JP2006145468A - Sealing structure of sensor, and sealing method of sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sealing method of a sensor for improving sealing properties of an inside space where a sensor module is arranged, and to provide a sealing structure of the sensor. <P>SOLUTION: A fluid pressure sensor 1 comprises a body 11 for arranging a strain gauge 20A of the sensor module 20 in the inside and a circuit part 30, and a sealing part 50 formed to inject synthetic resin in a gap with a housing fitted to a fitting wall part 15 of the body 11. Thereby, even in a state where a gasket part 41 of the housing 40 is fitted to the fitting wall part 15, when the gap occurs between the fitting wall part 15 and the gasket part 41, the gap is surely sealed with the sealing part 50 formed of the synthetic resin ejected. Thus, the sealing property of the inside space of the fluid pressure sensor 1 is improved. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a sensor sealing structure and a sensor sealing method.

  Conventionally, pressure sensors have been used to detect fluid pressure and the like. In this pressure sensor, a bottomed cylindrical pressure detection sensor module is disposed inside a metal case, and the cylindrical portion of this sensor module is fixed to one end of a joint by welding.

  The other end of this joint is screwed into a pipe or the like, and a fluid to be measured flowing through the pipe is introduced into the internal space of the sensor module by a pressure introduction hole formed in the pipe. The sensor module is electrically connected to a terminal through wiring and a circuit, and this terminal is fixed to the housing. The housing includes a flange portion at the base end portion, and the distal end portion of the case is caulked to the flange portion.

  Here, in order to protect the sensor module and the circuit, the internal space between the sensor and the housing in which these components are stored needs to be a sealed space.

  For this reason, conventionally, after the case is caulked to the housing, the locking portion by caulking between the case and the housing is sealed by applying a molding agent such as an adhesive (for example, Patent Document 1).

JP 2000-9572 (paragraph number “0007” and FIG. 3)

  In the conventional example, the space covered with the case and the housing is filled with an adhesive to form a seal structure. In this seal structure, the housing is displaced by external vibration and impact, and the space between the molding agent and the case is reduced. There is a problem in that a gap is generated in the substrate and the sealing performance is impaired, and sufficient reliability cannot be obtained.

  Furthermore, in the conventional example, the sealing agent is applied so as to close the gap between the caulking portions, but it takes time until the sealing agent is cured. Further, since the sealing is performed only with the adhesive force between the sealing agent and the mating member of the housing or the case, the sealing reliability is not sufficient from this point.

  In the conventional example, the sealant is applied so as to close the entrance of the gap of the caulking portion, but there is an exposed portion in the caulking portion of the case, and this exposed portion is used as an obstacle such as a fastener. It is not considered to protect against. Therefore, in some cases, an obstacle may interfere with the caulking portion, which may reduce the strength of the caulking portion, and thus the sealing performance.

  An object of the present invention is to provide a sensor sealing method and a sensor sealing structure capable of improving the sealing performance of an internal space in which a sensor module is arranged.

  For this reason, the sensor seal structure of the present invention is a sensor seal structure that seals between a case in which a sensor module is disposed and formed in a substantially cylindrical shape, and a housing disposed on one end surface side of the case. And the clearance gap between the said case and the said housing is sealed by the sealing part shape | molded by injection-molding synthetic resin, It is characterized by the above-mentioned.

  In the present invention having the above configuration, even if a gap is generated between the case and the housing, the gap is sealed with a sealing portion formed of injection-molded synthetic resin. If time passes immediately after injection-molding a sealing part, the synthetic resin which forms a sealing part will be hardened by cooling, and will seal a gap | interval reliably. In addition, the connection portion between the case and the housing can be protected from external force by the sealing portion.

  In the sensor seal structure of the present invention, the synthetic resin is preferably a polyamide resin.

  In the present invention having this configuration, the sealing portion is formed of a polyamide resin. Such polyamide resin is excellent in mechanical strength, abrasion resistance, electrical properties, chemical resistance, and heat resistance, so it can be securely sealed between the case and the housing under various circumstances. It becomes. Therefore, the sealing part formed of such a polyamide resin can be used for various purposes under various circumstances.

  Further, in the sensor seal structure of the present invention, it is preferable that an end portion of the housing is caulked on the one end face side of the case.

