CN204269516U - Optical platform of a lens-protected transmission opacimeter - Google Patents

Abstract

The utility model relates to diesel vehicle flue gas measurement mechanism; particularly relate to the optical table of the transmission-type smoke meter of a kind of lens protection; this platform comprises blower fan, testing pipes, air chamber pipeline, smoke inlet pipe and photodetector unit; the utility model adds protection lens devices; the engine discharge flue gas avoided containing oil gas directly contacts with lens surface; protection lens devices conveniently can transfer to cleaning, promotes property easy to use and the overall performance of instrument to a great extent.In addition, the utility model have employed standardize components processing, simplifies the structure of product, improves the efficiency of production and the accuracy of connection.

Description

Optical platform of a lens-protected transmission opacimeter

technical field

The utility model relates to a diesel vehicle flue gas measuring device.

Background technique

Pollutants emitted by diesel vehicles have caused great harm to human health and the environment. All countries in the world have enacted increasingly stringent emission regulations to limit the level of pollutants emitted by diesel engines. These increasingly stringent emission regulations not only promote the development of engine technology, but also promote the development of detection technology. There are two detection methods stipulated in GB3847-2005 "Vehicle Compression Ignition Engine and Compression Ignition Engine Vehicle Exhaust Smoke Emission Limits and Measurement Methods": free acceleration method and loading deceleration method. According to the long-term target outline of China's environmental protection, key cities should meet the second-level standard of the national air environment quality. In order to improve the air quality of urban environment as soon as possible, for the detection of diesel vehicles, various local standards gradually require various testing agencies to use the detection method of loading and deceleration to measure the emission concentration of particulate matter in the pollutants emitted by diesel vehicles. The detection of particulate matter emission concentration in diesel vehicle exhaust pollutants usually uses a transmission smoke meter, which uses the transmission coefficient of flue gas to determine the concentration of particulate matter. The transmission opacimeter uses the Beer-Lambert theorem to measure visible objects. When the parallel light beam passes through the gas chamber, the intensity of the light is attenuated due to absorption and scattering (reflection, refraction, etc.) by the visible objects in the gas chamber, and the detection equipment detects the changing photocurrent signal, thereby obtaining the detection result, the intensity attenuation = absorption amount + scatter amount. The transmission smoke meter is composed of a gas sampling module, an optical measurement module, and a control display module. The optical measurement module mainly includes an optical platform and data acquisition. Its main function is to continuously measure the smoke emitted by motor vehicles, dynamically reflect the changes in exhaust pollutants, and transmit the measurement results to the control display part for display. The optical platform The design is the core of the transmission opacimeter. The fans (centrifugal fans) on both sides of the optical platform blow outwards to form a negative pressure, and the exhaust gas enters the air chamber from the position of the intake pipe and flows to both sides under its action.

Especially when the diesel vehicle is loaded and decelerated, the dense smoke emitted by the diesel vehicle is not directly inhaled into the instrument by the effect of the air curtain, but is directly pressed into the optical table by the gas from the exhaust pipe, so that part of the injected gas will be Directly sprayed onto the collimating lens and converging lens in the optical table, the fume contains oil gas and carbon particles, and this mixture is very easy to form deposits on the surface of the collimating lens of the LED and the converging lens of the photodiode. If there is protective glass on the surface of these two lenses, dirt deposits will be formed on the surface of the protective glass, which will attenuate the light emitted by the light-emitting diode. If it is used for a long time, the signal received by the photodiode will be too weak to work normally. , especially for highly polluting diesel vehicles, the frequency of maintenance will be very frequent.

Contents of the invention

In order to solve the above-mentioned technical problems, the purpose of this utility model is to provide a new type of optical platform for a transmission opacimeter. performance.

In order to achieve the above-mentioned purpose, the utility model adopts the following technical solutions:

