JP2014118846A - Detection device for canister - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately detect thermal capacity of an adsorbent.SOLUTION: A thermal capacity sensor 40A includes: a first thermo-sensitive element 50A; a second thermo-sensitive element 51 superposed on the first thermo-sensitive element 50A through a silver electrode 52A; a silver electrode 52B separated from the silver electrode 52A and energizing the first thermo-sensitive element 50A; a silver electrode 52C separated from the silver electrode 52A and energizing the second thermo-sensitive element 51; a non-conductive insulation material 54 covering the surroundings of the first thermo-sensitive element 50A, the second thermo-sensitive element 51 and the silver electrodes 52A-C arranged in a casing 2; and a heat transfer plate 55 in which a root part 56 covered by the insulation material 54 on one end side is arranged adjacently to the first thermo-sensitive element 50A and a distal end part 57 projecting from the insulation material 54 on the other end side is exposed to an inside of the casing 2 filled with activated carbon 11.

Description

  The present invention relates to a canister detection apparatus including a canister sensor that detects a state of an adsorbent filled in a casing of a canister.

  Patent Document 1 discloses a heat capacity sensor that detects a heat capacity (adsorbed amount of evaporated fuel) of an adsorbent (activated carbon) filled in a casing, a temperature sensor that is adjacent to the heat capacity sensor and detects an ambient temperature, A canister detecting device including a sensor unit configured by the above is disclosed. The heat capacity sensor in Patent Document 1 detects the heat capacity of an adsorbent from the output voltage (or current) of a temperature sensitive element (thermistor). Since the temperature sensing element of the heat capacity sensor also changes depending on the ambient temperature, the heat capacity of the adsorbent detected by the heat capacity sensor is corrected by the detection value of the temperature sensor.

International Publication No. 2012/86529

  However, since the electric resistance value of the temperature sensing element (thermistor) of the heat capacity sensor varies depending on the temperature, even if the heat capacity of the adsorbent is actually the same, if the temperature of the temperature sensing element of the heat capacity sensor is different, the heat capacity sensor The output values from the two differ, and the heat capacity of the adsorbent may not be detected accurately.

  Accordingly, the present invention provides a first temperature sensing element that changes its own electrical resistance value in response to a temperature change, and a non-cover that covers the periphery of the first temperature sensing element disposed in a casing filled with an adsorbent. A conductive insulating material and a base portion on one end side covered with the insulating material are disposed adjacent to the first temperature sensing element, and a tip portion on the other end side protruding from the insulating material is the casing. A canister detection device comprising a canister sensor having a heat transfer plate exposed inside, wherein the canister sensor is superimposed on the first temperature sensing element, and its electric resistance value is changed according to a temperature change. A second temperature sensing element that changes, and the heat capacity of the adsorbent detected by the first temperature sensing element is corrected according to the temperature of the first temperature sensing element detected by the second temperature sensing element. It is characterized by doing.

  More specifically, a first electrode disposed between the first temperature sensing element and the second temperature sensing element and electrically connected to both the first temperature sensing element and the second temperature sensing element. A second electrode separated from the first electrode and electrically connected to the first temperature sensing element; and separated from the first electrode and electrically connected to the second temperature sensing element. The first temperature sensing element is energized by the first electrode and the second electrode, and the second temperature sensing element is energized by the first electrode and the third electrode. Is done.

  According to the present invention, the temperature of the first temperature sensing element can be directly detected by the second temperature sensing element, and the heat capacity of the adsorbent can be accurately detected by the canister sensor.

