Sensor device and method for manufacturing a sensor device

Abstract

The heat distribution of the two pressure sensors heated by the heater is set to the desired heat distribution. [Solution] The sensor device 10 includes a sensor head 30 which includes a pressure sensing pipe 31 extending in the left-right direction, a pressure sensor 32 fixed to the right end of the pressure sensing pipe 31, and a pressure sensor 33 fixed to the left end of the pressure sensing pipe 31. The sensor device 10 further includes a pressure sensing pipe 40 which extends in the up-down direction and is connected to the middle of the pressure sensing pipe 31, and which guides the pressure of the fluid to be measured to the pressure sensors 32 and 33 via the pressure sensing pipe 31, and a heater 50 which heats the pressure sensors 32 and 33. The sensor device 10 includes an insulating material 71 which covers the sensor head 30 and heater 50 from above, and an insulating material 75 which has a through hole 71A through which the pressure sensing pipe 40 passes and covers the sensor head 30 and heater 50 from above. The insulating performance of the insulating material 75 is higher than that of the insulating material 71.

Description

Technical Field

[0001] The present invention relates to a sensor device such as a vacuum gauge and a method for manufacturing the sensor device.

Background Art

[0002] As disclosed in Patent Document 1, a sensor device (vacuum gauge) for measuring the pressure of a gas is known. Such a sensor device includes a pressure sensor and a heater for heating the pressure sensor.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Sensor devices have a fixed measurement range for pressure measurement. Therefore, when a wider range of pressure measurement is required, multiple sensor devices with different measurement ranges are used in combination. Also, to ensure redundancy in case of pressure sensor failure, it is conceivable to use multiple sensor devices with the same measurement range. Using multiple sensor devices in combination results in poor space efficiency, and improvement in this regard is desirable. For example, in semiconductor manufacturing equipment, compact pressure adjustment chambers tend to be used, making the improvement of space efficiency important. To improve space efficiency, it is conceivable to mount at least two pressure sensors on a single sensor device. In such cases, the heat distribution of the two pressure sensors heated by the heater (e.g., the heat distribution of each pressure sensor, and / or the heat distribution of the two pressure sensors as a whole) may not be the desired heat distribution. For example, each of the two pressure sensors may not be heated uniformly, resulting in a temperature gradient between each of the two pressure sensors (not a uniform heat distribution). Or, the two pressure sensors may not be heated evenly, resulting in a temperature gradient between the two pressure sensors (not a uniform heat distribution).

[0005] The present invention aims to achieve a desired heat distribution in two pressure sensors heated by a heater. [Means for solving the problem]

[0006] The sensor device according to this invention comprises a sensor head including a first pipe extending in a first direction, a first pressure sensor fixed to a first end of the first pipe, and a second pressure sensor fixed to a second end of the first pipe different from the first end; a second pipe extending in a second direction different from the first direction and connected to the middle of the first pipe, which guides the pressure of the fluid to be measured to the first pressure sensor and the second pressure sensor via the first pipe; a heater for heating the first pressure sensor and the second pressure sensor; a first insulating material positioned at a first position covering the sensor head and the heater from the opposite side of the second pipe; and a second insulating material positioned at a second position having a through hole through which the second pipe passes and covering the sensor head and the heater from the second pipe side, wherein the insulating performance of the second insulating material is higher than that of the first insulating material.

[0007] Furthermore, the sensor device according to this invention includes a sensor head including a first pipe extending in a first direction, a first pressure sensor fixed to a first end of the first pipe, and a second pressure sensor fixed to a second end of the first pipe different from the first end; a second pipe extending in a second direction different from the first direction and connected to the middle of the first pipe, which guides the pressure of the fluid to be measured to the first pressure sensor and the second pressure sensor via the first pipe; a heater for heating the first pressure sensor and the second pressure sensor; a first heat insulating material positioned at a first position covering the sensor head and the heater from the opposite side of the second pipe; and a second heat insulating material positioned at a second position having a through hole through which the second pipe passes, which covers the sensor head and the heater from the second pipe side, wherein at least one of the first heat insulating material and the second heat insulating material has different heat insulating performance in the first portion covering the first pressure sensor and the second portion covering the second pressure sensor.

[0008] Furthermore, the manufacturing method of the sensor device according to this invention includes a sensor head including a first pipe extending in a first direction, a first pressure sensor fixed to a first end of the first pipe, and a second pressure sensor fixed to a second end of the first pipe different from the first end, a second pipe extending in a second direction different from the first direction and connected to the middle of the first pipe, which guides the pressure of the fluid to be measured to the first pressure sensor and the second pressure sensor via the first pipe, a heater for heating the first pressure sensor and the second pressure sensor, a first heat insulating material positioned in a first position to cover the sensor head and the heater from the opposite side of the second pipe, and a through hole through which the second pipe passes and which covers the sensor head and the heater from the second pipe side. A method for manufacturing a sensor device comprising a second thermal insulation material positioned at a second location, comprising: a first step of identifying the first thermal insulation material and the second thermal insulation material having thermal insulation performance such that the temperature gradient generated in the sensor head when the first pressure sensor and the second pressure sensor are heated by the heater becomes a desired temperature gradient; and a second step of arranging the first thermal insulation material and the second thermal insulation material identified in the second step at the first and second positions, respectively, wherein the first step involves identifying the first thermal insulation material and the second thermal insulation material having different thermal insulation performance, or identifying at least one of the first thermal insulation material and the second thermal insulation material having different thermal insulation performance in a first portion covering the first pressure sensor and a second portion covering the second pressure sensor. [Effects of the Invention]

[0009] According to the present invention, the heat distribution of two pressure sensors heated by a heater becomes a desired heat distribution. [Brief explanation of the drawing]

[0010] [Figure 1] This is an exploded perspective view of a sensor device relating to one embodiment of the present invention. [Figure 2] This is an exploded perspective view of the sensor section of the sensor device. [Figure 3] This is an exploded perspective view of the heater covering the sensor head of the sensor unit. [Figure 4]This is a schematic cross-sectional view of the sensor device, showing only the cut end face of the sensor head's interior. [Figure 5] This is a schematic cross-sectional view of the sensor device. [Figure 6] This is a schematic cross-sectional view of another example of a sensor device, showing only the cut end face of the sensor head's interior. [Figure 7] This is a flowchart showing the manufacturing method of a sensor device. [Modes for carrying out the invention]

