Sensor device and method for manufacturing a sensor device

Abstract

The heater is shared between the two pressure sensors. [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 extends from the position of the pressure sensor 32 to the position of the pressure sensor 33 in the left-right direction, and heats the front pressure sensor 32 and the front pressure sensor 33.

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] The measurement range of pressure measurement of the sensor device is determined. Therefore, when pressure measurement over a wider range is required, a plurality of sensor devices with different measurement ranges are used in combination. Also, for ensuring redundancy in case the pressure sensor fails, it is conceivable to use in combination a plurality of sensor devices having the same measurement range. The combined use of a plurality of sensor devices results in poor space efficiency of the installation space, and improvement thereof is desired. For example, in semiconductor manufacturing equipment, a compact pressure adjustment chamber tends to be adopted, and improvement of the above space efficiency is important.

[0005] An object of the present invention is to provide a sensor device and a method for manufacturing the sensor device capable of reducing the installation space. The present invention is particularly suitable for a sensor device (for example, a diaphragm type vacuum gauge) having a pressure sensor accompanied by heating by a heater.

Means for Solving the Problems

[0006] 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; and a heater that extends from the position of the first pressure sensor in the first direction to the position of the second pressure sensor, which heats the first pressure sensor and the second pressure sensor.

[0007] Furthermore, a method for manufacturing a sensor device according to the present invention comprises a first step of manufacturing the sensor head and the heater, and a second step of positioning the sensor head relative to the heater, wherein the second step includes adjusting the temperature gradient generated on the sensor head when heated by the heater by moving the heater relative to the sensor head. [Effects of the Invention]

[0008] According to the present invention, the installation space required for the sensor device is reduced. [Brief explanation of the drawing]

[0009] [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 figure shows an example of the relative movement of the heater to the sensor head. [Figure 7]This is a flowchart showing the manufacturing method of a sensor device. [Figure 8] This is a flowchart of part of the communication path identification process. [Figure 9] This diagram shows the relationship between the protrusion of the boss in the modified example and the through-hole of the heater into which the protrusion is inserted. [Figure 10] This diagram shows the relationship between the protrusion of the boss in the modified example and the through-hole of the heater into which the protrusion is inserted. [Figure 11] This diagram shows the relationship between the protrusion of the boss in the modified example and the through-hole of the heater into which the protrusion is inserted. [Modes for carrying out the invention]

[0010] [Principle 1 of this embodiment] By using a dual system with two pressure sensors in different ranges for sensor devices (such as vacuum gauges), a wider range is achieved while reducing the overall size. This reduces the installation space required for the sensor device. Furthermore, for example, with a diaphragm-type pressure sensor that uses a heater for heating, there is no problem in principle with the two pressure sensors being heated to the same temperature even if they are in different ranges, so the heater can be shared and integrated. In other words, if two conventional pressure sensors are simply integrated, there will also be two separate heaters, resulting in duplicate temperature sensors and wiring for temperature control by the heater, as well as wiring for supplying power to the heater, requiring additional installation space. However, by sharing a heater (effectively one), the temperature sensors and wiring can be reduced. The space efficiency of the pressure sensor itself, with its dual system of two sensors, is further improved.

[0011] [Principle 2 of this embodiment] When the heater of a sensor device (such as a vacuum gauge) has a shared and integrated structure, it is particularly important that the temperature control accuracy of two pressure sensors using the dual method can be compatible (the effect of the heater is to have uniform heating characteristics), that fine adjustment of the installation position and installation posture of the heater can be made, and that it can be firmly fixed. Therefore, the idea of adopting a fixing mechanism that can adjust and fix the heater position was conceived. That is, by fine-tuning the thermal balance, it becomes possible to improve the uniform heating characteristics.

[0012] [Details of the Embodiment] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In this embodiment, the vertical direction, the horizontal direction, and the front-rear direction that are orthogonal to each other are set, but these directions do not intend the mounting direction of the sensor device. For example, the vertical direction may coincide with the horizontal direction depending on the orientation of the sensor device 10.

[0013] The sensor device 10 shown in FIG. 1 is connected to a pipe connected to a pressure adjustment chamber (for example, a vacuum chamber) in a semiconductor manufacturing apparatus or the like, and measures the pressure of the fluid to be measured (for example, the atmospheric pressure of the process gas) introduced from the pressure adjustment chamber into the pipe by a diaphragm that receives this pressure. It is configured as a diaphragm vacuum gauge.

