JP2005195430A - Pressure switch and pressure monitoring system equipped therewith - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pressure switch and a pressure monitoring system capable of detecting the pressure state, while securing sufficiently internal airtightness, though having a simple structure. <P>SOLUTION: This pressure switch is equipped with a vessel-shaped casing 10 having a main opening part 10h, a diaphragm 11 installed so as to form a reference pressure chamber 14 sealed inside the casing 10 by closing the main opening part 10h, and having a conductive part facing to the inside of the reference pressure chamber 14, and a detection terminal 12 facing to the conductive part in the reference pressure chamber 14. The casing 10 is insulated to either of the conductive part and the detection terminal 12 through an intervening glass part 13. The diaphragm 11 can take at least two kinds of states, namely, the state where the conductive part abuts on the detection terminal 12 and the non-abutting state, in dependence on the magnitude of a pressure outside the reference pressure chamber 14. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a pressure switch used by being installed inside a tire or the like, and a pressure monitoring system for monitoring an internal pressure of the tire or the like.

  In a vehicle that travels with wheels equipped with tires, it is important for safety to keep the tire internal pressure within a normal range. Several pressure sensors and abnormality detection devices have been proposed to monitor whether the internal pressure of the tire has an abnormal value.

  For example, Japanese Patent No. 2647287 (Patent Document 1) proposes a pressure sensor including a pressure switch, a transmitter, and the like. The pressure switch used in this pressure sensor is composed of a movable electrode stretched in a film shape so as to be sandwiched between joint portions of two housings, and a fixed electrode held so as to face the movable electrode. And.

  As another example, there is a pressure switch disclosed in Japanese Patent No. 2593213 (Patent Document 2). This is provided with a bottomed cylindrical bellows that is a combination of a diaphragm and a bellows instead of a film-like electrode, ie, a diaphragm.

Yet another example is a pressure sensor disclosed in Japanese Patent Application Laid-Open No. 2001-305000 (Patent Document 3). This is because the diaphragm to which the movable electrode is attached is arranged so as to face the fixed electrode held in the housing, and the diaphragm is deformed by the external air pressure entering through the vent hole of the fixed electrode. The pressure is detected by causing contact / separation with the movable electrode.
Japanese Patent No. 2647287 Japanese Patent No. 2593213 JP 2001-305000 A

  In the pressure sensor disclosed in Patent Document 1, since the film-like movable electrode is held so as to be sandwiched between two housings, the whole is large.

  In the pressure switch disclosed in Patent Document 2, since the cylindrical bellophram is deformed, it is enlarged as a whole.

  The pressure sensor disclosed in Patent Document 3 has a complicated structure.

  Accordingly, an object of the present invention is to provide a pressure switch and a pressure monitoring system that can detect a pressure state while ensuring sufficient internal airtightness while having a simpler structure.

  To achieve the above object, a first pressure switch according to the present invention includes a container-like housing having a main opening, and a reference pressure chamber sealed inside the housing by closing the main opening. A diaphragm having a conductive portion facing the inside of the reference pressure chamber and a detection terminal facing the conductive portion in the reference pressure chamber, and the casing includes the conductive portion And the detection terminal is insulated by interposing a glass part, and the conductive part is detected by the conductive part depending on the pressure outside the reference pressure chamber. There can be at least two states: a state in contact with the terminal and a state in which the terminal is not in contact. By adopting this configuration, if the pressure outside the reference pressure chamber is sufficiently high, the conductive portion comes into contact with the detection terminal, so whether or not the pressure outside the reference pressure chamber is higher than a certain value is determined. It can be monitored by the presence or absence of conduction between the two.

  Preferably, in the above invention, the casing has a terminal through-hole, and each of the detection terminals is disposed so as to pass through the terminal through-hole and have one end exposed to the outside of the casing. A glass portion surrounds the detection terminal so as to prevent the body and the detection terminal from coming into direct contact with each other, thereby filling a gap inside the terminal through hole. By employ | adopting this structure, between a detection terminal and a housing | casing can be insulated in the state sealed reliably by the glass part.

  In order to achieve the above object, a second pressure switch according to the present invention includes a container-like housing having a main opening, and a reference pressure chamber sealed inside the housing by closing the main opening. A diaphragm having a conductive portion facing the inside of the reference pressure chamber, and a plurality of detection terminals facing the conductive portion in the reference pressure chamber, the plurality of detection terminals Each of the plurality of detection terminals is insulated from the casing by interposing a glass portion, and each of the plurality of detection terminals is determined by the magnitude of deformation of the diaphragm determined by the magnitude of pressure outside the reference pressure chamber. Depending on each of the plurality of detection terminals, each of the plurality of detection terminals is connected to the conductive portion. Abutting The size of the reference pressure chamber outside of the pressure required to maintain the different. By adopting this configuration, it depends on the degree of pressure outside the reference pressure chamber, how many of the detection terminals come into contact, so there is conduction between each detection terminal and the conductive part. By monitoring this, the degree of pressure outside the reference pressure chamber can be monitored.