[0011] (Summary of the embodiment) The inventor of the present invention has found the following:

[0012] First, by using a dual pressure sensor in a sensor device (e.g., a vacuum gauge), the overall size can be reduced compared to multiple sensor devices, each equipped with a single pressure sensor. In a sensor device with dual pressure sensors, the sensor head includes a first pipe extending in a first direction, and first and second pressure sensors fixed to both ends of this first pipe, respectively. Furthermore, a second pipe is connected to the first pipe to guide the pressure of the fluid to be measured to the first and second pressure sensors via the first pipe. For the heaters that heat the first and second pressure sensors, miniaturization of the sensor device can be promoted by, for example, making them a shared, integrated unit or by using a simple installation structure. However, due to the structure of a sensor device with dual pressure sensors, a trade-off arises in that the heating balance between the first and second pressure sensors tends to be poor. To resolve this trade-off, we focused on the use of multiple insulating materials around the heater and adjusted the insulating performance of each of the multiple insulating materials to equalize the heat distribution of the two pressure sensors during heating (the heat distribution of each pressure sensor, and / or the heat distribution of the two pressure sensors as a whole (in other words, the sensor head 30)).

[0013] In particular, in the sensor device described above, when the first and second pressure sensors are heated, the second pipe becomes a heat transfer path, and the temperature of the portion of the first and second pressure sensors on the second pipe side tends to decrease. Thus, the thermal insulation performance of the insulation material in the portion close to the heat transfer path, which is expected from the structure of the sensor device, is made higher than the thermal insulation performance of the insulation material farther from the heat transfer path. This equalizes the heat distribution of the two pressure sensors during heating (the heat distribution of each pressure sensor, and / or the heat distribution of the two pressure sensors as a whole (in other words, the sensor head 30)).

[0014] (Details of the embodiment) The embodiments of the present invention will now be described in detail with reference to the drawings. In this embodiment, mutually orthogonal vertical, horizontal, and front-to-back directions are set, but these directions are not intended to be the mounting directions of the sensor device. For example, the vertical direction may coincide with the horizontal direction depending on the orientation of the sensor device 10.

[0015] The sensor device 10 shown in Figure 1 is connected to piping connected to a pressure adjustment chamber (e.g., a vacuum chamber) in semiconductor manufacturing equipment, and is configured as a diaphragm vacuum gauge that measures the pressure of the fluid to be measured (e.g., the atmospheric pressure of a process gas) introduced into the piping from the pressure adjustment chamber using a diaphragm that receives this pressure.

[0016] The sensor device 10 includes a sensor unit 20 that detects the pressure of the fluid to be measured by converting the pressure into an electrical signal and outputs the detected pressure, i.e., the electrical signal indicating the pressure, as a pressure detection signal, and a control unit 90 that controls the operation of the sensor unit 20, processes the pressure detection signal from the sensor unit 20, derives the pressure of the fluid to be measured indicated by the pressure detection signal, and outputs the derived pressure to the outside. The pressure has been measured by this pressure deriving. The control unit 90 includes a circuit board, connectors, communication modules, etc., for pressure deriving and external output, and a housing 91 that houses these. The housing 91 is simplified in Figure 1, and in reality, it has vents for cooling the circuit board and various connectors are attached to it.

[0017] As shown in FIGS. 1 to 3, the sensor unit 20 includes a sensor head 30, a pressure pipe 40, a heater 50, a fixing mechanism 60, a heat insulating member 70, and a bracket 80.

[0018] As shown in FIGS. 3 and 4, the sensor head 30 includes a cylindrical pressure pipe 31 extending in the left - right direction, pressure sensors 32 and 33 respectively fixed to each opening at both left and right ends of the pressure pipe 31, and insulators 34 and 35 respectively fixed to the pressure sensors 32 and 33 by fixing tools (not shown) or an arbitrary joining method.

[0019] In the middle of the pressure pipe 31 (here, the central part in the left - right direction), the upper end of a cylindrical pressure pipe 40 extending in the up - down direction is connected. The combination of the pressure pipe 31 and the pressure pipe 40 is formed in a T - shape with the pressure pipe 31 as the horizontal bar of the T and the pressure pipe 40 as the vertical bar of the T.

[0020] As shown in FIGS. 2 and 3, the pressure pipe 40 has a joint 41 at its lower end. This joint 41 is connected to the above - mentioned pipe. The fluid to be measured and its pressure introduced into the pressure pipe 40 from the pipe through the joint 41 are introduced into the pressure sensors 32 and 33 through the pressure pipe 31 (see also the cross - sectional view in FIG. 4).

[0021] As shown in FIG. 4, the pressure sensor 32 includes a housing 32A, a support diaphragm 32B, a sensor element 32C, a plurality of conductive pins 32D, a plurality of spring contacts 32E, and a seal member 32F. In the cross - sectional view of FIG. 4, the plurality of conductive pins 32D and the plurality of spring contacts 32E are drawn as elevation views rather than cross - sectional views. The number of the conductive pins 32D and the spring contacts 32E is arbitrary.

[0022] The housing 32A has a reference pressure chamber (e.g., a vacuum chamber) R11 having a reference pressure (e.g., a vacuum pressure) and a pressure chamber R12 that communicates with the pressure sensing pipe 31 and through which the pressure of the fluid to be measured is transmitted. The reference pressure chamber R11 and the pressure chamber R12 are separated by a support diaphragm 32B and a sensor element 32C housed in the housing 32A.

[0023] The support diaphragm 32B is supported by the housing 32A, for example, by being sandwiched between housing members that make up the housing 32A. The support diaphragm 32B supports the sensor element 32C.

[0024] The sensor element 32C introduces the pressure of the fluid to be measured into the pressure chamber R12. The sensor element 32C includes a pressure-receiving diaphragm 32CA that receives the pressure of the fluid to be measured introduced inside. The pressure-receiving diaphragm 32CA faces the reference pressure chamber R11 and displaces with a degree of displacement corresponding to the difference between the pressure of the fluid to be measured and the reference pressure in the reference pressure chamber R11. The sensor element 32C converts the amount of displacement of the pressure-receiving diaphragm 32CA into an electrical signal and outputs it. The sensor element 32C can be any type of pressure-sensitive element. The sensor element 32C may be a capacitive pressure-sensitive element that converts the amount of displacement of the pressure-receiving diaphragm 32CA into an electrical signal indicating a change in capacitance, or it may be a type of pressure-sensitive element that converts the amount of displacement of the pressure-receiving diaphragm 32CA into an electrical signal using one or more piezoelectric elements (not shown). In the former case, the sensor element 32C in Figure 4 further has a member to the right of the pressure-receiving diaphragm 32CA that forms a volume chamber into which the air pressure of the reference pressure chamber R11 is introduced.

