JP2009198187A - Pressure sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pressure sensor for suppressing intrusion of water vapor into a pressure-detecting chamber 19 and preventing variation in the sensor output from a sensor chip 5. <P>SOLUTION: An annular groove 21 is formed on the entire surface of a case plug 1 so as to surround the pressure-detecting chamber 19, and an annular seal member 22 is arranged in the groove 21 so as to come into contact with the bottom surface of the groove 21 and a metal diaphragm 17. This sealing member 22 has an O-ring 22a and a metal member 22b. The entire surface of the part positioned on the outer peripheral wall surface 21a side of the groove 21 of the surface of the O-ring 22a, is covered with the metal member 22b, which comes into contact with the bottom surface of the groove 21 and the metal diaphragm 17. Such a pressure sensor can prevent infiltration of water vapor into the pressure-detecting chamber 19 and prevent variation in the sensor output from the sensor chip 5. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention is a pressure sensor in which a pressure detection chamber for housing a sensor element is formed by assembling a case plug and a housing, and the pressure detection chamber is hermetically sealed by a member sandwiched between the case plug and the housing. It is about.

  Conventionally, a pressure sensor has been disclosed in which a connector case on which a sensor element is mounted is housed in a recess formed in a housing, and the connector case and the housing are assembled together by caulking the opening end of the recess in the housing. (For example, refer to Patent Document 1). In this pressure sensor, the sensor element is accommodated in the pressure detection chamber covered with the metal diaphragm so that the sensor element is not directly exposed to the measurement medium, and the pressure applied to the metal diaphragm is transmitted to the sensor element. The pressure detection chamber is filled with oil serving as a pressure transmission member. The oil filled in the pressure detection chamber does not leak through the gap between the connector case and the metal diaphragm, and an O-ring made of oil-resistant silicone rubber or the like surrounding the pressure detection chamber between them. The pressure detection chamber is hermetically sealed.

In such a pressure sensor, when a pressure is applied to the metal diaphragm, the pressure is applied to the sensor element via oil filling the pressure detection chamber, and the sensor element outputs a sensor signal corresponding to the pressure to thereby generate pressure. Is detected.
JP 2000-329633 A

  However, in the above-described pressure sensor, since the housing and the connector case are assembled together by caulking the opening end of the recess in the housing in which the connector case is accommodated, there is a gap between the connector case and the housing. Thus, an air chamber is formed. For this reason, water may enter the air chamber. For example, when condensed water is generated when the usage environment of the pressure sensor changes from high temperature to room temperature, the pressure in the air chamber is lower than the outside of the sensor, so that it is easily sucked into the air chamber. And when the use environment of a pressure sensor changes from normal temperature to high temperature again, the water droplet drawn in into the air chamber changes into water vapor. At this time, if the pressure in the pressure detection chamber is lower than the pressure in the air chamber, the water vapor permeability of the O-ring considering only oil sealing is high, so that water vapor in the air chamber enters the pressure detection chamber, There is a problem that the sensor output from the sensor element is changed by changing the pressure.

  In view of the above points, an object of the present invention is to provide a pressure sensor that can prevent water vapor from entering the pressure detection chamber and prevent fluctuations in sensor output from the sensor element.

  In order to achieve the above object, according to the first aspect of the present invention, the case plug (1) in which the sensor portion (4) including the sensor chip (5) is disposed in the recess (2) is disposed in the housing recess of the housing (11). The case plug (1) and the housing (11) are assembled by inserting into the case plug (1) and caulking the open end (13) of the receiving recess (12) to the case plug (1). (11) is provided with a metal diaphragm (17a, 17b) so as to cover the recess (2), thereby forming a pressure detection chamber (19), and the pressure detection chamber (19) is filled with a pressure transmission member (20 ) And an annular groove (21) is formed on one surface of the case plug (1) so as to surround the recess (2), and the bottom surface of the groove (21) and the metal diaphragm (17a, 17a, 17b) and An annular seal member (22a, 22b) is disposed so as to touch, and the pressure detection chamber (19) is hermetically sealed by the seal member (22a, 22b), and the seal member (22a, 22b) is sealed. A portion having an O-ring (22a) and a metal member (22b), the portion of the surface of the O-ring (22a) located on the outer peripheral wall surface (21a) side of the groove (21) is defined as the bottom surface of the groove (21) and The entire surface is covered with a metal member (22b) in contact with the metal diaphragms (17a, 17b).