  In the invention of this configuration, the case and the housing are fixed by caulking the end portion of the housing to the one end face side of the case. Thereby, when forming a sealing part between the said case and the said housing, a position shift etc. do not occur, for example. Further, the gap between the case and the housing is reduced by caulking the housing. Therefore, when a sealing part is formed between the case and the housing, the gap between the case and the housing can be reliably sealed.

  In the sensor seal structure according to the present invention, the sensor module detects pressure, and a joint having an introduction hole for introducing pressure is attached to the other end surface of the case. It is preferable that the sensor module is attached to a joint, and a terminal electrically connected to the sensor module is attached to the housing.

  In this invention of this structure, it is a sensor module which detects a pressure, the said sensor module is attached to the said joint, and the said terminal is attached to the said housing. Thereby, the space surrounded by the case and the housing is reliably sealed. Therefore, by providing the sensor module in this space, the sensor module can reliably and accurately detect only the pressure introduced from the introduction hole, and the detection accuracy can be improved.

  In the sensor seal structure according to the present invention, it is preferable that at least one of the case and the housing is formed with a locking projection for locking with the sealing portion.

  In the present invention having such a configuration, the locking projection is formed on at least one of the case and the housing. Thereby, the said sealing part can be made in the state which sealed the clearance gap between the said case and the said housing by engaging this latching protrusion and the said sealing part. Therefore, the sealing part does not fall off, for example.

  According to the sensor sealing method of the present invention, a case in which the sensor module is arranged in advance and is formed in a substantially cylindrical shape, and a housing arranged on one end surface side of the case are arranged in the mold. In order to seal the gap between the case and the housing, a synthetic resin is injection molded into the mold to form a sealing portion.

In such a sealing method, even when a gap is generated between the case and the housing, the gap is sealed with a sealing portion formed of an injection molded synthetic resin. If time passes immediately after injection-molding a sealing part, the synthetic resin which forms a sealing part will be hardened by cooling, and will seal a gap | interval reliably.
Moreover, since the connection part between a case and a housing is covered with a sealing part, this connection part can be protected from external force.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a plan view showing a section of a fluid pressure sensor according to the present embodiment. FIG. 2 is a cross-sectional view of the fluid pressure sensor. FIG. 3 is a cross-sectional view of a diaphragm portion provided in the main body constituting the fluid pressure sensor. FIG. 4 is a cross-sectional view of the connecting portion of the main body and the housing constituting the fluid pressure sensor.

  In FIG. 1, reference numeral 1 denotes a fluid pressure sensor. The fluid pressure sensor 1 can measure the pressure of gas, liquid, and various other fluids flowing through a pipe, and particularly, highly corrosive acid gas, chemical liquid, brittleness. It is also possible to measure the fluid pressure of hydrogen gas or the like that causes the gasification. In the present embodiment, a fluid pressure sensor is exemplified, but the present invention is not particularly limited to this. For example, the present invention can be applied to a temperature sensor that detects temperature, a humidity detection sensor that detects humidity, and the like. The fluid pressure sensor 1 includes a main body 11, a sensor module 20, a circuit unit 30, and a housing 40.

[Body configuration]
The main body 11 includes a joint 12 having a connection portion 111 connected to a pipe (not shown) through which a fluid to be measured flows, and a substantially disc-shaped flange portion 13 formed on a part of the outer peripheral surface of the joint 12. Are integrally formed members, such as stainless steel.

  The joint 12 is formed in a substantially cylindrical shape. A columnar space provided on the inner peripheral side of the joint 12 serves as a flow path 110 as an introduction hole through which fluid flows. Further, a threaded portion 112 that is screwed with a pipe (not shown) is formed on the outer peripheral surface on one end side of the connecting portion 111 of the joint 12. And in the flow path 110, the one end by the side of the thread part 112 becomes the pressure introduction port 110A, and the fluid supplied from the piping which is not shown in figure flows in from here.

  The sensor module 20 is provided on the other end side of the main body 11 and is formed in a bottomed cylindrical shape that closes the flow path 110. The sensor module 20 is configured by integrally forming a diaphragm portion 120 having a substantially thin disk shape and a cylindrical portion 121 formed on the outer peripheral portion of the diaphragm portion 120. A strain gauge 20 </ b> A is provided on one surface side of the diaphragm portion 120.

