Detector unit and method for manufacturing the detector unit

Abstract

To provide a detector unit which facilitates exchange and fixation of a Peltier element, and a manufacturing method of the same.SOLUTION: A detector unit 1 has a detector 11, a detector case 12, a temperature adjustment unit 20 for adjusting a temperature of the detector, a heat absorbing / radiating member 50, and spacers 41 and 43 which are arranged between the detector case and the heat absorbing / radiating member. The temperature adjusting unit includes a plate-like Peltier element 21, a first heat conductive member 22 which can be compressed and is arranged on a first surface, and a second heat conductive member 23 which can be compressed and is arranged on a second surface. The first heat conductive member is brought into contact with a mounting surface 12a of the detector case, the second heat conductive member is brought into contact with the heat absorbing / radiating member, and the spacer is brought into contact with the mounting surface and the heat absorbing / radiating member. In a first direction Z, a length L1 of the spacer is shorter than a length L2 of the temperature adjusting unit in an unloaded condition and is longer than a length L3 of the Peltier element.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a detector unit and a method for manufacturing the detector unit.

Background Art

[0002] A detector detects various qualitative and quantitative information in a natural environment or an artificial environment and converts this information into a signal such as an electrical signal. Such a detector may be used in a state incorporated in a measuring instrument (for example, a gas concentration measuring device, etc.). For example, when the measuring instrument is used in a measuring environment with a low (or high) temperature, or when the detector is used while being cooled, in order to maintain the detection accuracy of the detector, the temperature of the detector is adjusted by a temperature adjusting member such as a Peltier element (for example, see Patent Document 1).

[0003] In the technique disclosed in Patent Document 1, a cooling block is attached to a detector (photomultiplier tube), and the heat absorption surface of a Peltier element is attached to the cooling block. The detector, the cooling block, and the Peltier element are housed in a box. Further, a heat radiating plate (so-called heat sink) having heat radiating fins is attached to the heat radiating surface of the Peltier element. In this cooling structure, the detector is cooled below room temperature by the Peltier element, and the heat from the Peltier element is radiated from the heat radiating plate.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In this technology, to prevent condensation from forming on the detector, cooling block, and Peltier element, the space (gaps) inside the box is filled with polyurethane foam, which functions as an insulating material. Therefore, in order to replace the detector or Peltier element in this technology, it is necessary to remove the polyurethane foam that has been filled in. As a result, the detector and Peltier element cannot be easily replaced in this technology.

[0006] Furthermore, when a Peltier element is sandwiched between a heat sink and a temperature-controlled object, the higher the contact between each surface of the Peltier element and the heat sink and temperature-controlled object, the more efficiently heat is transferred. Therefore, the Peltier element is sandwiched so as to be pressed between the heat sink and the temperature-controlled object. However, if excessive and / or uneven pressure is applied to the Peltier element, it may be damaged. For this reason, it is necessary to manage the tightening torque of the screws that adjust the pressure so that an appropriate and uniform pressure is applied to the Peltier element.

[0007] Furthermore, gaps arise between each surface of the Peltier element and the contact surface between the heat sink and the Peltier element being temperature-controlled, due to the surface roughness of these surfaces. Normally, thermal conductive grease is applied to each surface of the Peltier element to fill these gaps and improve the adhesion between the surfaces. In this case, variations in the application of the thermal conductive grease by the worker can easily result in unevenness in the thickness of the thermal conductive grease.

[0008] The present invention aims to provide a detector unit that allows for easy replacement and fixing of the Peltier element, and a method for manufacturing the detector unit. [Means for solving the problem]

[0009] The detector unit according to the present invention comprises a detector, a detector case housing the detector, a temperature control unit that adjusts the temperature of the detector by cooling or heating the detector case, a heat absorption / dissipation member that functions as a heat dissipation member or heat absorption member for the temperature control unit, and a spacer disposed between the detector case and the heat absorption / dissipation member around the temperature control unit, wherein the detector case has a mounting surface to which the temperature control unit is attached, and the temperature control unit comprises a plate-shaped Peltier element having a first surface and a second surface that functions as a heat dissipation surface or a heat absorption surface, a compressible first heat conductive member disposed on the first surface, and a compressible second heat conductive member disposed on the second surface, wherein the first heat conductive member abuts against the mounting surface, the second heat conductive member abuts against the heat absorption / dissipation member, and the spacer abuts against the mounting surface and the heat absorption / dissipation member, and in a first direction perpendicular to the mounting surface, the length of the spacer is smaller than the length of the temperature control unit in an unloaded state and larger than the length of the Peltier element. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide a detector unit in which the Peltier element can be easily replaced and fixed, and a method for manufacturing the detector unit. [Brief explanation of the drawing]

[0011] [Figure 1] This is an exploded perspective view showing an embodiment of the detector unit according to the present invention. [Figure 2] Figure 1 is a rear view of the detector unit. [Figure 3] (a) to (c) are schematic cross-sectional views of the spacer provided in the detector unit of Figure 1. [Figure 4] This is a partially enlarged cross-sectional view of the detector unit in Figure 1 along line AA in Figure 2. [Figure 5] This is a schematic enlarged cross-sectional view illustrating each step of the manufacturing method for the detector unit according to the present invention. [Modes for carrying out the invention]

[0012] Hereinafter, embodiments of the detector unit and the method for manufacturing the detector unit (hereinafter referred to as "this manufacturing method") according to the present invention will be described with reference to the drawings. In the following description, elements having the same structure or function will be denoted by the same reference numerals, and redundant explanations will be omitted. Furthermore, the dimensional ratios of each element are not limited to those shown in each drawing.