[0025] Each of the multiple spring contacts 32E is connected to the sensor element 32C. Multiple conductive pins 32D are connected one-to-one with the multiple spring contacts 32E. The multiple conductive pins 32D are supported by the housing 32A, for example, by a hermetic seal that penetrates the housing 32A. Each portion of the multiple conductive pins 32D that protrudes outside the housing 32A is covered and insulated by an insulator 34 fixed to the pressure sensor 32 and is connected to the control unit 90 via wiring (not shown).

[0026] The sealing member 32F seals the through-hole 32AA in the wall surface forming the reference pressure chamber R11 of the housing 32A. During the manufacturing of the pressure sensor 32, the reference pressure chamber R11 is evacuated through the through-hole 32AA. The sealing member 32F is provided to seal the through-hole 32AA after the evacuation is complete.

[0027] With the above configuration, the pressure sensor 32 converts the pressure of the fluid to be measured, introduced via the pressure-sensing pipes 40 and 31, into an electrical signal indicating the displacement of the pressure-receiving diaphragm 32CA, and supplies this electrical signal to the control unit 90 via wiring. The control unit 90 processes the electrical signal and derives the pressure of the fluid to be measured indicated by the electrical signal. This enables pressure measurement. The control unit 90 outputs the derived, i.e., measured, pressure to an external device via a connector (not shown).

[0028] The pressure sensor 33 has a similar configuration to the pressure sensor 32. Specifically, the pressure sensor 33 comprises a housing 33A, a support diaphragm 33B, a sensor element 33C, a plurality of conductive pins 33D, a plurality of spring contacts 33E, and a sealing member 33F. The housing 33A, together with the support diaphragm 33B and the sensor element 33C, forms a reference pressure chamber R21 and a pressure chamber to be measured R22. The sensor element 33C includes a pressure-receiving diaphragm 33CA. Each portion of the plurality of conductive pins 33D that protrudes outside the housing 33A is covered and insulated by an insulator 35 fixed to the pressure sensor 33 and connected to the control unit 90 via wiring (not shown). With this configuration, the pressure sensor 33 converts the pressure of the fluid to be measured, introduced via the pressure-sensing pipes 40 and 31, into an electrical signal indicating the displacement of the pressure-receiving diaphragm 33CA, and supplies this electrical signal to the control unit 90 via the plurality of wires. The control unit 90 processes the electrical signal, derives the pressure of the fluid being measured indicated by the electrical signal, and outputs it externally via a connector (not shown) or the like.

[0029] The pressure sensors 32 and 33 have, for example, different detection ranges for the pressure of the fluid being measured. For example, one has a high-pressure detection range and the other has a low-pressure detection range. The detection range is adjusted, for example, by the thickness of the pressure-receiving diaphragm. The pressure sensors 32 and 33 may be provided, for example, for redundancy, and their detection ranges may be the same.

[0030] The sensor head 30 also includes baffles 36 and 37 (see Figure 5 for baffle 36). Baffles 36 and 37 are located inside the pressure sensing pipe 31. Baffles 36 and 37 face the respective sensor elements 32C and 33C (in particular, the pressure-receiving diaphragms 32CA and 33CA) of the pressure sensors 32 and 33. When the pressure of the fluid to be measured is being sensed, baffles 36 and 37 divert the flow of the fluid to be measured from the pressure sensing pipe 31 into the pressure sensors 32 and 33, thereby preventing solid foreign objects from directly hitting the pressure-receiving diaphragms 32CA and 33CA. Baffles 36 and 37 may also be located on the pressure sensors 32 and 33, respectively.

[0031] As shown in Figures 3 to 5, the heater 50 is formed in a cylindrical shape that covers the sensor head 30 which extends in the left-right direction. Specifically, the central axis of the cylindrical heater 50 extends along the left-right direction. The heater 50 heats the sensor head 30, in particular the pressure sensors 32 and 33, when measuring the pressure of the fluid to be measured. The heater 50 operates as a single heater and is shared for heating the pressure sensing pipe 31 and the pressure sensors 32 and 33. For this shared heating, the heater 50 is formed to extend from one of the pressure sensors 32 and 33 to the other, and is formed to cover both pressure sensors 32 and 33.

[0032] The heating of the heater 50 is controlled by the control unit 90 shown in Figure 1. Specifically, the control unit 90 uses the temperature detected by the temperature sensor S (see Figure 4), which is located in the sensor head 30 and connected to the control unit 90 via wiring not shown, as a feedback value to feedback control the power supplied to the heater 50 so that the detected temperature approaches the target temperature. The target temperature is preset as the temperature at which the temperature of the sensor head 30, in particular, the pressure sensors 32 and 33, is the same as the temperature of the fluid being measured. The position of the temperature sensor S is arbitrary. The temperature sensor S may be located inside the sensor head 30, for example, in the reference pressure chamber R11 or R21, or inside the pressure sensing pipe 31, or on the heater 50. Since the heater 50 is configured as a single heater, it is controlled by one temperature control using one temperature sensor S.

[0033] The heater 50 comprises a heater body 51 and 52 that generates heat, and support members 53 and 54 that support the heater body 51 and 52, respectively.

[0034] Each of the heater bodies 51 and 52 is formed in a semi-cylindrical shape, which is the shape obtained by cutting a cylinder extending in the left-right direction with planes extending in the up-down and left-right directions. The heater bodies 51 and 52 are connected to the control unit 90 by wiring (not shown), and are uniformly heated by power supplied from the control unit 90 via the feedback control described above. This heat heats the sensor head 30, particularly the pressure sensors 32 and 33 and the pressure-conducting pipe 31. The power supplied by the feedback control is the same for both the heater bodies 51 and 52. Thus, both the heater bodies 51 and 52 are configured as a single heating element. The heater bodies 51 and 52 have a structure in which, for example, a heating wire passes through their interior. The heating wire generates heat due to the power from the control unit 90, causing the heater bodies 51 and 52 to heat up. Note that the cross-sections of the heater bodies 51 and 52 in Figure 5 are shown in a manner that omits the internal structure such as the heating wire.

