JP4138762B2 - Heat sensor - Google Patents

Description

  The present invention relates to a heat detector that senses heat in a monitoring area and issues an alarm or the like.

  Conventionally, heat detectors that detect the occurrence of a fire with the heat generated by the fire have been proposed. Such a heat sensor is generally configured to include a heat-sensitive part that senses heat in a monitoring region, and a sensor body that issues an alarm according to the sensing state of the heat-sensitive part.

  Among these, the heat sensitive unit is configured to include a sensor unit that senses heat in the monitoring region and converts the sensed state into another state change. A diaphragm that deforms due to expansion of air due to temperature rise, a thermistor that changes its resistance value according to temperature, or a bimetal that deforms in a predetermined direction according to temperature is used for this sensor unit (for example, a patent) Reference 1).

  FIG. 16 is a front view of a conventional thermistor type heat sensor, and FIG. 17 is a cross-sectional view of the heat sensor in FIG. The heat sensor 110 is generally configured by standing a thermistor 112 on one side of the sensor body 111. The thermistor 112 is erected in this way because the thermistor 112 is separated from the sensor body 111 as much as possible to prevent heat conduction between the sensor body 111 and the thermistor. This is because the thermal responsiveness of the thermistor 112 is enhanced by directly applying the heat to 112. Further, in order to protect the thermistor 112 standing upright from the outside, a thermistor guide 113 is provided around the thermistor 112.

JP 05-266377 A

  However, in such a conventional heat sensor 110, in addition to the thermistor 112 itself being bulky, the thermistor guide 113 is provided around the thermistor 112, so that the heat sensor 110 is relatively large as a whole. Therefore, it has been difficult to reduce the thickness of the heat sensor 110.

  In order to solve such a problem, the inventors of the present application have examined the use of a ceramic element, which is a ferroelectric substance that outputs a pyroelectric current due to the pyroelectric effect when the temperature changes, as a heat sensing element. Yes. Since this ceramic element can be formed into a thin film, the entire heat sensor can be miniaturized by using this ceramic element as a heat sensing element.

  Here, from the viewpoint of the thermal responsiveness of the heat detector, even when the ceramic element is used as described above, it is preferable to increase the thermal responsiveness by directly applying an air flow to the ceramic element as much as possible.

  On the other hand, from the viewpoint of the reliability of the heat sensor, even if a load is applied to the ceramic element for some reason, measures are taken to protect the ceramic element from damage. It is preferable to keep it. However, if the surface of the ceramic element is simply covered with a protective member or the like, the air flow with respect to the ceramic element is hindered, which is contrary to the demand for the thermal response.

  The present invention has been made in view of the above, and is a thermal sensor that improves the reliability by protecting the thermal sensing element while improving the thermal responsiveness of the thermal sensing element such as a ceramic element. The purpose is to provide.

In order to solve the above-described problems and achieve the object, the thermal sensor according to claim 1 is a thermal sensor for sensing the temperature of the monitoring area, and a sensor body fixed to the installation surface; A heat sensing element that is fixed to the sensor body, and is a ceramic element formed into a flat plate by sintering a ferroelectric substance that outputs a pyroelectric current in response to a temperature change; An opening is formed in the sensor body, and support means is formed in the opening, and the heat sensing element is disposed at an outer position away from the installation surface than the support means in the opening, A position where the support means does not contact the heat sensing element in a non-deformed state, and a position where the heat sensing element is supported by contacting the heat sensing element in a state deformed by a predetermined amount or more. It is arranged.

Further, the heat sensor according to claim 2 is the heat sensor according to claim 1, wherein the support means is a small disk that is in surface contact with the heat sensing element that is deformed by a predetermined amount or more. Or a mesh-like support portion formed of a plurality of linear support members that are in contact with the heat sensing element in a state of being deformed by a predetermined amount or more.

  According to the present invention, when the heat sensing element is deformed by a predetermined amount or more, the support means contacts the inside of the heat sensing element, and further deformation of the heat sensing element is prevented, so that the heat sensing element is damaged. Etc., and the reliability of the heat sensor can be improved.

  Further, according to the present invention, when the heat sensing element is in a non-deformed state, the heat sensing element and the support means can be maintained in a non-contact state, and heat conduction between the two is prevented. The thermal responsiveness of the heat sensing element can be maintained and improved.