[0014] 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, that is, the electrical signal indicating the pressure, as a pressure detection signal, and controls the operation of the sensor unit 20 and is based on the pressure detection signal from the sensor unit 20. And a control unit 90 that derives the pressure of the fluid to be measured and outputs the derived pressure to the outside. By deriving this pressure, the pressure 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.

[0015] 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.

[0016] 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 or an arbitrary joining method (not shown).

[0017] 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.

[0018] 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).

[0019] 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 �2D, 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.

[0020] 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.

[0021] 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.

[0022] 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.

[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 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).

[0024] 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.

[0025] 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).

[0026] 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.

[0027] 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.

[0028] 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 transmitted, 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. The above corresponds to a description of a specific embodiment of the dual system shown in Principle 1 of this embodiment.

[0029] 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.

[0030] 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. That is, the pressure sensors 32 and 33, into which the same fluid being measured is introduced, should be heated to the same temperature, and there is no problem with them being heated to the same temperature. 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.

[0031] 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.

[0032] 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 common to both the heater bodies 51 and 52. Thus, both the heater bodies 51 and 52 are configured as a single heating element. Therefore, the heater 50 is controlled by one temperature control using one temperature sensor S, and is configured as a single heater overall. The heater bodies 51 and 52 have a structure in which, for example, a heating wire passes through them. 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 internal structures such as heating wires.

[0033] 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. ​​The above corresponds to a description of a specific embodiment regarding the shared integration of the heater as shown in Principle 1 of this embodiment.

[0034] The heater 50 is fixed to the sensor head 30 by a fixing mechanism 60. The fixing mechanism 60 fixes the heater 50 to the sensor head 30 at one of several adjustable relative positions relative to the sensor head 30. 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 screw 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 view, not cross-section view.

[0035] 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.

[0036] 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.

[0037] When the support member 53, which supports the heater body 51, is attached to the boss 61, the protrusion 61B is inserted into the through hole 53AA, as shown in Figures 5 and 6. 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, that is, it is screwed in. Note that in Figure 6, a dot pattern is added to the protrusion 61B to ensure visibility.

[0038] As shown in Figure 6, both the through hole 53AA and the protrusion 61B are formed in an elongated shape in the left-right direction. When viewed from the front-back direction (the axis direction of the central part of the through hole 53AA), the through hole 53AA and the protrusion 61B are formed in an oval shape with semicircular ends on both sides and a rectangular center between the two ends. However, the through hole 53AA is longer in the left-right direction than the protrusion 61B. This is because the rectangular portion is longer in the through hole 53AA. Therefore, when not screwed in, the protrusion 61B can move relative to the through hole 53AA. Furthermore, the side surface 61BA of the protrusion 61B that extends in the left-right direction (the side surface of the rectangular portion) and the inner surface 53AAA of the through hole 53AA that extends in the left-right direction are flat surfaces that meet each other. This restricts the relative vertical movement and rotation between the through hole 53AA and the protrusion 61B. With the above configuration, the support member 53 supporting the heater body 51 is guided by the protrusion 61B and cannot move vertically or rotate relative to it, but it can move horizontally (see the elements drawn with solid lines and dashed lines respectively in Figure 6).

[0039] 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.

[0040] With the above configuration, the heater 50 is movable in the left-right direction by the protrusions 61B and 62B and the through holes 53AA and 54AA before being fixed by the fixing mechanism 60 (before being screwed in). Then, the heater 50 becomes immobile when fixed by the fixing mechanism 60. In other words, by moving in the left-right direction, the heater 50 can be adjusted to one of a plurality of relative positions that are continuous in the left-right direction with respect to the sensor head 30, and is fixed (screwed in) at that position. The above corresponds to the description of a specific embodiment of the fixing mechanism shown in Principle 2 of this embodiment.

[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. This allows the pressure sensing pipe 40 to be inserted into the opening 50A even if its position is slightly shifted due to, for example, dimensional errors. As shown in Figure 5, this opening 50A is composed 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 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.

[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 body and a thin plate member that adds rigidity to the thermal insulation 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] The bracket 80 is cup-shaped 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] 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.

