JP6436343B2 - Sensor unit for infrared gas analyzer and detector for infrared gas analyzer - Google Patents

Description

  The present invention relates to an infrared gas analyzer sensor unit and an infrared gas analyzer detector used in an infrared gas analyzer.

  When infrared rays pass through a gas, light having a specific wavelength that is unique to the gas is absorbed by the gas. An infrared gas analyzer performs analysis using this phenomenon. The infrared gas is transmitted through the sample gas and absorbed by the measurement target gas contained in the sample gas. The concentration of the measurement target gas contained in the sample gas is measured. As a prior art example of such an infrared gas analyzer, a single beam infrared gas analyzer is known.

  The single beam infrared gas analyzer will be described. As shown in FIG. 3, the infrared gas analyzer 1 includes a light source unit 10, an optical chopper 20, a sample cell 30, and an infrared gas analyzer detector 40.

  The light source unit 10 further includes a light source chamber 11, an infrared light source 12, and an infrared transmission window 13. The light source chamber 11 houses the infrared light source 12. The infrared light source 12 in the light source chamber 11 is connected to a power source and a drive circuit (not shown), generates heat when a drive voltage is applied, and emits infrared rays according to the heat generation temperature. The infrared transmission window 13 transmits this infrared ray. Such a light source unit 10 is disposed on one end side of the sample cell 30 and irradiates infrared rays toward the inside of the sample cell 30. This infrared light passes through the light chopper 20.

  The optical chopper 20 includes a rotating disk 21 and a motor 22. The rotating disk 21 is located between the light source unit 10 and the sample cell 30. The rotating disk 21 is formed with an opening or a notch through which infrared rays pass. When the motor 22 rotationally drives the rotating disk 21, the infrared light emitted from the light source unit 10 is turned on / off at a predetermined period and incident on the sample cell 30 as intermittent infrared light.

  The sample cell 30 includes a cell body 31, sample gas inlets / outlets 32a and 32b, and infrared transmission windows 33a and 33b. The cell body 31 has a cylindrical shape made of a metal material such as stainless steel, and infrared transmission windows 33a and 33b formed of an infrared transmission material are fixed to both ends thereof. The sample gas is introduced from one of the sample gas inlets 32a and 32b, flows through the cell body 31, and then is led out from the other of the sample gas inlets 32a and 32b.

  As shown in FIGS. 3 and 4, the infrared gas analyzer detector 40 includes a main body block 41, a first gas chamber 42, a second gas chamber 43, infrared transmission windows 44a, 44b, 44c, a first passage 45, A second passage 46 is provided. In detail, as shown in FIG. 4, a countersink hole 47, a recess 48, a sensor housing space 49, and an infrared gas analyzer sensor unit 50 are further provided. The infrared gas analyzer sensor unit 50 is configured to be detachable from the main body block 41. The infrared gas analyzer detector 40 is disposed on the other end side of the sample cell 30 (opposite side of the light source unit 10).

  First, details of the infrared gas analyzer sensor unit 50 will be described. As shown in FIGS. 4, 5, and 6, the infrared gas analyzer sensor unit 50 includes a hermetic terminal 51, a flow sensor 52, a connection terminal (lead pin) 53, a bonding wire 54, a sensor passage 55, and a sensor mounting surface. 56 and a glass sealing part 57 are provided.

  The hermetic terminal 51 is a multi-stage rotating body having a protrusion 51a on the side surface, and a sensor mounting surface 56 on which the flow sensor 52 is mounted is formed on the plane. The connection terminal (lead pin) 53 electrically connects the flow sensor 52 and an external device (not shown). The connection terminal (lead pin) 53 is held and fixed by the glass sealing portion 57 in a state of penetrating the mounting hole 51b drilled in the hermetic terminal 51, as particularly shown in FIGS. 6 (a) and 6 (b). One end of the sensor mounting surface 56 protrudes from the sensor mounting surface 56 and the other end protrudes from the lower surface.

  As shown in FIGS. 5A and 5B, the above-described sensor passage 50 is provided at the center of the hermetic terminal 51. Since part of the gas passage is formed, it can be easily incorporated into the infrared gas analyzer detector 40 after mounting.

