JP2018074152A - Electronic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic device capable of suppressing electric insulation between conductive members from decreasing in a container as water (moisture) enters a container through the inside of a cable.SOLUTION: An electronic device 9 comprises, in a container 75, a first chamber 113 which accommodates a circuit part 95, a second chamber 115 which adjoins the first chamber 113 and in which air is present, and a third chamber 117 which adjoins the second chamber 115 and is filled with resin J. First, second metal terminals 131, 133 extend from the circuit part 95 in the first chamber 113 into the second chamber 115, and a coaxial cable 13 extends from outside the container 75 into the second chamber 115 through the third chamber 117. In the air in the second chamber 115, a center conductor 83 and an outer peripheral conductor 87 of the coaxial cable 13 are exposed from an inside insulating coating 85 and an outside insulating coating 89 respectively to be electrically connected to the first metal terminals 131 and second metal terminal 133.SELECTED DRAWING: Figure 12

Description

  The present invention relates to an electronic device to which a sensor or the like is electrically connected.

  As an electronic device such as a control device to which a sensor or the like is electrically connected by a coaxial cable or the like, a sensor wiring that is electrically connected to the sensor in a container and a device that is electrically connected to an external device There is a thing provided with wiring (refer to patent documents 1).

  In addition, the electronic device includes, for example, a wiring board on which various electronic components are mounted as a circuit portion connected to the sensor wiring and the device wiring. In this wiring board, signal processing of the sensor signal input from the sensor via the sensor wiring is performed, and the result of the signal processing is transmitted to the external device via the device wiring.

Examples of sensors connected to the electronic device include gas sensors (oxygen sensors, NOx sensors, hydrogen sensors, etc.), temperature sensors, particulate sensors, and the like.
Such an electronic device may be used in various installation environments. For example, when used in an environment where the humidity may be high, moisture (humidity) may enter the container of the electronic device. There is.

When moisture enters the container of the electronic device, the moisture adheres to the wiring board and the wiring board breaks down, and there is a possibility that appropriate signal processing cannot be performed.
In order to solve such a problem, there is one that suppresses the ingress of moisture by using a resin container. For example, an electronic device P1 having a structure shown in FIG. 14A has been developed.

  In the electronic device P1, the container P2 is divided into a first chamber P4 and a second chamber P5 by a wall portion P3, and the wiring board P6 is accommodated in the first chamber P4, and from the outside via the second chamber P5. For example, a pair of cables (for example, coaxial cables) P7 is arranged so as to reach the first chamber P4, and the conductor P8 of the cable P7 and the wiring board P6 are connected in the first chamber P4.

  In the electronic device P1, the outer peripheral surface of the cable P7 (that is, the outer peripheral surface of the insulating coating P10) is sealed by the sealing material P11 so that water or the like does not enter the portion where the cable P7 penetrates the wall portion P3 or the outer wall P9. It is stopped (ie, sealed).

  As a result, it is possible to prevent moisture from entering the first chamber P4 through the gap between the outer peripheral surface of the cable P7 and the wall portion P3, but it is transmitted between the conductor P8 of the cable P7 and the insulation coating P10. Thus, it is not possible to prevent moisture from entering the first chamber P4.

As a countermeasure against this, an electronic device P12 having a structure shown in FIG. 14B has been developed.
In this electronic device P12, the container P13 is divided into a first chamber P15 and a second chamber P16 by a wall portion P14, the wiring board P17 is accommodated in the first chamber P15, and reaches the second chamber P16 from the outside. For example, a pair of cables P18 are arranged. In the second chamber P16, the conductor P19 of each cable P18 and each terminal P20 extending from the wiring board P17 are connected, and the second chamber P16 is filled with resin P21 and sealed.

  Also in the electronic device P12, the outer peripheral surface of the cable P18 (that is, the outer peripheral surface of the insulating coating P23) is sealed by the sealing material P24 at a portion where the cable P18 passes through the outer wall P22. Further, the terminal P20 penetrating the wall portion P14 is also sealed by the sealing material P25.

Japanese Patent Laying-Open No. 2015-129711

  However, even in the electronic device P12 in which the second chamber P16 is filled with the resin P21 as described above, moisture (humidity) may enter the inside of the electronic device P12 (specifically, the first chamber P15).

  Specifically, when moisture enters the second chamber P12 through the conductor P19 and the insulation coating P23 of the cable P18, the moisture causes the resin P21 filled in the second chamber P16 to absorb moisture. It may be in the state. In such a case, the electrical insulation between the pair of conductors P19 covered with the resin P21 in the second chamber P16 and between the pair of terminals 20 (for example, between the signal line and the ground line) is reduced (ie, There was a decrease in insulation resistance).