  The diaphragm 120 is elastically deformed by the pressure of the fluid when the fluid acts. The strain gauge 20A generates an electrical signal corresponding to the amount of strain due to the elastic deformation of the diaphragm 120, and detects a more accurate pressure value.

The flange portion 13 is formed on one end on the outer peripheral surface of the joint 12, that is, on the side on which the sensor module 20 is formed, extending in a disk shape toward the radially outer side of the joint 12. On the outer peripheral side of the flange portion 13, a flange cylinder portion 14 is formed as a cylindrical case that is coaxial with the axis of the joint 12. The flange cylinder portion 14 has an inner peripheral surface formed in a substantially cylindrical shape, and the outer peripheral surface has a two-sided or hexagonal cross section, and a spanner hook for screwing the threaded portion 112 to a pipe (not shown). Also used as Furthermore, a substantially cylindrical fitting wall 15 is formed at the end of the flange cylinder 14 opposite to the flange 13. The housing 40 is fitted to the fitting wall 15, and the housing 40 and the main body 11 are fixed by caulking toward the inner diameter side in a state where the housing 40 is fitted. Further, a part of the fitting wall portion 15 is formed with a substantially annular concave portion 151 along the outer peripheral surface of the fitting wall portion 15.
As shown in FIG. 3, the strain gauge 20 </ b> A includes a silicon oxide film 21 formed on the outer surface of the diaphragm portion 120 and a gauge body 22 formed on the surface of the silicon oxide film 21 opposite to the diaphragm portion 120. And. Then, the strain gauge 20 </ b> A converts the displacement amount of the diaphragm unit 120 into an electric signal and outputs it to the circuit unit 30.

[Configuration of circuit section]
The circuit unit 30 includes an amplification circuit board 31, a wire bond 500, and an input / output terminal 33 as a terminal. The circuit unit 30 has a function of amplifying an electrical signal generated in the gauge body 22 of the strain gauge 20A and transmitting the amplified electrical signal to the outside. Circuit components and electrodes are provided on the amplification circuit board 31. This circuit component performs a voltage application process on the gauge body 22 and a process of amplifying a weak electric signal transmitted from the gauge body 22. The electrodes in the amplifier circuit board 31 are connected to the pads by wire bonds 500 inside the amplifier circuit board 31. The input / output terminals 33 are, for example, three terminals that are electrically connected to the amplification circuit board 31 and communicate with an external terminal (not shown) and the circuit unit 30. The external terminal has a gauge body amplified by the circuit components. 22 electrical signals are output, and power is supplied to the circuit unit 30 from an external terminal.

  A cover body 34 is provided on the housing 40 side of the circuit unit 30. The cover body 34 includes a bottom portion 341 having substantially the same shape as the cross section of the inner peripheral surface of the flange cylindrical portion 14, and a cover cylindrical portion 342 formed on the outer peripheral edge of the bottom portion 341 along the inner peripheral surface of the flange cylindrical portion 14. Are integrally formed. For example, an adhesive seal member is filled between the cover cylindrical portion 342 and the inner peripheral surface of the flange cylindrical portion 14, and the cover cylindrical portion 342 is in close contact with the flange cylindrical portion 14. In addition, a window 343 is formed in part in the bottom 341, and a feedthrough capacitor 344 that is electrically connected to the amplifier circuit substrate 31 is formed in this window. The feedthrough capacitor 344 is provided along the peripheral portion of the window portion 343 of the bottom portion 341, and the window portion 343 and the feedthrough capacitor 344 are electrically connected and sealed by, for example, solder. A conductive portion is formed on the housing 40 side of the feedthrough capacitor 344, and a wiring 345 is connected from the conductive portion to the input / output terminal 33.