[0035] The support member 53 is formed in a semi-cylindrical shape to match the shape of the heater body 51. The support member 53 supports the heater body 51 in such a manner that its outer circumferential surface supports the inner circumferential surface of the heater body 51. Support methods include joining the outer and inner circumferential surfaces with adhesive or adhesive tape, or fixing with screws. Similarly, the support member 54 is formed in a semi-cylindrical shape to match the shape of the heater body 52. ​​The support member 54 supports the heater body 52 in such a manner that its outer circumferential surface supports the inner circumferential surface of the heater body 52.

[0036] The heater 50 is fixed to the sensor head 30 by a fixing mechanism 60. The fixing mechanism 60 has cylindrical bosses 61 and 62 that project in the front-rear direction from the outer circumferential surface of the sensor head 30, and screws 63 and 64 that are screwed into the bosses 61 and 62, respectively. The bosses 61 and 62 project from the left-right center of the sensor head 30, that is, from the left-right center of the outer circumferential surface of the pressure sensing pipe 31. The bosses 61 and 62 are integrally formed with the pressure sensing pipe 31. In Figure 5, the screws 63 and 64 are shown in elevation views, not cross-sections.

[0037] The heater 50 is fixed to the sensor head 30 by screwing the support members 53 and 54 of the heater 50 to bosses 61 and 62 with screws 63 and 64, respectively, while the support members 53 and 54 of the heater 50 support the heater body 51 and 52, respectively. The support members 53 and 54 each have flat screw fastening portions 53A and 54A, respectively. The screw fastening portions 53A and 54A each have through holes 53AA and 54AA that penetrate in the thickness direction.

[0038] The boss 61 to which the support member 53 is attached has a flat surface 61A at its top and a protrusion 61B that extends from the flat surface 61A. Furthermore, the boss 61 also has a screw hole 61C that opens in the center of the top surface of the protrusion 61B and engages with the screw 63.

[0039] When the support member 53, with the heater body 51 supported, is attached to the boss 61, the protrusion 61B is inserted into the through hole 53AA, as shown in Figure 5. At this time, the through hole 53AA (screw-fastening portion 53A) into which the protrusion 61B is inserted is exposed to the outside of the heater 50 through the through hole 51A formed in the heater body 51. By screwing the screw 63 into the screw hole 61C through this through hole 51A, the head of the screw 63 and the flat surface 61A sandwich the screw-fastening portion 53A of the support member 53. Therefore, the support member 53 is tightened and fixed to the boss 61 (especially the flat surface) by the screw 63, i.e., screwed in. Note that the shape of the protrusion 61B and the through hole 53AA can be approximately the same. This positions the heater body 51 relative to the boss 61 when the protrusion 61B is inserted into the through hole 53AA.

[0040] The boss 62 to which the support member 54 is attached has the same configuration as the boss 61. Specifically, the boss 62 comprises a flat surface 62A, a protrusion 62B, and a screw hole 62C. When the support member 54, with the heater body 52 supported, is attached to the boss 62, the protrusion 62B is inserted into the through hole 54AA, similar to the boss 61. At this time, the through hole 54AA (screw-fastening portion 54A) into which the protrusion 62B is inserted is exposed to the outside of the heater 50 through the through hole 52A formed in the heater body 52. ​​The support member 53 is screwed to the boss 62 by screwing a screw 64 into the screw hole 62C through this through hole 52A.

[0041] As described above, the heater 50 has a cylindrical shape and covers the outer circumference of the sensor head 30. However, to prevent interference with the pressure sensing pipe 40 connected to the sensor head 30, it is provided with an opening 50A, which is a through-hole through which the pressure sensing pipe 40 passes, at the lower part of the central part in the left-right direction. The opening 50A is formed with a gap between its inner wall and the outer surface of the pressure sensing pipe 40. As shown in Figure 5, this opening 50A is made up of semicircular notches 51B, 52B, 53B, and 54B provided in the heater body 51 and 52 and the support members 53 and 54, respectively.

[0042] The heat insulating member 70 surrounds the sensor head 30 and the heater 50, reducing the amount of heat dissipated from the heater 50 to the outside when heating the sensor head 30. As shown in Figures 2 and 4, the heat insulating member 70 comprises a substantially disc-shaped insulating material 71 that covers the sensor head 30 and the heater 50 from above, a support member 72 that supports the insulating material 71 from below, and a cylindrical support member 73 that supports the support member 72. The heat insulating member 70 further comprises a cylindrical insulating material 74 that surrounds the sensor head 30 and the heater 50 in the front, back, left, and right directions, and a substantially disc-shaped insulating material 75 that covers the sensor head 30 and the heater 50 from below. Examples of materials for the insulating materials 71, 74, and 75 include ceramic fiber and glass fiber.

[0043] The thermal insulation materials 74 and 75 are placed inside the support member 73. Thermal insulation material 74 is positioned on top of thermal insulation material 75. The support member 72 is provided with through-holes 72A through which multiple wires that electrically connect the control unit 90 and the sensor head 30 pass. Part of the through-holes 72A is blocked by the thermal insulation material 74, and the wires pass through the remaining part that is not blocked by the thermal insulation material 74. The thickness of the thermal insulation material 74 may be increased so that it completely covers the through-holes 72A. In this case, the wires are arranged to pass through the through-holes 72A, pushing aside the thermal insulation material 74.

[0044] The thermal insulation materials 71, 74, and 75 may consist of a combination of a flexible thermal insulation material body that provides thermal insulation and a thin plate member that adds rigidity to the thermal insulation material body. The thermal insulation material 75 has a through hole 75A in the center into which the pressure sensing pipe 40 is inserted. The thermal insulation material 75 also has a notch 75B for expanding the diameter of the through hole 75A. This allows the joint 41 to pass through the through hole 75A by expanding the diameter of the through hole 75A when the pressure sensing pipe 40 is passed through the thermal insulation material 75.