[0047] Subsequently, the manufacturer temporarily fixes the heater 50 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 (see Figure 6). Then, the manufacturer lightly screws the screws 63 and 64 into the screw holes 61C and 62C. As a result, the heater 50 is temporarily fixed to the sensor head 30 and can move relative to the sensor head 30. The direction of movement of the heater 50 is defined in the left-right direction as described above by the protrusions 61B and 62B inserted into the through holes 53AA and 54AA, respectively (see Figure 6).

[0048] The manufacturer adjusts the position of the heater 50 by moving the temporarily fixed heater 50 relative to the sensor head 30 (step S13). This adjusts the heating pattern of the sensor head 30 (particularly the pressure sensors 32 and 33) by the heater 50. For example, since the heater 50 is used to heat the pressure sensors 32 and 33, it is preferable to heat the sensor head 30, especially the pressure sensors 32 and 33, uniformly. In other words, it is desirable that no temperature gradient occurs between the pressure sensors 32 and 33 when heating by the heater 50. For this reason, in step S13, the position of the heater 50 is adjusted so that the temperature gradient during heating becomes zero.

[0049] The adjustment of the heater 50's position to make the temperature gradient zero will be explained with reference to Figure 4. The heat from the heater 50 that heats the sensor head 30 escapes through the pressure sensing pipe 40 that is not covered by the heater 50 (see arrow AR). In order to uniformly heat the pressure sensors 32 and 33 and make the temperature gradient between them zero, it is best to make the amount of heat transferred from the pressure sensor 32 side (right side) to the pressure sensing pipe 40 the same as the amount of heat transferred from the pressure sensor 33 side (left side) to the pressure sensing pipe 40. In order to make the former and latter amounts of heat the same, the distances D1 and D2 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, respectively, must be the same (by D1=D2, for example, the effect of the heater 50 on the sensor head 30 is made uniform on both sides, and the two amounts of heat escaping to the pressure sensing pipe 40 become the same). However, even if the sensor device 10 is designed so that distances D1 and D2 are the same, in actual manufacturing, dimensional errors in each component may prevent distances D1 from being equal to D2. Therefore, the position of the heater 50 is adjusted by moving it relative to the sensor head 30 in the left-right direction, thereby achieving D1 = D2.

[0050] The position of the heater 50 is adjusted, for example, by the manufacturer of the sensor device 10. The manufacturer adjusts the position of the heater 50 so that D1 = D2 while measuring the distances D1 and D2 with a caliper or the like. Alternatively, the manufacturer may adjust the position of the heater 50 while heating it and measuring the temperatures of the pressure sensors 32 and 33.

[0051] After adjusting the position of the heater 50, the manufacturer tightens screws 63 and 64 to screw the heater 50 to bosses 61 and 62, thereby fixing the heater 50 in place (step S14).

[0052] Subsequently, the manufacturer completes the sensor device 10 by performing the remaining assembly (step S15). Specifically, the wiring connections are made between the sensor head 30 and heater 50 and the control unit 90, the sensor head 30 and heater 50 are covered with the heat insulating member 70, and the sensor head 30, heater 50, and heat insulating member 70 are fixed to the housing 91 of the control unit 90 with the bracket 80. The above corresponds to the explanation of the specific implementation method for adjusting heat and position as shown in principle 2 of this embodiment.

[0053] As described above, the sensor device 10 according to this embodiment comprises a sensor head 30, a pressure sensing pipe 40, and a heater 50. The sensor head 30 includes a pressure sensing pipe 31 extending in the left-right direction, and pressure sensors 32 and 33 fixed to both left and right ends of the pressure sensing pipe (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 and is connected to the middle of the pressure sensing pipe 31, and is configured to guide the pressure of the fluid to be measured to the pressure sensors 32 and 33 via the pressure sensing pipe 31. As a result, the sensor device 10 is smaller and more compact than the entirety of two sensor devices, each having one pressure sensor, and as a result, the installation space of the sensor device 10 is reduced. Furthermore, the heater 50 extends from the position of the pressure sensor 32 to the position of the pressure sensor 33 in the left-right direction, heating the pressure sensors 32 and 33. With this configuration, the heater 50 is shared by the two pressure sensors 32 and 33. Therefore, compared to the case where one heater is provided for each of the two pressure sensors 32 and 33, the number of heater-related components (for example, the number of wires supplying power to the heater, the number of temperature sensors used for feedback control, the heater temperature detection circuit, the heater temperature control circuit, etc.) can be reduced, and as a result, the installation space for the components can also be reduced, which may allow the sensor device 10 itself to be made even smaller. In other words, since the space efficiency of the sensor device 10 itself can be improved in order to reduce the installation space of the sensor device 10 itself, this is preferable.