  Further, according to the present invention, the support means can be brought into line or surface contact with the heat sensing element, so that the load on the heat sensing element can be diffused from the point, and the heat sensing element can be prevented from being damaged. The reliability of the sensor can be improved.

  Further, according to the present invention, since the cover means is formed of the infrared absorbing member, the heat sensing element can be protected by the cover means and radiant heat can be conducted to the heat sensing element. The conflicting problem of improved responsiveness can be achieved at the same time.

  Embodiments of a heat sensor according to the present invention will be described below in detail with reference to the accompanying drawings. [I] First, the basic configuration of the present invention will be described, then [II] each embodiment of the present invention will be described, and [III] Finally, modifications to each embodiment of the present invention will be described.

[I] Basic Configuration of the Present Invention First, the basic configuration of the present invention will be described. The present invention relates to a heat sensor configured by housing a heat sensing element for sensing the temperature of a monitoring region in a sensor body, and an object thereof is to simultaneously improve the thermal response and reliability.

  Among them, the improvement of the thermal response includes (1) exposing at least a part of the heat sensing element or its proximity member to the outside, and (2) the cover means formed of the infrared absorbing member. To achieve. Further, the improvement in reliability is achieved by providing support means for supporting the heat sensing element from the inside. That is, in the conventional thermistor type heat sensor, the thermistor that is the heat sensing element is protected from the outside, whereas in the present invention, the outside of the heat sensing element is exposed, while this The heat sensing element is protected from the inside, thereby achieving both heat response and reliability. Here, the inner side is a direction close to the installation surface of the heat sensor, and the outer side is a direction opposite to the inner side with respect to each part of the heat sensor.

[II] Embodiments of the Present Invention Next, embodiments of the heat sensor according to the present invention will be described. However, the present invention is not limited by these embodiments.

[Embodiment 1]
First, the first embodiment will be described. 1 is a front view of the heat sensor according to the first embodiment, FIG. 2 is a cross-sectional view of the heat sensor of FIG. 1 taken along the line AA, and FIG. 3 is a rear view of the heat sensor of FIG. It is. As shown in each of these drawings, the heat sensor 1 according to the first embodiment is roughly configured to include a sensor body 10, a body cover 20, a heat sensing unit 30, and a circuit board 40. Yes.

(About sensor body)
Among these, the structure of the detector body 10 will be described. The sensor body 10 functions as a structure of the heat sensor 1 and corresponds to the sensor body in the claims. The sensor main body 10 accommodates the heat sensing unit 30 and the circuit board 40 together and protects them from the outside by housing the heat sensing unit 30 and the circuit board 40 therein. 4 is a front view of the sensor main body 10, FIG. 5 is a side view of the sensor main body 10 in FIG. 4, and FIG. 6 is a cross-sectional view of the sensor main body 10 in FIG.

  As shown in these drawings, the sensor body 10 includes a substantially annular base portion 11, a rising portion 12 that rises from the inner circle of the base portion 11 toward the outside at a substantially right angle, and the rising portion 12. And a support part 13 formed in the above, and these parts are integrally formed of a resin such as polycarbonate.

  Among these, the base part 11 functions as a base body of the sensor body 10, and a pair of attachment holes 11a are formed on both sides thereof. And the heat sensor 1 can be attached to the said installation surface by inserting the attachment screw (not shown) cast in installation surfaces, such as a ceiling, to this attachment hole 11a. An opening 12a is formed at the front center of the rising portion 12, and a support portion 13 is formed in the opening 12a. The support portion 13 supports the heat sensing unit 30 from the inside, and corresponds to the support means in the claims. The function of the support portion 13 will be described later. A step 12b having a diameter substantially corresponding to the heat sensing unit 30 is formed at the periphery of the opening 12a, and the heat sensing unit 30 (not shown in FIGS. 4 to 6) is disposed on the step 12b. The heat sensing unit 30 can be fixed to the sensor body 10 by fixing the heat sensing unit 30 to the stepped portion 12b by bonding or ultrasonic welding.

