and the laser receiving section 3A-
2 are integrally shown, and the laser emitting section 3C-1 and the laser receiving section 3C-2 are shown integrally.

4A and 4C are plates 2 respectively.
A shield plate provided between the laser emission unit 3A-1 (or the laser reception unit 3A-2) and the laser emission unit 3C-1 (or the laser reception unit 3C-2) and the exhaust pipe 1 on A; 2B is a shielding plate provided between the laser receiving unit 3B and the exhaust pipe 1 on the 2B, and among these shielding plates 4A to 4C, apertures 40A provided on the shielding plates 4A and 4B, respectively.
And 40B and openings 10A and 10B provided in the exhaust pipe 1.
Accordingly, the output light from the laser emitting unit 3A-1 is aligned so as to reach the laser receiving unit 3B or to be reflected in the exhaust pipe 1 to reach the laser receiving unit 3A-2. Further, the laser beam from the laser emitting section 3C-1 is shielded by the shielding plate 4C.
Exhaust gas outside the outlet of the exhaust pipe 1 is radiated through an opening 40C provided in the laser beam receiving section 3 and reflected laser light is emitted from the laser receiving section 3.
Position alignment is performed so that light can be received by C-2.

Reference numerals 51 to 55 denote a laser emitting section 3A-1, a laser receiving section 3A-2, and a laser emitting section 3C, respectively.
-1, an amplifier for amplifying an electric signal that monitors output light or input light from the laser light receiving unit 3C-2 and the laser light receiving unit 3B, and 6 converts the output signals from these amplifiers 51 to 55 into digital signals. It is a data calculation unit that converts and calculates a smoke measurement value described later.

The laser beams emitted from the exhaust pipe 1 via the plates 2A and 2B are transmitted to the laser light emitting portions 3A-1 (or 3A-2), the laser light receiving portion 3B, and the laser light emitting portions 30A to 30C, respectively. Is a floating platform for keeping it away from the section 3C-1 (or the laser receiving section 3C-2).
Are provided respectively. Further, 20A and 20B also have cutouts for preventing heat transfer between the plates 2A and 2B and the exhaust pipe 1.

The operation of such an embodiment will be described below with reference to the schematic plan view shown in FIG. In FIG. 2, white smoke (particles) that becomes harmful smoke is transparent water vapor in the exhaust pipe 1, but is cooled to white smoke after exiting the exhaust pipe 1 (however, harmful smoke and The steam white smoke to be removed is black smoke which is also smoke, and is shown to fly out of the exhaust pipe 1 in the direction of the arrow shown in the figure.

First, the laser beam output from the laser emitting section 3A-1 provided on the plate 2A passes through the opening 40A of the shielding plate 4A as shown in FIG. The exhaust gas in the exhaust pipe 1 is irradiated.

At this time, when the smoke in the exhaust gas is white smoke, the laser light is reflected and received by the laser light receiving section 3A-2 as shown in the figure, but is absorbed when the smoke is black smoke. It does not reach the laser light receiving unit 3B or the laser light receiving unit 3A-2. In addition, non-smoked steam white smoke that is cooled to white smoke after exiting the exhaust pipe 1 is transparent in the exhaust pipe 1 and passes through the laser light receiving unit 3B as it is.

When white smoke, water vapor white smoke, or black smoke comes out of the exhaust pipe 1 as shown in the drawing, the white smoke, the white smoke, or the white smoke from the laser emitting section 3C-1 traversing through the opening 40C of the shielding plate 4C. As a result of being exposed to the laser light, the smoke white smoke reflects the laser light and makes the laser light receiving unit 3C-2 receive the laser light, and the black smoke absorbs the laser light. Further, since the steam white smoke reflects the laser light similarly to the smoke white smoke, it is received by the laser receiving section 3C-2.

As a result, the laser receiving units 3B, 3A-2,
And the light receiving conditions in 3C-2 are as shown in Table 1 below. In addition, ○ indicates that the laser light receiving unit senses, and x indicates that it does not sense.

[0029]

[Table 1] Then, these laser receiving sections 3B, 3A-2, and 3
Receiving condition at C-2 and laser emitting units 3A-1 and 3C-
When the light emission status of No. 1 is input to the data calculation unit 6, the current exhaust gas is changed to smoke white smoke, steam white smoke or white smoke +
Or black smoke.

That is, the data calculation unit 6 determines (1) that when the same light reception level Ni2 exists in the laser light receiving units 3A-2 and 3C-2, the smoke flowing out of the exhaust pipe 1 is smoke white smoke. 2) The light receiving level Ni2 of the laser receiving section 3A-2
When the light receiving level Ni3 of the laser receiving section 3C-2 is higher (Ni2 <Ni3), smoke white smoke and water vapor white smoke are mixed, and (3) the light receiving level Ni3 of the laser receiving section 3C-2. When only the white smoke exists, it is determined that only the steam white smoke exists, and (4) the light receiving levels of both the laser receiving units 3A-2 and 3C-2 are "0" and the light receiving level is only in the laser receiving unit 3B. If there is, it is determined as black smoke.