  According to such a pressure sensor, the entire surface of the surface of the O-ring (22a) located on the outer peripheral wall surface (21a) side of the groove (21) is formed on the bottom surface of the groove (21) and the metal diaphragms (17a, 17b). Since it is covered with the metal member (22b) in contact with the water vapor, the metal member (22b) can prevent water vapor from permeating into the pressure detection chamber (19). For this reason, it can suppress that water vapor | steam penetrate | invades into a pressure detection chamber (19), and can prevent that the sensor output from a sensor chip (5) fluctuates.

  Further, as in the invention described in claim 2, the seal members (23a to 23d) are configured to have a metal ring (23a), and the seal members (23a to 23d) are arranged in the center of the seal members (23a to 23d). You may form the hollow part (23b) which goes around in the circumferential direction with respect to an axis | shaft.

  According to such a pressure sensor, since the metal ring (23a) does not transmit water vapor, it is possible to prevent water vapor from entering the pressure detection chamber (19), and sensor output from the sensor chip (5). Can be prevented from fluctuating.

  For example, as in the invention described in claim 3, the bottom surface of the groove (21) in a state where the seal member (23a to 23d) is elastically deformed between the bottom surface of the groove (21) and the metal diaphragm (17a, 17b). And you may make it contact a metal diaphragm (17a, 17b).

  Further, as in the invention described in claim 4, the cross section obtained by cutting the seal members (23a to 23d) in the radial direction with respect to the central axis of the seal members (23a to 23d) may be O-shaped.

  Further, as in the invention described in claim 5, the seal member (23a-23d) is formed with an opening (23c) that makes one round in the circumferential direction with respect to the central axis of the seal member (23a-23d), and the central shaft The cross section cut in the radial direction with respect to may be C-shaped, and the opening (23c) may be arranged toward the outer peripheral wall surface (21a) or the inner peripheral wall surface (21b) of the groove (21).

  Furthermore, it is good also as a structure which arrange | positions an O-ring (23d) in the hollow part (23b) of a sealing member (23a-23d) like invention of Claim 6.

  And like invention of Claim 7, as for the sealing member (24a-24c), the 1st member (24a) which has oil resistance, and the permeability | transmittance of water vapor | steam are lower than a 1st member (24a). A second member (24b) may be provided, and the second member (24b) may be disposed closer to the outer peripheral wall surface (21a) than the first member (24a) in the groove (21).

  According to such a pressure sensor, in the groove (21), the second member having lower water vapor permeability than the first member (24a) on the outer peripheral wall surface (21a) side of the first member (24a). Since (24b) is arranged, it is possible to suppress water vapor from entering the pressure detection chamber (19) as compared with the conventional pressure sensor, and the sensor output from the sensor chip (5) varies. This can be prevented.

  For example, as in the invention described in claim 8, the first member (24a) and the second member (24b) are arranged in the radial direction with respect to the central axis of the first member (24a) and the second member (24b). It is possible to make the cross section cut into a O-shape.

  Further, as in the ninth aspect of the present invention, the first member (24a) and the second member (24b) are arranged in the radial direction with respect to the central axis of the first member (24a) and the second member (24b). The cross section cut into two can be made into a rectangular shape.

  Further, as in the invention described in claim 10, the seal members (24a to 24c) are configured by joining the first member (24a) and the second member (24b), and the seal members (24a to 24c). ) In the radial direction with respect to the central axis of the sealing members (24a to 24c) can be O-shaped or rectangular.

  Moreover, like invention of Claim 11, a sealing member (24a-24c) is comprised including a 1st member (24a), a 2nd member (24b), and a metal ring (24c), and a groove | channel An annular metal ring (24c) is disposed on (21), and the first member (24a) and the second member (24b) are disposed between the metal ring (24c) and the bottom surface of the groove (21) and the metal ring ( 24c) and the metal diaphragm (17a, 17b), respectively, so that the first member (24a) and the second member (24b) are in contact with the bottom surface of the metal ring (24c) and the groove (21). While arrange | positioning, you may arrange | position so that a metal ring (24c) and a metal diaphragm (17) may be contacted.

  In addition, the code | symbol in the bracket | parenthesis of each means described in this column and the claim shows the correspondence with the specific means as described in embodiment mentioned later.