[Structure of housing]
The housing 40 is a substantially cylindrical protective case that protects the strain gauge 20A and the circuit unit 30 from moisture and dust entering from the outside. The housing 40 is formed of a connector housing resin having a high melting point of, for example, 220 ° C. or more, such as PBT (polybutylene terephthalate resin) containing glass fiber or nylon containing glass fiber. A cylindrical gasket portion 41 that engages with the fitting wall portion 15 formed in the flange tube portion 14 of the flange portion 13 is provided on one end side of the housing 40. Further, a gasket flange portion 411 that is fitted to the inner peripheral surface of the fitting wall portion 15 of the main body 11 is formed at the end portion of the gasket portion 41. The gasket flange 411 is caulked and fixed in a state of being fitted to the fitting wall 15. Further, a substantially cylindrical connector portion 42 having a bottom surface portion 421 is formed on the other end side of the housing 40, and a terminal hole 422 through which the input / output terminal 33 of the circuit portion 30 is inserted is formed in the bottom surface portion 421. Has been. Further, a molding agent 43 such as a synthetic resin is sealed on the inner diameter side of the gasket portion 41 of the housing 40 to fill a space between the bottom surface portion 421 and the cover body 34. The molding agent 43 can seal the internal space of the main body 11 in which the sensor module 20 and the amplifier circuit board 31 are provided from the terminal hole 422 of the bottom surface portion 421. In the present embodiment, the molding agent 43 may not be provided. For example, the gap between the terminal hole 422 and the input / output terminal 33 may be sealed with a seal member, for example.

  A sealing portion 50 is formed at a connection portion between the main body 11 and the housing 40, that is, an engaging portion where the fitting wall portion 15 and the gasket portion 41 are engaged. The sealing portion 50 is formed of a polyamide resin having excellent mechanical strength, wear resistance, electrical characteristics, chemical resistance, and heat resistance. Examples of the polyamide resin include nylon-based polyamide resin. In the present embodiment, a polyamide resin is exemplified, but the present invention is not limited to this. For example, it may be used with a polycarbonate resin having high tensile and compressive strength and excellent impact resistance and heat resistance, and a synthetic resin such as polybutylene terephthalate and polyethylene terephthalate. The sealing portion 50 is formed in close contact with the fitting wall portion 15 and the gasket portion 41 by filling a gap between the fitting wall portion 15 and the gasket portion 41. At this time, the sealing portion 50 is brought into close contact with the concave portion 151 and the gasket portion 41 protruding portion 412 of the fitting wall portion 15 so that the sealing portion 50 and the fitting wall portion 15 and The contact area with the gasket part 41 becomes large. In addition, the structure which seals and covers the gasket part 41 and the protrusion part 412 with the sealing part 50 comprises the seal structure of this invention.

[Method of forming the sealing portion]
Next, a method for forming the sealing portion 50 that connects the main body 11 and the housing 40 will be described. FIG. 5A is a cross-sectional view of a molding die for forming a sealing portion. FIG. 5B is a plan view of the molding die viewed from the main body side.

  The sealing portion 50 that fills the gap between the fitting wall portion 15 of the main body 11 and the gasket portion 41 of the housing 40 is formed by a molding die 60 as shown in FIGS. 5 (A) and 5 (B). That is, the molding die 60 includes a first die 61 and a second die 62. The first mold 61 and the second mold 62 have a clamping part 60A having the same dimensions as the outer dimensions of the flange cylinder part 14 and the fitting wall part 15 of the main body 11 and the gasket part 41 of the housing 40. Is formed. Further, when the fluid pressure sensor 1 is fitted and clamped to the clamping portion 60A, a connection portion in which a sealing portion 50 is formed at a portion where the connection portion between the fitting wall portion 15 and the gasket portion 41 is located. A molded part 60B is formed. The connection molding portion 60B is formed with an injection hole 63 for injecting polyamide resin. Further, when the fluid pressure sensor 1 is fitted and clamped in the clamping portion 60A, a cylindrical space portion 60C is formed in a portion where the joint 12 of the main body 11 and the connector portion 42 of the housing 40 are located. The clamping portion 60A may be formed in a shape that clamps the joint 12 and the connector portion 42, and may have a shape in which the space portion 60C is not formed.

  A method for molding the sealing portion 50 using such a molding die 60 will be described. First, the circuit unit 30 is attached to the main body 11, and the housing 40 enclosing the molding agent 43 is incorporated into the main body 11. Then, with the gasket portion 41 of the housing 40 fitted to the fitting wall portion 15 of the main body 11, the fitting wall portion 15 is bent toward the inner diameter side, and the gasket flange portion 411 is caulked and fixed to the main body 11.