[0013] Furthermore, in each figure, the X, Y, and Z axes are three mutually orthogonal axes, the "+X axis direction" is forward, the "-X axis direction" is backward, the "+Y axis direction" is left, the "-Y axis direction" is right, the "+Z direction" is upward, and the "-Z axis direction" is downward. The X axis direction is an example of the first direction in this invention.

[0014] In the following description, the detector unit according to the present invention is assumed to constitute a photomultiplier tube (PMT) unit incorporated into a NOx concentration measuring device for measuring the concentration of nitrogen oxides (NOx) in the atmosphere. That is, in the following description, a PMT is an example of a detector in the present invention.

[0015] ●Detector Unit● ● Detector unit configuration Figure 1 is an exploded perspective view showing an embodiment of the detector unit according to the present invention. Figure 2 is a rear view of the detector unit 1. For the sake of clarity, Figure 2 shows the heatsink 50, which will be described later, as a dashed line.

[0016] The detector unit 1 comprises a main unit 10, a temperature control unit 20, a heat insulating member 30, three spacers 41, 42, and 43, a heat sink 50, three spacer mounting screws B1, and four heat sink mounting screws B2.

[0017] The main body unit 10 includes a PMT 11 (see FIG. 4; the same applies hereinafter), a PMT case 12, a PMT socket (not shown; the same applies hereinafter), a socket holder 13, a reaction tank 14, and a reaction tank holder 15.

[0018] The PMT 11 detects chemiluminescence generated in the process where nitric oxide reacts with ozone to produce nitrogen dioxide. The PMT 11 is housed in the PMT case 12.

[0019] The PMT case 12 houses the PMT 11. The PMT case 12 is, for example, in the shape of a rectangular parallelepiped having faces in the up-down, left-right, front-back directions. The PMT case 12 is an example of the detector case in the present invention. The PMT case 12 includes a rear surface 12a that functions as an attachment surface in the present invention, and three female screw holes 12d, 12e, 12f. The female screw hole 12d is disposed at the left end of the rear surface 12a, and the female screw holes 12e, 12f are disposed at the right end of the rear surface 12a; the female screw hole 12e is disposed above the female screw hole 12f.

[0020] The PMT socket is a known socket for PMT to which the PMT 11 is connected and that mediates the transmission of an electrical signal from the connected PMT 11. The PMT socket is held by the socket holder 13.

[0021] The socket holder 13 holds the PMT socket inside. The socket holder 13 is attached to the right surface 12b of the PMT case 12. The socket holder 13 includes a rear surface 13a that is continuous with the rear surface 12a of the PMT case 12 to be flush.

[0022] The reaction tank 14 reacts the measurement target (nitric oxide) with ozone to generate chemiluminescence detected by the PMT 11. The reaction tank 14 is held by the reaction tank holder 15.

[0023] The reaction tank holder 15 holds the reaction tank 14. The reaction tank holder 15 is attached to the upper surface 12c of the PMT case 12. The reaction tank holder 15 includes a rear surface 15a that is continuous with the rear surface 12a of the PMT case 12 to be flush.

[0024] The temperature control unit 20 regulates the temperature of the PMT 11 via the PMT case 12 by cooling the PMT case 12. The temperature control unit 20 is mounted on the rear surface 12a of the PMT case 12. The temperature control unit 20 comprises a Peltier element 21 and two thermal conductive sheets 22 and 23.

[0025] The Peltier element 21 is a known Peltier element having a structure in which, for example, a plurality of p-type and n-type semiconductors connected in series via a metal are sandwiched between two insulating plates. The Peltier element 21 is a rectangular (square) plate and has a front surface 21a and a rear surface 21b (see Figure 5 for both; the same applies hereinafter). The front surface 21a is an example of the first surface in the present invention, and the rear surface 21b is an example of the second surface in the present invention. In this embodiment, the Peltier element 21 is used to lower the temperature of the PMT 11. Therefore, the front surface 21a functions as a heat-absorbing surface that absorbs heat from the PMT 11 (PMT case 12), and the rear surface 21b functions as a heat-dissipating surface that releases heat from the Peltier element 21.

[0026] The thermal conductive sheets 22 and 23 are, for example, known thermal conductive sheets made of an elastic acrylic resin. The thermal conductive sheets 22 and 23 are rectangular sheets having approximately the same area as the Peltier element 21. Thermal conductive sheet 22 is an example of the first thermal conductive member in the present invention, and thermal conductive sheet 23 is an example of the second thermal conductive member in the present invention. Thermal conductive sheet 22 is attached to the front surface 21a of the Peltier element 21, and thermal conductive sheet 23 is attached to the rear surface 21b of the Peltier element 21. That is, thermal conductive sheet 22 is located on the front surface 21a, and thermal conductive sheet 23 is located on the rear surface 21b.