(About the cover)
Next, the structure of the main body cover 20 of FIGS. 1-3 is demonstrated. The body cover 20 is a protection means for protecting the sensor body 10 from the outside. 7 is a front view of the main body cover 20, and FIG. 8 is a cross-sectional view of the main body cover 20 in FIG. As shown in these drawings, the main body cover 20 has a substantially annular front shape substantially corresponding to the outer shape of the sensor main body 10, and side walls 21 are integrally formed on the sides thereof. As shown in FIG. 2, the side wall 21 is formed with a thickness substantially corresponding to the thickness of the sensor main body 10 (the length from the inner end to the outer end), and the side of the sensor main body 10 is almost completely formed. It is possible to cover. 7 and 8, an opening 22 is formed in the main body cover 20, and the inner diameter of the opening 22 is equal to the outer diameter of the rising portion 12 of the sensor main body 10, as shown in FIG. It corresponds roughly. Accordingly, as shown in FIGS. 1 to 3, even when the main body cover 20 is attached to the sensor main body 10, the heat sensing unit 30 fixed to the opening 22 of the rising portion 12 is exposed to the outside. For this reason, an external airflow can be directly applied to the heat sensing unit 30, and the heat responsiveness of the heat sensing unit 30 can be improved. Further, unlike the case where a conventional thermistor guide is provided, there is no obstacle around the heat sensing unit 30 so that the air current in the monitoring area can be directly applied to the heat sensing unit 30 and the thermal response can be improved. It can be further enhanced.

(About heat sensing unit)
Next, the heat sensing unit 30 shown in FIGS. The heat sensing unit 30 is for detecting heat in the monitoring area by outputting a current corresponding to the temperature in the monitoring area. 9 is a diagram showing a front view and a longitudinal sectional view of the heat sensing unit 30 in relation to each other. FIG. 10 is a plan view and a longitudinal sectional view of a ceramic element and the like provided in the heat sensing unit 30 of FIG. It is the figure shown in relation to each other.

  As shown in these drawings, the heat sensing unit 30 covers the ceramic element 31, a pair of electrodes 32 and 33 provided on the outside and inside of the ceramic element 31, and the ceramic element 31 and the electrodes 32 and 33. A pair of laminate films 34 and 35 are provided.

  Of these, the ceramic element 31 converts the sensing state into another state change, and corresponds to the heat sensing element in the claims. The ceramic element 31 is formed by sintering a ferroelectric substance that outputs a pyroelectric current due to a pyroelectric effect when the temperature of the monitoring region changes. The thin ceramic element 31 is thus heated. By using it as a sensing element, the heat detector 1 can be made thin overall. In particular, by forming the ceramic element 31 in a flat plate shape, it is possible to perform heat sensing using a planar portion instead of heat sensing using a point-like portion like a conventional thermistor, and to improve thermal response.

  The electrodes 32 and 33 are electrode means for outputting the pyroelectric current output from the ceramic element 31 to the circuit board 40 via an electric wire (not shown), and by bonding a metal plate to the ceramic element 31, Alternatively, it is formed by evaporating metal on the ceramic element 31.

  The laminate films 34 and 35 cover the ceramic element 31 and the electrodes 32 and 33, and correspond to cover means in the claims. The laminated films 34 and 35 are substantially thin disc-shaped film materials having a diameter larger than that of the ceramic element 31 and the electrodes 32 and 33, and the ceramic elements 31 and the electrodes 32 and 33 are sandwiched between them. By adhering, the ceramic element 31 and the electrodes 32 and 33 are covered while being in contact with the ceramic element 31 and the electrodes 32 and 33. The inner laminate film 35 has a notch 35a, and by directly soldering an unillustrated electric wire to the electrodes 32 and 33 partially exposed from the notch 35a, the electric wire is connected to the electrode 32, 33 can be electrically connected.

(About circuit boards)
Next, the circuit board 40 of FIGS. 1-3 is demonstrated. The circuit board 40 is for electrically connecting the electrical components of the heat sensor 1 to each other, and is housed inside the sensor body 10. A lead wire 41 for supplying electric power to the heat sensor 1 and for outputting from the heat sensor 1 is connected to the inside of the circuit board 40, and this electric wire is connected to the heat sensor 1. Connected to an external device. In this state where the lead wire 41 is pulled out, the space in the vicinity of the inside of the circuit board 40 is sealed with a filler 42 such as a silicon-based adhesive, which prevents water from entering the circuit board 40 or the like. Is prevented.