  Preferably, in the above invention, the casing has a plurality of terminal through holes corresponding to the plurality of detection terminals, and each of the detection terminals individually penetrates the corresponding terminal through hole, and one end thereof is the casing. It is arranged so as to be exposed to the outside of the body, and the glass part surrounds each of the detection terminals so that the casing and the detection terminals are not in direct contact with each other. Buried. By employ | adopting this structure, between a detection terminal and a housing | casing can be insulated separately in the state sealed reliably by the glass part.

  In order to achieve the above object, a third pressure switch according to the present invention has a main opening, is made of a conductor, and closes the main opening by using a container-like housing and closing the main opening. And a diaphragm having a conductive portion facing the inside of the reference pressure chamber, and 2 arranged to face the conductive portion in the reference pressure chamber, respectively. Two or more detection terminals, and a glass part interposed so as to cut off an electrical connection in a path along the housing between the conductive part and the detection terminal, and the diaphragm includes the reference pressure Depending on the magnitude of the pressure outside the room, there can be at least two states: a state in which the conductive portion is in contact with two or more of the detection terminals, and a state in which it is not. By adopting this configuration, when the pressure is high, two or more detection terminals abut against the conductive part at the same time, so detection is possible without providing a continuity detection terminal on the casing itself, which is a conductor. The degree of pressure outside the reference pressure chamber can be monitored simply by monitoring the presence or absence of conduction between the terminals.

  In order to achieve the above object, a fourth pressure switch according to the present invention has a main opening, is made of a non-conductive material, and closes the main opening by using a container-like housing and the main opening. It is attached so as to form a reference pressure chamber sealed inside, a diaphragm having a conductive portion facing the inside of the reference pressure chamber, and disposed to face the conductive portion in the reference pressure chamber, And two or more detection terminals that are not directly electrically connected to each other, and the diaphragm is configured such that the conductive portion has two detection terminals depending on the magnitude of pressure outside the reference pressure chamber. There can be at least two states: a state in contact with the above and a state in which it is not. By adopting this configuration, it is possible to monitor the degree of pressure outside the reference pressure chamber only by monitoring the presence or absence of conduction between the detection terminals without having to pull out the conduction detection terminal from the conductive part. Can do.

  In order to achieve the above object, a fifth pressure switch according to the present invention includes a detection terminal support plate, a glass portion formed in an annular shape on the surface of the detection terminal support plate, and the detection terminal via the glass portion. By being arranged so as to face the support plate, a sealed reference pressure chamber is formed in a region surrounded by the glass portion, and a diaphragm having a conductive portion facing the inside of the reference pressure chamber, Two or more detection terminals arranged to face the conductive portion in the reference pressure chamber, respectively, and the diaphragm is configured so that the conductive portion is dependent on the magnitude of the pressure outside the reference pressure chamber. There can be at least two states: a state in contact with two or more of the detection terminals and a state in contact with less than two. By adopting this configuration, if the pressure outside the reference pressure chamber is sufficiently high, the conductive portion comes into contact with the detection terminal, so whether or not the pressure outside the reference pressure chamber is higher than a certain value is determined. It can be monitored by the presence or absence of conduction between the two.

  Preferably, in the above invention, an integrated circuit electrically connected to the detection terminal and an antenna electrically connected to the integrated circuit are provided, and the integrated circuit is based on an external radio wave via the antenna. This is for outputting self-identification information via the antenna according to the input. By adopting this configuration, a signal by radio waves is transmitted from the outside of this pressure switch, and whether or not the pressure outside the pressure switch is above a certain level by checking whether there is a response from this pressure switch. Can be monitored.

  Preferably, in the above invention, an integrated circuit electrically connected to the detection terminal and an antenna electrically connected to the integrated circuit are provided, and the integrated circuit is based on an external radio wave via the antenna. According to the input, self identification information and a conduction state of the plurality of detection terminals with respect to the partition are output via the antenna. By adopting this configuration, a person who has transmitted a signal by radio waves from the outside transmits a signal by radio waves from the outside of this pressure switch, and detects the content of the response from this pressure switch. It is possible to monitor in which range the pressure is within.

  Preferably, in the above invention, the integrated circuit is disposed inside the reference pressure chamber. By adopting this configuration, the whole of the pressure switch including the IC tag can be made substantially the same size as the case of the pressure switch alone, so that the whole can be made compact.

  In order to achieve the above object, a pressure monitoring system according to the present invention includes a plurality of any of the pressure switches described above, and serves as a threshold value for determining whether or not the diaphragm contacts the detection terminal. The pressure values of the plurality of pressure switches are set to be different from each other, the integrated circuit electrically connected to the detection terminals of the plurality of pressure switches, and the integrated circuit The integrated circuit is for outputting a conduction state of the detection terminal with respect to the partition wall in each of the plurality of pressure switches via the antenna. By adopting this configuration, even if there is only one integrated circuit, by interrogating this single integrated circuit with radio waves, the pressure of the environment in which a plurality of pressure switches are placed falls within any range. It can be grasped.