[0054] The shape of the heater 50 may be other than that of the above embodiment, but it is preferable that it be cylindrical (including cylindrical and polygonal cylindrical). This allows the pressure sensors 32 and 33 to be heated from all directions around their 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 their outer circumference.

[0055] Specific examples of the fixing mechanism 60 of the sensor device 10 are not limited to the above embodiment. The fixing mechanism 60 may be configured to fix the heater 50 to the sensor head 30 at one of a plurality of adjustable relative positions (for example, a plurality of positions arranged continuously in the left-right direction, allowing the position of the heater 50 to be continuously changed in the left-right direction). Such a fixing mechanism 60 allows adjustment of the heating mode of the sensor head 30 by the heater 50. Furthermore, in the sensor device 10 described above, the temperature gradient between the pressure sensors 32 and 33 due to heating of the sensor head 30 by the heater 50 is adjusted depending on which of the plurality of relative positions the heater 50 is fixed at. Note that the temperature gradient only needs to be adjusted to a desired gradient and does not need to be adjusted to 0 (no gradient). It may also be adjusted to increase the temperature gradient. This makes the temperature of the pressure sensors 32 and 33 when heated by the heater 50 suitable for pressure measurement. The relative position of the heater 50 with respect to the sensor head 30 may be changed only during the manufacturing of the sensor device 10 and not after its manufacture. To achieve this, screws 63 and 64 may be configured so that they can only be operated with special tools. The relative position of the heater 50 with respect to the sensor head 30 may also be adjusted after the sensor device 10 is manufactured by disassembling the sensor device 10.

[0056] Furthermore, in the above embodiment, the heater 50 has a plurality of heater bodies 51 and 52, and the fixing mechanism 60 is configured to individually fix each of the plurality of heater bodies 51 and 52 to the sensor head 30 at one of a plurality of relative positions with respect to the sensor head 30. As a result, the position of the heater 50 can be adjusted on a per-heater-body basis, so the heating mode for the sensor head 30 can be finely adjusted.

[0057] Furthermore, in the above embodiment, the fixing mechanism 60 includes a screw 63 (64) and a boss 61 (62) each having a protrusion 61B (62B) into which a screw hole 61C (62C) formed in the sensor head 30 opens. The heater 50 includes through holes 53AA (54AA) into which the protrusions 61B (62B) are each inserted. The above-mentioned multiple relative positions are positions in which the relative positions of the through holes 53AA (54AA) into which the protrusions 61B (62B) are inserted differ with respect to the protrusions 61B (62B), depending on the position of the heater 50. The fixing mechanism 60 fixes the heater 50 to the sensor head 30 at one of the relative positions by screwing the screws 63 (64) and screw holes 61C (62C) into the through holes 53AA (54AA) with the protrusions 61B (62B) respectively, thereby screwing the heater 50 to the boss 61 (62). With this configuration, the protrusions 61B (62B) can guide the movement and fixing of the heater 50.

[0058] Furthermore, the heater 50 is formed in a cylindrical shape that covers the sensor head 30 and has an opening 50A through which the pressure sensing pipe 40 passes. The pressure sensing pipe 40 extends in a vertical direction perpendicular to the left-right direction in which the pressure sensing pipe 31 extends. The length of the through hole 53AA (54AA) in the left-right direction is longer than the length of the protrusion 61B (62B) in the left-right direction, and the aforementioned multiple relative positions include multiple positions aligned along the left-right direction. As a result, the direction of movement of the heater 50 is guided in the left-right direction by the protrusion 61B, so that, for example, the above distances D1 and D2 can be easily adjusted.