BRIEF DESCRIPTION OF THE DRAWINGS Explanatory drawing which showed typically the system configuration | structure of the detection apparatus of the canister which concerns on this invention. 1 is a cross-sectional view of a canister to which the present invention is applied. Sectional drawing along the AA line of FIG. The characteristic view which shows the temperature characteristic of a temperature sensing element. The characteristic view which showed the correlation with the temperature difference of a temperature sensing element and circumference | surroundings, and the heat capacity of the activated carbon detected. Explanatory drawing which showed typically the structure of the heat capacity sensor which is the principal part of this invention. Explanatory drawing which showed typically a part of structure of the heat capacity sensor which is the principal part of this invention. Explanatory drawing which showed the structure of the temperature sensor typically.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is an explanatory view schematically showing a system configuration of a detection apparatus according to the present invention.

  The casing 2 of the canister 1 is made of a synthetic resin material, and generally includes a main case 3 and a cap 4 that closes an opening on the other end side in the longitudinal direction of the main case 3.

  The main case 3 is provided with a substantially cylindrical elongated first cylindrical portion 7 provided with a purge port 5 and a charge port 6 adjacent to each other on one end side, and an atmospheric port 8 communicating with the atmosphere on one end side. And an elongated second cylindrical portion 9. The other end of the first tubular portion 7 and the other end of the second tubular portion 9 are each open and closed by the cap 4 described above.

  The first tubular portion 7 and the second tubular portion 9 are arranged so as to be adjacent to each other and are connected by a reinforcing rib 10.

  The first cylindrical portion 7 and the second cylindrical portion 9 have elongated first and second filling chambers 12 and 13 filled with activated carbon 11 as an adsorbent capable of adsorbing and desorbing evaporated fuel, respectively. Is formed.

  One end side of the first filling chamber 12 communicates with the charge port 6 through the first screen member 14 having air permeability and also communicates with the purge port 5 through the second screen member 15 having air permeability. .

  The first screen member 14 and the second screen member 15 are the first filling chamber from the one end side wall surface 7A of the first cylindrical portion 7 toward the other end side of the first cylindrical portion 7 (the lower side in FIG. 1). 12 is partitioned by a partition wall 16 protruding into the interior.

  The other end side of the first filling chamber 12 is connected to the other end portion (the lower end portion in FIG. 1) of the main case 3 and the cap 4 through a third screen member 17 having air permeability. Communicating with The third screen member 17 is urged toward one end side (the upper side in FIG. 1) of the first filling chamber 12 by the perforated plate 20 that receives the spring force of the spring 19.

  One end side (the upper side in FIG. 1) of the second filling chamber 13 communicates with the atmospheric port 8 through a fourth screen member 21 having air permeability. The other end side (the lower side in FIG. 1) of the second filling chamber 13 communicates with the connection path 18 via a fifth screen member 22 having air permeability. The fifth screen member 22 is biased toward the one end side of the second filling chamber 13 by the perforated plate 24 that receives the spring force of the spring 23.

  Each of the screen members 14, 15, 17, 21, and 22 is made of, for example, urethane or non-woven fabric, and has a function of holding the activated carbon 11 that is an adsorbent while preventing it from falling off.

  The other end of the first filling chamber 12 and the other end of the second filling chamber 13 are connected via a connection path 18, and the inside of the casing 2 has a substantially U-shaped passage structure that is folded back at the connection path 18. ing. That is, the canister 1 has a structure in which the charge port 6 and the purge port 5 are provided on one end side of the flow path in the casing 2 and the atmospheric port 8 is provided on the other end side of the flow path.

  Here, the charge port 6 is connected to a fuel tank 26 of the vehicle via a charge line (charge pipe) 25. The purge port 5 is connected to the intake passage 29 of the internal combustion engine 28 via the purge line 27 on the downstream side of the throttle valve 30 that throttles intake air. A purge control valve 31 is interposed in the purge line 27. The operation of the purge control valve 31 is controlled by a control unit 32 capable of storing and executing various engine controls.