  According to the present invention, when the pressure outside the reference pressure chamber is sufficiently high, the conductive portion comes into contact with the detection terminal, so whether or not the pressure outside the reference pressure chamber is higher than a certain value is determined. It can be monitored by the presence or absence of conduction between the two. In particular, when this pressure switch is combined with an IC tag and the ID information is returned in response to an external signal, it is installed in the target space where the pressure is to be monitored, for example, inside the tire. If so, it is possible to monitor whether or not the pressure is normal.

(Embodiment 1)
(Constitution)
With reference to FIG. 1, the pressure switch in Embodiment 1 based on this invention is demonstrated. This pressure switch includes a container-like housing 10 having a main opening 10 h, a diaphragm 11 attached to the housing 10, and a detection terminal 12. The diaphragm 11 is made of metal. The diaphragm 11 forms a reference pressure chamber 14 sealed inside the housing 10 by closing the main opening 10h. Further, the detection terminal 12 is arranged so that a contact portion 12 a which is one end thereof faces the diaphragm 11 in the reference pressure chamber 14. The casing 10 is made of a conductor and is electrically connected to the diaphragm 11 but is insulated from the detection terminal 12 while maintaining the sealed state of the reference pressure chamber 14 by interposing the glass portion 13. Yes. The housing 10 includes an external connection terminal 15 on the outer surface.

  The diaphragm 11 depends on the magnitude of the pressure outside the reference pressure chamber 14 and is in at least two states: a contact state and a non-contact state with respect to the contact portion 12a of the detection terminal 12. The positional relationship is set so that For example, when the external pressure is sufficiently high, the diaphragm 11 bends toward the inside of the housing 10, and as a result, the diaphragm 11 contacts the contact portion 12 a of the detection terminal 12. Conversely, when the external pressure is lower than a certain level, the diaphragm 11 bends toward the outside of the housing 10, and as a result, the diaphragm 11 does not contact the detection terminal 12.

  In the present embodiment, preferably, the housing 10 has a terminal through hole 10i, and the detection terminal 12 is disposed so as to penetrate the terminal through hole 10i and have one end exposed to the outside of the housing 10. Yes. An end of the detection terminal 12 exposed to the outside is an external connection portion 12b. The glass portion 13 fills a gap inside the terminal through hole 10i so as to surround the detection terminal 12 so that the housing 10 and the detection terminal 12 do not directly contact each other.

(Action / Effect)
In the present embodiment, the glass terminal 13 is not directly connected between the detection terminal 12 and the housing 10, but when the pressure outside the reference pressure chamber 14 is sufficiently high, Since the diaphragm 11 is in contact with the contact portion 12 a of the detection terminal 12, electrical connection is established between the external connection portion 12 b of the detection terminal 12 and the external connection terminal 15 of the housing 10 through the diaphragm 11. Will be. On the other hand, when the pressure outside the reference pressure chamber 14 is lower than a certain level, the diaphragm 11 does not come into contact with the detection terminal 12, so that there is no communication between the external connection portion 12 b and the external connection terminal 15. Therefore, it is possible to monitor the presence or absence of an abnormal decrease in the external pressure only by monitoring whether or not the external connection portion 12b and the external connection terminal 15 are electrically connected.

  In particular, if this pressure switch is combined with an IC tag and the ID information is returned in response to an external signal, if it is installed inside the tire as shown in FIG. It is possible to monitor the presence or absence of an abnormal drop in internal pressure.

  In the example of FIG. 2, an IC tag 4 with a pressure switch is installed inside a tire 1 attached to the wheel 2. The tire 1 has a valve 3 for taking in and out air. An IC tag reader 5 for reading the ID information of the IC tag 4 with a pressure switch is disposed at a suitable location outside the tire 1.

  The IC tag 4 with a pressure switch combines the above-mentioned pressure switch with a passive IC tag, and when the pressure switch is conducting, it operates as an IC tag in response to a call signal from the IC tag reader 5, and the pressure switch is conducted. If not, even if there is a call signal from the IC tag reader 5, the IC tag does not operate.

  The “passive IC tag” does not have a built-in battery, and generates electric power using the induced electromotive force generated by the radio wave when receiving the radio wave transmitted from the IC tag reader. The information recorded in the memory in the IC tag is transmitted. At this time, if the information recorded in the memory is different for each IC tag, that is, an ID number for identifying each IC tag, a plurality of tires 1 in which such IC tags 4 with pressure switches are installed are provided. Even if there is a case, it is possible to distinguish which tire signal from the ID number returned from the IC tag reader 5, so individual internal pressure monitoring for each tire is performed collectively by one IC tag reader 5. be able to.

  In the present embodiment, the diaphragm 11 is made of metal. However, the diaphragm 11 may be a diaphragm that faces the inside of the reference pressure chamber 14 and has a conductive portion. In the present embodiment, since the entire diaphragm 11 is a conductor, it can be said that the entire diaphragm is a conductive portion. In addition to such a configuration, the diaphragm itself is a non-conductor, and a structure in which a conductive film as a conductive part is locally provided in a portion of the entire diaphragm that is opposed to and in contact with the detection terminal 12 may be used. Good. For example, in the configuration of FIG. 1, when a conductive portion is locally provided on the diaphragm, the wiring is extended from the conductive portion of the diaphragm to a portion where the diaphragm 11 and the housing 10 are in contact with each other. If the configuration is electrically connected, the same effect as described in this embodiment can be obtained.