[0027] The thermal insulation member 30 is made of an elastic, porous material such as polyethylene foam. The thermal insulation member 30 is a rectangular plate with an area capable of covering the entire rear surfaces 12a and 15a of the PMT case 12 and the reaction vessel holder 15, respectively, and the left end of the rear surface 13a of the socket holder 13. The thermal insulation member 30 is positioned between the main unit 10 and the heat sink 50. The thermal insulation member 30 comprises a unit housing section 30a and three spacer housing sections 30b, 30c, and 30d.

[0028] The unit housing section 30a is a rectangular (square) opening that houses the temperature control unit 20. The unit housing section 30a is located approximately in the center of the heat insulating member 30.

[0029] Spacer housing sections 30b and 30c are rectangular holes for housing spacers 41 and 42, and spacer housing section 30d is a rectangular notch for housing spacer 43. In the vertical direction, the length of spacer housing section 30b is the same as the length of unit housing section 30a, and the lengths of spacer housing sections 30c and 30d are approximately half the length of unit housing section 30a. Spacer housing section 30b is located to the left of unit housing section 30a, and spacer housing sections 30c and 30d are located to the right of unit housing section 30a. Spacer housing section 30d is located below spacer housing section 30c and is continuous with the outer edge of the heat insulating member 30.

[0030] Figure 3(a) is a schematic cross-sectional view of spacer 41, (b) is a schematic cross-sectional view of spacer 42, and (c) is a schematic cross-sectional view of spacer 43. The figure shows a cross-section of each spacer 41-43 cut in the center in the shorter direction (left-right direction in this embodiment). Figure 1 will also be referred to as appropriate in the following description of spacers 41-43.

[0031] Spacers 41-43 adjust the load (compressive force) on the temperature control unit 20 and the heat insulation member 30, which are controlled by the heat sink 50 described later. Spacers 41-43 are made of synthetic resin, such as ABS resin. Spacers 41-43 are elongated rectangular plates in the vertical direction.

[0032] The spacer 41 comprises a through hole 41a and two female screw holes 41d and 41e. The through hole 41a comprises a first hole portion 41b and a second hole portion 41c. The front half of the through hole 41a constitutes the first hole portion 41b. The rear half of the through hole 41a continuously expands in diameter towards the rear, forming a frustoconical second hole portion 41c. The through hole 41a and the female screw holes 41d and 41e are arranged side by side in the vertical direction and penetrate the spacer 41 in the front-to-back direction. The through hole 41a is located between the female screw holes 41d and 41e.

[0033] The spacer 42 includes a through hole 42a and a female screw hole 42d. The through hole 42a includes a first hole portion 42b and a second hole portion 42c. The front half of the through hole 42a constitutes the first hole portion 42b. The rear half of the through hole 42a continuously expands in diameter towards the rear, forming a frustoconical second hole portion 42c. The through hole 42a and the female screw hole 42d are arranged side by side in the vertical direction and penetrate the spacer 42 in the front-to-back direction. The through hole 42a is located below the female screw hole 42d.

[0034] The spacer 43 includes a through hole 43a and a female screw hole 43d. The through hole 43a includes a first hole portion 43b and a second hole portion 43c. The front half of the through hole 43a constitutes the first hole portion 43b. The rear half of the through hole 43a continuously expands in diameter towards the rear, forming a frustoconical second hole portion 43c. The through hole 43a and the female screw hole 43d are arranged side by side in the vertical direction and penetrate the spacer 43 in the front-to-back direction. The through hole 43a is located above the female screw hole 43d.

[0035] Return to Figure 1 and Figure 2. The heat sink 50 is a known heat sink that dissipates heat from the temperature control unit 20 (Peltier element 21). The heat sink 50 consists of a rectangular plate-shaped base 51 and a plurality of fins 52 protruding rearward from the base 51. The base 51 has four through holes (not shown). In this embodiment, the heat sink 50 functions as a heat dissipation member for the temperature control unit 20. The heat sink 50 is an example of a heat absorption and dissipation member in the present invention.

[0036] The spacer mounting screw B1 is, for example, a known countersunk screw. The spacer mounting screw B1 is made of a metal such as stainless steel. The spacer mounting screw B1 comprises an inverted frustoconical head B1a and a male threaded portion B1b extending from the small diameter end of the head B1a. The spacer mounting screw B1 is an example of a mounting screw in the present invention.

[0037] The heat sink mounting screw B2 is, for example, a known hexagonal bolt. The heat sink mounting screw B2 is, for example, made of metal such as stainless steel.

[0038] ● Relationship of lengths of each component in the front-to-back direction Next, the relationship between the lengths (thickness) of each component in the front-to-back direction (first direction) will be explained below. Figure 1 will also be referred to as appropriate in the following explanation.

[0039] Figure 4 is a partially enlarged cross-sectional view of the detector unit 1 along line AA in Figure 2. The figure shows a magnified view of the rear surface 12a portion of the detector unit 1. For the sake of explanation, the figure also shows the state with the heat sink 50 removed (a state where no load (compressive force), described later, is applied to each component: no-load state).