(Details of support part)
Next, the structure and function of the support portion 13 that supports the heat sensing unit 30 will be described in more detail. As described above, the support portion 13 is formed in the opening portion 12a of the rising portion 12 of the sensor body 10, and the heat sensing unit 30 is disposed on the outside thereof. Here, the support portions 13 are not in contact with each other when the heat sensing unit 30 is not deformed (non-deformed state), and only when the heat sensing unit 30 is deformed by a predetermined amount or more. It arrange | positions in the vicinity position which has predetermined spacing with respect to the heat sensing unit 30 so that it may contact.

  11 is an enlarged cross-sectional view showing the positional relationship between the heat sensing unit 30 and the support portion 13 in the non-deformed state, and FIG. 12 is an enlarged cross-sectional view showing the positional relationship between the heat sensing unit 30 and the support portion 13 in the deformed state. It is. As shown in FIG. 11, the heat sensing unit 30 in the non-deformed state and the support portion 13 are arranged at a distance t from each other. Therefore, in this state, the support portion 13 and the heat sensing unit 30 are not in contact with each other, and heat conduction between them is prevented, so that the thermal response of the heat sensing unit 30 can be maintained and improved. . In addition, as shown in FIG. 12, in a state where the heat sensing unit 30 is deformed by an interval t or more by applying a load F to the heat sensing unit 30, the support portion 13 contacts the inside of the deformed heat sensing unit 30. As a result, further deformation of the heat sensing unit 30 is prevented. Here, the specific value of the interval t (allowable deformation amount of the heat sensing unit 30) is arbitrary, but is larger than the expansion amount of the heat sensing unit 30 due to the temperature change (the support portion 13 does not contact at the time of expansion due to the temperature change). And the like, and it is preferably set to about several mm so as to be smaller than the deformation amount causing damage or the like to the heat sensing unit 30.

  In addition, the specific front shape of the support portion 13 is basically arbitrary, but in the present embodiment, the support portion 13 includes a plurality of linear support bodies 13a and a curved support body as shown in FIG. The body 13b is combined and formed integrally, and an opening region 13c is formed between the plurality of supports 13a and 13b. That is, the support portion 13 may be formed in a flat plate shape so as to close the substantially entire region of the opening portion 12a of the rising portion 12, but in the present embodiment, the linear support body 13a and the curved support member are supported. Only the body 13b is provided, and the space between them is open. Therefore, the overall volume of the support portion 13 can be reduced to reduce its heat capacity, the influence of the thermal response that the support portion 13 gives to the heat sensing unit 30 can be reduced, and the heat responsiveness of the heat sensing unit 30 is impaired. Can be prevented. Further, since the gas can freely flow from the outside to the inside of the support portion 13 through the opening region 13c, even when the gas existing between the heat sensing unit 30 and the support portion 13 expands or the like. Since the gas escapes to the circuit board 40 side, it is possible to prevent a pressure from being applied to the support portion 13 and adversely affect the heat sensing. Furthermore, since the opening region 13c exists, even when a relatively large electronic element is arranged on the circuit board 40, the electronic element and the support portion 13 can be prevented from interfering with each other. Further, an electric wire (not shown) of the heat sensing unit 30 can be connected to the circuit board 40 through the opening region 13c.

  Further, in the present embodiment, the support portion 13 can be brought into line contact with the heat sensing unit 30. That is, the support portion 13 may be formed in a rod shape, or a protrusion may be provided on the support portion 13 so that when the heat sensing unit 30 is deformed, the support portion 13 makes point contact with the heat sensing unit 30. In this case, the load is concentrated in a minute range called a contact point, which may cause deformation or breakage of the heat sensing unit 30. In order to reduce such a risk, in the present embodiment, by providing a plurality of linear supports 13a, when the heat sensing unit 30 is deformed, the support 13 is connected to the heat sensing unit 30. Contact is made and the load is diffused from point to line to prevent the heat sensing unit 30 from being damaged.

