Sensor device

Abstract

Reduce the distance between the pressure-receiving diaphragm and the baffle of each of the two pressure sensors. [Solution] The sensor device 10 comprises a sensor head 30 and a pressure sensing pipe 40. The sensor head 30 includes a pressure sensing pipe 31 and pressure sensors 32 and 33 fixed to the left and right ends of the pressure sensing pipe 31, respectively. The pressure sensing pipe 40 is connected in 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 sensor head 30 comprises a baffle 36 located inside the pressure sensing pipe 31 and facing the pressure-receiving diaphragm 32CA of the sensor element 32C, and a baffle 37 located inside the pressure sensing pipe 31 and facing the pressure-receiving diaphragm 33CA of the sensor element 33C.

Description

Technical Field

[0004] , , , ,

[0001] The present invention relates to a sensor device such as a vacuum gauge.

Background Art

[0002] As disclosed in Patent Document 1, a sensor device (vacuum gauge) for measuring the pressure of a fluid to be measured such as a gas is known. Such a sensor device includes a pressure sensor. The pressure sensor includes a pressure-receiving diaphragm that receives the pressure of the fluid to be measured, and is configured to convert the pressure received by this pressure-receiving diaphragm into an electrical signal. Further, the sensor device also includes a baffle that the fluid to be measured hits before reaching the pressure-receiving diaphragm. When the fluid to be measured hits this baffle, deposition of foreign matter on the pressure-receiving diaphragm due to the fluid to be measured is suppressed.

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 a case, one baffle is used for two pressure sensors. However, in this configuration, the distance between each pressure-receiving diaphragm of the two pressure sensors and the baffle becomes long. When each distance increases, for example, the spatial volume between the baffle and each pressure-receiving diaphragm increases, and the response speed of pressure detection of the two pressure sensors decreases.

[0005] The present invention aims to shorten the distance between the pressure-receiving diaphragm and the baffle of each of the two pressure sensors. [Means for solving the problem]

[0006] The sensor device according to this invention further includes a sensor head comprising 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, and a second pipe extending in a second direction different from the first direction and connected in 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, wherein the first pressure sensor comprises a first pressure receiving diaphragm that receives the pressure of the fluid to be measured and converts the pressure received by the first pressure receiving diaphragm into an electrical signal, the second pressure sensor comprises a second pressure receiving diaphragm that receives the pressure of the fluid to be measured and converts the pressure received by the second pressure receiving diaphragm into an electrical signal, and the sensor head further comprises a first baffle disposed inside the first pipe and facing the first pressure receiving diaphragm, and a second baffle disposed inside the second pipe and facing the second pressure receiving diaphragm. [Effects of the Invention]

[0007] According to the present invention, the distance between the pressure-receiving diaphragm and the baffle of each of the two pressure sensors is shortened. [Brief explanation of the drawing]

[0008] [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, and the inside of the sensor head is shown only in the cross-sectional view where appropriate, with only the cut end faces visible. [Figure 5] This is a schematic cross-sectional view of the sensor device. [Figure 6] This is a perspective view of the pressure sensing pipe and two baffles of the sensor head. [Modes for carrying out the invention]

[0009] (Summary of Embodiment 1) The inventors of the present invention have found the following: First, by using a dual number of pressure sensors in a sensor device for measuring the pressure of a fluid to be measured (e.g., a vacuum gauge), the overall size can be reduced compared to a sensor device with multiple sensors, 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. The first pressure sensor has a first pressure-receiving diaphragm used to detect the pressure of the fluid to be measured, and the second pressure sensor has a second pressure-receiving diaphragm used to detect the pressure of the fluid to be measured.