An optical platform of a transmission type smoke meter protected by a lens, the platform includes a fan, a detection pipe, a gas chamber pipe, a flue gas inlet pipe and a photoelectric detection unit, the fan and the detection pipe are respectively two sets, and the detection pipe is connected In the fan, the two detection pipes are respectively connected to the two ends of the air chamber pipe, the smoke inlet pipe is arranged in the middle of the air chamber pipe, the photoelectric detection unit is arranged on the detection pipe, and the photoelectric detection unit includes a photoelectric receiving circuit board , photoelectric board fixing seat, collimating lens and converging lens. The photoelectric board fixing seat is provided with interconnected cavities, light-transmitting holes and lens installation ports in sequence. The cavity is arranged at the left end of the photoelectric board fixing seat. The photoelectric receiving circuit board It is arranged at the end of the cavity to close the cavity, the lens installation port is arranged at the right end of the photoelectric plate fixing seat, and the collimating lens and the converging lens are installed in the lens installation port; the photoelectric receiving The center of the circuit board is provided with a photoelectric receiving tube, which is located on the focal plane of the converging lens; the side wall of the detection pipeline is provided with a detection hole, and a lens protection device is arranged between the detection hole and the photoelectric detection unit, and the lens protection The device is composed of an insert holder and a protective insert. The insert holder is provided with a horizontal light through hole and a longitudinal insert hole. One end of the transverse light through hole is connected to the detection hole, and the other end is connected to the photoelectric board holder. The lens installation port is connected to each other; the protective insert is inserted in the longitudinal insert hole to cut off the horizontal light through hole, the protective insert is provided with a glass installation port, and the left side of the glass installation port is provided with a protective glass. Set the horizontal light through hole.

Preferably, the photoelectric panel fixing seat is fixed on the insert fixing seat by bolts, and the insert fixing seat and the detection pipeline are connected by bolts. The bolt connection is convenient for disassembly and maintenance.

Preferably, a first sealing ring is provided at the junction of the transverse light through hole and the lens installation port. The setting of the first sealing ring can prevent gas from entering the cavity and contaminating electronic equipment such as photoelectric receiving tubes.

As a preference, a second sealing ring is provided on the right side of the glass installation opening, and the second sealing ring seals the gap between the insert and the longitudinal insert hole. The second sealing ring is used to reduce gas contamination of the converging lens.

Preferably, a bolt connection port is provided between the photoelectric board fixing seat and the circuit board of the photoelectric detection unit, and the circuit board of the photoelectric detection unit is provided with an external connection joint, which is directly connected to the external drive and processing control unit.

As a preference, the gas chamber pipeline and the detection pipeline are connected with a connecting seat, the detection pipelines on both sides are of asymmetric structure, the airflow inlets of the detection pipeline are connected to the fans respectively, and the gas chamber pipeline and the detection pipeline are connected to each other. connected to the flue gas inlet.

Preferably, the air chamber pipe adopts a bent structure, and the outlet of the air chamber pipe is arranged obliquely to the flue gas inlet of the detection pipe. Without affecting the transmission and reception in the optical path system, the direction of the airflow is changed, which greatly avoids the problem of direct pollution of the lens caused by the direct injection of the engine.

As a preference, a heating device is provided on the outside of the gas chamber pipeline, and the heating device is fixed on both sides of the gas chamber pipeline by two heating strips powered by direct current, which greatly improves the production efficiency.

As a preference, the middle part of the gas chamber pipe is fixed with a fixing plate by screws, the fixing plate is inserted into the opening groove, and a smoke inlet pipe is arranged on the fixing plate; the smoke inlet pipe adopts a curved structure. The pressure of the air inlet is buffered to a large extent, and the gas will form a uniform airflow in the air chamber pipe, and the gas will be discharged by the effect of the air curtain, which can not only achieve the uniform diffusion of the gas, but also avoid the direct impact of the airflow Spray onto the lens surface.

Preferably, the platform further includes a photoelectric detection reference unit, the side wall of the cavity is provided with a reference unit installation opening, and the photoelectric detection reference unit is arranged on the reference unit installation opening. The problem of low measurement sensitivity caused by the attenuation of the LED itself is automatically adjusted through the reference channel, and the measurement sensitivity of the optical system is improved.

The utility model adopts the above-mentioned technical scheme and adds a protective lens device, which avoids the direct contact between the engine exhaust gas containing oil and gas and the lens surface, and the protective lens device can be conveniently pulled out for cleaning, which greatly improves the use of the instrument Convenience and overall performance. In addition, the utility model adopts standardized part processing, simplifies the structure of the product, and improves the efficiency of production and the accuracy of connection.

Description of drawings

Figure 1 is a schematic diagram of the front section of the utility model.

Fig. 2 is the front view of the utility model.

FIG. 3 is a top view of FIG. 2 .

Fig. 4 is a right side view of Fig. 2 .

Fig. 5 is a sectional view of A-A in Fig. 2 .

FIG. 6 is a schematic structural diagram of a photodetection unit.

Fig. 7 is a schematic structural diagram of the lens protection device.

Fig. 8 is a schematic diagram of the structure of the protection insert.