(Embodiment 2)
(Constitution)
With reference to FIG. 3, the pressure switch in Embodiment 2 based on this invention is demonstrated. In the first embodiment, there is one detection terminal, and a method of detecting the presence / absence of conduction between the external connection portion 12b of the single detection terminal 12 and the external connection terminal 15 of the housing 10 (see FIG. 1). However, in the pressure switch according to the second embodiment, two detection terminals are provided as shown in FIG. That is, the detection terminals 121 and 122 are provided. The casing 10 is not provided with an equivalent to the external connection terminal. The detection terminals 121 and 122 are arranged so as to face the diaphragm 11 in the reference pressure chamber 14 respectively. At the same time, the detection terminals 121 and 122 pass through the terminal through holes 101i and 102i provided in the casing 10 respectively, and one end of the detection terminals 121 and 122 10 so as to be exposed to the outside.

  The housing 10 is made of a conductor, for example, metal, and the housing 10 is electrically connected to the diaphragm 11. On the other hand, the casing 10 is insulated from both the detection terminals 121 and 122 by interposing glass portions 131 and 132, respectively, while maintaining the sealed state of the reference pressure chamber 14. In other words, the glass portions 131 and 132 are interposed so as to block electrical connection in a path along the housing 10 between the diaphragm 11 and the detection terminals 121 and 122.

  The ends of the detection terminals 121 and 122 that are exposed to the outside of the housing 10 are external connection portions 121b and 122b.

  Depending on the magnitude of the pressure outside the reference pressure chamber 14, the diaphragm 11 is at least in a state where it is in contact with both of the contact portions 121a, 122a of the detection terminals 121, 122 and in a state where it is not. The positional relationship is set so that two states can be taken. In this case, for example, when the external pressure is sufficiently high, the diaphragm 11 bends toward the inside of the housing 10, and as a result, the diaphragm 11 contacts both the contact portions 121 a and 122 a of the detection terminals 121 and 122. Touch. On the other hand, when the external pressure is lower than a certain level, the diaphragm 11 bends toward the outside of the housing 10, and as a result, the diaphragm 11 can be removed from one or both of the contact portions 121 a and 122 a of the detection terminals 121 and 122. Leave.

  Since the configuration and details of the other parts are the same as those shown in the first embodiment, description thereof will not be repeated here.

(Action / Effect)
In the present embodiment, the glass portion 13 is not directly connected between the detection terminal 121 and the detection terminal 122, but when the pressure outside the reference pressure chamber 14 is sufficiently high, Since the diaphragm 11 abuts both the abutting portions 121a and 122a of the detection terminals 121 and 122, electrical connection is established between the external connection portions 121b and 122b via the diaphragm 11. On the other hand, when the pressure outside the reference pressure chamber 14 is lower than a certain level, the diaphragm 11 is separated from one or both of the contact portions 121a and 122a, so that the external connection portions 121b and 122b are not connected to each other. Therefore, it is possible to monitor the presence or absence of an abnormal decrease in the external pressure only by monitoring whether or not the external connection parts 121b and 122b are electrically connected.

  In addition, although the terminal through-holes 101i and 102i exist corresponding to the detection terminals 121 and 122 individually here and the glass parts 131 and 132 were formed individually, the terminal through-hole is common here. It is also possible to have a structure in which two detection terminals are respectively held in a state of being insulated from each other by the glass portion.

  The point that this pressure switch can be used in combination with the IC tag for monitoring the tire internal pressure or the like is the same as in the first embodiment.

(Embodiment 3)
(Constitution)
With reference to FIG. 4, the pressure switch in Embodiment 3 based on this invention is demonstrated. This pressure switch includes a housing 10n made of a non-conductor. The housing 10n has a container shape having a main opening, and detection terminals 171 and 172 are arranged inside the bottom surface thereof. Wiring extends from the detection terminals 171 and 172, and the wiring penetrates the side wall of the housing 10n to reach the outer surface of the housing 10n. The ends of the wirings are external connection terminals 191 and 192 on the lower surface of the housing 10n. The diaphragm 11 is attached so as to form a reference pressure chamber 14 sealed inside the housing 10n by closing the main opening of the housing 10n. The diaphragm 11 is attached to the housing 10n via an adhesive layer 18 made of glass or alloy.

  Since the configuration and details of other parts are the same as those shown in the first and second embodiments, description thereof will not be repeated here.