[0045] As shown in Figures 1, 2, and 4, the bracket 80 is formed in a cup shape and is fixed to the control unit 90 while housing the sensor head 30, the upper part of the pressure sensing pipe 40, the heater 50, the fixing mechanism 60, and the heat insulating member 70. The bracket 80 is formed in a mesh-like manner, including a combination of a first member 81 and a second member 85.

[0046] As described above, the heat insulating member 70 shown in Figures 2 and 4 surrounds the sensor head 30 and the heater 50, reducing the heat dissipation from the heater 50 to the outside when heating the sensor head 30. However, because the pressure sensing pipe 40 penetrates the heat insulating member 70 (heat insulating material 75), the heat transferred from the heater 50 to the pressure sensors 32 and 33 of the sensor head 30 easily escapes through the uninsulated pressure sensing pipe 40 (see arrow AR). As a result, the amount of heat at the lower part of the pressure sensors 32 and 33 is less than the amount of heat at the upper part, creating a temperature gradient in the vertical direction for each of the heated pressure sensors 32 and 33. Specifically, the lower part, which is on the side of the pressure sensing pipe 40, is at a lower temperature than the upper part, which is on the opposite side of the pressure sensing pipe 40. In this embodiment, in order to reduce this temperature gradient, the heat insulating performance of the upper heat insulating material 71 and the lower heat insulating material 75 that constitute the heat insulating member 70 are adjusted. More specifically, the thermal insulation performance of the lower insulation material 75 is higher than that of the upper insulation material 71. Due to this difference in thermal insulation performance, less heat from the heater 50 is released from the lower part to the insulation material 75 than from the upper part to the insulation material 71. As a result, more heat is retained in the lower part of the heater 50 and used to heat the lower parts of the pressure sensors 32 and 33. Therefore, by increasing the thermal insulation performance of the insulation material 75, the aforementioned temperature gradient is reduced.

[0047] In order to ensure that the thermal insulation performance of the lower insulation material 75 is higher than that of the upper insulation material 71, in this embodiment, the thickness D2 of the insulation material 75 is greater than the thickness D1 of the insulation material 71 (see Figure 4), and the insulation material 75 is larger than the insulation material 71 when viewed from the direction in which the pressure sensing pipe 40 extends (see Figures 2 and 3). Furthermore, the level of thermal insulation performance may be adjusted by making the thermal conductivity of the insulation material 71 and the thermal conductivity of the insulation material 75 different (in this case, by making the thermal conductivity of the insulation material 75 lower). One example of making the thermal conductivity of the two different is to use different materials. The level of thermal insulation performance can be adjusted by adjusting at least one of the thickness, area, and thermal conductivity.

[0048] The method for selecting the thermal insulation materials 71 and 75 to reduce the above temperature gradient is arbitrary. Since the above temperature gradient is due to the structure of the sensor head 30 and the pressure sensing pipe 40, the thermal insulation materials to be used as thermal insulation materials 71 and 75 may be determined at the design stage of the sensor device 10. In such cases, the relationship between the temperature gradient and the thermal insulation performance is simulated. The determination of the thermal insulation material may also be carried out experimentally during manufacturing or other processes. For example, various thermal insulation materials can be tried while measuring the temperature of the pressure sensors 32 and 33 that are actually heated by the heater 50, and a suitable thermal insulation material can be adopted.

[0049] As described above, the sensor device 10 according to this embodiment comprises a sensor head 30, a pressure sensing pipe 40, a heater 50, and heat insulating materials 71 and 75. The sensor head 30 includes a pressure sensing pipe 31 extending in the left-right direction (first direction), and pressure sensors 32 and 33 fixed to both the left and right ends of the pressure sensing pipe 31 (one end in the left-right direction and the other end different from this end (in this case, the opposite end)). The pressure sensing pipe 40 extends in the up-down direction (second direction) perpendicular to the left-right direction and is connected to the middle of the pressure sensing pipe 31, and guides the pressure of the fluid to be measured to the pressure sensors 32 and 33 via the pressure sensing pipe 31. The heater 50 heats the sensor head 30, in particular the pressure sensors 32 and 33. The heat insulating material 71 covers the sensor head 30 and the heater 50 from the opposite side of the pressure sensing pipe 40, i.e., from above. Furthermore, the insulation material 75 has a through-hole through which the pressure sensing pipe 40 passes, and covers the sensor head 30 and heater 50 from the pressure sensing pipe 40 side, i.e., from below. The insulation performance of the lower insulation material 75 is higher than that of the upper insulation material 71. As an example, the thickness of the insulation material 75 is greater than that of the insulation material 71, or the insulation material 75 is larger than the insulation material 71 when viewed from the vertical direction in which the pressure sensing pipe 40 extends (in particular, the insulation material 71 is entirely contained inside the outer circumference of the insulation material 75), or the thermal conductivity of the insulation material 75 is lower than that of the insulation material 71. Alternatively, two or more of these three conditions may be met. The statement that the insulation material 75 is larger than the insulation material 71 when viewed from the vertical direction in which the pressure sensing pipe 40 extends includes the case where the area of ​​the main surface of the insulation material 75 is larger than that of the main surfaces of the plate-shaped insulation materials 75 and 71 facing in the vertical direction. Note that the directions in which the pressure sensing pipes 31 and 40 extend do not necessarily have to be perpendicular.

[0050] With the above configuration, the temperature gradient between the upper part opposite to the pressure sensing pipe 40 and the lower part on the pressure sensing pipe 40 side, which occurs in each of the pressure sensors 32 and 33 when the heater 50 is heated, can be made smaller than when the adiabatic performance of both is the same. As a result, the heat distribution (here, the heat distribution of each of the pressure sensors 32 and 33) when the two pressure sensors 32 and 33 of the sensor device 10 are heated by the heater 50 (i.e., when they are heated by the heater 50) becomes the desired heat distribution, in this case, a heat distribution in which the temperature gradient between the upper and lower parts is smaller (including making it zero) than when the adiabatic performance of both is the same.

