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CN-116399827-B - Gas concentration infrared sensor

CN116399827BCN 116399827 BCN116399827 BCN 116399827BCN-116399827-B

Abstract

The invention belongs to the technical field of gas detection, and particularly provides a gas concentration infrared sensor which comprises a barrel and a circuit board, wherein the circuit board is arranged in the barrel and divides the barrel into a first space and a second space, an infrared light emitting assembly is arranged in the first space, an infrared detection assembly is arranged in the second space, a first reflection assembly is arranged in the first space, a second reflection assembly is arranged in the second space, a notch is formed in the edge of the circuit board and is communicated with the first space and the second space, a third reflection assembly is arranged at the notch position, and infrared light can be reflected among the first reflection assembly, the third reflection assembly and the second reflection assembly in sequence and transmitted to the infrared detection assembly. The invention can form a double-layer reflection light path in the cylinder body, and ensure that the outer diameter and the thickness of the infrared sensor are smaller than set values under the condition of ensuring the light path length, thereby realizing the miniaturization design of the infrared sensor.

Inventors

  • LI BIN
  • ZHANG ZHIQIANG
  • SUN SHAOKUN
  • NING PENG
  • DU YANXUE
  • GUAN WEI

Assignees

  • 青岛澳瑞德电子有限公司

Dates

Publication Date
20260505
Application Date
20230317

Claims (7)

  1. 1. A gas concentration infrared sensor, characterized by comprising A cylinder body with two ends open; the circuit board is arranged in the cylinder body and divides the cylinder body into a first space and a second space along the axial direction, an infrared light emitting component is arranged in the first space, and an infrared detection component is arranged in the second space; The first space is internally provided with a first reflection assembly, the first reflection assembly comprises a plurality of first reflection pieces arranged on the inner wall of the cylinder, the second space is internally provided with a second reflection assembly, the second reflection assembly comprises a plurality of second reflection pieces arranged on the inner wall of the cylinder, the edge of the circuit board is provided with a notch, the notch is communicated with the first space and the second space, the notch is provided with a third reflection assembly, and the third reflection assembly comprises a plurality of third reflection pieces; The first reflection parts can receive infrared light emitted by the infrared light emitting assembly and sequentially reflect the infrared light in a first space and then transmit the infrared light to the third reflection parts, the third reflection assembly can transmit the infrared light to the second reflection assembly, and the second reflection parts can sequentially reflect the infrared light and transmit the infrared light to the infrared detection assembly; The end caps are respectively sleeved at two ends of the cylinder body, and each end cap comprises a cylinder sleeved outside the cylinder body and an end cover at the end part of the cylinder, wherein the end covers are provided with air inlets; An elastic reset piece is arranged between the two cylinders, and can accumulate elastic potential energy when the cylinders move towards the circuit board to reach a compression state and release the elastic potential energy when the cylinders move away from the circuit board and reach an expansion state; the barrel comprises a rigid part and elastic parts respectively arranged at two ends of the rigid part, one end, far away from the rigid part, of the elastic part is provided with an end cover, an air inlet hole is formed in the end cover, and the rigid part is internally provided with the first reflecting component, the second reflecting component and the circuit board.
  2. 2. The gas concentration infrared sensor according to claim 1, wherein said elastic restoring member comprises a spring having no elastic force when said cylinder is in said expanded state, and said spring accumulating elastic potential energy when said cylinder is in a compressed state.
  3. 3. The gas concentration infrared sensor of claim 1, wherein the first reflecting member of the first reflecting assembly is divided into a concave mirror and a flat mirror, the second reflecting assembly comprises a concave mirror and a flat mirror, and the third reflecting member is a flat mirror.
  4. 4. A gas concentration infrared sensor according to claim 1 or 3, wherein the first reflecting assembly comprises at least one first concave mirror and a plurality of first plane mirrors which are arranged in sequence along the optical path and have reflecting surfaces perpendicular to the circuit board, and one first plane mirror at the extreme end of the optical path is used for transmitting infrared light parallel to the circuit board to the third reflecting assembly.
  5. 5. The gas concentration infrared sensor according to claim 1 or 3, wherein the third reflecting component comprises a second plane mirror in the first space and a third plane mirror in the second space, the second plane mirror and the third plane mirror face the circuit board respectively and have an included angle of 45 degrees with the circuit board, the second plane mirror can receive the infrared light parallel to the circuit board reflected by the first reflecting component and transmit the infrared light to the third plane mirror along the direction perpendicular to the circuit board, and the third plane mirror can receive the infrared light along the direction perpendicular to the circuit board and transmit the infrared light to the second reflecting component along the horizontal direction.
  6. 6. A gas concentration infrared sensor according to claim 1 or 3, wherein the second reflecting assembly comprises a plurality of fourth plane mirrors and at least one second concave mirror, which are arranged in sequence along the optical path and have reflecting surfaces perpendicular to the circuit board, the second concave mirror reflecting infrared light to the infrared detecting assembly.
  7. 7. The gas concentration infrared sensor according to claim 1, wherein the first, second and third reflecting members are formed of protrusions and recessed surfaces of an inner wall surface of the cylinder toward the inner cavity of the cylinder, and a reflective coating is coated at the protrusions and recessed surfaces to form a reflective surface.