(First embodiment)
A pressure sensor to which an embodiment of the present invention is applied will be described. FIG. 1 is an overall sectional view of a pressure sensor according to the present embodiment, and FIG. 2 is an enlarged view of a two-dot chain line portion shown in FIG. Based on these FIG. 1 and FIG. 2, the structure of the pressure sensor of this embodiment is demonstrated.

  As shown in FIG. 1, the pressure sensor is provided with a case plug 1. The case plug 1 is made by molding a resin such as PPS (polyphenylene sulfide) which is a heat insulating resin material, for example. In this embodiment, it is cylindrical. A recess 2 is formed on one surface of one end of the case plug 1, and an opening 3 is formed on the other end.

  The recess 2 is provided with a sensor unit 4, and the sensor unit 4 includes a sensor chip 5 and a base 6, and the sensor chip 5 and the base 6 are anodically bonded. A diaphragm 7 is formed on the sensor chip 5, and the diaphragm 7 is provided with a gauge resistor formed so as to constitute a bridge circuit (not shown). That is, in this sensor chip 5, when pressure is applied to the diaphragm 7, the resistance value of the gauge resistance changes, the voltage of the bridge circuit changes, and a sensor output signal is output in accordance with the change of the voltage. belongs to.

  Further, the case plug 1 is provided with a plurality of metal rod-like terminals 8 for electrically connecting the sensor chip 5 and an external circuit or the like. Each terminal 8 is held in the case plug 1 by being integrally formed with the case plug 1 by insert molding.

  Specifically, each terminal 8 passes through the case plug 1, one end of each terminal 1 protrudes from the case plug 1 into the recess 2, and the other end extends from the case plug 1 into the opening 3. Protruding. The end of each terminal 8 protruding into the recess 2 is electrically connected to the sensor chip 5 via a bonding wire 9, and the end of each terminal 8 protruding into the opening 3 is shown in the figure. It is electrically connected to an external circuit through an external wiring member such as a wire harness.

  And the sealing material 10 which consists of silicone resin, for example is arrange | positioned in the part which the terminal 8 protrudes among the recessed parts 2. FIG. This sealing material 10 is for sealing the gap between the recess 2 and the terminal 8.

  A housing 11 is assembled to the case plug 1. Specifically, the housing 11 is provided with a housing recess 12, and one surface of the case plug 1 where the recess 2 is formed is inserted into the housing recess 12, and the housing 11 has an opening of the housing recess 12. The case plug 1 and the housing 11 are assembled by caulking the end 13 to the case plug 1. The housing 11 is made of, for example, a metal material such as SUS, and includes a pressure introduction hole 14 for introducing the measurement medium and a screw portion 15 for fixing the pressure sensor to the outer peripheral wall surface of the pressure introduction hole 14. ing. Since the case plug 1 and the housing 11 are assembled by caulking, an air chamber 16 is formed between the case plug 1 and the housing 11.

  A circular metal diaphragm 17 is disposed between the bottom surface of the housing recess 12 in the housing 11 and one surface of the case plug 1 where the recess 2 is formed. Specifically, the metal diaphragm 17 is formed of a thin film and is disposed at a diaphragm portion 17a to which the pressure of the measurement medium is applied, and an outer edge portion of the diaphragm portion 17a, and the outer edge portion of the diaphragm portion 17a is disposed on the housing 11. And a ring weld 17b that is fixed to the structure. And the outer edge part and the ring weld 17b are joined by the welding part 18 welded by laser welding etc. among the housing 11 and the diaphragm part 17a.

  In the case plug 1 and the housing 11 configured as described above, a pressure detection chamber 19 is configured in a portion surrounded by the recess 2 and the metal diaphragm 17. The pressure detection chamber 19 is filled with oil 20 that transmits the pressure applied to the metal diaphragm 17 to the sensor chip 5. In the present embodiment, the oil 20 corresponds to a pressure transmission member.

  An annular groove 21 is formed on one surface of the case plug 1 where the recess 2 is provided so as to surround the recess 2. As shown in FIG. 2, an annular seal member 22 is disposed in the groove 21 so as to contact the bottom surface of the groove 21 and the metal diaphragm 17, and the pressure detection chamber 19 is hermetically sealed by the seal member 22. ing. The seal member 22 includes an O-ring 22a and a metal member 22b, and a portion of the surface of the O-ring 22a located on the outer peripheral wall surface 21a side of the groove 21 contacts the bottom surface of the groove 21 and the metal diaphragm 17. The entire surface is covered with the metal member 22b. Silicone rubber or the like can be used for the O-ring 22a as in the conventional case, and Al or the like can be used for the metal member 22b.