[0051] The shape of the heater 50 may be other than that of the above embodiment, but as in the above embodiment, it is preferable that it is cylindrical (including cylindrical and polygonal cylindrical) and extends from the position of the pressure sensor 32 to the position of the pressure sensor 33 in the left-right direction. This allows the pressure sensors 32 and 33 to be heated by a single heater 50, and that the heater 50 heats them from all directions around the outer circumference. Furthermore, the shape of the heater 50 is preferably cylindrical as described above. This allows the pressure sensors 32 and 33 to be heated uniformly from all directions around the outer circumference. Even if the shape of the heater 50 is as described above, by setting the thermal insulation performance of the thermal insulation materials 71 and 75 as described above, the heat distribution of the two pressure sensors 32 and 33 when heated by the heater 50 (here, the heat distribution of each of the pressure sensors 32 and 33) can be set to the desired heat distribution. Note that the heater 50 may be configured to include two sensors that heat the two pressure sensors 32 and 33, respectively.

[0052] As described above, it is preferable that the heater 50 uniformly heats the sensor head 30, particularly the pressure sensors 32 and 33, so that the internal temperature of each pressure sensor 32 and 33 becomes the same as the temperature of the fluid being measured. In other words, it is desirable that no temperature gradient occurs between the pressure sensors 32 and 33 when heating by the heater 50. However, due to misalignment of the heater 50 relative to the sensor head 30, or uneven heating of the heater 50, it may not be possible to heat the pressure sensors 32 and 33 uniformly. An example of this can be seen in Figure 6, where, for example, dimensional errors in the components of the sensor head 30, heater 50, and fixing mechanism 60 may cause the left-right relative position of the heater 50 to deviate from the intended relative position. In such cases, for example, the distances D3 and D4 between the inner wall of the opening 50A of the heater 50 on the pressure sensor 32 side and the inner wall on the pressure sensor 33 side, respectively, and the pressure sensing pipe 40 are different. As a result, the areas of the heater head 30 and the pressure sensing pipe 40 that are not directly heated by the heater 50 are not evenly distributed on the left and right sides. Consequently, the amount of heat escaping from the pressure sensor 32 side (right side) through the pressure sensing pipe 40 (see arrow AR1) and the amount of heat escaping from the pressure sensor 33 side (left side) through the pressure sensing pipe 40 (see arrow AR2) may not be uniform. Consequently, the heat distribution of the pressure sensors 32 and 33 when heated by the heater 50 may not be the desired heat distribution, in this case, a uniform heat distribution. This can result in a temperature gradient between the pressure sensors 32 and 33.

[0053] Therefore, in addition to the structure described above, or when the vertical temperature gradients occurring in the pressure sensors 32 and 33 are not a problem, the thermal insulation performance of the first portion 71X that covers the pressure sensor 32 from above and the second portion 71Y that covers the pressure sensor 33 from above may be made different from the structure described above, as shown in Figure 6. Furthermore, the thermal insulation performance of the first portion 75X that covers the pressure sensor 32 from below and the second portion 75Y that covers the pressure sensor 33 from below may be made different from the thermal insulation performance of the first portion 71X that covers the pressure sensor 33 from below. In the example in Figure 6, the first portion 71X is made thicker than the second portion 71Y, and the thermal insulation performance of the first portion 71X is made higher than that of the second portion 71Y. However, as another example, the first portion 71X may be made larger than the second portion 71Y when viewed from the vertical direction in which the pressure sensing pipe 40 extends, or the thermal conductivity of the first portion 71X may be made lower than that of the second portion 71Y. The same applies to the first portion 75X and the second portion 75Y of the insulation material 75. In Figure 6, the first portion 71X is larger than the second portion 71Y when viewed from the vertical direction in which the pressure sensing pipe 40 extends (its length in the horizontal direction is slightly longer). It is also possible to make only one of the insulation materials 71 and 75 have different thermal insulation performance. For example, if the amount of heat escaping through the pressure sensing pipe 40 is greater on the pressure sensor 32 side than on the pressure sensor 33 side when the thermal insulation performance of insulation materials 71 and 75 is uniform, the thermal insulation performance of the first portion 71X and / or 71Y on the pressure sensor 32 side is increased as described above. This increases the amount of heat applied to the heated pressure sensor 32 and reduces the temperature gradient between the pressure sensors 32 and 33.

[0054] As described above, by making the thermal insulation performance different between the first part 71X and the second part 71Y of the thermal insulation material 71, and / or between the first part 75X and the second part 75Y of the thermal insulation material 75, the heat distribution when the two pressure sensors 32 and 33 of the sensor device 10 are heated by the heater 50 (here, the entire pressure sensors 32 and 33, in other words, the heat distribution at the sensor head 30) can be made into a desired heat distribution, here, a heat distribution with a small temperature gradient between the pressure sensors 32 and 33 (including a heat distribution with a temperature gradient of 0). In some cases, a heat distribution with a large temperature gradient may be used as the desired heat distribution. The same applies to the heat distribution in the vertical direction of the pressure sensors 32 and 33. For example, the thermal insulation material 71 and the thermal insulation material 75 may have different thermal insulation performance.

[0055] The method for creating different thermal insulation performance, that is, the method for selecting which thermal insulation materials 71 and 75 to reduce the above-mentioned temperature gradient, is arbitrary. For example, the positional relationship between the sensor head 30 and the heater 50 may be measured, and the thermal insulation materials to be used as thermal insulation materials 71 and 75 may be determined by simulation based on the measured positional relationship. The determination of the thermal insulation material may also be carried out experimentally during manufacturing. For example, various thermal insulation materials may be tried while measuring the temperature of the pressure sensors 32 and 33 that are actually heated by the heater 50, and the most suitable thermal insulation material may be adopted.

[0056] As described above, the thermal insulation materials 71 and 75 should be provided in such a way that they can adjust the temperature gradient generated in the sensor head 30 when the pressure sensors 32 and 33 are heated by the heater 50 (the temperature gradient generated in each of the pressure sensors 32 and 33, and / or the temperature gradient generated between the pressure sensors 32 and 33). Adjusting the temperature gradient includes both being able to adjust the temperature gradient by changing the type of thermal insulation material (thickness, size, shape, or thermal conductivity) actually used as thermal insulation material 71 and 75 during manufacturing or design, and being able to adjust the temperature gradient by disassembling the sensor device 10 after manufacturing and replacing the thermal insulation materials 71 and 75.