  Then, the main body 11 and the housing 40 are fitted and clamped in the clamping portions 60A of the first mold 61 and the second mold 62 of the molding die 60. In this state, the polyamide resin melted at a high temperature is injected from the injection hole 63. At this time, the injected polyamide resin is heated and melted at, for example, 220 degrees, and is injected at an injection pressure of, for example, 0.2 MPa. The injection temperature of the polyamide resin may be, for example, 220 degrees or more, or less than 220 degrees, and the injection pressure may be, for example, 0.2 MPa or more, or less than 0.2 MPa. . However, when the housing 40 is formed of a synthetic resin, if the injection temperature or injection pressure of the polyamide resin is increased too much, the housing 40 may be damaged. If the injection temperature or injection pressure is too low, the polyamide 40 may be damaged. May solidify or make injection difficult. Therefore, in the present embodiment, the injection temperature of the polyamide resin is optimally around 220 degrees that is lower than the melting point of the connector housing resin forming the housing 40, and the injection pressure is optimally around 0.2 MPa. By the injection of the polyamide resin, the gap between the fitting wall portion 15 of the main body 11 and the gasket portion 41 of the housing 40 is filled with the molten polyamide resin and brought into close contact therewith.

  Then, the injected polyamide resin is cooled, for example, for 20 seconds, whereby the high-temperature polyamide resin is cooled and cured, and the sealing portion 50 is formed. Further, the injection pressure is continuously applied from the injection hole 63 during the period for cooling the polyamide resin. By cooling the polyamide resin while applying injection pressure, the polyamide resin self-contracts in a state of being in close contact with the gasket portion 41 and the fitting wall portion 15.

[Effects of Embodiment]
In the fluid pressure sensor 1 of the above-described embodiment as described above, the main body 11 in which the strain gauge 20A and the circuit unit 30 are disposed, and the housing fitted to the fitting wall portion 15 of the main body 11 are provided. A sealing portion 50 is formed by injecting synthetic resin into the gap, and seals the internal space. For this reason, even if a gap is generated between the fitting wall 15 and the gasket 41 in a state where the gasket 41 of the housing 40 is fitted to the fitting wall 15, the gap is made of the injected synthetic resin. It can seal with the formed sealing part 50. FIG. In addition, when time elapses immediately after the sealing portion 50 is injection-molded, the synthetic resin that forms the sealing portion 50 is cooled and cured, so that a force that condenses the sealing portion 50 toward the inner diameter side acts. The connecting portion between the fitting wall portion 15 and the gasket portion 41 is pressed down. Therefore, the clearance gap between the fitting wall part 15 and the gasket part 41 can be sealed reliably. Moreover, the sealing part 50 can protect the crimping part of the fitting wall part 15 and the gasket part 41 from external force. Therefore, for example, even if force is applied to the caulking portion with a tightening tool or the like, the fitting wall portion 15 and the gasket portion 41 can be fixed by caulking without causing a gap or damage due to deformation of the caulking portion.

  Moreover, the sealing part 50 is formed by injecting a polyamide resin. For this reason, since the sealing part 50 has the property which was excellent in mechanical strength, abrasion resistance, an electrical property, chemical resistance, and heat resistance, the fluid pressure sensor 1 has mechanical strength and heat resistance, such as a motor vehicle, for example. Even when placed under the required conditions or exposed to corrosive chemicals, the gap between the fitting wall 15 and the gasket 41 is surely sealed without being damaged. Can do.

  Further, the gasket flange portion 411 of the gasket portion 41 of the housing 40 is caulked by the fitting wall portion 15 of the main body 11. For this reason, the main body 11 and the housing 40 can be reliably fixed. Therefore, it is possible to prevent positional deviation when the sealing portion 50 is formed at the connection portion between the main body 11 and the housing 40. Moreover, the gap between the fitting wall 15 and the gasket 41 is reduced by caulking the gasket flange 411 with the fitting wall 15 of the main body 11. Therefore, the sealing part 50 can seal the clearance gap between the fitting wall part 15 and the gasket part 41 more reliably.