Description

Gas concentration infrared sensor Technical Field The invention belongs to the technical field of gas detection, and particularly provides a gas concentration infrared sensor. Background NDIR gas sensors are based on the principle of non-dispersive infrared absorption, when infrared light passes through a gas to be measured, these gas molecules absorb infrared light of a specific wavelength, whose absorption relationship obeys Lambert-Beer law of absorption, and because of the vibration between molecules, the gas molecules have different, specific atomic absorption wavelengths in the infrared band, and thus the gas concentration can be detected by measuring the absorption of optical energy at a specific wavelength. In the prior patent application CN202320487495.X, a mounting groove is arranged at a base, a plurality of reflecting pieces are arranged in the mounting groove, the reflecting pieces are positioned at the inner side wall of the mounting groove and far away from an end cover structure at the top, infrared light emitted by an infrared light emitter is reflected among the plurality of reflecting pieces in sequence and then enters an infrared detector, when the infrared light passes through gas in the mounting groove along a light path, the concentration of the gas in the mounting groove is obtained by measuring the loss of the infrared light. In the technical scheme, the transmission light path of the infrared light is basically parallel to the circuit board and the end cover at the base, namely, the end cover does not participate in reflection of infrared light, so that the air inlet at the end cover does not need to consider avoiding light paths, and the number and the size of the air inlet are convenient to increase. The inventor believes that the above-mentioned scheme is favorable to reducing the length of infrared sensor in the direction of perpendicular circuit board (i.e. base axial), but is unfavorable to reducing the external diameter size of infrared sensor along circumference, and reflector itself needs to occupy certain volume at the inner wall of mounting groove, and the light path length is not enough when the reflection piece quantity of arranging is less, and when the reflection piece quantity of arranging is more, the mounting groove volume that needs becomes big for the circumference size of base and infrared sensor is too big. That is, this solution is inconvenient to achieve a balance of the axial dimension of the gas concentration infrared sensor in the direction perpendicular to the circuit board and the circumferential dimension. In addition, in the technical scheme, although the air inlet hole is arranged at the end cover of the infrared sensor and is used for communicating the mounting groove with the external environment, the size and the number of the air inlet holes are designed to be problematic, and particularly, when the size of the air inlet hole is small, the air inlet hole is slow, sundries and dust can be prevented from entering the mounting groove, but the characteristic of slow air inlet enables the infrared sensor to react slowly and cannot realize measurement quickly, and when the size of the air inlet hole is large, although the air inlet is fast and can be measured quickly, the protection of internal electric elements is poor. Disclosure of Invention It is an object of the present invention to provide a gas concentration infrared sensor to solve at least one of the above-mentioned technical problems. In order to solve the problems in the prior art, one or more embodiments of the present invention provide a gas concentration infrared sensor, which comprises a barrel and a circuit board, wherein two ends of the barrel are opened, the circuit board is arranged in the barrel, the barrel is axially divided into a first space and a second space by the circuit board, an infrared light emitting component is arranged in the first space, an infrared detection component is arranged in the second space, a first reflection component is arranged in the first space, the first reflection component comprises a plurality of first reflection components arranged on the inner wall of the barrel, a second reflection component is arranged in the second space, the second reflection component comprises a plurality of second reflection components arranged on the inner wall of the barrel, a notch is arranged at the edge of the circuit board, the notch is communicated with the first space and the second space, a third reflection component is arranged at the notch position, the third reflection component comprises a plurality of third reflection components, the plurality of first reflection components can receive infrared light emitted by the infrared light emitting component and transmit the infrared light to the third reflection components after sequentially reflecting the infrared light in the first space, the third reflection components can transmit the infrared light to the second