  The evaporated fuel generated in the fuel tank 26 is introduced into the casing 2 of the canister 1 from the charge port 6 through the charge line 25 and is adsorbed by the activated carbon 11 in the casing 2. Then, when the internal combustion engine 28 is in a predetermined operation state, the purge of the evaporated fuel in the casing 2 is started by opening the purge control valve 31. At the time of this purge, the evaporated fuel is introduced into the casing 2 from the atmospheric port 8 due to the pressure difference between the negative pressure downstream of the throttle valve 30 in the intake passage 29 and the atmospheric pressure, and is adsorbed by the activated carbon 11 in the casing 2. Is desorbed or purged. The purge gas containing the evaporated fuel desorbed from the activated carbon 11 is supplied from the purge port 5 through the purge line 27 to the intake passage 29 and is combusted in the combustion chamber of the internal combustion engine 28.

  As shown in FIG. 3, a sensor unit 41 including a pair of canister sensors 40 (40 </ b> A, 40 </ b> B) arranged in parallel with each other at a predetermined distance is attached to the side wall 3 </ b> A of the main case 3. . The sensor unit 41 has a mounting bracket 42 that holds a pair of canister sensors 40. The mounting bracket 42 is fixed to the main case side wall 3 </ b> A by screwing a nut 44 into the tip of a screw portion 43 that penetrates the main case side wall 3 </ b> A. Between the main case side wall 3A and the flange portion 45 projecting to the side of the mounting bracket 42, an O-ring 46 that seals the gap between them is interposed.

  The sensor unit 41 is installed at a detection position according to a request. For example, as shown in FIG. 1, a position R1 near the one end side of the first filling chamber 12 and a position R2 near the other end side of the first filling chamber 12 are provided. The second filling chamber 13 is disposed at one or a plurality of positions R3 near one end and the position R4 near the other end of the second filling chamber 13. As an example, FIG. 2 shows a mode in which sensor units 41 are attached to two locations R3 and R4 of the second filling chamber 13, respectively.

  A pair of canister sensors 40 mounted on one sensor unit 41 includes a heat capacity sensor 40A that detects the heat capacity (adsorbed amount of the activated carbon) 11 (adsorbent), and a temperature sensor 40B that detects the ambient temperature. , Is configured.

  The heat capacity sensor 40A and the temperature sensor 40B have substantially the same configuration. In the heat capacity sensor 40 </ b> A, a predetermined current is supplied to the first temperature sensing element 50 </ b> A such as a thermistor whose electric resistance value changes depending on the temperature via a conduction line 53 to generate heat. Further, in the heat capacity sensor 40A, the temperature of the first temperature sensing element 50A decreases due to the heat deprived by the activated carbon 11 that has adsorbed the evaporated fuel via the heat transfer plate 55, and thus the output voltage of the first temperature sensing element 50A. By detecting (or current) by the control unit 32, the heat capacity of the activated carbon 11 can be detected (estimated) from this output voltage. 3 is an insulating material (details will be described later).

  The temperature sensor 40B detects the temperature of the surrounding activated carbon 11 by applying a predetermined constant voltage to the first temperature sensing element 50B. In the temperature sensor 40B, the ambient temperature can be estimated from the output voltage by reducing the voltage applied to the first temperature sensing element 50B and reducing the heat generation.

  As the first temperature sensing element 50, for example, as shown in FIG. 4, an NTC ceramic element having a negative characteristic in which resistance decreases with increasing temperature is used. In addition, when the NTC ceramic element having such a negative characteristic is used for the first temperature sensing element 50, the magnitude of the output signal (output voltage) from the sensor unit 41 also decreases as the temperature rises.

  FIG. 5 shows the difference between the temperature difference between the first temperature sensing element 50A of the heat capacity sensor 40A and the surrounding activated carbon 11 and the heat capacity of the activated carbon 11 detected by the heat capacity sensor 40A under the condition that the heat capacity of the activated carbon 11 is constant. It is the characteristic view which showed the correlation.

  When the temperature of the first temperature sensing element 50A is higher than the temperature of the surrounding activated carbon 11, the amount of heat released from the first temperature sensing element 50A to the activated carbon 11 is relatively large. Therefore, the heat capacity of the activated carbon 11 detected by the heat capacity sensor 40A in such a state is detected as a value larger than the actual value as shown in FIG.