[0040] In the front-to-back direction, the length (thickness) L1 of each spacer 41 to 43 is the same. The length L1 of spacers 41 to 43 is smaller than the length (thickness) L2 of the temperature control unit 20 and the length (thickness) L4 of the heat insulating member 30, but larger than the length (thickness) L3 of the Peltier element 21. The length L2 of the temperature control unit 20 is the same as, or slightly smaller than, the length L4 of the heat insulating member 30. The length L5 of the head B1a of the spacer mounting screw B1 is smaller than the length (depth) L6 of the corresponding second holes 41c, 42c, and 43c. In the following description, unless otherwise specified, the lengths L1 to L6 of each member refer to the lengths in the front-to-back direction.

[0041] ● Manufacturing method of the detector unit Next, the manufacturing method will be explained below. Figures 1 to 4 will be referred to as appropriate in the following explanation.

[0042] Figure 5 is a schematic, enlarged cross-sectional view illustrating each stage of this manufacturing process. The figure schematically shows a cross-section of the detector unit 1 along line AA in Figure 2, focusing on the area around the spacer 41.

[0043] First, each spacer 41-43 is attached to the rear surface 12a of the PMT case 12 by spacer mounting screws B1. Specifically, each spacer mounting screw B1 is inserted into the corresponding insertion hole 41a-43a and screwed into the corresponding female screw hole 12d-12f. As a result, each spacer 41-43 is positioned so that its longitudinal direction is aligned with the vertical direction and is in contact with the rear surface 12a of the PMT case 12.

[0044] As mentioned above, the length L5 of the head B1a of the spacer mounting screw B1 is smaller than the length (depth) L6 of the corresponding second holes 41c to 43c. Therefore, the head B1a is housed (positioned) within the corresponding second holes 41c to 43c and does not protrude further back than the rear surfaces 41f, 42e, and 43e of the spacers 41 to 43.

[0045] Next, the temperature control unit 20 is temporarily placed at a predetermined position on the rear surface 12a of the PMT case 12. The "predetermined position" is between spacers 41 and 42, 43, and is near the position on the rear surface 12a where the temperature control unit 20 will ultimately be placed. At this time, the heat conductive sheet 22 is in contact with the rear surface 12a.

[0046] Next, the heat insulating member 30 is attached to the rear surface 12a of the PMT case 12. At this time, the heat insulating member 30 is positioned appropriately relative to the rear surface 12a by housing the corresponding spacers 41 to 43 in the spacer housing sections 30b to 30d, respectively. The position of the temperature control unit 20 is also moved as appropriate, and the temperature control unit 20 is housed in the unit housing section 30a. As a result, in a view in the front-to-back direction, the heat insulating member 30 surrounds the entire circumference of the temperature control unit 20 and covers the rear surface 12a. In this way, the temperature control unit 20 is easily positioned by the heat insulating member 30.

[0047] The heat insulating member 30 covers and abuts the entire rear surfaces 12a and 15a of the PMT case 12 and the reaction vessel holder 15, respectively, and the left end of the rear surface 13a of the socket holder 13. In a rear view, spacer 41 is positioned opposite to the left of the center of the left side of the temperature control unit 20, spacer 42 is positioned opposite to the right of the upper part of the right side of the temperature control unit 20, and spacer 43 is positioned opposite to the right of the lower part of the right side of the temperature control unit 20. As a result, in a rear view, parts of each of spacers 41 to 43 are positioned around the temperature control unit 20, near the four corners of the temperature control unit 20.

[0048] "Near the corner" refers, for example, to a position in a rear view, that is opposite to the part of the temperature control unit 20's edge that is closer to the corner than to the center. That is, for example, in a rear view, the vicinity of the upper left corner is the position opposite to the upper quarter of the left edge of the temperature control unit 20 that includes the said corner, and the position opposite to the left quarter of the top edge of the temperature control unit 20 that includes the said corner.

[0049] As mentioned above, the length L1 of spacers 41-43 is shorter than the length L4 of the heat insulating member 30, and the length L2 of the temperature control unit 20 is approximately the same as the length L4 of the heat insulating member 30. Therefore, the temperature control unit 20 and the heat insulating member 30 protrude further back than the rear surfaces 41f, 42e, and 43e of spacers 41-43.

[0050] Next, the heatsink 50 is attached to the rear surfaces 41f, 42e, and 43e of the spacers 41-43 by heatsink mounting screws B2. Specifically, each heatsink mounting screw B2 is inserted into the corresponding through hole (not shown) of the base 51 and screwed into the corresponding female screw holes 41d, 41e, 42d, and 43d until the front surface 50a of the heatsink 50 abuts against the rear surfaces 41f, 42e, and 43e of the spacers 41-43. As a result, the temperature control unit 20, the heat insulating member 30, and the spacers 41-43 each abut against the PMT case 12 (rear surface 12a) and the heatsink 50, and are positioned between them. At this time, in the front-to-back direction, the temperature control unit 20 and the heat insulating member 30 are compressed (pressed) by the heatsink 50 towards the rear surfaces 12a, 13a, and 15a until their respective lengths L2 and L4 become the length L1 of the spacers 41-43. In other words, a load (compressive force) is applied to the temperature control unit 20 and the heat insulating member 30, respectively, based on the difference between their respective lengths L2 and L4 and the length L1 of the spacers 41 to 43. As mentioned above, the spacers 41 to 43 are located near the corners of the temperature control unit 20, at the left and right ends of the rear surface 12a. Therefore, the load is applied evenly across the entire surface of both the temperature control unit 20 and the heat insulating member 30.