  Such a pressure sensor is basically manufactured in the same manner as the conventional one except that the seal member 22 is disposed in the groove 21 (see, for example, Japanese Patent Laid-Open No. 2000-329633). The seal member 22 is manufactured by disposing a metal member 22b by vapor deposition or the like on a portion of the surface of the O-ring 22a located on the outer peripheral wall surface 21a side of the groove 21, and the groove before the case plug 1 and the housing 11 are caulked. 21.

  The basic detection operation of such a pressure sensor will be described.

  When the measurement medium is applied to the diaphragm portion 17 b through the pressure introduction hole 14, pressure is applied to the diaphragm 7 formed in the sensor chip 5 through the oil 20 filled in the pressure detection chamber 19. The diaphragm 7 is provided with a gauge resistor formed so as to constitute a bridge circuit. When pressure is applied to the diaphragm 7, the resistance value of the gauge resistor changes due to the piezoresistive effect. For this reason, in the sensor chip 5, the output voltage of the bridge circuit changes and a sensor signal corresponding to the applied pressure is output. This sensor signal is transmitted from the sensor chip 5 to the outside via the bonding wire 9 and the terminal 8, and based on this, the pressure of the measurement medium is detected.

  In such a pressure sensor, when the usage environment of the pressure sensor changes from high temperature to room temperature, condensed water adheres to the outer surface of the pressure sensor. And since the pressure in the air chamber 16 is lower than the outside of the pressure sensor, the condensed water is easily drawn into the air chamber 16, and when the usage environment of the pressure sensor changes from normal temperature to high temperature again, the inside of the air chamber 16 The condensed water drawn into the water changes into water vapor. At this time, if the pressure in the pressure detection chamber 19 is lower than that in the air chamber 16, the water vapor in the air chamber 16 tends to enter the pressure detection chamber 19. However, according to the pressure sensor of the present embodiment, the portion of the surface of the O-ring 22a located on the outer peripheral wall surface 21a side of the groove 21 is entirely covered by the metal member 22b in contact with the bottom surface of the groove 21 and the metal diaphragm 17. Since it covers, water vapor can be prevented from permeating through the metal member 22b. For this reason, it can suppress that water vapor | steam penetrate | invades in the pressure detection chamber 19, and can prevent that the sensor output from the sensor chip 5 fluctuates.

(Second Embodiment)
A second embodiment of the present invention will be described. The pressure sensor of the present embodiment is obtained by changing the configuration of the seal member 22 with respect to the first embodiment, and the other parts are the same as those of the first embodiment, and thus the description thereof is omitted here.

  FIG. 3 shows a partially enlarged view of the pressure sensor of the present embodiment. 3 corresponds to the two-dot chain line portion shown in FIG. 1, and the other portions of the pressure sensor of the present embodiment are the same as those in FIG.

  As shown in FIG. 3, in the pressure sensor of the present embodiment, the annular seal member 23 is disposed so as to contact the bottom surface of the groove 21 and the metal diaphragm 17. Specifically, the seal member 23 of the present embodiment is a metal ring 23a formed by molding or the like. Further, the sealing member 23 is formed with a hollow portion 23b that makes one round in the circumferential direction with respect to the central axis of the sealing member 23 so as to be crushed by caulking pressure by caulking. The seal member 23 is in contact with the bottom surface of the groove 21 and the metal diaphragm 17 and is disposed between the bottom surface of the groove 21 and the metal diaphragm 17 in an elastically deformed state. In addition, the metal ring 23a which comprises the sealing member 23 is manufactured using Al etc. similarly to the metal member 22b, and the cross section cut | disconnected in the radial direction with respect to the central axis is made into O shape.

  According to such a pressure sensor, since the pressure detection chamber 19 can be hermetically sealed while preventing the water vapor from being transmitted through the metal ring 23a, the same effect as in the first embodiment can be obtained. The seal member 23 of the present embodiment is composed of a metal ring 23a and has oil resistance, so that the seal member 23 does not corrode and the oil 20 does not leak from the pressure detection chamber 19. Further, in this embodiment, the seal member 23 is disposed between the bottom surface of the groove 21 and the metal diaphragm 17 in a state where the seal member 23 is brought into contact with the bottom surface of the groove 21 and the metal diaphragm 17 and is elastically deformed. You may arrange | position between the bottom face of the groove | channel 21, and the metal diaphragm 17 in the state where it met.