  When the temperature of the first temperature sensing element 50A is lower than the temperature of the surrounding activated carbon 11, the amount of heat released from the first temperature sensing element 50A to the activated carbon 11 is relatively small. Therefore, the heat capacity of the activated carbon 11 detected by the heat capacity sensor 40A in such a state is detected as a value smaller than the actual value as shown in FIG.

  That is, the heat capacity of the activated carbon 11 detected by the heat capacity sensor 40A varies due to the temperature difference between the first temperature sensing element 50A and the surrounding activated carbon 11. Therefore, it is important to always accurately grasp the temperature of the first temperature sensing element 50A of the heat capacity sensor 40A, but the temperature detected by the temperature sensor 40B is the temperature of the first temperature sensing element 50A of the heat capacity sensor 40A. It is not always consistent with temperature. Therefore, the temperature detected by the temperature sensor 40B may not be able to accurately correct the heat capacity of the activated carbon 11 detected by the heat capacity sensor 40A.

  Therefore, in this embodiment, a second temperature sensing element 51 (described later) is superimposed on the first temperature sensing element 50A of the heat capacity sensor 40A, and the temperature of the first temperature sensing element 50A is directly detected. Then, the output value of the first temperature sensing element 50A of the heat capacity sensor 40A is corrected using the output value of the second temperature sensing element 51 of the heat capacity sensor 40A.

  The temperature of the activated carbon 11 detected by the temperature sensor 40B is used for estimating the concentration of the evaporated fuel in the purge gas. This evaporated fuel concentration is used for, for example, correction of the fuel injection amount by air-fuel ratio feedback control and correction of the opening degree of the purge control valve 31.

  6 and 7 are explanatory views schematically showing the structure of the heat capacity sensor 40A, which is the main part of the present invention.

  The heat capacity sensor 40 </ b> A includes a first temperature sensing element 50 </ b> A and a second temperature sensing element 51 whose electric resistance value varies with temperature. As the first temperature sensing element 50A and the second temperature sensing element 51, a thermistor or the like that generates heat when energized and whose electric resistance value changes with temperature is used. The heat capacity sensor 40A uses an external power source to detect changes in the electrical resistance values of the first temperature sensing element 50A and the second temperature sensing element 51 due to temperature, and the first temperature sensing element 50A and the second temperature sensing element 51. This is a so-called active sensor that energizes the sensor.

  The first temperature sensing element 50A has a rectangular plate shape, and both side surfaces thereof are sandwiched between a silver electrode 52A as a first electrode and a silver electrode 52B as a second electrode. Electric power is supplied to each silver electrode 52A, 52B from an external power supply via the energization line 53 (refer FIG. 3). As shown in FIG. 7, lead wires 53A and 53B constituting the conductive wire 53 are electrically connected to the silver electrodes 52A and 52B, respectively, by soldering or the like. That is, the silver electrodes 52A and 52B are energization units that energize the first temperature sensing element 50A.

  The silver electrodes 52A and 52B are formed by applying a silver paste to the first thermosensitive element 50A by screen printing or the like. A silver electrode is formed on both the first temperature sensing element 50A and the second temperature sensing element 51, and the silver electrode of the first temperature sensing element 50A and the second temperature sensing are formed by conductive adhesive or reflow soldering. The silver electrodes of the element 51 may be bonded to form 52A and 52B.

  On the surface of the silver electrodes 52A and 52B, an adhesive layer 61 is applied to a portion other than a connection portion with the lead wires 53A and 53B and a position where the second temperature sensing element 51 is overlapped.

  The second temperature sensing element 51 is superimposed on the first temperature sensing element 50A from above the silver electrode 52A, and is adhered to the silver electrode 52A with, for example, a conductive adhesive.