  Next, an infrared gas analyzer detector 40 incorporating such an infrared gas analyzer sensor unit 50 will be described. As shown in FIGS. 3 and 4, the first gas chamber 42 and the second gas chamber 43 of the infrared gas analyzer detector 40 are arranged side by side from the sample cell 30 side along the infrared optical path. . In addition, infrared transmission windows 44a, 44b and 44c made of an infrared transparent material are provided. The first gas chamber 42 and the second gas chamber 43 are partitioned by an infrared transmission window 44b. An infrared transmission window 44 a is provided on the front side of the first gas chamber 42, and an infrared transmission window 44 c is provided on the rear side of the second gas chamber 43. Such first gas chamber 42 and second gas chamber 43 form a single space. In each of the first gas chamber 42 and the second gas chamber 43, a filling gas having the same absorption characteristics as the measurement target gas is enclosed.

  A stepped recess 48 including a small diameter hole 48 a and a large diameter hole 48 b is formed in the lower part of the main body block 41. The main body portion of the multi-stage rotating body-shaped hermetic terminal 51 is fitted into the large-diameter hole portion 48 b of the recess 48. The counterbore hole 47 is formed so as to be fitted to the protrusion 51 a of the hermetic terminal 51.

  Then, in a state where the hermetic terminal 51 is fitted into the concave portion 48 of the main body block 41 with the sensor mounting surface 56 facing upward, the outer peripheral edge portion of the sensor mounting surface 56 contacts the stepped portion of the concave portion 48 of the main body block 41. Thus, the sensor housing space 49 is formed. The sensor housing space 49 is a space defined by the small diameter hole portion 48 a of the main body block 41 and the sensor mounting surface 56 of the infrared gas analyzer sensor unit 50.

  Since the filling gas is sealed in the first gas chamber 42 and the second gas chamber 43, it is necessary to keep airtight stably for a long period of time, and a hermetic terminal using an adhesive having excellent airtightness such as an epoxy adhesive. 51 is bonded to the main body block 41. With the attachment, the flow sensor 52 is arranged in the sensor accommodating space 49 in a state where the infrared gas analyzer sensor unit 50 is fixed without any gap.

  The first passage 45 is a passage formed in the main body block 41 such that one end communicates with the first gas chamber 42 and the other end communicates with the small diameter hole portion 48a. The second passage 46 is a passage formed in the main body block 41 so that one end communicates with the second gas chamber 43 and the other end communicates with the side wall of the large-diameter hole 48b.

  Inside the hermetic terminal 51, an in-sensor passage (third passage) 55 extending from the center of the hermetic terminal 51 toward the outer peripheral direction is formed. One end of the sensor inner passage (third passage) 55 communicates with the center of the sensor mounting surface 56 and the other end communicates with the side wall (circumferential wall) of the hermetic terminal 51.

  Then, the hermetic terminal 51 is fitted into the recess 48 of the main body block 41 so that the opening of the sensor inner passage (third passage) 55 and the opening of the second passage 46 of the main body block 41 coincide with each other. A gas passage including a passage 45, a second passage 46, and a sensor inner passage (third passage) 55 is connected, and the first gas chamber 42, the sensor accommodating space 49, and the second gas chamber 43 communicate with each other. Then, the flow sensor 52 in the sensor accommodating space 49 can detect the flow of fluid from the first gas chamber 42 to the second gas chamber 43.

  Next, gas analysis by the infrared gas analyzer 1 of the prior art example will be described. As shown in FIG. 3, the sample cell 30 is in a state where the sample gas is introduced from one of the sample gas inlets 32 a and 32 b and flows through the sample cell 30.

  Infrared rays (IR) radiated from the infrared light source 12 are turned on and off at a predetermined cycle by an optical chopper 20 that is rotationally driven by a motor 22 to become intermittent infrared rays. The infrared light is incident on the sample cell 30 whose both ends are sealed by the infrared transmission windows 33a and 33b, and passes through the sample gas including the measurement target gas. At this time, infrared rays are absorbed with an absorption amount corresponding to the concentration of the measurement target gas contained in the sample gas. Then, the infrared light after the absorption is incident on the infrared gas analyzer detector 40.