  Further, in the present embodiment, the curved support 13b is disposed in the vicinity of the front center position where the deformation amount of the heat sensing unit 30 is likely to be maximized, and the supports 13a and 13b around the front center position are arranged. Therefore, the rigidity of the support portion 13 can be improved and the strength thereof can be increased. Further, by arranging the curved support 13b in this way, the density of the supports 13a and 13b is increased to substantially form a surface structure, and when the heat sensing unit 30 is deformed, the heat sensing unit 30 is deformed. The support portion 13 is substantially brought into surface contact. As a result, the load is diffused from the point to the surface, thereby preventing the heat sensing unit 30 from being damaged more effectively. In order to maximize this effect, when the influence of the thermal response by the support portion 13 and the fluidity of the airflow can be ignored, the support portion 13 is formed in a flat plate shape by supporting all or a part thereof. The portion 13 may be completely in surface contact with the heat sensing unit 30. In addition, although the material and formation method of this support part 13 are arbitrary, manufacturing cost can be reduced by integrally molding with the same material as the sensor main body 10, for example.

(About details of laminate film)
Next, the structure and function of the laminate films 34 and 35 in FIG. 9 will be described in more detail. Laminate films 34 and 35 in the present embodiment are formed of infrared absorbing members, and furthermore, substantially the entire laminate films 34 and 35 are exposed. Therefore, in addition to the conventional heat transfer by the air flow, infrared rays generated in a fire in the monitoring area are radiated and absorbed by the laminate films 34 and 35, and the temperature of the laminate films 34 and 35 is increased. Here, since the laminate films 34 and 35 are in direct contact with the ceramic element 31 or indirectly through the electrodes 32 and 33, the temperature change of the laminate films 34 and 35 is efficiently conducted to the ceramic element 31. Therefore, the thermal responsiveness can be further improved, and the heat sensing speed can be improved. That is, the laminate films 34 and 35 can simultaneously achieve the conflicting problems of protecting the ceramic element 31 and improving its thermal response.

  The specific material of the laminate films 34 and 35 is arbitrary. For example, a resin such as Lexan film (registered trademark), epoxy or polycarbonate, which is a kind of thermoplastic resin polycarbonate film, borosilicate glass, Alternatively, a ceramic such as alumina can be used. For example, since polycarbonate has a high absorptance with respect to infrared rays of 1 μm or more, the heat sensing unit 30 may be configured by pasting it on the ceramic element 31 and the electrodes 32 and 33. Alternatively, since alumina has a very high absorptance with respect to infrared rays having wavelengths longer than the mid-infrared ray, it is possible to form a thin film by depositing it on the ceramic element 31 and the electrodes 32 and 33, thereby obtaining good infrared absorption. Can be obtained. However, when a hard material is used, the laminate films 34 and 35 may become brittle, and when an external load is directly applied to the laminate film 34, the damage may be caused. From this point of view, it is more preferable to use a soft material.

  In particular, in the first embodiment, the laminate films 34 and 35 are substantially white as in the main body cover 20. From the viewpoint of heat absorption, it is preferable that the laminate films 34 and 35 are made of black or the like having a high heat absorption rate. However, the heat detector 1 installed in a general house or office building has a design. This is because black and the like tended to be sparse from the request. Thus, by making the laminate films 34 and 35 substantially white, it is possible to improve the thermal response while satisfying the design requirements. In addition, although the specific method for coloring the laminate films 34 and 35 in this way is arbitrary, it can carry out by mixing a pigment with polycarbonate, for example.

  As described above, according to the first embodiment, an external airflow can be directly applied to the heat sensing unit 30, and the ceramic element 31 is formed in a flat plate shape to perform heat sensing by a planar portion. Thermal responsiveness can be increased. Furthermore, when the heat sensing unit 30 is in a non-deformed state, heat conduction between the two is prevented, so that the heat responsiveness of the heat sensing unit 30 can be maintained and improved. Further, when the heat sensing unit 30 is deformed by a predetermined amount or more, the support portion 13 contacts the inside of the heat sensing unit 30, and further deformation of the heat sensing unit 30 is prevented. Further, since the opening region 13c is formed between the plurality of supports 13a and 13b, the influence of the thermal response of the support 13 on the heat sensing unit 30 can be reduced, and the heat responsiveness of the heat sensing unit 30 is impaired. It is possible to prevent the thermal sensing from being adversely affected by the pressure applied to the support portion 13 even when the gas expands. Furthermore, by making the support portion 13 line or surface contactable with the heat sensing unit 30, the load on the heat sensing unit 30 can be diffused from the point, and damage to the heat sensing unit 30 can be prevented. Further, since the laminate films 34 and 35 are formed of an infrared absorbing member, the laminate films 34 and 35 can simultaneously achieve the conflicting problems of protecting the ceramic element 31 and improving its thermal response.