  The second temperature sensing element 51 has a rectangular plate shape smaller than the first temperature sensing element 50A, and both side surfaces thereof are sandwiched between the silver electrode 52A and the silver electrode 52C as the third electrode. Electric power is supplied to the silver electrode 52C from an external power source via the energization line 53 (see FIG. 3). As shown in FIG. 7, the lead wire 53C constituting the conducting wire 53 is electrically connected to the silver electrode 52C by soldering or the like. That is, the silver electrodes 52 </ b> A and 52 </ b> C are energization units that energize the second temperature sensing element 51.

  The silver electrode 52A is disposed between the first temperature sensing element 50A and the second temperature sensing element 51 and is electrically connected to both the first temperature sensing element 50A and the second temperature sensing element 51. The silver electrode 52B is separated from the silver electrode 52A and is electrically connected to the first temperature sensing element 50A. The silver electrode 52 </ b> C is separated from the silver electrode 52 </ b> A and is electrically connected to the second temperature sensing element 51. In the present embodiment, the lead wire 53 </ b> A serves as a common ground for the first temperature sensing element 50 </ b> A and the second temperature sensing element 51.

  The periphery of the first temperature sensing element 50A, the second temperature sensing element 51, and the silver electrode 52 disposed in the casing 2 is covered with a thick non-conductive insulating material 54 (see FIGS. 3 and 5). ing. That is, the first temperature sensing element 50A, the second temperature sensing element 51, and the silver electrode 52 arranged in the casing 2 are completely embedded in the insulating material 54 without being exposed to the outside. The insulating material 54 is made of, for example, a synthetic resin material having high electrical insulation and excellent strength.

  The heat capacity sensor 40A has a pair of heat transfer plates 55 formed of a metal material having high thermal conductivity, excellent corrosion resistance and durability, low heat capacity, and low cost. The heat transfer plate 55 is formed by bending a rectangular plate-shaped metal plate, and is positioned between the root portion 56 and the tip portion 57 that are parallel to each other, and between the root portion 56 and the tip portion 57, and orthogonal to both. And a bent portion 58. In the center of the end portion of the root portion 56, a notch 59 cut out in a substantially U shape is formed so that the lead wire 53A or the lead wire 53B can be connected to the silver electrode 52A or the silver electrode 52B. The heat transfer plate 55 on the silver electrode 52A side of the pair of heat transfer plates 55 is more than the second temperature sensor 51 so that the second temperature sensor 51 can be superimposed on the first temperature sensor 50A. A substantially rectangular through hole 60 that is one size larger is formed.

  The heat transfer plate 55 has a root portion 56 on one end side embedded (covered) in the insulating material 54 adjacent to the temperature sensing element 51 and a tip portion 57 on the other end side protruding from the insulating material 54. , Exposed in the casing 2 and in contact with the activated carbon 11 filled in the casing 2.

  The root portions 56 of the pair of heat transfer plates 55 are respectively bonded to the silver electrodes 52A and 52B through the thin film adhesive layer 61 so as to sandwich the pair of silver electrodes 52A and 52B.

  The adhesive layer 61 has high thermal conductivity so as not to hinder heat transfer between the first temperature sensing element 50A and the heat transfer plate 55, and excellent electrical insulation so as not to cause leakage or sparks. For example, it is formed of a material such as a silicone-based adhesive. The adhesive layer 61 is made as thin as possible and has a wide contact area so that heat transfer between the first temperature sensing element 50A and the heat transfer plate 55 is improved.

  Of the heat transfer plate 55, at least the root portion 56 is formed with an insulating layer 63 (63A, 63B) by surface treatment. More specifically, the heat transfer plate 55 of the present embodiment is made of aluminum alloy (made of aluminum alloy) mainly composed of lightweight and inexpensive aluminum, and is electrolyzed (anode) with itself (heat transfer plate 55) as an anode. And an insulating layer 63 which is an alumite layer is formed on the surface thereof.