(Action / Effect)
In the present embodiment, the detection terminals 171 and 172 are not directly electrically connected to each other. However, when the pressure outside the reference pressure chamber 14 is sufficiently high, the diaphragm 11 is connected to both the detection terminals 171 and 172. Since they abut, electrical connection is established between the external connection portions 191 and 192 via the diaphragm 11. On the other hand, when the pressure outside the reference pressure chamber 14 is lower than a certain level, the diaphragm 11 is separated from both or one of the detection terminals 171 and 172, so that there is no communication between the external connection portions 191 and 192. Therefore, it is possible to monitor the presence or absence of an abnormal decrease in the external pressure only by monitoring whether or not the external connection portions 191 and 192 are electrically connected.

  The diaphragm 11 may be a diaphragm having a conductive portion facing the inside of the reference pressure chamber 14. However, the two detection terminals 171 and 172 face the conductive portion. In the example of FIG. 4, the entire diaphragm 11 is formed of metal and the whole is a conductive part. However, as another example, the conductive part 20 is provided in the inner central region as in the diaphragm 11 n shown in FIG. 5. The other part may be a diaphragm made of a non-conductive material. As a non-conductive material constituting the diaphragm, for example, ceramic and glass are conceivable. Alternatively, the diaphragm 11n shown in FIG. 5 may be formed of silicon having an insulating film.

  4 and 5, the external connection terminals 191 and 192 are both disposed on the back side of the bottom surface of the housing 10n, but the two external connection terminals are disposed anywhere on the outer surface of the housing 10n. Or is free. If the pressure switch is disposed on the back side of the bottom surface as in the examples of FIGS. 4 and 5, this pressure switch can be attached to the surface of another substrate as a surface mount type element, which is preferable.

(Embodiment 4)
(Constitution)
With reference to FIG. 6, the pressure switch in Embodiment 4 based on this invention is demonstrated. The pressure switch includes a diaphragm 11 and a detection terminal support plate 16 made of a conductor so as to face the diaphragm 11. The detection terminal support plate 16 has a detection terminal 17 formed as a protrusion at one location on the main surface. A glass portion 13r is formed in an annular shape on the surface of the detection terminal support plate 16. By sandwiching the glass part 13 r between the diaphragm 11 and the detection terminal support plate 16, a region surrounded by the glass part 13 r is a sealed reference pressure chamber 14.

  A portion made of a conductor extends further outward from the end of the detection terminal support plate 16, and the tip thereof serves as an external connection portion 211. On the other hand, the external connection part 212 is exposed to the outside in the form of being electrically connected from the conductive part of the diaphragm 11. In the example of FIG. 6, the entire diaphragm 11 is a conductive part, and thus the external connection part 212 is provided so as to extend the end of the diaphragm 11 as it is.

  Since the configuration and details of the other parts are the same as those shown in the first embodiment, description thereof will not be repeated here.

(Action / Effect)
In this embodiment, the detection terminal 17 and the diaphragm 11 are not electrically connected along the wall of the reference pressure chamber 14 due to the glass portion 13r interposed therebetween. When the pressure is sufficiently high, the diaphragm 11 abuts on the detection terminal 17, so that the external connection terminal 211 that is electrically connected to the detection terminal 17 and the diaphragm 11 are electrically connected. A connection with the external connection terminal 212 can be established through the diaphragm 11. On the other hand, when the pressure outside the reference pressure chamber 14 is lower than a certain level, the diaphragm 11 does not come into contact with the detection terminal 17, so that the external connection terminals 211 and 212 are not connected to each other. Therefore, it is possible to monitor the presence or absence of an abnormal decrease in the external pressure only by monitoring whether or not the external connection terminals 211 and 212 are electrically connected.

  In addition, although the external connection terminals 211 and 212 protrude toward the same side in the example of FIG. 6, the external connection terminals 211 and 212 are not limited to the same side and may protrude to different sides. However, if the two external connection terminals protrude toward the same side, it is convenient when electrically connecting to other components.

(Embodiment 5)
(Constitution)
With reference to FIG. 7 and FIG. 8, the pressure switch in Embodiment 5 based on this invention is demonstrated. This pressure switch is a development of the concept of the pressure switch (see FIG. 1) described in the first embodiment. In this pressure switch, the conductive portion is the entire diaphragm 11 as shown in FIG. The housing 10 is made of a conductor. The housing 10 is provided with an external connection terminal 15. This pressure switch includes a plurality of detection terminals 221, 222, and 223 that face the conductive portion inside the reference pressure chamber 14. Further, each of the plurality of detection terminals 221, 222, and 223 is insulated from the housing 10 while maintaining the sealed state of the reference pressure chamber 14 by interposing glass portions 131, 132, and 133, respectively. As shown in the perspective view of FIG. 8, the detection terminals 221, 222, and 223 include portions where metal thin plates are bent. However, in FIG. 8, for the convenience of explanation, the state in which the diaphragm 11 is removed is displayed.

  Each of the plurality of detection terminals 221, 222, and 223 is not in contact with the state in contact with the conductive portion depending on the deformation magnitude of the diaphragm 11 determined by the magnitude of the pressure outside the reference pressure chamber 14. It arrange | positions so that at least two types of states can be taken. Each of the plurality of detection terminals 221, 222, and 223 is set such that the magnitude of the pressure outside the reference pressure chamber 14 necessary for maintaining the state of being in contact with the conductive portion is different. For example, in the example shown in FIGS. 7 and 8, the height at which each detection terminal protrudes from the bottom surface of the housing 10 is different.