[0051] As mentioned above, the length L3 of the Peltier element 21 is smaller than the length L1 of the spacers 41-43. Also, the thermal conductive sheets 22 and 23 are elastic. Therefore, when the heat sink 50 is attached to the spacers 41-43, the thermal conductive sheet 22 is compressed and comes into close contact with the rear surface 12a and the front surface 21a of the Peltier element 21, and the thermal conductive sheet 23 is compressed and comes into close contact with the rear surface 21b of the Peltier element 21 and the front surface 50a of the heat sink 50. As a result, the thermal conduction efficiency between the Peltier element 21 and the rear surface 12a via the thermal conductive sheet 22, and the thermal conduction efficiency between the Peltier element 21 and the heat sink 50 via the thermal conductive sheet 23, are improved compared to the thermal conduction efficiency when they are not in close contact. In other words, the thermal conductive sheets 22 and 23 are functioning effectively (the thermal conductive sheets 22 and 23 are performing their intended function (thermal conductivity)). Furthermore, a portion of the load on the Peltier element 21 is absorbed by the compression of the thermal conductive sheets 22 and 23. Therefore, no excessive load is applied to the Peltier element 21 that would cause it to be damaged. In this way, the temperature control unit 20 is fixed (placed) between the main unit 10 (PMT case 12) and the heat sink 50, with no excessive load applied to the Peltier element 21 and with the thermal conductive sheets 22 and 23 functioning effectively.

[0052] Furthermore, the compression ratio of the thermal conductive sheets 22 and 23 is adjusted by the length L1 of the spacers 41 to 43 and the length L2 of the temperature control unit 20 so that excessive load is not applied to the Peltier element, and the compression ratio is appropriate to the design of the thermal conductive sheets 22 and 23 (for example, 20% to 60%). As a result, the Peltier element is not damaged, and the thermal conductive sheets 22 and 23 can perform their functions as designed (function effectively). In addition, the distribution of the load on the thermal conductive sheets 22 and 23 is adjusted by the position of the spacers 41 to 43 so that it is applied evenly to the entire temperature control unit 20. As a result, even if there is variation in the mounting torque of the heat sink mounting screws B2, the thermal conductive sheets 22 and 23 are compressed evenly, and no uneven load is applied to the Peltier element 21.

[0053] As mentioned above, the heat insulating member 30 is made of an elastic porous material (polyethylene foam). Therefore, when the heat sink 50 is attached to the spacers 41-43, the fine internal spaces (bubble portions) of the heat insulating member 30 are compressed, causing the heat insulating member 30 to be compressed. Consequently, the space between the main unit 10 (PMT case 12, the left end of the socket holder 13, and the reaction vessel holder 15) and the heat sink 50 is filled with the compressed heat insulating member 30, except for the unit housing section 30a and the spacer housing sections 30b-30d. In other words, when viewed from the rear, the entire circumference of the temperature control unit 20 is surrounded by the compressed heat insulating member 30.

[0054] Here, if the thermal insulation member 30 is an open-cell structure, as the cells are compressed, some of the air contained within the thermal insulation member 30 before compression is released to the outside. As a result, the amount of air contained within the thermal insulation member 30 decreases in accordance with the load, the connections between some cells are broken, and the moisture permeability of the thermal insulation member 30 decreases. Therefore, when the rear surface 12a of the PMT case 12 is cooled by the temperature control unit 20, the occurrence of condensation inside the thermal insulation member 30 and on the rear surfaces 12a, 13a, and 15a covered by the thermal insulation member 30 is suppressed compared to the thermal insulation member 30 before compression. On the other hand, if the thermal insulation member 30 is an open-cell structure, the thermal insulation member 30 does not permeate moisture, and condensation inside the thermal insulation member 30 and on the rear surfaces 12a, 13a, and 15a covered by the thermal insulation member 30 (almost) does not occur.

[0055] Return to Figure 5. Furthermore, as mentioned above, the head B1a of the spacer mounting screw B1 does not protrude further back than the rear surfaces 41f, 42e, and 43e of the spacers 41-43. A gap S with a length L7, corresponding to "length L6 - length L5", is formed between the head B1a and the front surface 50a of the heatsink 50. Therefore, the spacer mounting screw B1 attached to the rear surface 12a of the PMT case 12 does not come into contact with the front surface 50a of the heatsink 50. In other words, the metal heatsink 50 does not come into contact with the metal spacer mounting screw B1, and synthetic resin spacers 41-43 are interposed between the heatsink 50 and the spacer mounting screw B1. Generally, the thermal conductivity of resin and air is significantly lower than that of metal. Therefore, the heat from the heatsink 50 is blocked by the spacers 41-43 and the gap S, and hardly any of it is transferred to the rear surface 12a via the spacer mounting screw B1, but is released into the outside air.

[0056] In the detector unit 1 configured in this way, the temperature control unit 20 and the heat insulating member 30 can each be easily removed simply by removing the heat sink 50. That is, the Peltier element 21 in the detector unit 1 can be easily replaced. Furthermore, torque management for adjusting the load (compression force) applied to the Peltier element 21 is unnecessary. Moreover, the thermal conductive sheets 22 and 23 are compressed evenly. Therefore, problems such as uneven thickness of thermal conductive grease, which can occur in conventional detectors using thermal conductive grease, do not occur. Furthermore, because the heat insulating member 30 is elastic, it returns to its pre-compression state when the heat sink 50 is removed. That is, the heat insulating member 30 is reversibly deformable by the load (compression force). Therefore, the heat insulating member 30 can be reused repeatedly.