[0010] Baffles are placed in the flow path of the fluid to be measured in such a sensor device. The baffles function as obstructions that the fluid to be measured encounters before it reaches the first and second pressure-receiving diaphragms, reducing the amount of foreign matter deposited on the first and second pressure-receiving diaphragms. For example, if the fluid to be measured is an active gas, when the fluid to be measured comes into contact with the baffles, the active substances constituting the fluid react with the surface of the baffles and deposit on the surface as foreign matter. This reduces the amount of foreign matter deposited on the first and second pressure-receiving diaphragms due to similar reactions. Such baffles can be shared between the first and second pressure-receiving diaphragms, i.e., the first and second pressure sensors. Sharing baffles reduces the number of parts in the sensor device. However, when baffles are shared, the distance from the baffle to the first pressure-receiving diaphragm (in other words, the spatial volume between the two) and the distance from the baffle to the second pressure-receiving diaphragm (in other words, the spatial volume between the two) inevitably become longer in order to balance these distances. As this distance increases, the spatial volume increases, and the response speed from the time the pressure of the fluid being measured changes until the new pressure is detected by the first or second pressure sensor becomes slower. Therefore, in this embodiment, one baffle is provided for each of the first and second pressure-receiving diaphragms. This allows each baffle to be positioned closer to the first and second pressure-receiving diaphragms, respectively, resulting in a faster response speed than when the baffles are shared.

[0011] (Summary of Embodiment 2) If the baffles are not shared but are instead arranged separately, the distance between each separately arranged baffle and the first and second pressure-receiving diaphragms can be adjusted individually. In this case, by making the distances between each separately arranged baffle and the first and second pressure-receiving diaphragms different, the response speeds of the first and second pressure sensors can be set to desired response speeds according to the characteristics of the first and second pressure sensors.

[0012] For example, when the pressure detection range of the sensor device is wide-range, the pressure detection ranges of the first pressure sensor and the second pressure sensor will be different. For example, the first pressure sensor may have a first pressure detection range on the high-pressure side, and the second pressure sensor may have a second pressure detection range on the lower-pressure side than the first measurement range. Also, the baffle for the first pressure sensor may be called the first baffle, and the baffle for the second pressure sensor may be called the second baffle. Here, the flow of the fluid to be measured changes from viscous flow to molecular flow as the pressure decreases. And as the flow changes from viscous flow to molecular flow, the ease of flow of the fluid to be measured decreases. Therefore, the lower the pressure of the fluid to be measured, the lower the response speed (the period becomes longer), when the pressure sensor is configured to detect the pressure of the fluid to be measured at a low pressure. This reduces the difference in response speed that occurs depending on the pressure being measured, that is, which pressure sensor is used to detect the pressure, resulting in a sensor device with minimal difference in response speed across the entire wide measurement range.

[0013] (Details of the embodiment) The details of embodiments of the present invention will be described below 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.

[0014] The sensor device 10 shown in Figure 1 is connected to piping connected to a pressure adjustment chamber (e.g., a vacuum chamber) in a semiconductor control device or the like, 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 from the pressure adjustment chamber into the piping using a diaphragm that receives this pressure.

[0015] The sensor device 10 includes a sensor unit 20 that detects the pressure of the fluid to be measured by converting the pressure of the fluid to be measured into an electrical signal and outputs the detected pressure, that is, 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, and externally outputs the pressure of the fluid to be measured indicated by the pressure detection signal. By deriving this pressure, the pressure of the fluid to be measured is measured. The control unit 90 includes a circuit board, a connector, a communication module, etc. for deriving and externally outputting the pressure, and a housing 91 that houses these. The housing 91 is simplified in FIG. 1. Actually, it has a ventilation port for cooling the circuit board and various connectors are attached to it.

[0016] As shown in FIGS. 1 to 3, the sensor unit 20 includes a sensor head 30, a pressure guiding pipe 40, a heater 50, a fixing mechanism 60, a heat insulating member 70, and a bracket 80.

[0017] As shown in FIGS. 3 and 4, the sensor head 30 includes a cylindrical pressure guiding 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 guiding pipe 31, and insulators 34 and 35 respectively fixed to the pressure sensors 32 and 33 by fixing tools or an arbitrary joining method not shown.