  In the infrared gas analyzer detector 40, infrared light that has passed through the sample cell 30 in the preceding stage is incident on the first gas chamber 42 and the second gas chamber 43. The first gas chamber 42 and the second gas chamber 43 are filled with a filling gas having the same absorption characteristics as the measurement target gas. A part of infrared rays is first absorbed in the first gas chamber 42, and then the rest is absorbed in the second gas chamber 43. This infrared ray is a heat source, and the filling gas in each of the first gas chamber 42 and the second gas chamber 43 expands in proportion to the amount of infrared absorption, and the pressure in the first gas chamber 42 and the second gas chamber 43 is increased. An increase occurs.

  Therefore, due to the pressure difference based on the difference in the infrared absorption amount of the filling gas in the first gas chamber 42 and the second gas chamber 43, the direction from the first gas chamber 42 to the second gas chamber 43 in the direction of arrow G (see FIG. 4). A minute gas flow occurs. The first passage 45 provided in the main body block 41 leads to the second passage 46 provided in the main body block 41 via the sensor housing space 49 and the sensor inner passage (third passage) 55 of the hermetic terminal 51. Such a minute gas flow is detected by the flow sensor 52 as a resistance change corresponding to a change in pressure or flow rate, and a concentration signal V is output. The concentration signal V is configured to be converted into an electric signal (gas concentration detection signal) by an arithmetic processing circuit (not shown) and output to the outside. Then, for example, the measurement gas concentration can be obtained by the “Lambert-Beer equation”. A similar conventional technique is also disclosed in Patent Document 1, for example.

JP 2013-185867 A (FIGS. 1 and 4)

  As shown in FIG. 6, the hermetic terminal 51 of the prior art has an integral structure in which the connection terminal (lead pin) 53 is directly attached to the attachment hole 51b, but the flow sensor 52 and the connection terminal (lead pin) 53 are mechanical machines. Since the apparatus performs wire bonding, it is necessary to fix the connection terminal (lead pin) 53 to the hermetic terminal 51 while performing accurate positioning. For example, a dedicated manufacturing jig is used to fix the connection terminal 51 to the mounting hole 51b of the hermetic end 51. The glass sealing portion 57 was formed and fixed in a state where the connection terminal (lead pin) 53 was positioned.

  Now, the flow sensor 52 as shown in FIG. 5 detects a minute gas flow, and is improved frequently. When the shape and dimensions of the flow sensor 52 are changed due to the improvement, the hermetic terminal 51 for fixing the flow sensor 52 needs to be newly designed again. In addition, as the shape and dimensions of the hermetic terminal 51 are changed, it is necessary to newly redesign the manufacturing jig. Furthermore, depending on the case, it is necessary to determine the conditions for wire bonding anew.

  As described above, the sensor unit 50 for the infrared gas analyzer is frequently changed in design. However, it takes time and effort to change the design, and there is a situation where it is desired to save as much effort as possible when changing the design. there were.

  Therefore, the present invention has been made in view of the above problems, and its purpose is to reduce the number of parts to be changed in design even when the flow sensor is improved, and to be able to manufacture without a manufacturing jig, An object of the present invention is to provide an infrared gas analyzer sensor unit that reduces manufacturing costs and labor, and an infrared gas analyzer detector equipped with the infrared gas analyzer sensor unit.

In order to achieve the above object, the sensor unit for an infrared gas analyzer according to claim 1 comprises:
A flow sensor for measuring the flow of gas;
A sensor mounting surface on which the flow sensor is mounted, and a plurality of mounting holes in which the sensors are attached surface and communicating, and missing closure is formed, a sensor base having a
What der those previously fixed to the connection terminal and an annular cover the glass sealing portion, it is brought into contact with the exit fasten the axial end of the annular cover is fitted to the annular cover to the mounting holes of the multiple A plurality of hermetic terminals that are each fixed using an adhesive in
A plurality of bonding wires that connect to one end of a plurality of pre Kise' connection terminals projecting from the front Symbol sensor mounting surface and an electrode portion of the flow sensor,
It is characterized by providing .

The detector for an infrared gas analyzer according to claim 2 is:
A sensor unit for an infrared gas analyzer according to claim 1;
A main body block having a stepped recess composed of a large diameter hole portion and a small diameter hole portion,
Before SL and fitted to said sensor base Previous Symbol recess toward the sensor mounting surface inwardly to a state of being fixed to the infrared gas analyzer sensor unit to the body block, the outer peripheral edge portion of the sensor mounting surface before the flow sensor is disposed in the sensor housing space formed by the stepped portion of the serial recess and abuts, characterized and Turkey.