[0057] ●Summary According to the embodiment described above, the detector unit 1 comprises a PMT 11, a PMT case 12, a temperature control unit 20, a heat sink 50, and spacers 41 to 43. The PMT case 12 houses the PMT 11 and has a rear surface 12a to which the temperature control unit 20 is attached. The temperature control unit 20 adjusts the temperature of the PMT 11 by cooling the PMT case 12 and comprises a Peltier element 21 and thermal conductive sheets 22 and 23. The thermal conductive sheet 22 is placed on the front surface 21a of the Peltier element 21 and is in contact with the rear surface 12a. The thermal conductive sheet 23 is placed on the rear surface 21b of the Peltier element 21 and is in contact with the heat sink 50. The spacers 41 to 43 are placed around the temperature control unit 20 between the PMT case 12 and the heat sink 50 and are in contact with each of them. In the front-to-back direction, the length L1 of spacers 41-43 is smaller than the length L2 of the temperature control unit 20 in an unloaded (uncompressed) state, but larger than the length L3 of the Peltier element 21. With this configuration, when the heat sink 50 is attached and in contact with the spacers 41-43, the temperature control unit 20 is subjected to a load (compressive force) from the heat sink 50. At this time, the temperature control unit 20 is positioned (fixed) between the main unit 10 (PMT case 12, left end of socket holder 13, reaction vessel holder 15) and the heat sink 50, with no excessive load applied to the Peltier element 21 and with the thermal conductive sheets 22 and 23 functioning effectively. Furthermore, the temperature control unit 20 (Peltier element 21) can be easily replaced simply by removing the heat sink 50. Thus, in this invention, the replacement and fixing of the Peltier element 21 is made easy.

[0058] Furthermore, according to the embodiment described above, the detector unit 1 is equipped with metal spacer mounting screws B1 for attaching spacers 41 to 43 to the rear surface 12a. Spacers 41 to 43 are equipped with through holes 41a to 43a through which the spacer mounting screws B1 are inserted. The through holes 41a to 43a are equipped with first holes 41b to 43b and second holes 41c to 43c. The length L5 of the head B1a of the spacer mounting screw B1 is smaller than the length (depth) L6 of the corresponding second holes 41c, 42c, and 43c. With this configuration, a gap S having a length L7 corresponding to "length L6 - length L5" is formed between the head B1a and the front surface 50a of the heat sink 50. Therefore, the spacer mounting screws B1 attached to the rear surface 12a of the PMT case 12 do not come into contact with the front surface 50a of the heat sink 50. In other words, the metal heatsink 50 does not come into contact with the metal spacer mounting screws B1, and synthetic resin spacers 41-43 are interposed between the heatsink 50 and the spacer mounting screws B1. Therefore, the heat from the heatsink 50 is blocked by the spacers 41-43 and the gap S, and hardly any of it is transferred to the rear surface 12a via the spacer mounting screws B1, but is released into the outside air. As a result, the temperature control of the PMT 11 by the temperature control unit 20 is stable.

[0059] Furthermore, according to the embodiment described above, the heatsink 50 is attached to the spacers 41-43. With this configuration, the heatsink 50 does not come into contact with the rear surface 12a of the PMT case 12, and the heat from the heatsink 50 is blocked by the spacers 41-43 and hardly transferred to the rear surface 12a. As a result, the temperature control of the PMT 11 by the temperature control unit 20 is stable.

[0060] Furthermore, according to the embodiment described above, the detector unit 1 includes a heat insulating member 30 positioned between the PMT case 12 and the heat sink 50. In a rear view, the heat insulating member 30 surrounds the entire circumference of the temperature control unit 20 and covers the rear surface 12a of the PMT case 12, the rear surface 15a of the reaction vessel holder 15, and the left end of the rear surface 13a of the socket holder 13. With this configuration, the space between each rear surface 12a, 13a, 15a and the heat sink 50 is filled with the heat insulating member 30. As a result, the heat from the heat sink 50 is blocked by the heat insulating member 30 and hardly transferred to the main unit 10 (PMT case 12, left end of socket holder 13, reaction vessel holder 15).

[0061] Furthermore, according to the embodiment described above, the heat insulating member 30 is made of an elastic porous material (polyethylene foam). In the front-to-back direction, the length L4 of the heat insulating member 30 in an unloaded state is greater than the length L1 of the spacers 41-43. With this configuration, when the heat sink 50 is in contact with the spacers 41-43, the heat insulating member 30 is compressed by the heat sink 50. At this time, the heat insulating member 30 is compressed by the compression of the fine internal spaces (bubble portions) of the heat insulating member 30. As a result, when the rear surface 12a of the PMT case 12 is cooled by the temperature control unit 20, the occurrence of condensation inside the heat insulating member 30 and on the respective rear surfaces 12a, 13a, and 15a covered by the heat insulating member 30 is suppressed.