(Third embodiment)
A third embodiment of the present invention will be described. The pressure sensor of the present embodiment is obtained by changing the structure of the seal member 23 with respect to the second embodiment, and the other parts are the same as those of the second embodiment, and thus the description thereof is omitted here.

  FIG. 4 shows a partially enlarged view of the pressure sensor of the present embodiment. 4 corresponds to the two-dot chain line portion shown in FIG. 1, and the other portions of the pressure sensor of this embodiment are the same as those in FIG.

  As shown in FIG. 4, in the pressure sensor of this embodiment, the seal member 23 is formed with an opening 23 c that makes one round in the circumferential direction with respect to the central axis, and the seal member 23 is cut in the radial direction with respect to the central axis. The cross section is C-shaped. The opening 23 c is disposed in the groove 21 so as to face the inner peripheral wall surface 21 b of the groove 21.

  According to such a pressure sensor, the contact area between the metal ring 23a and the bottom surface of the groove 21 and the metal diaphragm 17 can be increased as compared with the second embodiment. For this reason, it is also possible to improve the hermetic sealing property of the pressure detection chamber 19 while obtaining the same effect as the first embodiment.

  In this embodiment, the seal member 23 is arranged with the opening 23c facing the inner peripheral wall 21b side of the groove 21, but the opening 23c is arranged facing the outer peripheral wall 21a side of the groove 21. It may be. Further, in the present embodiment, the cross section cut in the radial direction with respect to the central axis of the seal member 23 is a C-shape in which the bottom surface of the groove 21 and the portion in contact with the metal diaphragm 17 are straight. 23 may have a C shape in which the end of the opening 23 c is separated from the bottom surface of the groove 21 and the metal diaphragm 17.

(Fourth embodiment)
A fourth embodiment of the present invention will be described. The pressure sensor of the present embodiment is obtained by changing the configuration of the seal member 23 with respect to the third embodiment, and the other components are the same as those of the third embodiment, and thus the description thereof is omitted here.

  FIG. 5 shows a partially enlarged view of the pressure sensor of the present embodiment. 5 corresponds to the two-dot chain line portion shown in FIG. 1, and the other portions of the pressure sensor of the present embodiment are the same as those in FIG.

  As shown in FIG. 5, in the pressure sensor of this embodiment, the seal member 23 is configured to have a metal ring 23a and an O-ring 23d, and the O-ring 23d is disposed in the hollow portion 23b of the metal ring 23a. Has been.

  According to such a pressure sensor, when the case plug 1 and the housing 11 are assembled by caulking and the seal member 23 is crushed by caulking pressure, the metal ring 23a and the bottom surface of the groove 21 and the metal diaphragm are caused by the elastic force of the O-ring 23d. The contact with 17 can be improved. For this reason, it is also possible to improve the hermetic sealing property of the pressure detection chamber 19 while obtaining the same effect as the first embodiment.

(Fifth embodiment)
A fifth embodiment of the present invention will be described. The pressure sensor of the present embodiment is obtained by changing the configuration of the seal member 22 with respect to the first embodiment, and the other parts are the same as those of the first embodiment, and thus the description thereof is omitted here.

  FIG. 6 shows a partially enlarged view of the pressure sensor of the present embodiment. 6 corresponds to the two-dot chain line portion shown in FIG. 1, and the other portions of the pressure sensor of the present embodiment are the same as those in FIG.

  As shown in FIG. 6, in the pressure sensor of this embodiment, the annular seal member 24 is disposed so as to contact the bottom surface of the groove 21 and the metal diaphragm 17. Specifically, the seal member 24 is made of a material having oil resistance, for example, a first member 24a made of silicone rubber, and a material having a lower water vapor permeability than the first member 24a, for example, ethylene propylene rubber. And a second member 24b composed of Each of the first member 24a and the second member 24b has an O-shaped cross section cut in the radial direction with respect to the central axis, and the second member 24b is formed in the groove 21 from the first member 24a. Are also disposed on the outer peripheral wall surface 21a side.