Particularly preferably, in the present embodiment, the housing 10 has a plurality of terminal through holes corresponding to the plurality of detection terminals 221, 222, and 223. Each of the detection terminals 221, 222, and 223 is disposed so as to individually penetrate the corresponding terminal through hole and one end is exposed to the outside of the housing 10. The portions exposed to the outside are external connection portions 221b, 222b, and 223b, respectively.
Further, the glass portions 131, 132, and 133 surround the detection terminals 221, 222, and 223 so that the housing 10 and the detection terminals 221, 222, and 223 are not in direct contact with each other. Is buried.

(Action / Effect)
In the present embodiment, the detection terminals 221, 222, and 223 and the housing 10 are not directly electrically connected through the glass portions 131, 132, and 133, but are external to the reference pressure chamber 14. Depending on the height of the pressure, a part of the detection terminals 221, 222, and 223 comes into contact with the diaphragm 11. Since the detection terminals 221, 222, and 223 are different in height, the position to which the detection terminals 221, 222, and 223 come into contact varies depending on the magnitude of pressure. Therefore, by monitoring the presence / absence of a conduction state between the external connection terminal 15 and each of the detection terminals 221, 222, and 223, it is possible to grasp at which stage the external pressure is.

  In particular, this pressure switch is combined with an IC tag to return its own ID information and the continuity between the external connection terminal 15 and each detection terminal 221, 222, 223 in response to an external signal. If a thing is installed in the inside of a tire as shown in FIG. 2, the change of the internal pressure of a tire can be monitored.

  In the present embodiment, each of the detection terminals 221, 222, and 223 passes through a separately provided terminal through hole, and has a structure in which separate glass portions 131, 132, and 133 are provided. However, even if it is the structure which penetrates the same terminal through-hole which two or more detection terminals share, what is necessary is just to insulate the detection terminals by a glass part.

  In this embodiment, by changing the height of the detection terminal, the pressure value that becomes the boundary of whether to contact the conductive portion of the diaphragm is made different for each detection terminal, but in addition to such a method, As shown in FIG. 9, even if the detection terminals have the same height, the corresponding diaphragms 11a, 11b, 11c, and 11d are provided separately for each of the detection terminals, and the diaphragms 11a, 11b, 11c, and 11d are provided separately. The deformation characteristics with respect to the external pressure may be different. Even in this case, if attention is paid to each of the detection terminals, depending on the magnitude of the deformation of the diaphragm determined by the magnitude of the pressure outside the reference pressure chamber, the state where it is in contact with the conductive portion and the state where it is not in contact In order to maintain the state where each of the detection terminals is in contact with the conductive portion, the magnitude of the pressure outside the reference pressure chamber 14 is different from each other. It is not changed to being set to. In FIG. 9, the diaphragms 11 a, 11 b, 11 c, and 11 d are arranged in one horizontal row, but the plurality of diaphragms can be arranged in plan view. For example, when five combinations of diaphragms and detection terminals are provided, they may be arranged in a positional relationship such that the overall outer shape is a square as shown in FIG.

(Embodiment 6)
(Constitution)
With reference to FIG. 11, a pressure switch according to Embodiment 6 of the present invention will be described. This pressure switch includes an integrated circuit 7 electrically connected to the detection terminal 17 e and an antenna 6 electrically connected to the integrated circuit 7. The integrated circuit 7 is for outputting its own identification information via the antenna 6 in response to an external radio wave input via the antenna 6. The integrated circuit 7 is disposed inside the reference pressure chamber 14. The antenna 6 is disposed on the back surface of the substrate 8 disposed on the back side of the bottom surface of the housing 10. The detection terminal 12 penetrates the bottom surface of the housing 10 and further penetrates the substrate 8, and the external connection portion 12 b that is the tip of the detection terminal 12 outside the housing 10 is connected to the antenna 6. The tip of the detection terminal 12 inside the housing 10 is a contact portion 12a. Similarly to the detection terminal 12, the external connection terminal 19 electrically connected to the integrated circuit 7 also penetrates the bottom surface of the housing 10 and the substrate 8, and the tip thereof is connected to the antenna 6. The contact portion 12 a and the detection terminal 17 e of the detection terminal 12 are opposed to the diaphragm 11. Depending on the magnitude of the pressure outside the reference pressure chamber 14, the diaphragm 11 is at least in a state where it is in contact with both the contact portion 12a and the detection terminal 17e of the detection terminal 12 and in a state where it is not. The positional relationship is set so that two states can be taken.

  Since the configuration and details of other parts are the same as those shown in the first and second embodiments, description thereof will not be repeated here.