The infrared gas analyzer detector according to claim 3, wherein the infrared gas analyzer detector according to claim 2,
The main body block has first and second gas chambers filled with a filling gas having the same absorption characteristics as the measurement target gas,
Before SL body block and said sensor base, the first, which further comprises a gas passage communicating with the second gas chamber,
The gas passage is formed in the main body block so that one end opens into the first gas chamber and the other end opens into the small-diameter hole, and the first gas chamber communicates with the small-diameter hole. The first passage and one end open into the second gas chamber and the other end opens toward the side wall of the large-diameter hole, and the second gas chamber communicates with the large-diameter hole. A second passage formed in the main body block and formed in the sensor base so as to extend in an outer peripheral direction from the center of the sensor base so that one end opens at the center of the sensor mounting surface and the other end opens at the side wall. The third passage,
Wherein the first said sensor base in a state fitted to the recess, the second, third passage is configured to communicate with each other.

  According to the present invention, even when the flow sensor is improved, the number of parts to be changed in design is reduced, and the sensor for an infrared gas analyzer can be manufactured without a manufacturing jig so as to reduce manufacturing cost and labor. And a detector for an infrared gas analyzer equipped with the infrared gas analyzer sensor unit can be provided.

It is a block diagram of the sensor part for infrared gas analyzers of the form for implementing this invention, Fig.1 (a) is a top view, FIG.1 (b) is AA sectional drawing. It is explanatory drawing of the state which removed the flow sensor from the sensor part for infrared gas analyzers, FIG.2 (a) is a top view, FIG.2 (b) is BB sectional drawing, FIG.2 (c) is a hermetic terminal. It is explanatory drawing. It is a block diagram of an infrared gas analyzer. It is a block diagram of the detector for infrared gas analyzers. FIG. 5A is a structural diagram of a sensor unit for an infrared gas analyzer according to a prior art example, FIG. 5A is a plan view, and FIG. 5B is a CC cross-sectional view. It is explanatory drawing of the state which removed the flow sensor from the sensor part for infrared gas analyzers of a prior art example, Fig.6 (a) is a top view, FIG.6 (b) is DD sectional drawing.

  Subsequently, an infrared gas analyzer sensor unit and an infrared gas analyzer detector according to an embodiment for carrying out the present invention will be described. In the present invention, the structure of the infrared gas analyzer sensor unit 100 (see FIGS. 1 and 2) is novel. The structure of the infrared gas analyzer detector 40 (see FIG. 4) on which the infrared gas analyzer sensor unit 100 is mounted is also novel.

  Hereinafter, the infrared gas analyzer sensor unit 100 will be described, and the infrared gas analyzer detector 40 shown in FIG. 4 is used in the infrared gas analyzer sensor unit 50 (FIG. 4). 5 (see FIG. 6), it is assumed that the infrared gas analyzer sensor unit 100 (see FIG. 1 and FIG. 2) of the present invention is mounted, and the configuration and analysis functions are the same. Is omitted.

  Further, as for the infrared gas analyzer, the infrared gas analyzer sensor unit 100 (FIG. 1) of the present invention is used instead of the infrared gas analyzer sensor unit 50 (see FIGS. 5 and 6) of the infrared gas analyzer 1 of FIG. , Refer to FIG. 2), and the configuration and analysis function are the same. Only the infrared gas analyzer sensor unit 100 will be described below.

  As shown in FIGS. 1A and 1B, the infrared gas analyzer sensor unit 100 includes a hermetic terminal 101, a sensor base 102, a flow sensor 103, a bonding wire 104, a sensor passage 105, and a sensor mounting surface. 106.

  The flow sensor 103 is a pyroelectric flow sensor including a pyroelectric detection unit including, for example, an upper electrode, a pyroelectric thin film, a lower electrode, a heater, and the like. The center and the center of the through hole of the pyroelectric detection unit are fixed on the sensor mounting surface 106 so as to coincide with each other.