  According to such a pressure sensor, the pressure detection chamber 19 can be hermetically sealed by the first member 24a. Then, the second member 24b having a lower water vapor permeability than the first member 24a disposed on the outer peripheral wall surface 21a side of the first member 24a in the groove 21 causes the water vapor to have a pressure higher than that of the conventional pressure sensor. Intrusion into the detection chamber 19 can be suppressed, and the sensor output from the sensor chip 5 can be prevented from fluctuating.

(Sixth embodiment)
A sixth embodiment of the present invention will be described. The pressure sensor of the present embodiment is obtained by changing the configuration of the seal member 24 with respect to the fifth embodiment, and the other parts are the same as those of the fifth embodiment, and thus description thereof is omitted here.

  FIG. 7 shows a partially enlarged view of the pressure sensor of the present embodiment. 7 corresponds to the two-dot chain line portion shown in FIG. 1, and the other portions of the pressure sensor of the present embodiment are the same as those in FIG.

  In the pressure sensor of the present embodiment, the first member 24a and the second member 24b constituting the seal member 24 have a rectangular cross section cut in the radial direction with respect to the central axis. Then, as shown in FIG. 7, the first member 24a and the second member 24b are cut in the radial direction with respect to the respective central axes by being crushed by the bottom surface of the groove 21 and the metal diaphragm 17 by caulking pressure due to caulking. The cross section is a drum shape.

  According to such a pressure sensor, the contact area between the sealing member 24 and the bottom surface of the groove 21 and the metal diaphragm 17 can be increased. For this reason, the airtight sealing property of the pressure detection chamber 19 can be improved while obtaining the same effect as the fifth embodiment.

(Seventh embodiment)
A seventh embodiment of the present invention will be described. The pressure sensor of the present embodiment is obtained by changing the configuration of the seal member 24 with respect to the fifth embodiment, and the other parts are the same as those of the fifth embodiment, and thus description thereof is omitted here.

  FIG. 8 shows a partially enlarged view of the pressure sensor of the present embodiment. 8 corresponds to the two-dot chain line portion shown in FIG. 1, and the other portions of the pressure sensor of the present embodiment are the same as those in FIG.

  As shown in FIG. 8, in the pressure sensor of the present embodiment, the seal member 24 includes a first member 24 a and a second member 24 b that are semicircular in cross section with respect to the central axis. It is configured by joining. The boundary between the first member 24 a and the second member 24 b of the outer wall surface of the seal member 24 is disposed so as to be in contact with the bottom surface of the groove 21, and is disposed so as to be in contact with the metal diaphragm 17. ing. At this time, similarly to the fifth embodiment, the second member 24b is disposed in the groove 21 so as to be positioned closer to the outer peripheral wall surface 21a than the first member 24a.

  Even with such a pressure sensor, the same effects as those of the fifth embodiment can be obtained. Note that the sealing member 24 has a cross section cut in the radial direction with respect to the central axis, and the O-shaped first member 24a and the second member 24b are each bisected in the circumferential direction with respect to the central axis. It cut | disconnects so that these may be bonded by vulcanization adhesion.

(Eighth embodiment)
An eighth embodiment of the present invention will be described. The pressure sensor of the present embodiment is obtained by changing the configuration of the seal member 24 with respect to the fifth embodiment, and the other parts are the same as those of the fifth embodiment, and thus description thereof is omitted here.

  FIG. 9 shows a partially enlarged view of the pressure sensor of the present embodiment. 9 corresponds to the two-dot chain line portion shown in FIG. 1, and the other portions of the pressure sensor of the present embodiment are the same as those in FIG.

  As shown in FIG. 9, in the pressure sensor of the present embodiment, the seal member 24 includes a first member 24a, a second member 24b, and a metal ring 24c. The metal ring 24 c has the same shape as the metal ring 23 a of the third embodiment and is disposed in the groove 21. The first member 24 a and the second member 24 b are formed between the metal ring 24 c and the bottom surface of the groove 21. And between the metal ring 24 c and the metal diaphragm 17.

  Specifically, the first member 24a and the second member 24b are disposed so as to be in contact with the metal ring 24c and the bottom surface of the groove 21, and are disposed so as to be in contact with the metal ring 24c and the metal diaphragm 17. Has been. In the present embodiment, the first member 24a and the second member 24b are rectangular in cross section cut in the radial direction with respect to the central axis. Even with such a pressure sensor, the same effect as that of the fifth embodiment can be obtained.