(Action / Effect)
In this embodiment, the pressure switch itself also serves as an IC tag. When the external pressure is sufficiently high and both the contact portion 12a and the detection terminal 17e are in contact with the diaphragm 11, there is conduction between them, so there was an input from the outside via the antenna 6. Sometimes the integrated circuit 7 can operate and outputs its own identification information via the antenna 6. However, when the external pressure is low to some extent and at least one of the contact portion 12a and the detection terminal 17e is separated from the diaphragm 11, the two are electrically disconnected from each other. The integrated circuit 7 does not operate even if there is an input by the radio wave. Therefore, a person who has transmitted a signal by radio waves outside can know that the pressure outside the pressure switch has dropped below a certain value by not receiving a response from the pressure switch.

  In addition to the integrated circuit 7, a battery may be arranged in the pressure switch so that the integrated circuit 7 can be operated by the battery. However, the integrated circuit 7 operates without an external radio wave as an energy source. It is preferable to use a type that can be used because it can be used stably over a longer period of time.

  In the present embodiment, the integrated circuit 7 is disposed inside the reference pressure chamber 14, but is not limited to this example, and may be disposed outside the reference pressure chamber 14. However, it is preferable to arrange the integrated circuit 7 inside the reference pressure chamber 14 as in the present embodiment because the whole can be made compact.

  The concept of the present embodiment may be applied to the pressure switch described in the third embodiment, and the integrated circuit 7 may be provided inside the reference pressure chamber 14 as shown in FIG. In this case as well, the same effect as this embodiment can be obtained.

(Embodiment 7)
(Constitution)
With reference to FIG. 13, the pressure monitoring system in Embodiment 7 based on this invention is demonstrated. As shown in FIG. 11, this pressure monitoring system includes a plurality of pressure switches 801, 802, 803, and 804. The pressure switches 801, 802, 803, and 804 may be any of the pressure switches shown in the first to fourth embodiments. An integrated circuit 507 for outputting a conduction state with respect to the partition wall of the detection terminal in each pressure switch is electrically connected to the detection terminals of the plurality of pressure switches 801, 802, 803, and 804. The integrated circuit 507 is electrically connected to an antenna 506 for transmitting and receiving signals. However, the pressure value outside the reference pressure chamber, which is a threshold value as to whether or not the diaphragm in each pressure switch abuts against the detection terminal, is different between the plurality of pressure switches 801, 802, 803, and 804. Is set to

  For example, this pressure monitoring system is placed inside a sealed object 501 as shown in FIG. 13 and used to monitor the internal pressure of the object 501. An IC tag reader 505 is installed outside the object 501, and information on the internal pressure of the object 501 can be obtained by sending a signal by radio waves from the IC tag reader 505. The object 501 may be a tire.

(Action / Effect)
If the pressure monitoring system is configured in this way, even if there is one integrated circuit, the conduction state of a plurality of pressure switches can be monitored at once, and the pressure value serving as a threshold for each pressure switch can be monitored. Since they are different, the number of pressure switches in the conductive state varies depending on the range to which the pressure value belongs. Therefore, it is possible to grasp the approximate value of the pressure of the environment in which the plurality of pressure switches 801, 802, 803, and 804 are placed by interrogating the single integrated circuit 507 from the IC tag reader 505 with radio waves. it can.

  In addition, the said embodiment disclosed this time is an illustration in all the points, Comprising: It is not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and includes all modifications within the scope and meaning equivalent to the terms of the claims.

It is sectional drawing of the pressure switch in Embodiment 1 based on this invention. It is explanatory drawing of the usage example of the IC tag with a pressure switch in Embodiment 1 based on this invention. It is sectional drawing of the pressure switch in Embodiment 2 based on this invention. It is sectional drawing of the pressure switch in Embodiment 3 based on this invention. It is sectional drawing of the modification of the pressure switch in Embodiment 3 based on this invention. It is sectional drawing of the modification of the pressure switch in Embodiment 4 based on this invention. It is sectional drawing of the pressure switch in Embodiment 5 based on this invention. It is a perspective view of the pressure switch in Embodiment 5 based on this invention. It is sectional drawing of the modification of the pressure switch in Embodiment 5 based on this invention. It is a top view of the further another example of the pressure switch in Embodiment 5 based on this invention. It is sectional drawing of the pressure switch in Embodiment 6 based on this invention. It is sectional drawing of the modification of the pressure switch in Embodiment 6 based on this invention. It is a conceptual diagram of the pressure monitoring system in Embodiment 7 based on this invention.

Explanation of symbols

  1 tire, 2 wheel, 3 valve, 4 IC tag with pressure switch, 5,505 IC tag reader, 6,506 antenna, 7,507 integrated circuit, 8 substrate, 10 (made of conductor) housing, 10h main opening 10i, 101i, 102i Terminal through hole, 10n housing (made of non-conductive material), 11, 11u diaphragm, 12, 121, 122, 17, 17e, 171, 172, 221, 222, 223 detection terminal, 12a Contact part, 12b, 121b, 122b, 221b, 222b, 223b external connection part, 13, 131, 132, 133 glass part, 13r (annular) glass part, 14 reference pressure chamber, 15, 19, 191, 192, 211 , 212 External connection terminal, 16 (conductive) detection terminal support plate, 18 adhesive layer, 20 conductive part, 501 , 801, 802, 803, and 804 pressure switch.