[0018] In the middle of the pressure guiding pipe 31 (here, the center in the left - right direction), the upper end of a cylindrical pressure guiding pipe 40 extending in the up - down direction is connected. The combination of the pressure guiding pipe 31 and the pressure guiding pipe 40 is formed in a T - shape with the pressure guiding pipe 31 as the horizontal bar of the T and the pressure guiding pipe 40 as the vertical bar of the T. [[ID=​​​​​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 depicted as elevation views rather than cross-sections. The number of the conductive pins 32D and the spring contacts 32E is arbitrary. In FIG. 4, the thicknesses of the support diaphragm 32B and the sensor element 32C (particularly the pressure-receiving diaphragm 32CA described later) are exaggerated. This is the same for the pressure sensor 33.

[0021] The housing 32A includes a cylindrical housing member 32AA, a plate-shaped housing member 32AB that covers the opening at one end (here, the right end) of the housing member 32AA, and an annular housing member 32AC connected to the other end of the housing member 32AA. The housing members 32AA and 32AC support the support diaphragm 32B by sandwiching the peripheral edge of the support diaphragm 32B. The support diaphragm 32B supports the sensor element 32C. The housing members 32AA and 32AB together with the support diaphragm 32B and the sensor element 32C form a reference pressure chamber (for example, a vacuum chamber) R11 having a reference pressure (for example, a vacuum pressure). The housing member 32AC is connected to one end (the right end) of the pressure guiding pipe. The housing member 32AC together with the support diaphragm 32B and the sensor element 32C forms a pressure-to-be-measured chamber R12. The pressure-to-be-measured chamber R12 communicates with the internal space of the pressure guiding pipe 31, and the pressure of the fluid to be measured is pressure-guided into the pressure-to-be-measured chamber R12 by the inflow of the fluid to be measured from the pressure guiding pipe 31.

[0022] The sensor element 32C introduces the fluid to be measured (more specifically, 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 of the reference pressure chamber R11. The sensor element 32C converts the amount of displacement of the pressure-receiving diaphragm 32CA (i.e., the pressure received by 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.

[0023] 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 hermetic seals, passing through the housing member 32AC of 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).

[0024] The sealing member 32F seals the through-hole H1 of the housing member 32AA, which forms the reference pressure chamber R11. During the manufacturing of the pressure sensor 32, the reference pressure chamber R11 is evacuated through the through-hole H1. The sealing member 32F is provided to seal the through-hole H1 after the evacuation is complete.

[0025] With the above configuration, the pressure sensor 32 receives the pressure of the fluid to be measured, introduced via the pressure sensing pipes 40 and 31, with the pressure receiving diaphragm 32CA. The pressure received by the pressure receiving diaphragm 32CA is converted into an electrical signal, and this electrical signal is supplied to the control unit 90 via wiring as a pressure detection signal. The pressure sensor 32 detects the pressure by converting the pressure into an electrical signal. The control unit 90 processes the pressure detection signal and derives the pressure of the fluid to be measured indicated by the pressure detection signal. This completes the pressure measurement. The control unit 90 outputs the derived, i.e., measured, pressure to an external device via a connector (not shown).

[0026] The pressure sensor 33 has the same configuration as the pressure sensor 32. That is, the pressure sensor 33 comprises a housing 33A (housing members 33AA to 33AC), 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 members 33AA and 33AB of housing 33A, together with the support diaphragm 33B which is supported between housing members 33AA and 33AC, and the sensor element 33C which is fixed to and supported by the support diaphragm 33B, form a reference pressure chamber R21. The through hole H1 of housing member 33AA is sealed by the sealing member 33F. The housing member 33AC of housing 33A, together with the support diaphragm 33B and the sensor element 33C, forms a pressure chamber R22. The sensor element 33C includes a pressure receiving diaphragm 33CA. Each portion of the multiple 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 (more specifically, an electrical signal indicating the displacement of the pressure-receiving diaphragm 33CA), and supplies this electrical signal as a pressure detection signal to the control unit 90 via multiple wires. The control unit 90 processes the electrical signal, derives the pressure of the fluid to be measured indicated by the pressure detection signal, and outputs it externally via a connector (not shown) or the like.