[0057] Here, the manufacturing method of the sensor device 10 will be explained with reference to Figure 7. First, the manufacturer of the sensor device 10 prepares the sensor head 30 and the heater 50 (step S11). The sensor head 30 is connected to the pressure sensing pipe 40 and is provided with bosses 61 and 62 of the fixing mechanism 60. In the manufacturing of the sensor head 30, for example, a metal member is prepared in which the pressure sensing pipe 31, the pressure sensing pipe 40, and the bosses 61 and 62 are integrally formed, and the pressure sensors 32 and 33 are fixed to both the left and right ends of the pressure sensing pipe 31 by welding or the like, thereby preparing the unit of the sensor head 30, the pressure sensing pipe 40, and the bosses 61 and 62.

[0058] Subsequently, the manufacturer fixes the heater 50 to the sensor head 30 by fixing it to the fixing mechanism 60 (step S12). Specifically, the manufacturer first inserts the protrusions 61B and 62B of the bosses 61 and 62 into the through holes 53AA and 54AA of the support members 53 and 54 of the heater 50. Then, the manufacturer screws the screws 63 and 64 into the screw holes 61C and 62C, and screws the heater 50 to the bosses 61 and 62. This positions and fixes the heater 50.

[0059] In steps S11-S12, the heater 50 is positioned relative to the sensor head 30, to which the pressure sensing pipe 40 is connected to the pressure sensing pipe 31.

[0060] Subsequently, the manufacturer identifies insulating materials 71 and 75 (more specifically, thickness, size, thermal conductivity, etc.) that have the thermal insulation performance to make the temperature gradient generated in the pressure sensors 32 and / or 33 (temperature gradient generated in the sensor head 30) a desired temperature gradient (specifically, to reduce the temperature gradient) when the pressure sensors 32 and 33 (sensor head 30) are heated by the heater 50 (step S13). The method of identification may be the above simulation, experiment, etc.

[0061] Subsequently, the manufacturer connects the wiring between the sensor head 30 and the heater 50 and the control unit 90, and covers the sensor head 30 and the heater 50 with the heat insulating member 70, which includes the heat insulating materials 71 and 75 identified in step S13 (step S14). This positions the heat insulating materials 71 and 75 identified in step S13 in the desired location to cover the sensor head 30 and the heater 50 from above and below.

[0062] Subsequently, the manufacturer fixes the sensor head 30, heater 50, and heat insulating member 70 to the housing 91 of the control unit 90 using the bracket 80 (step S15). This completes the sensor device 10.

[0063] According to the manufacturing method described above, the heat distribution of the pressure sensors 32 and 33 during heating by the heater 50 can be adjusted by adjusting the heat insulating materials 71 and 75 (for example, the heat distribution of each pressure sensor, and / or the heat distribution of the two pressure sensors 32 and 33 as a whole (sensor head 30)), and the heat distribution can be set to a desired heat distribution.

[0064] The present invention has been described above with reference to embodiments and modifications, but the present invention is not limited to the above embodiments and modifications. The shapes of each of the above elements can be changed as appropriate. Furthermore, the present invention includes various modifications to the above embodiments and modifications that can be understood by those skilled in the art within the scope of the technical concept of the present invention. The configurations listed in the above embodiments and modifications can be combined as appropriate within a non-contradictory range.

[0065] (Note) A configuration based on the above embodiment and its modifications is described below as an example. (Note 1) A sensor head including a first pipe extending in a first direction, a first pressure sensor fixed to a first end of the first pipe, and a second pressure sensor fixed to a second end of the first pipe different from the first end, A second pipe extending in a second direction different from the first direction and connected to the middle of the first pipe, which guides the pressure of the fluid to be measured to the first pressure sensor and the second pressure sensor via the first pipe, A heater for heating the first pressure sensor and the second pressure sensor, A first insulating material is positioned in a first location that covers the sensor head and the heater from the opposite side of the second pipe, The device comprises a second insulating material having a through-hole through which the second pipe passes, and positioned at a second location that covers the sensor head and the heater from the second pipe side, The thermal insulation performance of the second insulation material is higher than that of the first insulation material. Sensor device. (Note 2) The heater extends from the position of the first pressure sensor in the first direction to the position of the second pressure sensor and is formed in a cylindrical shape that covers the sensor head. The sensor device described in Appendix 1. (Note 3) The thickness of the second insulation material is greater than the thickness of the first insulation material. The sensor device described in Appendix 1 or 2. (Note 4) The second insulation material is larger than the first insulation material when viewed from the second direction. A sensor device as described in any of the appendices 1 to 3. (Note 5) The thermal conductivity of the second insulating material is lower than that of the first insulating material. A sensor device as described in any of the appendices 1 to 4. (Note 6) At least one of the first and second thermal insulation materials has different thermal insulation performance in the first portion covering the first pressure sensor and the second portion covering the second pressure sensor. A sensor device as described in any of the appendices 1 to 5. (Note 7) At least one of the first and second insulating materials has different thicknesses, dimensions when viewed from the second direction, and thermal conductivity in the first and second portions, thereby having different thermal insulation performance in the first and second portions. The sensor device described in Appendix 6. (Note 8) A sensor head including a first pipe extending in a first direction, a first pressure sensor fixed to a first end of the first pipe, and a second pressure sensor fixed to a second end of the first pipe different from the first end, A second pipe extending in a second direction different from the first direction and connected to the middle of the first pipe, which guides the pressure of the fluid to be measured to the first pressure sensor and the second pressure sensor via the first pipe, A heater for heating the first pressure sensor and the second pressure sensor, A first insulating material is positioned in a first location that covers the sensor head and the heater from the opposite side of the second pipe, The second pipe has a through-hole through which the second pipe passes, and the second insulating material is positioned at a second location that covers the sensor head and the heater from the second pipe side, At least one of the first and second thermal insulation materials has different thermal insulation performance in the first portion covering the first pressure sensor and the second portion covering the second pressure sensor. Sensor device. (Note 9) A sensor head including a first pipe extending in a first direction, a first pressure sensor fixed to a first end of the first pipe, and a second pressure sensor fixed to a second end of the first pipe different from the first end, A second pipe extending in a second direction different from the first direction and connected to the middle of the first pipe, which guides the pressure of the fluid to be measured to the first pressure sensor and the second pressure sensor via the first pipe, A heater for heating the first pressure sensor and the second pressure sensor, A first insulating material is positioned in a first location that covers the sensor head and the heater from the opposite side of the second pipe, A second insulating material is positioned at a second location that has a through-hole through which the second pipe passes, and covers the sensor head and the heater from the second pipe side. A method for manufacturing a sensor device comprising: The first step is to identify the first and second insulating materials having thermal insulation properties that cause the temperature gradient generated in the sensor head to become a desired temperature gradient when the first and second pressure sensors are heated by the heater, The second step includes arranging the first and second insulation materials identified in the second step at the first and second positions, respectively. In the first step, identify a first thermal insulation material and a second thermal insulation material having different thermal insulation properties, or identify at least one of the first thermal insulation material and the second thermal insulation material having different thermal insulation properties in a first portion covering the first pressure sensor and a second portion covering the second pressure sensor. A method for manufacturing a sensor device. [Explanation of Symbols]