[0062] Furthermore, according to the embodiment described above, the heat insulating member 30 comprises a unit housing section 30a and spacer housing sections 30b to 30d. The temperature control unit 20 is housed in the unit housing section 30a, and the corresponding spacers 41 to 43 are housed in the spacer housing sections 30b to 30d. With this configuration, the heat insulating member 30 can be easily positioned by the spacers 41 to 43, and the temperature control unit 20 can be easily positioned by the heat insulating member 30.

[0063] ●Other embodiments Furthermore, the detector in this invention is not limited to a PMT. Also, the measuring instrument into which the detector unit according to the present invention is incorporated is not limited to a NOx concentration measuring device. That is, for example, the measuring instrument may be an arsine gas detection device.

[0064] Furthermore, in the present invention, the temperature control unit may be used to heat the detector depending on the operating temperature of the detector. In this case, the heat sink functions as a heat-absorbing member.

[0065] Furthermore, in the present invention, the detector unit may comprise a plurality of temperature control units. In this case, the heat insulating member may comprise a plurality of unit housing sections corresponding to each temperature control unit.

[0066] Furthermore, in the present invention, the thermal conductive sheet only needs to have a structure that can be compressed by the load of the heat sink and a thermal conductivity that is typical for thermal conductive sheets, and is not limited to acrylic resin-based thermal conductive sheets. That is, for example, the thermal conductive sheet may be a silicone resin-based thermal conductive sheet.

[0067] Furthermore, in the present invention, the first heat conductive member may consist of a heat conductive sheet and heat conductive grease applied to the front or both sides of the heat conductive sheet. The second heat conductive member may also consist of a heat conductive sheet and heat conductive grease applied to the rear or both sides of the heat conductive sheet. In this case as well, the length of the spacer in the front-to-back direction is set to be smaller than the length of the temperature control unit. Preferably, in the front-to-back direction, the length of the spacer is set to be smaller than the combined length of the two heat conductive sheets and the Peltier element. In these configurations, the heat conductive grease is also compressed. Therefore, even if there are inconsistencies in the thickness of the heat conductive grease, the thickness of the heat conductive grease is leveled during the compression process. Furthermore, even if distortion or surface roughness occurs on the front surface of the thermal conductive sheet, Peltier element, heat sink base, and rear surface of the PMT case, the presence of thermal conductive grease ensures good adhesion between these components and the first thermal conductive member (second thermal conductive member), and the thermal conduction efficiency by the first thermal conductive member (second thermal conductive member) does not deteriorate.

[0068] Furthermore, in the present invention, the first and second heat conductive members may be made of heat conductive grease instead of heat conductive sheets. In this case, the heat conductive grease is applied to both sides of the Peltier element such that, in the front-to-back direction, the thickness of the heat conductive grease is greater than the length of the spacer. In this configuration, the heat conductive grease is also compressed. Therefore, even if there are inconsistencies in the thickness of the heat conductive grease, the thickness of the heat conductive grease is leveled during the compression process.

[0069] Furthermore, in the present invention, the material of the heat insulating member may be any material that is reversibly (elastically) or irreversibly (plasticly) deformable by a load (compressive force), does not deteriorate due to heat from the Peltier element, and whose moisture permeability can be ignored, and is not limited to polyethylene foam. That is, for example, the heat insulating member may be made of expanded polystyrene.

[0070] Furthermore, in this invention, the length (thickness) of the heat insulating member in the front-to-back direction may be the same as the length of the spacer. In this case, the amount of air contained within the heat insulating member does not decrease, but the transfer of heat between the main unit and the heat sink is suppressed by the heat insulating member.

[0071] Furthermore, in the present invention, the position and shape of the unit housing only need to correspond to the position and shape of the temperature control unit, and the invention is not limited to this embodiment.

[0072] Furthermore, in the present invention, the position and shape of the spacer housing only need to correspond to the position and shape of the spacer, and the invention is not limited to this embodiment.

[0073] Furthermore, in the present invention, the configuration (number, shape) of the spacers is not limited to this embodiment, as long as it ensures that the load on the temperature control unit by the heat sink is evenly distributed. That is, for example, the spacer may consist of a single U-shaped or C-shaped member. Alternatively, the spacer may consist of two or four L-shaped members. Furthermore, the spacer may consist of a single square or circular frame-shaped member.

[0074] Furthermore, in the present invention, the arrangement of the spacers is not limited to this embodiment, as long as the load on the temperature control unit by the heat sink is applied evenly. That is, for example, the spacers may be positioned opposite each side of the temperature control unit when viewed from the rear.

[0075] Furthermore, in the present invention, the shape of the second hole portion of the spacer insertion hole only needs to correspond to the shape of the head of the spacer mounting screw, and is not limited to this embodiment.

[0076] Furthermore, in this invention, the material of the spacer may be any resin or metal that does not deform, break, or deteriorate due to the load (compressive force) and heat from the Peltier element, and is not limited to ABS. In this case, a resin spacer is preferable from the viewpoint of temperature control of the PMT. On the other hand, a metal spacer is preferable from the viewpoint of deformation, breakage, and deterioration.

[0077] Furthermore, in the present invention, the arrangement of the spacers relative to the temperature control unit is not limited to this embodiment, as long as the load is applied evenly to the temperature control unit. That is, for example, in a rear view, the spacers may be positioned opposite each side of the temperature control unit.