[0027] The pressure detection ranges of the fluid being measured by pressure sensors 32 and 33 are different from each other. Specifically, pressure sensor 32 has a high-pressure detection range, and pressure sensor 33 has a low-pressure detection range. This enables a wide range for the overall pressure detection range of the sensor device 10. The high-pressure detection range is located on the higher pressure side than the low-pressure detection range. As an example, there may be some overlap between the two detection ranges. For example, the upper limit of the high-pressure detection range may be higher than the upper limit of the low-pressure detection range, the lower limit of the high-pressure detection range may be higher than the lower limit of the low-pressure detection range, and the lower limit of the high-pressure pressure detection range may be lower than the upper limit of the low-pressure pressure detection range. The detection range is adjusted, for example, by the materials and / or thicknesses of the pressure-receiving diaphragms 32CA and 33CA.

[0028] As shown in Figures 4 to 6, the sensor head 30 also includes baffles 36 and 37, each formed as a single plate. Baffles 36 and 37 are formed to be the same shape as each other. Baffle 36 comprises a plate-shaped baffle body 36A and three protruding portions 36B that extend radially from the baffle body 36A. The three protruding portions 36B are fixed to the rightward-facing annular surface 31A of the inner surface of the pressure sensing pipe 31, which is on the side of the pressure receiving diaphragm 32CA, by welding, screwing, or the like. Similarly, baffle 37 comprises a baffle body 37A and three protruding portions 37B. The three protruding portions 37B are fixed to the leftward-facing annular surface 31B of the inner surface of the pressure sensing pipe 31, which is on the side of the pressure receiving diaphragm 33CA, by welding, screwing, or the like.

[0029] With the above configuration, baffles 36 and 37 are arranged inside the pressure sensing pipe 31 and supported by the pressure sensing pipe 31. Baffles 36 and 37 face the sensor elements 32C and 33C of the pressure sensors 32 and 33, in particular the pressure-receiving diaphragms 32CA and 33CA, respectively. Baffles 36 and 37 have an in-plane direction perpendicular to the left-right direction, which is the direction in which the pressure sensing pipe 31 extends. Baffles 36 and 37 are provided parallel to the pressure-receiving diaphragms 32CA and 33CA, respectively. Baffle 36 is located inside the pressure sensing pipe 31 on the side of the pressure sensor 32 that is closer to the pressure sensing pipe 40. Therefore, baffle 36 is located upstream of the pressure sensor 32 and downstream of the pressure sensing pipe 40. Baffle 37 is located inside the pressure sensing pipe 31 on the side of the pressure sensor 33 that is closer to the pressure sensing pipe 40. Therefore, baffle 37 is located upstream of the pressure sensor 33 and downstream of the pressure sensing pipe 40.

[0030] The fluid being measured, flowing from the pressure sensing pipe 31 towards the pressure sensor 32, comes into contact with baffle 36. The fluid being measured, flowing from the pressure sensing pipe 31 towards the pressure sensor 33, comes into contact with baffle 37. As a result, foreign matter originating from the fluid being measured accumulates on baffles 36 and 37. This accumulation reduces the amount of foreign matter that accumulates on the pressure-receiving diaphragms 32CA and 33CA, which are located downstream of baffles 36 and 37.

[0031] As shown in Figure 4, the pressure sensing pipe 40 is connected to the center of the pressure sensing pipe 31 in the left-right direction. The position of the annular surface 31A of the pressure sensing pipe 31 in the left-right direction (the direction in which the pressure sensing pipe 31 extends) is closer to the pressure sensing pipe 40 than the position of the annular surface 31A in the left-right direction. Also, the pressure sensors 32 and 33 have substantially the same structure. As a result, the distance D1 between the baffle 36 and the pressure-receiving diaphragm 32CA facing the baffle 36 is longer than the distance D2 between the baffle 37 and the pressure-receiving diaphragm 33CA facing the baffle 37. Note that distance D1 can be, for example, the distance between the surface of the baffle 36 facing the pressure-receiving diaphragm 32CA and the surface of the pressure-receiving diaphragm 32CA facing the baffle 36. Similarly, distance D2 can be, for example, the distance between the surface of the baffle 37 facing the pressure-receiving diaphragm 33CA and the surface of the pressure-receiving diaphragm 33CA facing the baffle 37.

[0032] 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, and has an opening 50A through which the pressure sensing pipe 40 passes. 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, respectively.