In these cases, (1) the concentration of smoked white smoke is Ni2 / No (No is the laser emitting portion 3A- or 3C-1).
(2) The concentration of smoke white smoke and steam white smoke is expressed as Ni3 / No (where Ni2 <Ni3), and (3) the concentration of steam white smoke is N
i3 / No−Ni2 / No, and (4) the density of black smoke is calculated by taking into account the light receiving level Ni1 at the laser light receiving section 3B.
i1 / No-Ni3 / No, and each such concentration can be used, for example, for fuel injection control.

In the above embodiment, even if the smoke SMK in the exhaust gas is exhausted from the openings 10A and 10B, most of the smoke SMK is shielded by the shielding plates 4A, 4B and 4C. In addition, it is possible to prevent smoke from reaching the laser light receiving unit, and to maintain good accuracy of smoke measurement due to adhesion of smoke.

The exhaust pipe 1 has a high temperature (600 to 700 °).
If the heat is directly received by the laser emitting units and the light receiving units, the smoke density cannot be measured stably or an internal failure occurs. Therefore, it is necessary to protect the laser light emitting unit and the laser light receiving unit from heat, but these light emitting units 3A-1 (light receiving unit 3A-2), 3C-1 (light receiving unit 3C-2) and light receiving unit 3
B is floated by the pontoons 30A to 30C and the plate 2
Openings 31A to 31C and notches 20A, 2A
Since 0B is provided, heat from the exhaust pipe 1 is radiated so that heat is not easily transmitted.

FIG. 3 shows a modification of the present invention.
In this example, the shielding portions 4A to 4C as shown in FIG.
By providing the rectifying plate 8 on the exhaust upstream side of the exhaust pipe 10B, the exhaust gas is deflected by the rectifying plate 8 to the inside of the exhaust pipe 1, and the smoke is emitted from the openings 10A and 10B provided in the exhaust pipe 1. It becomes difficult to jump out. Therefore, the shielding plates 4A-
The smoke detector can be reduced in size by the amount excluding 4C.

In the above-described embodiment, the smoke detector is directly attached to the exhaust pipe of the vehicle.
This auxiliary exhaust pipe may be connected to the exhaust pipe 1 without performing a work of providing a hole in the exhaust pipe 1 by a joint rubber hole or the like.

[0036]

As described above, in the smoke detector according to the present invention, the output light of the first laser emitting section directed to the exhaust pipe of the vehicle is transmitted as the first light and the reflected light from the exhaust gas. The third laser light receiving unit receives the output light of the second laser light emitting unit toward the outside of the outlet of the exhaust pipe as reflected light from the exhaust gas. Based on the received light level of the black smoke, white smoke, steam white smoke, or both white smoke, the mixed state is determined and the concentration is measured. By combining the data with data such as the flow rate, the number of revolutions, and the temperature, it is possible to perform optimal engine control with less undesirable smoke.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of a smoke detector according to the present invention.

FIG. 2 is a plan view schematically illustrating the smoke detector according to the present invention shown in FIG. 1;

FIG. 3 is a sectional view showing a modified example of the smoke detector according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF REFERENCE NUMERALS 1 exhaust pipe 2A, 2B plate 3A-1, 3C-1 first and second laser light emitting units 3B, 3A-2, 3C-2 first to third laser light receiving units 4A to 4C shielding plates 10A, 10B 40A to 40C Opening portion 8 Rectifier plate In the drawings, the same reference numerals indicate the same or corresponding parts.

Continuation of the front page (56) References JP-A-2-280032 (JP, A) JP-A-60-196652 (JP, A) JP-A-61-260145 (JP, A) JP-A-2-49145 (JP, A) , A) JP-A-59-101554 (JP, A) JP-A-4-353748 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01N 21/00-21/01 G01N 21/17-21/61 F02B 77/08 G01M 15/00

Claims (4)

(57) [Claims] 1. A first laser emitting section directed to an exhaust pipe of a vehicle, and an output light of the first laser emitting section is transmitted through an opening of the exhaust pipe to transmit light from exhaust gas and First and second laser light receiving portions that receive reflected light, a second laser light emitting portion directed to the outside of the outlet of the exhaust pipe, and reflection of output light of the second laser light emitting portion from the exhaust gas. Based on the third laser light receiving section received as light and the input light of each laser light receiving section, black smoke, smoked white smoke, non-smoked water vapor white smoke, or a mixed state of both white smokes is determined, and the concentration measurement is performed. A smoke detector, comprising: a data operation unit for performing the operation. 2. The first laser emitting section, the first and second laser receiving sections, and the exhaust pipe, and the second laser emitting section, the third laser receiving section, and the exhaust pipe. 2. The smoke detector according to claim 1, further comprising a shielding plate having an opening aligned with the opening of the exhaust pipe. 3. The smoke detector according to claim 2, wherein a rectifying plate is provided inside the exhaust pipe on the exhaust upstream side of the opening of the exhaust pipe instead of providing the shielding plate. 4. The smoke detector according to claim 1, wherein plates on which the respective laser light emitting portions and the laser light receiving portions are mounted are provided on both sides of the exhaust pipe.