(Other embodiments)
You may comprise a pressure sensor combining the said each embodiment. For example, the O-ring 23d may be arranged in the hollow portion 23b of the metal ring 23a by combining the second embodiment with the fourth embodiment. Further, by combining the sixth embodiment and the seventh embodiment, the seal member 24 is formed by joining a first member 24a and a second member 24b having a rectangular cross section with respect to the central axis, and a seal. Of the members 24, the boundary between the first member 24 a and the second member 24 b may be disposed so as to contact the bottom surface of the groove 21 and may be disposed so as to contact the metal diaphragm 17.

  Furthermore, in the said 8th Embodiment, it is good also considering the metal ring 24c as the shape similar to the metal ring 23a of the said 2nd Embodiment. Moreover, the cross section which cut | disconnected the 1st member 24a and the 2nd member 24b in the radial direction with respect to each center axis | shaft is good also as O shape. Then, as in the seventh embodiment, the sealing member 24 is configured by joining the first member 24a and the second member 24b having a semicircular cross section with respect to the central axis on each plane. May be.

It is a figure which shows the cross-sectional structure of the pressure sensor in 1st Embodiment of this invention. It is a figure which shows the enlarged view of the dashed-two dotted line part shown in FIG. It is a figure which shows the elements on larger scale of the pressure sensor concerning 2nd Embodiment of this invention. It is a figure which shows the elements on larger scale of the pressure sensor concerning 3rd Embodiment of this invention. It is a figure which shows the elements on larger scale of the pressure sensor concerning 4th Embodiment of this invention. It is a figure which shows the elements on larger scale of the pressure sensor concerning 5th Embodiment of this invention. It is a figure which shows the elements on larger scale of the pressure sensor concerning 6th Embodiment of this invention. It is a figure which shows the elements on larger scale of the pressure sensor concerning 7th Embodiment of this invention. It is a figure which shows the elements on larger scale of the pressure sensor concerning 8th Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Case plug 2 Recessed part 5 Sensor chip 11 Housing 12 Receiving recessed part 17 Metal diaphragm
21 groove 22a O-ring 22b metal member 23a metal ring 23b hollow portion 23c opening 23d O-ring 24a first member 24b second member 24c metal ring

Claims (11)