Detailed ways

Below in conjunction with accompanying drawing, specific embodiment of the present utility model is described in detail.

As shown in Figures 1 to 4, an optical platform of a lens-protected transmissive opacimeter includes a fan 4, a detection pipeline 3, an air chamber pipeline 2, a flue gas inlet pipe 1, a photoelectric detection reference unit and The photoelectric detection unit 10 includes two sets of the fan 4 and the detection pipe 3 , the two detection pipes 3 are respectively connected to the two ends of the air chamber pipe 2 , and the flue gas inlet pipe 1 is arranged in the middle of the air chamber pipe 2 . The air chamber pipe 2 adopts a bent structure, and the outlet of the air chamber pipe 2 is arranged obliquely to the flue gas inlet of the detection pipe 3 . The gas chamber pipeline 2 and the detection pipeline 3 are connected by a connecting seat 8, the detection pipeline 3 on both sides is an asymmetric structure, the air inlet of the detection pipeline 3 is connected with the fan 4 respectively, and the gas chamber pipeline 2 and the detection pipeline 3 connected to the flue gas inlet. The outside of the gas chamber pipeline 2 is provided with a heating device 15, and the heating device 15 is fixed on both sides of the gas chamber pipeline 2 with two heating strips powered by direct current, and the middle part of the gas chamber pipeline 2 is fixed with a fixing plate by screws. The fixed plate is inserted in the open slot, and the fixed plate is provided with a flue gas inlet pipe 1, and the flue gas inlet pipe 1 adopts a structure with a bending angle.

As shown in Figures 5 and 6, the photoelectric detection unit 10 is arranged on the detection pipeline 3. The photoelectric detection unit 10 includes a photoelectric receiving circuit board 7, a photoelectric board fixing seat 6, a collimating lens 11 and a converging lens 12. A cavity 61, a light-transmitting hole 62 and a lens installation port 63 are sequentially arranged in the board fixing seat 6, the cavity 61 is arranged at the left end of the photoelectric board fixing seat 6, and the photoelectric receiving circuit board 7 is arranged at the end of the cavity 61. The cavity 61 is partially closed, and the side wall of the cavity 61 is provided with a reference unit installation port, and the photoelectric detection reference unit 10 is arranged on the reference unit installation port. The problem of low measurement sensitivity caused by the attenuation of the LED itself is automatically adjusted through the reference channel, and the measurement sensitivity of the optical system is improved. As shown in Figure 5, the described lens installation port 63 is arranged on the right end of the photoelectric board holder 6, and the described collimating lens 11 and the converging lens 12 are installed and arranged in the lens installation port 63; the photoelectric receiving circuit board The center of 7 is provided with a photoelectric receiving tube 71 , and the photoelectric receiving tube 71 is located on the focal plane of the converging lens 12 . A bolt connection port is provided between the photoelectric board fixing seat 6 and the circuit board of the photoelectric detection unit 10, and the circuit board of the photoelectric detection unit 10 is provided with an external connection joint, which is directly connected to an external drive and processing control unit.

As shown in Fig. 1 and Fig. 7, a detection hole 31 is provided on the side wall of the detection pipeline 3, and a lens protection device is arranged between the detection hole 31 and the photoelectric detection unit 10, and the lens protection device consists of an insert holder 5 and a The protection insert 9 is formed, the insert holder 5 is connected with the detection pipeline 3 by bolts, and the photoelectric panel holder 6 is fixed on the insert holder 5 by bolts. The insert holder 5 is provided with a transverse light through hole 51 and a longitudinal insert hole 52. One end of the transverse light through hole 51 is in contact with the detection hole 31, and the other end is opposite to the lens installation port 63 on the photoelectric board holder 6. and a first sealing ring 13 is provided at the junction of the transverse light through hole 51 and the lens installation opening 63 . As shown in Figure 8, the protective insert 9 is inserted in the longitudinal insert hole 52 to cut off the transverse light through hole 51, the protective insert 9 is provided with a glass installation opening 91, and the left side of the glass installation opening 90 is provided with Protective glass 91, the protective glass 91 is set facing the horizontal light through hole 51, and the right side of the glass installation port 90 is provided with a second sealing ring 92, and the second sealing ring 92 seals and protects the insertion piece 9 and the longitudinal insertion hole 52 the gap between.