  Accordingly, the present invention has been made to solve the above-described problems, and moisture (humidity) enters the container through the inside of a cable such as a coaxial cable, and thereby conducts in the container. It is an object of the present invention to provide an electronic device capable of suppressing a decrease in electrical insulation between conductive members.

  (1) In the first aspect of the present invention, a circuit unit that performs signal processing is accommodated in a container, and the circuit unit and an external device are electrically connected by a cable whose conductor is covered with an electrical insulating material. The present invention relates to an electronic device to be connected.

  In this electronic device, the container is provided with a first chamber that houses the circuit portion, a second chamber in which air is present, and a third chamber that is filled with resin. Further, a circuit-side conductor extends from the circuit portion in the first chamber to the second chamber, and a cable extends from the outside of the container to the second chamber through the third chamber. In the air in the second chamber, the cable conductor is exposed from the electrical insulating material and is electrically connected to the circuit-side conductor.

  As described above, in the first aspect, the cable conductor is exposed from the electrical insulating material in the second chamber (ie, the air chamber) where air is present, and is electrically connected to the circuit-side conductor in the air. ing. Therefore, even when moisture enters the second chamber from between the conductor of the cable and the electrical insulating material, the resin is not in a humidified state as in the prior art. Therefore, the electrical insulation between the conductive members does not decrease (that is, the insulation resistance does not decrease) due to the humidified resin.

  Even if moisture (humidity) enters from the interface between the cable and the container, the moisture can be stopped by the resin in the third chamber. At this time, the conductor of the cable is not exposed in the third chamber, and the electrical insulating material of the cable is exposed. Therefore, even if the resin absorbs moisture, the electrical insulation between the cables does not deteriorate. .

  Furthermore, although the moisture is stopped by the resin in the third chamber, there is a risk that moisture (humidity) may enter the second chamber from the third chamber due to the moisture absorption of the resin. However, even in that case, since the second chamber is a hollow space, the resin is not in a humidified state as in the prior art. Therefore, the electrical insulation between the conductive members is not deteriorated by the humidified resin.

Thus, in this 1st aspect, it can suppress that the electrical insulation between electroconductive members, such as a circuit side conductor and the conductor of a cable, falls in a 2nd chamber.
For example, even when a plurality of conductors are arranged in the second chamber (for example, when the central conductor of the coaxial cable and the outer conductor covering the outer periphery thereof are arranged), a circuit connected between the plurality of conductors or to each conductor The electrical insulation between the side conductors can be suitably maintained.

  As a result, even when a sensor connected to an electronic device is used in a harsh environment where moisture is high (that is, humidity is high), the cable conductor, the circuit-side conductor, and thus the circuit portion of the electronic device are not affected by moisture. There is an effect that the signal processing can be executed with accuracy over a long period of time. That is, there is an advantage that occurrence of malfunction of the circuit portion due to moisture (humidity) can be suppressed.

(2) In the second aspect of the present invention, the first chamber and the second chamber are adjacent to each other via a wall portion, and the second chamber and the third chamber are adjacent to each other via another wall portion.
In the second aspect, a preferred arrangement of the first chamber, the second chamber, and the third chamber is illustrated.

(3) In the third aspect of the present invention, a coaxial cable can be used as the cable.
In the third aspect, the cables used are illustrated. In the case of a coaxial cable, since it has a complicated structure in which a plurality of electrical insulating materials and one or a plurality of outer peripheral conductors are arranged around a central conductor, moisture easily enters through these members. In the third aspect, it is possible to suitably suppress a decrease in electrical insulation due to moisture intrusion.

  (4) In the fourth aspect of the present invention, the conductor is a central conductor and an outer peripheral conductor of a coaxial cable, and a pair of circuit side conductors extending from the circuit portion are connected to the central conductor and the outer peripheral conductor, respectively.

In the fourth aspect, in the case of a coaxial cable, the connection state between each conductor of the coaxial cable and the circuit side conductor is illustrated.
(5) In the fifth aspect of the present invention, a part of the circuit side conductor penetrates the wall part and is provided integrally with the wall part in the wall part separating the first chamber and the second chamber.

  In the fifth aspect, since the circuit-side conductor penetrates the wall portion and is provided integrally with the wall portion, the configuration of the electronic device can be simplified. Moreover, there exists an advantage that the sealing performance in a wall part is also high.