[0033] 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, particularly 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.

[0034] 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. These members are provided with semicircular notches that form a through hole 50A.

[0035] Each of the heater bodies 51 and 52 is formed in a semi-cylindrical shape. The heater bodies 51 and 52 are connected to the control unit 90 by wiring (not shown) and generate heat uniformly when power is supplied from the control unit 90. This heat heats the sensor head 30, particularly the pressure sensors 32 and 33 and the pressure-conducting pipe 31. The control unit 90 acquires the temperature detected by the temperature sensor S (see Figure 4) by wiring (not shown) and uses the acquired temperature as a feedback value to feedback control the power supplied to the heater bodies 51 and 52 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, particularly the pressure sensors 32 and 33, is the same as the temperature of the fluid being measured. The heater bodies 51 and 52 have a structure in which, for example, a heating wire passes through the inside for generating heat. The cross-sections of the heater bodies 51 and 52 in Figure 5 are shown in a manner in which the internal structure such as the heating wire is omitted.

[0036] 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.

[0037] 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 protrude in the front-rear direction from the outer surface of the sensor head 30 (specifically, the center of the pressure sensing pipe 31 in the left-right direction), and screws 63 and 64 that are screwed into the bosses 61 and 62, respectively. In Figure 5, the screws 63 and 64 are shown in elevation views, not cross-sections.

[0038] As shown in Figures 3 and 5, the support members 53 and 54 of the heater 50 are screwed to bosses 61 and 62 with screws 63 and 64, respectively, while supporting the heater bodies 51 and 52. This fixes the heater 50 to the sensor head 30.

[0039] The heat insulating member 70 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. 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.

[0040] 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.

[0041] 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.

[0042] As shown in Figures 1, 2, and 4, the bracket 80 includes a plurality of bracket members 81 and 82 that face each other in the left-right direction from which the sensor head 30 extends and are combined with each other, and is formed as a whole into a cup shape. This bracket 80 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. Here, it is fixed to the housing 91 of the control unit 90 by screws (not shown).

[0043] As described above, the sensor device 10 according to this embodiment comprises a sensor head 30 and a pressure sensing pipe 40. 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 pressure sensor 32 includes a pressure-receiving diaphragm 32CA that receives the pressure of the fluid to be measured and converts the pressure received by the pressure-receiving diaphragm 32CA into an electrical signal. Furthermore, the pressure sensor 33 includes a pressure-receiving diaphragm 33CA that receives the pressure of the fluid to be measured and converts the pressure received by the pressure-receiving diaphragm 33CA into an electrical signal. The sensor head 30 is located inside the pressure sensing pipe 31 and includes a baffle 36 facing the pressure-receiving diaphragm 32CA of the sensor element 32C, and a baffle 37 located inside the pressure sensing pipe 31 and facing the pressure-receiving diaphragm 33CA of the sensor element 33C.

[0044] In this embodiment, with the above configuration, one baffle 36 and one baffle 37 are provided for each of the pressure sensors 32 and 33, i.e., the pressure-receiving diaphragms 32CA and 33CA. Here, if a baffle is provided in common for both pressure sensors 32 and 33, as in the case of baffle B described above, this baffle is provided as baffle B, for example, shown by the dashed line in Figure 4. As is clear from Figure 4, the distances D1 and D2 between baffles 36 and 37 and the pressure-receiving diaphragms 32CA and 33CA are shorter than the distances between baffle B and the pressure-receiving diaphragms 32CA and 33CA. Thus, according to this embodiment, the distances between each of the pressure-receiving diaphragms and baffles of the two pressure sensors can be shortened.

[0045] Furthermore, as described above, the greater the distance between the baffle and the pressure-receiving diaphragm, or more specifically, the larger the spatial volume between the baffle and the pressure-receiving diaphragm, the slower the response speed becomes from the time the pressure of the fluid being measured changes until this changed pressure is detected by the pressure sensor 32 or 33 (specifically, until this changed pressure reaches the pressure-receiving diaphragm and is converted into an electrical signal). In this embodiment, since the distances D1 and D2 can be made shorter than the respective distances between the baffle B and the pressure-receiving diaphragms 32CA and 33CA, the response speed is particularly faster compared to the case where one baffle is shared by two pressure sensors 32 and 33.