[Embodiment 2]
Next, a second embodiment will be described. In the second embodiment, a support portion having a shape different from that of the first embodiment is provided. However, the structure that is not particularly described is the same as the structure of the first embodiment described above, and the same components are denoted by the same reference numerals as necessary.

  FIG. 13 is a front view of the sensor body according to the second embodiment. As shown in FIG. 13, the sensor body 50 according to the first embodiment is integrally formed with a support portion 60. The support portion 60 includes a plurality of linear support bodies 60a and a small disk-like support body 60b integrally formed at the intersection of the support bodies 60a. In this way, a part of the support portion 60 may be formed not only in a linear shape but also in a planar shape. In such a configuration, when the heat sensing unit 30 (not shown) is deformed, the small disk-shaped support body 60b comes into surface contact with the heat sensing unit 30, thereby dispersing the load of the heat sensing unit 30. Further deformation of the heat sensing unit 30 can be prevented.

  As described above, according to the second embodiment, the support unit 60 is in surface contact with the heat sensing unit 30 to prevent further deformation of the heat sensing unit 30 while distributing the load of the heat sensing unit 30. be able to.

[Embodiment 3]
Next, Embodiment 3 will be described. In the third embodiment, a support portion having a shape different from that of the first embodiment is provided. However, the structure that is not particularly described is the same as the structure of the first embodiment described above, and the same components are denoted by the same reference numerals as necessary.

  FIG. 14 is a front view of the sensor body according to the third embodiment. As shown in FIG. 14, a support portion 80 is integrally formed with the sensor body 70 according to the third embodiment. The support 80 is configured by arranging a plurality of linear supports 80a and 80b in a predetermined direction. In particular, the support body 80a disposed at the center position is formed wider than the other support bodies 80b. In this way, the linear supports 80a and 80b may be formed with different widths. In such a configuration, when the heat sensing unit 30 (not shown) is deformed, the wide support body 80b is in surface contact with the heat sensing unit 30 to disperse the load of the heat sensing unit 30 and to dissipate the heat. Further deformation of the sensing unit 30 can be prevented.

  As described above, according to the third embodiment, the support unit 80 is in surface contact with the heat sensing unit 30 to prevent further deformation of the heat sensing unit 30 while distributing the load of the heat sensing unit 30. be able to.

[Embodiment 4]
Next, a fourth embodiment will be described. In the fourth embodiment, a support portion having a shape different from that of the first embodiment is provided. However, the structure that is not particularly described is the same as the structure of the first embodiment described above, and the same components are denoted by the same reference numerals as necessary.

  FIG. 15 is a front view of the sensor body according to the third embodiment. As shown in FIG. 15, the support body 100 is integrally formed with the sensor main body 90 according to the fourth embodiment. The support portion 100 is formed in a mesh shape by a large number of linear metallic supports 100a. Thus, the support part 100 may be comprised from a metal, and may be formed in mesh shape. In such a configuration, when the heat sensing unit 30 (not shown) is deformed, the mesh-shaped support body 101a comes into surface contact with the heat sensing unit 30 to disperse the load of the heat sensing unit 30 and Further deformation of the sensing unit 30 can be prevented.

  As described above, according to the fourth embodiment, the support unit 100 is brought into surface contact with the heat sensing unit 30 to prevent further deformation of the heat sensing unit 30 while distributing the load of the heat sensing unit 30. be able to.

[III] Modifications to Embodiments Although the embodiments of the present invention have been described above, the specific configuration and means of the present invention are within the scope of the technical idea of each invention described in the claims. Can be arbitrarily modified and improved. Hereinafter, such a modification will be described.

(Regarding the field of application of the present invention)
The application target of the present invention is not limited to the heat sensor 1 as described above, and can be applied to all devices that sense heat in the monitoring region, for example, a heat detector.

(About problems to be solved and effects of the invention)
In addition, the problems to be solved by the invention and the effects of the invention are not limited to the above-described contents, and the present invention solves the problems not described above or has the effects not described above. There are also cases where only some of the described problems are solved or only some of the described effects are achieved. For example, even if the protection against the heat sensor is not completely achieved, the object of the present invention is achieved as long as the thermal response is slightly improved.