[0066] 10...Sensor device, 20...Sensor unit, 30...Sensor head, 31...Pressure sensing pipe, 32...Pressure sensor, 32A...Housing, 32AA...Through hole, 32B...Support diaphragm, 32C...Sensor element, 32CA...Pressure receiving diaphragm, 32D...Conductive pin, 32E...Spring contact, 32F...Sealing member, 33...Pressure sensor, 33A...Housing, 33B...Support diaphragm, 33C...Sensor element, 33CA...Pressure receiving diaphragm, 33D...Conductive pin, 33E...Spring contact, 33F...Sealing member, 34...Insulator, 35...Insulator, 36...Baffle, 37...Baffle, 40...Pressure sensing pipe, 41...Fitting, 50...Heater, 50A...Opening, 51...Heater body, 51A...Through hole, 52...Heater body, 52A...Through hole, 53...Support member, 53A ...Screw fastening part, 53AA...Through hole, 53AAA...Inner surface, 54...Support member, 54A...Screw fastening part, 54AA...Through hole, 60...Fixing mechanism, 61...Boss, 61A...Flat surface, 61B...Convex part, 61BA...Side surface, 61C...Screw hole, 62...Boss, 62A...Flat surface, 62B...Convex part, 62C...Screw hole, 63...Screw, 64...Screw, 70...Insulation member, 71...Insulation material, 71X...First part, 71Y... Part 2, 72...support member, 72A...through hole, 73...support member, 74...insulation material, 75...insulation material, 75A...through hole, 75X...Part 1, 75Y...Part 2, 80...bracket, 81...Part 1, 85...Part 2, 90...control unit, 91...housing, D1~D4...distance, R11...reference pressure chamber, R12...pressure chamber under measurement, R21...reference pressure chamber, R22...pressure chamber under measurement, S...temperature sensor.

Claims

1. A sensor head including a first pipe extending in a first direction, a first pressure sensor fixed to a first end of the first pipe, and a second pressure sensor fixed to a second end of the first pipe different from the first end, A second pipe extending in a second direction different from the first direction and connected to the middle of the first pipe, which guides the pressure of the fluid to be measured to the first pressure sensor and the second pressure sensor via the first pipe, A heater for heating the first pressure sensor and the second pressure sensor, A first insulating material is positioned in a first location that covers the sensor head and the heater from the opposite side of the second pipe, The device comprises a second insulating material having a through-hole through which the second pipe passes, and positioned at a second location that covers the sensor head and the heater from the second pipe side, The thermal insulation performance of the second thermal insulation material is higher than that of the first thermal insulation material. Sensor device.

2. The heater extends from the position of the first pressure sensor in the first direction to the position of the second pressure sensor and is formed in a cylindrical shape that covers the sensor head. The sensor device according to claim 1.

3. The thickness of the second insulation material is greater than the thickness of the first insulation material. The sensor device according to claim 1.

4. The second insulation material is larger than the first insulation material when viewed from the second direction. The sensor device according to claim 1.

5. The thermal conductivity of the second insulating material is lower than that of the first insulating material. The sensor device according to claim 1.

6. At least one of the first and second thermal insulation materials has different thermal insulation performance in the first portion covering the first pressure sensor and the second portion covering the second pressure sensor. The sensor device according to claim 1.

7. At least one of the first and second insulating materials has different thicknesses, dimensions when viewed from the second direction, and thermal conductivity in the first and second portions, thereby having different thermal insulation performance in the first and second portions. The sensor device according to claim 6.

8. A sensor head including a first pipe extending in a first direction, a first pressure sensor fixed to a first end of the first pipe, and a second pressure sensor fixed to a second end of the first pipe different from the first end, A second pipe extending in a second direction different from the first direction and connected to the middle of the first pipe, which guides the pressure of the fluid to be measured to the first pressure sensor and the second pressure sensor via the first pipe, A heater for heating the first pressure sensor and the second pressure sensor, A first insulating material is positioned in a first location that covers the sensor head and the heater from the opposite side of the second pipe, The second pipe has a through-hole through which the second pipe passes, and the second insulating material is positioned at a second location that covers the sensor head and the heater from the second pipe side, At least one of the first and second thermal insulation materials has different thermal insulation performance in the first portion covering the first pressure sensor and the second portion covering the second pressure sensor. Sensor device.

9. A sensor head including a first pipe extending in a first direction, a first pressure sensor fixed to a first end of the first pipe, and a second pressure sensor fixed to a second end of the first pipe different from the first end, A second pipe extending in a second direction different from the first direction and connected to the middle of the first pipe, which guides the pressure of the fluid to be measured to the first pressure sensor and the second pressure sensor via the first pipe, A heater for heating the first pressure sensor and the second pressure sensor, A first insulating material is positioned in a first location that covers the sensor head and the heater from the opposite side of the second pipe, The second insulating material is positioned at a second location that has a through-hole through which the second pipe passes, and covers the sensor head and the heater from the second pipe side, A method for manufacturing a sensor device comprising: The first step is to identify the first and second insulating materials having thermal insulation properties that cause the temperature gradient generated in the sensor head to become a desired temperature gradient when the first and second pressure sensors are heated by the heater, The second step includes arranging the first and second insulation materials identified in the second step at the first and second positions, respectively. In the first step, identify a first thermal insulation material and a second thermal insulation material having different thermal insulation performance, or identify at least one of the first thermal insulation material and the second thermal insulation material having different thermal insulation performance in a first portion covering the first pressure sensor and a second portion covering the second pressure sensor. A method for manufacturing a sensor device.

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