  The insulating layer 63 is formed on the side surface portion (63 </ b> A) inside the root portion 56 adjacent to the silver electrode 52 through at least the adhesive layer 61 in the heat transfer plate 55. In the present embodiment, in the heat transfer plate 55, the insulating layer 63 is provided on both side portions (63 </ b> A, 63 </ b> B) over a partial range of the root portion 56 to the bent portion 58, and the activated carbon 11 is filled. The insulating layer 63 made of an alumite layer is not provided on the front end portion 57 of the heat transfer plate 55 exposed in the casing 2 by masking or the like in the surface treatment. As described above, in this embodiment, the insulating layers 63 are provided on both side surfaces (63A, 63B) of the heat transfer plate 55 in consideration of the ease of mask processing during the surface treatment, and the insulating layers 63 are provided. The insulating layer 63 is intentionally omitted from the front end portion 57 of the heat transfer plate 55 in order to ensure heat transfer with the activated carbon 11.

  Therefore, as shown in FIG. 6, in the heat capacity sensor 40A, the silver electrode 52, the adhesive layer 61, the insulating layer 63, and the root portion 56 of the heat transfer plate 55 are laminated in layers on both sides of the first temperature sensing element 50A. The silver electrode 52 and the heat transfer plate 55 are doubly insulated by the adhesive layer 61 and the insulating layer 63.

  In addition, at the front end portion 57 of the heat transfer plate 55, the gap ΔD1 between the pair of heat transfer plates 55 is larger than that of the root portion 56, and is bent outward in a stepped manner via the bent portion 58. Configured. The gap ΔD1 between the pair of heat transfer plates 55 at the tip portion 57 is set to be sufficiently larger than at least the diameter of the activated carbon 11 so that the activated carbon 11 surely enters the gap ΔD1.

  As shown in FIG. 8, the temperature sensor 40B has a configuration in which the second temperature sensing element 51 is omitted from the above-described heat capacity sensor 40A, and basically has the same configuration as the heat capacity sensor 40A.

  The temperature sensor 40B has a pair of silver electrodes 52A and 52B sandwiching both side surfaces of the plate-like first temperature sensing element 50B as an energization portion for energizing the first temperature sensing element 50B, and the silver electrodes 52A and 52B. Is supplied with electric power from an external power source via an energization line 53 (see FIG. 3). On the surface of the silver electrodes 52 </ b> A and 52 </ b> B, an adhesive layer 61 is applied to a portion other than the connection portion with the conducting wire 53. The periphery of the first temperature sensing element 50B and the silver electrodes 52A, 52B disposed in the casing 2 is covered with a thick non-conductive insulating material 54 (see FIGS. 3 and 5). And the base part 56 in a pair of heat exchanger plates 55 is each adhere | attached on silver electrode 52A, 52B through the contact bonding layer 61 so that a pair of silver electrode 52A, 52B may be pinched | interposed. The tip portions 57 of the pair of heat transfer plates 55 are exposed in the casing 2 and are in contact with the activated carbon 11 filled in the casing 2. Of the heat transfer plate 55, at least the root portion 56 is formed with an insulating layer 63 (63A, 63B) made of an alumite layer by surface treatment. Further, the gap ΔD1 between the pair of heat transfer plates 55 at the front end portion 57 of the heat transfer plate 55 is set to be sufficiently larger than at least the diameter of the activated carbon 11 so that the activated carbon 11 surely enters the gap ΔD1. .

  In this embodiment, the temperature of the first temperature sensing element 50A is set with a simple configuration in which the second temperature sensing element 51 is superimposed on the first temperature sensing element 50A that detects the heat capacity of the activated carbon 11. The second temperature sensing element 51 can always be detected with high accuracy. That is, the heat capacity of the activated carbon 11 can be accurately detected by the heat capacity sensor 40A while avoiding the complexity of the structure of the heat capacity sensor 40A. More specifically, the heat capacity of the activated carbon 11 detected from the output value of the first temperature sensing element 50A of the heat capacity sensor 40A depends on the temperature of the first temperature sensing element 50A detected from the output value of the second temperature sensing element 51. The heat capacity of the activated carbon 11 can be detected with high accuracy. As a result, the concentration of the evaporated fuel in the purge gas using the heat capacity sensor 40A can be estimated with higher accuracy.