(About heat sensing unit)
The specific configuration of the heat sensing unit 30 can also take various forms. For example, when the protective effect and infrared absorption effect by the laminate films 34 and 35 can be ignored, the laminate films 34 and 35 are omitted. Also good. Moreover, the thermal responsiveness may be further enhanced by providing openings in the laminate films 34 and 35 and exposing the ceramic element 31 from the openings.

(About support part)
In each of the first to fourth embodiments described above, the support portion is described as being in surface contact with the heat sensing unit 30. However, if the possibility of damage or the like in the heat sensing unit 30 can be ignored, For example, the sensing unit 30 may be supported in a point-like manner. Further, the support portion may be configured separately from the sensor main body, and both may be connected by adhesion, ultrasonic welding, or the like.

(About laminated film)
In the first embodiment, the ceramic element 31 and the electrodes 32 and 33 are covered from both sides by the pair of laminate films 34 and 35, but may be arranged only on one side. Further, when the laminate films 34 and 35 are disposed on both sides, the laminate films 34 and 35 formed of an infrared absorbing member on the outside of the ceramic element 31 and the electrodes 32 and 33, and the non-infrared absorbing member on the inside. Laminate films 34 and 35 formed in this manner may be provided. Further, by making the laminate films 34 and 35 transparent or coloring them in an arbitrary color, the design properties when the laminate films 34 and 35 are exposed to the outside can be improved.

  According to the present invention, it is possible to improve the reliability by protecting the heat sensor while improving the thermal responsiveness of the heat sensing unit such as a ceramic element, and to perform heat sensing quickly and stably.

It is a front view of the heat sensor which concerns on this Embodiment 1. FIG. It is AA arrow sectional drawing of the heat sensor of FIG. It is a rear view of the heat sensor of FIG. It is a front view of a sensor main body. It is a side view of the sensor main body of FIG. It is a BB arrow sectional view of the sensor main part of Drawing 4. It is a front view of a main body cover. It is CC arrow sectional drawing of the main body cover of FIG. It is the figure which showed the front view and longitudinal cross-sectional view of the heat sensing unit which were related with each other. It is the figure which showed the top view and longitudinal cross-sectional view of a ceramic element etc. which are provided in the heat sensing unit of FIG. 9 in relation to each other. It is an expanded sectional view which shows the positional relationship of the heat sensing unit and support part in a non-deformation state. It is an expanded sectional view which shows the positional relationship of the heat sensing unit and support part in a deformation | transformation state. It is a front view of the sensor main body which concerns on Embodiment 2. FIG. It is a front view of the sensor main body which concerns on Embodiment 3. It is a front view of the sensor main body which concerns on Embodiment 4. It is a front view of the conventional thermistor type heat sensor. It is DD arrow sectional drawing of the heat sensor of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,110 Thermal sensor 10, 50, 70, 90, 111 Sensor main body 11 Base part 11a Mounting hole 12 Rising part 12a Opening part 12b Step part 13, 60, 80, 100 Support part 13a, 13b, 60a, 60b , 80a, 80b, 100a Support 13c Opening region 20 Main body cover 21 Side wall 22 Opening 30 Heat sensing unit 31 Ceramic element 32, 33 Electrode 34, 35 Laminate film 40 Circuit board 41 Lead wire 42 Filler 112 Thermistor 113 Thermistor guide

Claims (2)

A thermal sensor for sensing the temperature of the monitored area,
A sensor body fixed to the installation surface;
A heat sensing element that is fixed to the sensor body, and is a ceramic element formed into a flat plate by sintering a ferroelectric substance that outputs a pyroelectric current in response to a temperature change;
An opening is formed in the sensor body, and support means is formed in the opening.
The heat sensing element is disposed at an outer position away from the installation surface than the support means in the opening,
A position where the support means does not contact the heat sensing element in a non-deformed state, and a position where the heat sensing element is supported by contacting the heat sensing element in a state deformed by a predetermined amount or more. Arranged,
A heat sensor characterized by The support means is provided with a small disk-like support that comes into surface contact with the heat sensing element that is deformed by a predetermined amount or more, or is in contact with the heat sensing element that is deformed by a predetermined amount or more. Providing a mesh-like support portion formed from a plurality of linear supports,
The heat sensor according to claim 1.

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