Claims (11)

A container-like housing having a main opening;
A diaphragm having a conductive portion facing the inside of the reference pressure chamber, which is attached so as to form a sealed reference pressure chamber inside the casing by closing the main opening,
A detection terminal facing the conductive portion in the reference pressure chamber;
The housing is insulated by interposing a glass portion with respect to either the conductive portion or the detection terminal,
The diaphragm can take at least two states depending on the pressure level outside the reference pressure chamber: a state where the conductive portion is in contact with the detection terminal and a state where the conductive portion is not in contact with the detection terminal. ,pressure switch.   The housing has a terminal through hole, and each of the detection terminals is disposed so as to pass through the terminal through hole and have one end exposed to the outside of the housing. The housing, the detection terminal, The pressure switch according to claim 1, wherein a gap inside the terminal through-hole is filled so that a glass portion surrounds the detection terminal so as not to contact directly. A container-like housing having a main opening;
A diaphragm having a conductive portion facing the inside of the reference pressure chamber, which is attached so as to form a sealed reference pressure chamber inside the casing by closing the main opening,
A plurality of detection terminals facing the conductive portion in the reference pressure chamber;
Each of the plurality of detection terminals is insulated by interposing a glass portion with respect to the housing,
Each of the plurality of detection terminals is in contact with the conductive portion and not in contact with the conductive portion, depending on the deformation magnitude of the diaphragm determined by the pressure outside the reference pressure chamber. It is arranged so that it can take at least two states,
Each of the plurality of detection terminals is a pressure switch in which the magnitude of the pressure outside the reference pressure chamber necessary for maintaining the state in contact with the conductive portion is different.   The casing has a plurality of terminal through holes corresponding to the plurality of detection terminals, and each of the detection terminals individually penetrates the corresponding terminal through hole and one end is exposed to the outside of the casing. The glass portion fills a gap inside the terminal through-hole so as to surround each of the detection terminals so that the casing and the detection terminals do not directly contact each other. 3. The pressure switch according to 3. A main opening, made of a conductor, and a container-like housing;
A diaphragm having a conductive portion facing the inside of the reference pressure chamber, which is attached so as to form a sealed reference pressure chamber inside the casing by closing the main opening,
Two or more detection terminals arranged to face the conductive portion in the reference pressure chamber,
A glass part interposed so as to interrupt electrical connection in a path along the housing between the conductive part and the detection terminal;
The diaphragm has at least two states, a state where the conductive portion is in contact with two or more of the detection terminals and a state where it is not, depending on the magnitude of pressure outside the reference pressure chamber. Can take a pressure switch. A main opening, made of a non-conductive material, and a container-like housing;
A diaphragm having a conductive portion facing the inside of the reference pressure chamber, which is attached so as to form a sealed reference pressure chamber inside the casing by closing the main opening,
Two or more detection terminals that are arranged so as to face the conductive parts in the reference pressure chamber and are not directly electrically connected to each other,
Depending on the magnitude of pressure outside the reference pressure chamber, the diaphragm has at least two states: a state in which the conductive portion is in contact with two or more of the detection terminals and a state in which the conductive portion is not in contact. Possible pressure switch. A detection terminal support plate;
A glass portion formed in an annular shape on the surface of the detection terminal support plate;
By being arranged so as to face the detection terminal support plate via the glass part, a sealed reference pressure chamber is formed in a region surrounded by the glass part, and faces the inside of the reference pressure chamber. A diaphragm having a conductive portion;
Two or more detection terminals arranged so as to face the conductive parts in the reference pressure chamber,
The diaphragm has a state in which the conductive portion is in contact with two or more of the detection terminals and a state in which only less than two are in contact depending on the magnitude of pressure outside the reference pressure chamber. A pressure switch that can be in at least two states.   An integrated circuit electrically connected to the detection terminal; and an antenna electrically connected to the integrated circuit, wherein the integrated circuit is self-responsive in response to an external radio wave input via the antenna. The pressure switch according to any one of claims 1, 2, 5, 6, and 7, which is for outputting identification information via the antenna.   An integrated circuit electrically connected to the detection terminal; and an antenna electrically connected to the integrated circuit, wherein the integrated circuit is self-responsive in response to an external radio wave input via the antenna. The pressure switch according to claim 3 or 4, which is used for outputting identification information and a conduction state of the plurality of detection terminals with respect to the partition through the antenna.   The pressure switch according to claim 8 or 9, wherein the integrated circuit is disposed inside the reference pressure chamber. A plurality of pressure switches according to claim 1 or 2, wherein a pressure value outside the previous reference pressure chamber, which is a threshold value as to whether or not the diaphragm comes into contact with the detection terminal, is determined between the plurality of pressure switches. Are set to be different,
Furthermore, an integrated circuit electrically connected to the detection terminals of the plurality of pressure switches, and an antenna electrically connected to the integrated circuit,
The integrated circuit is a pressure monitoring system for outputting a conduction state of the detection terminal with respect to the partition wall in each of the plurality of pressure switches via the antenna.

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