[0046] The positions of baffles 36 and 37 can be changed, but as shown in Figure 4, baffle 36 is preferably positioned inside the pressure sensing pipe 31 on the side of the pressure sensor 32 (i.e., to the right) of the pressure sensing pipe 40. Furthermore, baffle 37 is also preferably positioned inside the pressure sensing pipe 31 on the side of the pressure sensor 33 (i.e., to the right) of the pressure sensing pipe 40. This shortens the distances D1 and D2 and also provides the following effect: Each fluid under test, which flows in from the pressure sensing pipe 40 and splits into left and right in the pressure sensing pipe 31, can strike baffles 36 and 37 from a direction perpendicular to baffles 36 and 37 (left and right direction) or a direction close to that direction. This makes it easier for foreign matter from the fluid under test to accumulate on baffles 36 and 37, and reduces the amount of foreign matter that accumulates on the pressure receiving diaphragms 32CA and 33CA.

[0047] Furthermore, the pressure detection range of pressure sensor 32 is located on the higher pressure side than the pressure detection range of pressure sensor 33. As described above, the lower the pressure detection range is, the lower the response speed of the pressure sensor. Therefore, in this embodiment, the distance D2 on the pressure sensor 33 side is made shorter than the distance D1 on the pressure sensor 32 side. As a result, the response speed of pressure sensor 33 is increased by the amount that distance D2 has been shortened. This reduces the difference between the response speed of pressure sensor 32 on the high-pressure side and the response speed of pressure sensor 33 on the low-pressure side. This realizes a sensor device 10 in which the difference in response speed is small across the entire wide pressure detection range.

[0048] Furthermore, depending on the processing requirements of the control unit 90, distance D2 > D1 may be set to increase the difference in response speed between pressure sensors 32 and 33. This allows the control unit 90 to perform processing that utilizes the difference in response speed. In other words, distances D1 and D2 may be made different in order to adjust the response speed of pressure sensors 32 and 33 to a desired speed. Alternatively, distances D1 and D2 may be set to be the same. In this case, pressure sensors 32 and 33 may be configured to have the same detection range not to widen the pressure detection range of the sensor device 10, but to ensure redundancy.

[0049] The baffles 36 and 37 may be formed in the same shape as described above, but they may also be formed in different shapes while remaining the same plate shape. Alternatively, the baffles 36 and 37 may not be plate-shaped but rather three-dimensional porous baffles having fine pores through which the fluid to be measured passes, with each pore having a shape that causes the fluid to meander. For example, they may be constructed as laminated baffles formed by stacking donut-shaped plates with numerous grooves on the main surface through which the fluid to be measured passes. The porous baffles reduce the accumulation of foreign matter on the pressure-receiving diaphragm downstream by deactivating the active substances constituting the fluid to be measured. Since the response speed of the pressure sensors 32 and 33 will differ between porous baffles and plate-shaped baffles, the distances D1 and D2 may be set taking into consideration the type of baffle.

[0050] The housing members 32AC and 33AC of the pressure sensors 32 and 33 may be considered as part of the pressure sensing pipe 31, and these housing members 32AC and 33AC may support the baffles 36 and 37. In this case, the pressure sensors 32 and 33 do not have the pressure chambers R12 and R22 to be measured, and these are considered to be provided in the pressure sensing pipe 31.

[0051] 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.