  Further, when the heat capacity of the activated carbon 11 detected from the output value of the first temperature sensing element 50A of the heat capacity sensor 40A is corrected by the temperature detected by the temperature sensor 40B, it is attempted to detect the heat capacity of the activated carbon 11 continuously. If at least an interval is not provided until the temperature of the activated carbon 11 around the tip portion 57 of the heat transfer plate 55 in the heat capacity sensor 40A and the temperature of the first temperature sensing element 50A are equal, the temperature of the first temperature sensing element 50A is accurately detected. Can not do it.

  However, in the heat capacity sensor 40A in the present embodiment, the temperature of the first temperature sensing element 50A can be detected with high accuracy at any time, so that the heat capacity of the activated carbon 11 can be detected continuously with high accuracy.

  In this embodiment, the silver electrode 52A located between the first temperature sensing element 50A and the second temperature sensing element 51 of the heat capacity sensor 40A is replaced by the first temperature sensing element 50A and the second temperature sensing element 51. The electrodes are common to both. That is, by superimposing the second temperature sensing element 51 on the first temperature sensing element 50A, the silver electrode 52A can be shared between the two temperature sensing elements 50A and 51, and not the four electrodes but the 3 The two temperature sensitive elements 50A and 51 can be energized with one electrode (silver electrodes 52A to 52C), and further cost reduction can be achieved by reducing the number of components.

  In the above-described embodiment, the sensor unit 41 includes the heat capacity sensor 40A and the temperature sensor 40B. However, if only the heat capacity of the activated carbon 11 is detected, the temperature sensor 40B is omitted from the sensor unit 41. Is also possible. In this case, the sensor unit 41 can be reduced in size, and the layout of the sensor unit 41 is improved.

DESCRIPTION OF SYMBOLS 1 ... Canister 2 ... Casing 3 ... Main case 3A ... Main case side wall 40 ... Sensor 40A ... Heat capacity sensor 40B ... Temperature sensor 41 ... Sensor unit 50 ... 1st temperature sensing element 51 ... 2nd temperature sensing element 52 ... Silver electrode 53 ... Current-carrying wire 54 ... Insulating material 55 ... Heat transfer plate 56 ... Root part 57 ... Tip part 58 ... Bending part 61 ... Adhesive layer 63 ... Insulating layer

Claims (2)

The first temperature sensing element whose electric resistance value changes according to the temperature change, the energization section for energizing the first temperature sensing element, and the first temperature sensing element disposed in the casing filled with the adsorbent. A non-conductive insulating material that covers the periphery of the element and the current-carrying portion and a root portion on one end side that is covered with the insulating material are disposed adjacent to the first temperature-sensitive element and protrude from the insulating material. In a canister detection device comprising a canister sensor having a heat transfer plate with a tip portion on the other end side exposed in the casing,
The canister sensor has a second temperature sensing element that is superposed on the first temperature sensing element and changes its electrical resistance value in response to a temperature change.
A canister detection device that corrects the heat capacity of the adsorbent detected by the first temperature sensing element in accordance with the temperature of the first temperature sensing element detected by the second temperature sensing element. The energization portion is disposed between the first temperature sensing element and the second temperature sensing element, and is electrically connected to both the first temperature sensing element and the second temperature sensing element. A second electrode spaced apart from the first electrode and electrically connected to the first temperature sensing element; and spaced apart from the first electrode and electrically connected to the second temperature sensing element. A third electrode,
2. The first temperature sensing element is energized by the first electrode and the second electrode, and the second temperature sensing element is energized by the first electrode and the third electrode. The canister detection device described.

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