  In the fluid pressure sensor 1, the strain gauge 20 </ b> A and the circuit unit 30 are attached to the main body 11, covered with the housing 40, and sealed with the sealing unit 50. Such a fluid pressure sensor 1 can reliably seal the strain gauge 20 </ b> A and the circuit unit 30 of the sensor module 20, so that it is not affected by the outside other than the pressure introduced from the joint 12. Therefore, the pressure introduced from the joint 12 can be detected accurately, and the detection accuracy can be improved.

  In addition, a concave portion 151 is formed in a part of the fitting wall portion 15, and a protruding portion 412 is formed in the gasket portion 41. For this reason, the sealing part 50 is engaged with the concave part 151 and the protrusion part 412, and the contact area between the sealing part 50, the gasket part 41, and the fitting wall part 15 can be increased. Therefore, the sealing part 50, the gasket part 41, and the fitting wall part 15 can be stuck with stronger force. Therefore, the adhesion between the sealing portion 50, the gasket portion 41, and the fitting wall portion 15 does not become weak or fall off.

  Further, the sealing portion 50 is formed by injecting a polyamide resin into the molding die 60. For this reason, since the melted polyamide resin is injected, the liquid polyamide resin is poured into the gap between the gasket portion 41 and the fitting wall portion 15 and can be reliably closed. And by cooling such a polyamide resin, the clearance gap between the gasket part 41 and the fitting wall part 15 can be reliably sealed by the sealing part 50.

  Furthermore, a polyamide resin is injected into a molding die and cooled and cured in a state where an injection pressure is applied. For this reason, the sealing part 50 can be hardened without a gap being produced between the sealing part 50 and the gasket part 41 or the fitting wall part 15 due to condensation due to cooling. And since the connection part of the gasket part 41 and the fitting wall part 15 is pressed down by the self-condensation by the cooling of the polyamide resin, the gasket part 41 and the fitting are fixed in a state where the gasket part 41 is fixed to the fitting wall part 15 more firmly. The clearance gap of the joint wall part 15 can be sealed.

  The housing 40 is made of a connector housing resin having a melting point higher than the injection temperature of the polyamide resin, such as PBT containing glass fiber or nylon containing glass fiber. For this reason, when the molten polyamide resin is injected, the housing 40 is not damaged, and the sensor module 20 and the circuit unit 30 disposed in the internal space are not affected by heat.

[Modification of Embodiment]
Although the present invention has been described with reference to preferred embodiments, the present invention is not limited to the above-described embodiments, and modifications and the like within a scope that can achieve the object of the present invention are included in the present invention. It is.

  For example, in the above-described embodiment, the example in which the substantially annular concave portion 151 is formed in the fitting wall portion 15 and the substantially annular protrusion 412 is formed in the gasket portion 41 is shown, but the present invention is not limited thereto. For example, a protrusion may be formed on both the fitting wall 15 and the gasket 41, or a concave portion may be formed. Further, these protrusions and concave portions may be formed over the periphery of the gasket portion 41 and the fitting wall portion 15. Moreover, these concave-shaped part and protrusion part do not need to be formed in substantially cyclic | annular form. That is, the concave portion may be a part of the fitting wall portion 15 or the gasket portion 41 formed in a concave shape, and the protrusion portion may be a portion of the fitting wall portion 15 or the gasket portion 41. Further, it may be formed to project outward in the radial direction.

  Further, as shown in FIG. 6, the concave portion 151 and the protruding portion 412 may not be formed. Even in such a configuration, the sealing portion 50, the fitting wall portion 15 and the gasket portion 41 can be sufficiently adhered by cooling and curing the synthetic resin from a high temperature.

  Further, as shown in FIG. 7, the fitting wall portion 15A of the main body 11 may be formed to protrude radially outward from the outer peripheral portion of the flange cylindrical portion 14A. In such a configuration, the sealing portion 50 can be formed from the gasket portion 41 to the boundary between the flange cylindrical portion 14A and the fitting wall portion 15A. Therefore, when the sealing portion 50 is cooled from a high temperature, the sealing portion 50 not only condenses in the inner diameter direction, but also condenses in the direction in which the gasket portion 41 is pressed against the main body 11 side. Adhesiveness with the joint wall portion 15A can be enhanced. Further, the caulking portions of the gasket portion 41 and the fitting wall portion 15A can be protected from external force or impact. Therefore, the gasket portion 41 and the fitting wall portion can be kept fixed without applying a force to the caulking portion with a tightening tool or the like, and without causing a fixing force due to caulking.