[0059] As a variation, for example, as shown in Figure 8, the longitudinal direction of the through-hole 53AA (54AA) and the protrusion 61B (62B) may be changed to the vertical direction in which the pressure sensing pipe 40 extends. In this case, the vertical length of the through-hole 53AA (54AA) is longer than the vertical length of the protrusion 61B (62B), and the aforementioned multiple relative positions are positions in which the vertical relative position of the through-hole 53AA (54AA) into which the protrusion 61B (62B) is inserted is different. This guides the movement direction of the heater 50 in the vertical direction. As explained above, since heat from the sensor head 30 escapes from the pressure sensing pipe 40, a temperature gradient may occur between the lower part of the pressure sensor 32 on the side of the pressure sensing pipe 40 and the upper part on the opposite side when heated by the heater 50 (the lower part will be colder). The same applies to the pressure sensor 33. Therefore, as in this modified example, by making the vertical relative position of the heater 50 with respect to the sensor head 30 adjustable, the heater 50 can be moved upward and brought closer to the bottom of the sensor head 30, thereby reducing the temperature gradient (including making it 0 (no gradient)).

[0060] In addition, in the configurations shown in Figures 6 and 8, the protrusion 61B (62B) may be cylindrical, allowing the heater 50 to rotate relative to the protrusion 61B (62B) (see Figure 9. The thick arrows in Figure 9 indicate the direction of movement or rotation of the heater 50). The through-hole 53AA (54AA) may also be circular, allowing the protrusion 61B (62B) and the through-hole 53AA (54AA) to rotate relative to the protrusion 61B (62B) (see Figure 10. The thick arrows in Figure 9 indicate the direction of rotation of the heater 50). These also allow for adjustment of the heating characteristics of the heater 50. Furthermore, the protrusion 61B (62B) may be made smaller, allowing for multiple directions of relative movement between the protrusion 61B (62B) and the through-hole 53AA (54AA) (see Figure 11. The thick arrows in Figure 9 indicate the direction of movement of the heater 50). In this case, relative rotation is also permitted. The multiple relative positions mentioned above include rotational positions.

[0061] Furthermore, in the above embodiment, the protrusion 61B has a flat side surface 61BA, and the inner surface of the through hole 53AA includes a flat inner surface 53AAA that aligns with the side surface 61BA. This suppresses the rotation of the heater 50.

[0062] A method for manufacturing the sensor device 10 may include, for example, a first step (e.g., step S11) of preparing (including manufacturing) a sensor head 30 and a heater 50, and a second step (e.g., steps S12 to S14) of fixing the heater 50 to the sensor head 30. In the second step, the heater 50 is moved relative to the sensor head 30 to adjust the temperature gradient generated on the sensor head 30 when heated by the heater 50 (for example, after adjusting so that the temperature gradient becomes 0) (e.g., step S13), and then the heater 50 is fixed (e.g., step S14). By this method, a sensor device 10 is obtained in which the heater 50 is shared by pressure sensors 32 and 33. Furthermore, a sensor device 10 is obtained in which the temperature gradient generated on the sensor head 30 when heated by the heater 50 is adjusted.

[0063] 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.