  As shown in FIG. 1A, at the four corners of the rectangular flow sensor 52, there are a total of four electrode portions for extracting an upper electrode, an electrode portion for extracting a lower electrode, and two electrode portions for extracting a heater electrode. Two electrode portions are formed. Then, one end of the four connection terminals 101a protrudes from the sensor mounting surface 106 so as to be close to the four sides of the flow sensor 103, and each electrode portion and the connection terminal 101a are connected by a bonding wire 104. .

  As shown in FIG. 2C, the hermetic terminal 101 includes a connection terminal (lead pin) 101a, an annular cover 101b, and a glass sealing portion 101c. In a state where the connection terminal (lead pin) 101a formed of a conductive material is inserted into the annular cover 101b formed of metal, glass sealing resin 101c is formed by filling the annular cover 101b with glass resin. The hermetic terminal 101 is formed by curing the sealing portion 101c. The annular cover 101b is made of a material such as SUS in detail, and the surface is gold-plated to reduce the influence of corrosive gas or the like. A large number of such hermetic terminals 101 are formed in advance.

The sensor base 102 includes a mounting hole 102b as shown in FIGS. 2 (a) and 2 (b). The attachment hole 102b is formed with the same diameter as the outer diameter of the annular cover 101b. Further, the mounting holes 102b are missing fastened 102c is formed, it is fixed at a predetermined position when in contact with the 102c fastening omission axial end of the annular cover 101b. The sensor base 102 is made of a material such as SUS, and the surface is plated with gold in order to reduce the influence of a corrosive gas or the like.

  A plurality (four in this embodiment) of the attachment holes 102b are formed in the sensor base 102, and the hermetic terminals 101 are fixed to all of the attachment holes 102b with an adhesive.

  Then, one surface (plane) of the sensor base 102 is used as a sensor mounting surface 106, and the flow sensor 103 is fixed to the sensor mounting surface 106. A flat mounting structure capable of automatic wire bonding is employed for connection between each electrode portion of the flow sensor 103 and the connection terminal 101 a of the hermetic terminal 101. The bonding wire 104 is formed by wire bonding, and the infrared gas analyzer sensor unit 100 is formed. By employing wire bonding, manual wiring work can be eliminated, the efficiency of sensor mounting can be improved, and reliability can be improved. The function of the infrared gas analyzer sensor unit 100 is the same as that of the infrared gas analyzer sensor unit 50 described above.

  The infrared gas analyzer sensor unit 100 of the present invention described above has the following advantages.

(1) The infrared gas analyzer sensor unit 100 of the present invention is easy to manufacture.
In the conventional infrared gas analyzer sensor unit 40, four connection terminals (lead pins) 53 are positioned with respect to the hermetic terminal 51 using a manufacturing jig, and are integrally formed by glass sealing. The manufacture was not easy.

On the other hand, an annular cover in the infrared gas analyzer sensor unit 100 of the present invention, when fixing the hermetic terminal 101 to the sensor base 102, the mounting hole 102b of the sensor base 102, is fitted an annular cover 101b of the hermetic terminal 101 it is fixed by an adhesive being in contact with the axial end portion of the dropout catch 102c of 101b, can in fixed while positioning, by eliminating the need for manufacturing jig, mounting is easy.

  In addition, the hermetic terminal 101 itself is also positioned in advance with respect to the annular cover 101b, and a single hermetic terminal 101 in which one connection terminal (lead pin) 101a is fixed by forming a glass sealing portion 101c by glass sealing. The positioning and manufacturing of each component of the hermetic terminal 101 are easy. Even when a manufacturing jig for the hermetic terminal 101 is used, even if the design of the flow sensor 52 is changed, it is not necessary to change the manufacturing jig.

(2) The design of the infrared gas analyzer sensor unit 100 of the present invention can be easily changed.
In the conventional sensor unit 40 for infrared gas analyzer, when the flow sensor 52 is improved, the shape of the hermetic terminal 51 is also changed and the manufacturing for attaching the connection terminal (lead pin) 52 to the hermetic terminal 51 is performed. It was necessary to change the jig, which required labor and cost.

  In the infrared gas analyzer sensor unit 100 of the present invention, even when the flow sensor is improved, the hermetic terminal 101 can be attached to the sensor base 102 without a manufacturing jig. Is reduced.