Claims (10)

1. An optical platform of a transmission smoke meter protected by a lens, the platform includes a fan (4), a detection pipe (3), a gas chamber pipe (2), a flue gas inlet pipe (1) and a photoelectric detection unit, the There are two sets of fan (4) and detection pipeline (3) described above, the detection pipeline (3) is connected to the fan (4), and the two detection pipelines (3) are respectively connected to the two ends of the air chamber pipeline (2). The flue gas inlet pipe (1) is arranged in the middle of the gas chamber pipe (2), and the photoelectric detection unit is arranged on the detection pipe (3). The photoelectric detection unit includes a photoelectric receiving circuit board (7), a photoelectric board fixing seat ( 6), collimating lens (11) and converging lens (12), characterized in that: the photoelectric panel fixing seat (6) is sequentially provided with interconnected cavities (61), light-transmitting holes (62) and lens installation ports (63), the cavity (61) is set at the left end of the photoelectric board fixing seat (6), and the photoelectric receiving circuit board (7) is set at the end of the cavity (61) to close the cavity (61), the The lens mounting port (63) is set at the right end of the photoelectric board fixing seat (6), and the collimating lens (11) and the converging lens (12) are installed in the lens mounting port (63); the photoelectric receiving The center of the circuit board (7) is provided with a photoelectric receiving tube (71), and the photoelectric receiving tube (71) is located on the focal plane of the converging lens (12); the side wall of the detection pipeline (3) is provided with a detection hole (31) , a lens protection device is provided between the detection hole (31) and the photoelectric detection unit, the lens protection device is composed of an insert holder (5) and a protection insert (9), and the insert holder (5) is provided with a horizontal light The through hole (51) and the longitudinal insertion hole (52), one end of the transverse light through hole (51) is in contact with the detection hole (31), and the other end is connected to the photoelectric board fixing seat (6) with a lens installation port ( 63) docking; the protective insert (9) is inserted in the longitudinal insert hole (52) to cut off the horizontal light through hole (51), and the protective insert (9) is provided with a glass installation port (90), A protective glass (91) is arranged on the left side of the glass installation opening (90), and the protective glass (91) is arranged facing the horizontal light through hole (51). 2. The optical platform of a lens-protected transmissive opacimeter according to claim 1, characterized in that: the photoelectric board fixing seat (6) is fixed on the insert fixing seat (5) by bolts, and the insert Bolts are provided between the fixing seat (5) and the detection pipeline (3). 3. The optical platform of a lens-protected transmissive opacimeter according to claim 1, characterized in that a first sealing ring ( 13). 4. The optical platform of a lens-protected transmissive opacimeter according to claim 1, characterized in that: a second sealing ring (92) is provided on the right side of the glass installation port (90), and the second sealing ring (92) Seal the gap between the protection insert (9) and the longitudinal insert hole (52). 5. The optical platform of a lens-protected transmissive opacimeter according to claim 1, characterized in that: a bolt connection port is provided between the photoelectric board fixing seat (6) and the circuit board of the photoelectric detection unit, and the photoelectric board The circuit board of the detection unit is provided with an external connection joint, which is directly connected to the external drive and processing control unit. 6. The optical platform of a lens-protected transmissive opacimeter according to claim 1, characterized in that: the gas chamber pipe (2) and the detection pipe (3) are connected by a connecting seat (8), The detection pipes (3) on both sides are of asymmetrical structure, the air inlets of the detection pipes (3) are respectively connected with the fans (4), the gas chamber pipes (2) and the flue gas inlets of the detection pipes (3) connected. 7. The optical platform of a lens-protected transmissive opacimeter according to claim 6, characterized in that: the air chamber pipe (2) adopts a bent structure, and the outlet of the air chamber pipe (2) is diagonally opposite to the detection pipe (3) The flue gas inlet setting. 8. The optical platform of a lens-protected transmissive opacimeter according to claim 1, characterized in that: a heating device (15) is provided on the outside of the gas chamber pipe (2), and the heating device (15 ) are fixed on both sides of the air chamber pipeline (2) by two pieces of heating strips powered by direct current. 9. The optical platform of a lens-protected transmissive opacimeter according to claim 1, characterized in that: the middle part of the gas chamber pipe (2) is fixed with a fixing plate by screws, and the fixing plate is inserted in the opening groove Inside, a flue gas inlet pipe (1) is arranged on the fixed plate; the flue gas inlet pipe (1) adopts a curved structure. 10. The optical platform of a lens-protected transmissive opacimeter according to claim 1, characterized in that the platform also includes a photoelectric detection reference unit (10), and the side wall of the cavity (61) is provided with A reference unit installation port, the photoelectric detection reference unit (10) is arranged on the reference unit installation port.