[0064] (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 that extends from the position of the first pressure sensor to the position of the second pressure sensor in the first direction, and heats the first pressure sensor and the second pressure sensor, A sensor device equipped with the following features. (Note 2) The heater is formed in a cylindrical shape that covers the sensor head. The sensor device described in Appendix 1. (Note 3) The heater is further provided with a fixing mechanism for fixing it to the sensor head at one of a plurality of relative positions with respect to the sensor head. The sensor device described in Appendix 1 or 2. (Note 4) The sensor device as described in Appendix 3, wherein the temperature gradient between the first pressure sensor and the second pressure sensor due to heating of the heater is adjusted depending on which of the plurality of relative positions the heater is fixed at. (Note 5) The heater has a plurality of heater bodies, The fixing mechanism individually fixes each of the plurality of heater bodies to the sensor head at one of a plurality of relative positions with respect to the sensor head. The sensor device described in Appendix 3 or 4. (Note 6) The fixing mechanism comprises a screw and a boss formed on the sensor head, having a protrusion with a screw hole that engages with the screw. The heater has a through hole into which the protrusion is inserted, Depending on which of the plurality of relative positions the heater is located in, the relative position of the through hole into which the protrusion is inserted to the protrusion will differ. The fixing mechanism fixes the heater to the sensor head at one of the plurality of relative positions by screwing the screw and the screw hole together with the protrusion inserted into the through hole, thereby screwing the heater to the boss. A sensor device as described in any of the appendices 3 to 5. (Note 7) The heater is formed in a cylindrical shape that covers the sensor head and has an opening through which the second pipe passes. The first direction and the second direction are orthogonal, The length of the through hole in the first direction is longer than the length of the protrusion in the first direction. The plurality of relative positions include a plurality of positions aligned along the first direction, The sensor device described in Appendix 6. (Note 8) The heater is formed in a cylindrical shape that covers the sensor head and has an opening through which the second pipe passes. The first direction and the second direction are orthogonal, The length of the through hole in the second direction is longer than the length of the protrusion in the second direction. The plurality of relative positions include a plurality of positions aligned along the second direction, The sensor device described in Appendix 6. (Note 9) The aforementioned protrusion has a flat side surface, The inner surface of the through hole includes a flat inner surface that is aligned with the side surface. A sensor device as described in any of the appendices 6 to 8. (Note 10) The first pipe has a first end and a second end at both ends in the first direction. A sensor device as described in any of the appendices 1 to 9. (Note 11) A method for manufacturing a sensor device as described in any of the appendices 1 to 10, The first step is to prepare the sensor head and the heater, The second step is to fix the heater to the sensor head, In the second step, the heater is moved relative to the sensor head to adjust the temperature gradient generated on the sensor head when heated by the heater, and then the heater is fixed in place. A method for manufacturing a sensor device. [Explanation of Symbols]

[0065] 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, 72...support member, 72A...through hole, 73...support member, 74...insulation material, 75...insulation material, 75A...through hole, 80...bracket, 81...first member, 85...second member, 90...control unit, 91...housing, D1...distance, D2...distance, 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, 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 that extends from the position of the first pressure sensor to the position of the second pressure sensor in the first direction, and heats the first pressure sensor and the second pressure sensor, A sensor device equipped with the following features.

2. The heater is formed in a cylindrical shape that covers the sensor head. The sensor device according to claim 1.

3. The heater is further provided with a fixing mechanism for fixing it to the sensor head at one of a plurality of relative positions with respect to the sensor head. The sensor device according to claim 1.

4. The temperature gradient between the first pressure sensor and the second pressure sensor due to heating of the heater is adjusted depending on which of the plurality of relative positions the heater is fixed at. The sensor device according to claim 3.

5. The heater has a plurality of heater bodies, The fixing mechanism individually fixes each of the plurality of heater bodies to the sensor head at one of a plurality of relative positions with respect to the sensor head. The sensor device according to claim 3.

6. The fixing mechanism comprises a screw and a boss formed on the sensor head, having a protrusion with a screw hole that engages with the screw. The heater has a through hole into which the protrusion is inserted, Depending on which of the plurality of relative positions the heater is located in, the relative position of the through hole into which the protrusion is inserted to the protrusion will differ. The fixing mechanism fixes the heater to the sensor head at one of the plurality of relative positions by screwing the screw and the screw hole together with the protrusion inserted into the through hole, thereby screwing the heater to the boss. The sensor device according to claim 3.

7. The heater is formed in a cylindrical shape that covers the sensor head and has an opening through which the second pipe passes. The first direction and the second direction are orthogonal, The length of the through hole in the first direction is longer than the length of the protrusion in the first direction. The plurality of relative positions include a plurality of positions aligned along the first direction, The sensor device according to claim 6.

8. The heater is formed in a cylindrical shape that covers the sensor head and has an opening through which the second pipe passes. The first direction and the second direction are orthogonal, The length of the through hole in the second direction is longer than the length of the protrusion in the second direction. The plurality of relative positions include a plurality of positions aligned along the second direction. The sensor device according to claim 6.

9. The aforementioned protrusion has a flat side surface, The inner surface of the through hole includes a flat inner surface that is aligned with the side surface. The sensor device according to claim 6.

10. The first pipe has a first end and a second end at both ends in the first direction. The sensor device according to claim 1.

11. A method for manufacturing a sensor device according to claim 1, The first step is to prepare the sensor head and the heater, The second step is to fix the heater to the sensor head, In the second step, the heater is moved relative to the sensor head to adjust the temperature gradient generated on the sensor head when heated by the heater, and then the heater is fixed in place. A method for manufacturing a sensor device.

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