[0052] (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, The system includes a second pipe that extends in a second direction different from the first direction and is connected to the first pipe midway, and which guides the pressure of the fluid to be measured to the first pressure sensor and the second pressure sensor via the first pipe, The first pressure sensor includes a first pressure-receiving diaphragm that receives the pressure of the fluid to be measured, and converts the pressure received by the first pressure-receiving diaphragm into an electrical signal. The second pressure sensor includes a second pressure-receiving diaphragm that receives the pressure of the fluid to be measured, and converts the pressure received by the second pressure-receiving diaphragm into an electrical signal. The aforementioned sensor head is A first baffle is disposed inside the first pipe and faces the first pressure-receiving diaphragm, The present invention further includes a second baffle disposed inside the second pipe and facing the second pressure-receiving diaphragm, Sensor device. (Note 2) The first baffle is positioned inside the first pipe, on the side of the second pipe that is closer to the first pressure sensor. The second baffle is positioned inside the first pipe, on the side of the second pressure sensor that is closer to the second pipe. The sensor device described in Appendix 1. (Note 3) The first distance between the first baffle and the first pressure-receiving diaphragm and the second distance between the second baffle and the second pressure-receiving diaphragm are different. The sensor device described in Appendix 1 or 2. (Note 4) The first pressure detection range of the first pressure sensor is located on the higher pressure side than the second pressure detection range of the second pressure sensor. The sensor device described in any of the appendices 1 to 3. (Note 5) The second distance is shorter than the first distance. The sensor device described in Appendix 3 or 4. [Explanation of Symbols]

[0053] 10...Sensor device, 20...Sensor unit, 30...Sensor head, 31...Pressure sensing pipe, 31A...Annular surface, 31B...Annular surface, 32...Pressure sensor, 32A...Housing, 32AA...Housing member, 32AB...Housing member, 32AC...Housing member, 32B...Support diaphragm, 32C...Sensor element, 32CA...Pressure receiving diaphragm, 32D...Conductive pin, 32E...Spring contact, 32F...Sealing member, 33...Pressure sensor, 33A...Housing, 33AA...Housing member, 33AB...Housing member, 33AC...Housing member, 33B...Support diaphragm, 33C...Sensor element, 33CA...Pressure receiving diaphragm, 33D...Multiple conductive pins, 33E...Spring contact, 33F...Sealing member, 34...Insulator, 35...Insulator, 36...Baffle, 36A...Baffle body, 3 6B...Protruding part, 37...Baffle, 37A...Baffle body, 37B...Protruding part, 40...Pressure sensing pipe, 41...Joint, 50...Heater, 50A...Through hole, 51...Heater body, 52...Heater body, 53...Support member, 54...Support member, 60...Fixing mechanism, 61...Boss, 62...Boss, 63...Screw, 64...Screw, 70...Insulation member, 71...Insulation material, 72...Support member, 72A...Through hole, 73...Support member, 74...Insulation material, 75...Insulation material, 75A...Through hole, 75B...Notch, 80...Bracket, 81...Bracket member, 82...Bracket member, 90...Control unit, 91...Housing, B...Baffle, D1...Distance, D2...Distance, H1...Through hole, H2...Through hole, R11...Reference pressure chamber, R12...Measured pressure chamber, R21...Reference pressure chamber, R22...Measured pressure chamber, 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, The system includes a second pipe that extends in a second direction different from the first direction and is connected to the first pipe midway, and which guides the pressure of the fluid to be measured to the first pressure sensor and the second pressure sensor via the first pipe, The first pressure sensor includes a first pressure-receiving diaphragm that receives the pressure of the fluid to be measured, and converts the pressure received by the first pressure-receiving diaphragm into an electrical signal. The second pressure sensor includes a second pressure-receiving diaphragm that receives the pressure of the fluid to be measured, and converts the pressure received by the second pressure-receiving diaphragm into an electrical signal. The aforementioned sensor head is A first baffle is disposed inside the first pipe and faces the first pressure-receiving diaphragm, The present invention further includes a second baffle disposed inside the second pipe and facing the second pressure-receiving diaphragm, Sensor device.

2. The first baffle is positioned inside the first pipe, on the side of the second pipe that is closer to the first pressure sensor. The second baffle is positioned inside the first pipe, on the side of the second pressure sensor that is closer to the second pipe. The sensor device according to claim 1.

3. The first distance between the first baffle and the first pressure-receiving diaphragm and the second distance between the second baffle and the second pressure-receiving diaphragm are different. The sensor device according to claim 1.

4. The first pressure detection range of the first pressure sensor is located on the higher pressure side than the second pressure detection range of the second pressure sensor. The sensor device according to claim 3.

5. The second distance is shorter than the first distance. The sensor device according to claim 4.

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