[0078] Furthermore, in this invention, the spacer mounting screws may be made of synthetic resin. Even in this case, the heat from the heat sink is blocked by the spacer and the gap, and hardly any heat is transferred to the rear surface via the spacer mounting screws. Also, if the spacer mounting screws are made of synthetic resin with relatively low thermal conductivity, the length of the head may be the same as the length of the second hole. [Explanation of Symbols]

[0079] 1 Detector Unit 11 PMT (detector) 12 PMT case (detector case) 12a Rear surface (mounting surface) 20 Temperature control unit 21 Peltier element 21a Front (first side) 21b Back side (2nd side) 22. Thermal conductive sheet (first thermal conductive member) 23. Thermal conductive sheet (second thermal conductive component) 30 Insulation material 30a Unit housing section 30b Spacer housing 30c Spacer housing 30d Spacer housing 41 Spacer 41a Through hole 41b 1st hole 41c 2nd hole 42 Spacers 42a Through hole 42b 1st hole 42c 2nd hole 43 Spacers 43a Through hole 43b 1st hole 43c 2nd hole 50 Heat sink (heat absorption / dissipation component) B1 Spacer mounting screw (mounting screw) B1a head B1b Male thread section L1 Spacer length (thickness) L2 Temperature control unit length (thickness) L3 Peltier element 21 length (thickness) L4 Length (thickness) of the insulation material L5 Head length L6 Length (depth) of the second hole

Claims

1. Detector and A detector case for housing the aforementioned detector, A temperature control unit that adjusts the temperature of the detector by cooling or heating the detector case, A heat absorption / dissipation member that functions as a heat dissipation member or heat absorption member for the temperature control unit, A spacer is disposed between the detector case and the heat absorption / dissipation member around the temperature control unit, Mounting screws for attaching the spacer to the detector case, It has, The detector case is Mounting surface on which the temperature control unit is attached, Equipped with, The temperature control unit is A plate-shaped Peltier element having a first surface and a second surface that function as a heat dissipation surface or a heat absorption surface, A first heat conductive member is compressible and arranged on the first surface, A second heat conductive member is compressible and positioned on the second surface, Equipped with, The first heat conductive member is in contact with the mounting surface, The second heat conductive member is in contact with the heat absorption / dissipation member, The previous spacer is The mounting screws attach the unit to the mounting surface. The mounting surface and the heat absorption / dissipation member are in contact with each other. The insertion hole through which the aforementioned mounting screw is inserted, Equipped with, The aforementioned insertion hole is The first hole through which the male threaded portion of the mounting screw is inserted, The second hole in which the head of the mounting screw is positioned, Equipped with, In a first direction perpendicular to the mounting surface, The length of the spacer is smaller than the length of the temperature control unit in the unloaded state and larger than the length of the Peltier element. The length of the second hole is greater than the length of the head. A detector unit characterized by the following features.

2. The heat absorption / dissipation member is attached to the spacer. The detector unit according to claim 1.

3. A heat insulating member is placed between the detector case and the heat absorption / dissipation member. It has, In a view perpendicular to the mounting surface, the heat insulating member surrounds the entire circumference of the temperature control unit and covers the mounting surface. The detector unit according to claim 1.

4. The aforementioned heat insulating member is made of a material that can be reversibly or irreversibly deformed by the applied compressive force. In the first direction, the length of the heat insulating member in an unloaded state is greater than or equal to the length of the spacer. The detector unit according to claim 3.

5. The aforementioned heat insulating member is The unit housing section in which the temperature control unit is housed, A spacer housing section in which the aforementioned spacer is housed, Equipped with, The detector unit according to claim 3.

6. The first heat conductive member is composed of an elastic sheet-like member, The second heat conductive member is composed of an elastic sheet-like member. The detector unit according to any one of claims 1 to 5.

7. Detector and A detector case for housing the aforementioned detector, A temperature control unit is attached to the mounting surface of the detector case and adjusts the temperature of the detector by cooling or heating the detector case. A heat absorption / dissipation member that functions as a heat dissipation member or heat absorption member for the temperature control unit, A spacer is disposed between the detector case and the heat absorption / dissipation member, Mounting screws for attaching the spacer to the mounting surface, A method for manufacturing a detector unit having, The temperature control unit is A plate-shaped Peltier element having a first surface and a second surface that function as a heat dissipation surface or a heat absorption surface, A first heat conductive member is compressible and arranged on the first surface, A second heat conductive member is compressible and positioned on the second surface, Equipped with, The previous spacer is The insertion hole through which the aforementioned mounting screw is inserted, Equipped with, The aforementioned insertion hole is The first hole through which the male threaded portion of the mounting screw is inserted, The second hole in which the head of the mounting screw is positioned, Equipped with, In a first direction perpendicular to the mounting surface, the length of the spacer is smaller than the length of the temperature control unit in an unloaded state and larger than the length of the Peltier element. The spacer is attached to the mounting surface by the mounting screws, The temperature control unit is attached to the mounting surface, In the first direction, the first heat conduction member and the second heat conduction member are compressed by the heat absorber / dissipator until the heat absorber / dissipator member contacts the spacer; Includes, When the spacer is attached to the mounting surface by the mounting screw, in the first direction, the length of the second hole is greater than the length of the head. A method for manufacturing a detector unit characterized by the above.

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