  In addition, the material of the sensor base 102 can be easily changed. For example, when a corrosive gas is sealed, the material can be easily changed to a material that takes corrosion resistance into consideration. Further, in wire bonding, if the material and position of the connection terminal (lead pin) 101a of the hermetic terminal 101 can be made the same, the bonding condition becomes the same, so that re-evaluation of the bonding condition and the like is not necessary.

(3) The infrared gas analyzer detector 40 of the present invention is easy to manufacture.
The sensor base 102 of the infrared gas analyzer sensor unit 100 is fitted into the concave portion 48 of the main body block 41 with the sensor mounting surface 106 facing inward, and the outer peripheral edge of the sensor mounting surface 106 and the step of the concave portion of the main body block 41 are fitted. Since the flow sensor 103 is arranged in the predetermined sensor accommodating space 49 simply by contacting the attached portion, the assembly of the infrared gas analyzer sensor unit 100 to the main body block 41 can be easily completed. Improves work efficiency.

  The present invention as described above can be used for an infrared gas analyzer that measures the concentration of a measurement target gas contained in a sample gas by using the infrared absorption effect inherent to gas molecules. Used for process monitoring related to gas concentration, combustion gas analysis in boilers and furnaces, air pollution monitoring, measurement of automobile exhaust gas, etc.

1: Infrared gas analyzer 10: Light source 11: Light source chamber 12: Infrared light source
13: Infrared transmission window 20: Optical chopper 21: Rotating disk 22: Motor 30: Sample cell 31: Cell body 32a, 32b: Sample gas inlet / outlet port 33a, 33b: Infrared transmission window 40: Infrared gas analyzer detector 41: Main body block 42: first gas chamber 43: second gas chambers 44a, 44b, 44c: infrared transmission window 45: first passage 46: second passage 47: counterbore 48: recess
48a: Small-diameter hole 48b: Large-diameter hole 49: Sensor accommodation space 100: Sensor unit for infrared gas analyzer
101: Hermetic terminal 101a: Connection terminal (lead pin)
101b: annular cover 101c: glass sealing part
102: sensor base 102a: protrusion 102b: mounting hole
102c: retainer 103: flow sensor 104: bonding wire 105: sensor passage 106: sensor mounting surface V: sensor output

Claims (3)

A flow sensor for measuring the flow of gas;
A sensor mounting surface on which the flow sensor is mounted, and a plurality of mounting holes in which the sensors are attached surface and communicating, and missing closure is formed, a sensor base having a
What der those previously fixed to the connection terminal and an annular cover the glass sealing portion, it is brought into contact with the exit fasten the axial end of the annular cover is fitted to the annular cover to the mounting holes of the multiple A plurality of hermetic terminals that are each fixed using an adhesive in
A plurality of bonding wires that connect to one end of a plurality of pre Kise' connection terminals projecting from the front Symbol sensor mounting surface and an electrode portion of the flow sensor,
A sensor unit for an infrared gas analyzer, comprising: A sensor unit for an infrared gas analyzer according to claim 1;
A main body block having a stepped recess composed of a large diameter hole portion and a small diameter hole portion,
Before SL and fitted to said sensor base Previous Symbol recess toward the sensor mounting surface inwardly to a state of being fixed to the infrared gas analyzer sensor unit to the body block, the outer peripheral edge portion of the sensor mounting surface before infrared gas analyzer for the detector where the flow sensor in the sensor housing space formed by the stepped portion abuts is characterized and placed Turkey the serial recess. The detector for an infrared gas analyzer according to claim 2,
The main body block has first and second gas chambers filled with a filling gas having the same absorption characteristics as the measurement target gas,
Before SL body block and said sensor base, the first, which further comprises a gas passage communicating with the second gas chamber,
The gas passage is formed in the main body block so that one end opens into the first gas chamber and the other end opens into the small-diameter hole, and the first gas chamber communicates with the small-diameter hole. The first passage and one end open into the second gas chamber and the other end opens toward the side wall of the large-diameter hole, and the second gas chamber communicates with the large-diameter hole. A second passage formed in the main body block and formed in the sensor base so as to extend in an outer peripheral direction from the center of the sensor base so that one end opens at the center of the sensor mounting surface and the other end opens at the side wall. The third passage,
The sensor base of the first in a state fitted to the recess, second, infrared gas analyzer detector, wherein a third passage is configured to communicate with each other.

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