A sensor unit (4) including a sensor chip (5) for outputting a sensor output signal corresponding to the pressure of the measurement medium;
A case plug (1) provided with a recess (2) on one surface, and the recess (2) with the sensor part (4);
By having a housing recess (12), the case plug (1) is inserted into the housing recess (12), and the opening end (13) of the housing recess (12) is caulked to the case plug (1). A housing (11) assembled integrally with the case plug (1);
Metal diaphragms (17a, 17b) disposed between the one surface of the case plug (1) and the bottom surface of the housing recess (12) of the housing (11), when pressure of the measurement medium is applied;
By assembling the case plug (1) and the housing (11), the pressure detection chamber (19) formed by the portion surrounded by the recess (2) and the metal diaphragm (17a, 17b) A pressure transmitting member (20) to be filled;
An annular groove (21) formed on the one surface of the case plug (1) so as to surround the recess (2);
The groove (21) is disposed so as to come into contact with the bottom surface of the groove (21) and the metal diaphragms (17a, 17b), and partitions the pressure detection chamber (19) and the outside of the pressure detection chamber (19). And an annular seal member (22a, 22b) for hermetically sealing the pressure detection chamber (19),
The seal member (22a, 22b) is configured to include an O-ring (22a) and a metal member (22b), and an outer peripheral wall surface (21a) of the groove (21) among the surfaces of the O-ring (22a). The pressure sensor is characterized in that the portion located on the side is entirely covered with the metal member (22b) in contact with the bottom surface of the groove (21) and the metal diaphragms (17a, 17b). A sensor unit (4) including a sensor chip (5) for outputting a sensor output signal corresponding to the pressure of the measurement medium;
A case plug (1) provided with a recess (2) on one surface, and the recess (2) with the sensor part (4);
By having a housing recess (12), the case plug (1) is inserted into the housing recess (12), and the opening end (13) of the housing recess (12) is caulked to the case plug (1). A housing (11) assembled integrally with the case plug (1);
Metal diaphragms (17a, 17b) disposed between the one surface of the case plug (1) and the bottom surface of the housing recess (12) of the housing (11), when pressure of the measurement medium is applied;
By assembling the case plug (1) and the housing (11), the pressure detection chamber (19) formed by the portion surrounded by the recess (2) and the metal diaphragm (17a, 17b) A pressure transmitting member (20) to be filled;
An annular groove (21) formed on the one surface of the case plug (1) so as to surround the recess (2);
The groove (21) is disposed so as to come into contact with the bottom surface of the groove (21) and the metal diaphragms (17a, 17b), and partitions the pressure detection chamber (19) and the outside of the pressure detection chamber (19). And an annular seal member (23a-23d) for hermetically sealing the pressure detection chamber (19),
The seal members (23a to 23d) are configured to have a metal ring (23a), and the seal members (23a to 23d) are hollow that makes one round in the circumferential direction with respect to the central axis of the seal members (23a to 23d). A pressure sensor having a hollow shape having a portion (23b).   The sealing members (23a to 23d) are elastically deformed between the bottom surface of the groove (21) and the metal diaphragm (17a, 17b), and the bottom surface of the groove (21) and the metal diaphragm (17a, 17b). The pressure sensor according to claim 2, wherein the pressure sensor is in contact with the pressure sensor.   The pressure sensor according to claim 2 or 3, wherein the seal member (23a to 23d) has an O-shaped cross section cut in a radial direction with respect to the central axis.   The sealing member (23a to 23d) is formed with an opening (23c) that makes one round in the circumferential direction with respect to the central axis, and a cross section cut in the radial direction with respect to the central axis is C-shaped, The pressure sensor according to claim 2 or 3, wherein the opening (23c) is directed toward the outer peripheral wall surface (21a) or the inner peripheral wall surface (21b) of the groove (21).   The pressure sensor according to any one of claims 2 to 5, wherein an O-ring (23d) is disposed in the hollow portion (23b) of the seal member (23a to 23d). A sensor unit (4) including a sensor chip (5) for outputting a sensor output signal corresponding to the pressure of the measurement medium;
A case plug (1) provided with a recess (2) on one surface, and the recess (2) with the sensor part (4);
By having a housing recess (12), the case plug (1) is inserted into the housing recess (12), and the opening end (13) of the housing recess (12) is caulked to the case plug (1). A housing (11) assembled integrally with the case plug (1);
Metal diaphragms (17a, 17b) disposed between the one surface of the case plug (1) and the bottom surface of the housing recess (12) of the housing (11), when pressure of the measurement medium is applied;
By assembling the case plug (1) and the housing (11), the pressure detection chamber (19) formed by the portion surrounded by the recess (2) and the metal diaphragm (17a, 17b) A pressure transmitting member (20) to be filled;
An annular groove (21) formed on the one surface of the case plug (1) so as to surround the recess (2);
The groove (21) is disposed so as to come into contact with the bottom surface of the groove (21) and the metal diaphragms (17a, 17b), and partitions the pressure detection chamber (19) and the outside of the pressure detection chamber (19). And an annular seal member (24a-24c) for hermetically sealing the pressure detection chamber (19),
The sealing members (24a to 24c) include a first member (24a) having oil resistance and a second member (24b) having a lower water vapor permeability than the first member (24a). The pressure sensor, wherein the second member (24b) is disposed on the outer peripheral wall surface (21a) side of the first member (24a) in the groove (21).   The first member (24a) and the second member (24b) have an O-shaped cross section cut in the radial direction with respect to the central axis of the first member (24a) and the second member (24b). The pressure sensor according to claim 7, wherein the pressure sensor is provided.   The first member (24a) and the second member (24b) have a rectangular cross section cut in the radial direction with respect to the central axis of the first member (24a) and the second member (24b). The pressure sensor according to claim 7, wherein:   The sealing members (24a to 24c) have an O-shaped or rectangular cross section in the radial direction with respect to the central axis of the sealing members (24a to 24c), and the first member (24a) and the second member The pressure sensor according to claim 7, wherein the pressure sensor is joined to the member (24 b).   The seal members (24a to 24c) are configured to include the first member (24a), the second member (24b), and a metal ring (24c), and the groove (21) has an annular shape. A metal ring (24c) is disposed, and the first member (24a) and the second member (24b) are disposed between the metal ring (24c) and the bottom surface of the groove (21) and the metal ring (24c). ) And the metal diaphragm (17a, 17b), and the first member (24a) and the second member (24b) are formed of the metal ring (24c) and the groove (21). 11. Arranged in contact with the bottom surface and arranged in contact with the metal ring (24c) and the metal diaphragm (17). The pressure sensor of any one.

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