  Furthermore, although the structure which seals the housing 40 and the main body 11 as a case with the sealing part 50 was shown, it is not restricted to this. For example, the sealing unit 50 may be incorporated in another configuration for sealing another internal space in which the strain gauge 20A and the circuit unit 30 are not disposed.

  And in this Embodiment, although the sensor module 20 showed the example provided with 20 A of strain gauges, it is not restricted to this. For example, the sensor module may be a capacitance type pressure sensor module that recognizes pressure by detecting a change in capacitance due to displacement of the diaphragm unit 120.

  Moreover, although the gasket part 41 of the housing 40 was caulked and fixed by the fitting wall parts 15 and 15A of the main body 11, and the structure sealed by the sealing part 50 was shown, it is not restricted to this. For example, you may form the sealing part 50 in the state which fixed the gasket part 41 and the fitting wall parts 15 and 15A with other fixing means, such as an adhesive agent. Further, the sealing portion 50 may be formed in a state where the gasket portion 41 is not crimped, that is, not fixed, and the gasket portion 41 may be fixed to the fitting wall portions 15 and 15A by the sealing portion 50.

  Furthermore, as described above, the example in which the seal structure of the present invention is applied to the fluid pressure sensor 1 has been described. However, the present invention is not limited to this example. It is good also as a structure which incorporates the sealing structure by the sealing part 50 in this. A measuring instrument in which such a seal structure is incorporated can be used for various applications such as a hydraulic piping of automobiles and piping installed in factories.

  In addition, the specific structure and procedure for carrying out the present invention can be changed as appropriate to other structures and the like within the scope of achieving the object of the present invention.

  The present invention can be used for measuring devices such as a temperature sensor for detecting temperature and a humidity sensor for detecting humidity in addition to the pressure sensor.

It is the top view which displayed and displayed a part of fluid pressure sensor as one embodiment of the present invention. It is sectional drawing of a fluid pressure sensor. It is sectional drawing of the diaphragm part provided in the main body which comprises a fluid pressure sensor. It is sectional drawing of the connection part of the main body and housing which comprise a fluid pressure sensor. (A) is sectional drawing of the shaping die which forms a sealing part. (B) is the top view which looked at the shaping die from the main body side. It is sectional drawing which shows other embodiment of the connection part of a main body and a housing. It is sectional drawing which shows other embodiment of a fluid pressure sensor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fluid pressure sensor 11 Main body 12 Joint 14 Flange cylinder part as a case 20 Sensor module 33 Input / output terminal as a terminal 40 Housing 50 Sealing part 110 Flow path as an introduction hole 412 Projection part as a locking projection

Claims (6)

  A sensor sealing structure that seals between a case in which a sensor module is disposed and formed in a substantially cylindrical shape, and a housing that is disposed on one end surface side of the case, and is provided between the case and the housing. The sensor sealing structure is characterized in that the gap is sealed with a sealing portion formed by injection molding synthetic resin. The sensor seal structure according to claim 1,
The sensor sealing structure, wherein the synthetic resin is a polyamide resin. The sensor seal structure according to claim 1 or 2,
An end portion of the housing is caulked on the one end face side of the case. The sensor seal structure according to any one of claims 1 to 3,
The sensor module detects pressure, and on the other end surface side of the case, a joint in which an introduction hole for introducing pressure is formed is attached, and the sensor module is attached to the joint, and the housing A sensor sealing structure, wherein a terminal electrically connected to the sensor module is attached to the sensor module. In the seal structure of the sensor according to any one of claims 1 to 4,
At least one of the case and the housing is formed with a locking projection for locking with the sealing portion.   A case in which the sensor module is arranged in advance and formed in a substantially cylindrical shape, and a housing arranged on one end surface side of the case are arranged in the mold, and a gap between the case and the housing A sealing method for a sensor, characterized in that a sealing portion is formed by injection molding a synthetic resin in the mold to seal the seal.

Images