(6) In the sixth aspect of the present invention, the circuit unit receives a weak signal having a current value of 10 μA or less via a cable.
In a circuit unit that receives a weak signal, there is a possibility that the weak signal cannot be normally received even if a relatively small insulation drop occurs due to an increase in humidity.

  In an electronic device including such a circuit portion, in the second chamber, which is an air chamber, by adopting the above configuration that connects the conductor of the cable and the circuit side conductor, even when used in a high humidity environment, The possibility that the circuit unit cannot normally receive the weak signal can be reduced, and the possibility that the signal processing in the circuit unit becomes abnormal can be reduced.

<Here, each configuration of the present invention will be described>
Examples of the cable include a biaxial coaxial cable and a triaxial (or more multiaxial) coaxial cable. Moreover, the cable which covered the surface of conductors, such as a single wire, with the electrical insulating material other than a coaxial cable is mentioned.

Examples of the container include a resin, metal, or a double-structure container in which the outside of the resin container is covered with a metal container.
The circuit unit is a device that processes a signal input from the outside (for example, a sensor). Examples of the circuit unit include a wiring board on which electronic components such as a microcomputer are mounted.

  Examples of the circuit-side conductor include a metal terminal that is joined to the circuit portion and extends toward the second chamber.

  According to the electronic device of the present invention, even when moisture (humidity) enters the second chamber through the cable, the electrical insulation between the conductive members such as the conductors of the cable is reduced in the second chamber. (That is, a decrease in insulation resistance) can be suppressed.

It is explanatory drawing for demonstrating the whole structure of the microparticle detection system which concerns on 1st Embodiment. It is sectional drawing which fractures | ruptures and shows a microparticle sensor along an axial direction. It is explanatory drawing which showed typically schematic structure of the front-end | tip part of a microparticle sensor. (A) is the perspective view which looked at the electronic device from the lid side, (b) is the perspective view which looked at the electronic device from the metal case side. It is a top view which removes the lid of a container and shows the inside of a metal case, etc. It is a perspective view which shows the structure provided with the metal terminal etc. It is a top view which shows the structure provided with the metal terminal etc. It is a perspective view which shows the 1st-9th metal terminal. (A) is a top view which shows the apparatus side connector with which the coaxial cable was attached, (b) is a top view which shows a coaxial cable. It is a perspective view which shows the state which the sensor side connector decomposed | disassembled and the assembled state. It is explanatory drawing which shows a mode that the state which obstruct | occludes each chamber of an electronic device with a cover was seen from the opening part side. An electronic device is shown typically, (a) is a top view showing the inside of a container typically, (b) is an explanatory view showing typically the neighborhood of the longitudinal section (AA section) in a container. . (A) is a top view which shows typically the inside of the container of the electronic device of 2nd Embodiment, (b) is a top view which shows typically the inside of the container of the electronic device of 3rd Embodiment. It is explanatory drawing of a prior art.

Embodiments to which the present invention is applied will be described below with reference to the drawings.
[1. First Embodiment]
[1-1. overall structure]
The configuration of the particle detection system according to the first embodiment will be described.

  As shown in FIG. 1, the particulate detection system 1 according to the first embodiment includes particulates such as soot contained in a gas to be measured such as exhaust gas EG flowing through an exhaust pipe 5 of an internal combustion engine (engine) 3 of an automobile. It is a system that detects the amount of.

  The particle detection system 1 includes a particle sensor 7, an electronic device 9 that is a sensor control device that controls the operation of the particle sensor 7, and an extended conductive portion 11 that extends from the particle sensor 7 to the electronic device 9. The extended conductive portion 11 includes a coaxial cable 13, a first heater conducting wire 15, a second heater conducting wire 17, and a braided tube 19.

  The particulate sensor 7 is attached to the pipe attachment portion 21 of the exhaust pipe 5 that is set to the ground potential (PVE). The exhaust pipe 5 and the pipe mounting portion 21 are made of metal. The electronic device 9 is electrically connected to a vehicle electronic control device 23 that controls the operation of the automobile via another cable 24.

Each configuration will be described below.
[1-2. Fine particle sensor]
Here, the configuration and operation of the particle sensor 7 will be described.

<Configuration of particulate sensor>
As shown in FIG. 2, the fine particle sensor 7 includes a cylindrical outer metal fitting 31 and a cylindrical inner metal fitting 33 disposed inside the outer metal fitting 31. The inner metal fitting 33 is electrically insulated from the outer metal fitting 31.

  The outer metal fitting 31 is composed of, for example, a cylindrical outer cylinder 35 having a cylindrical shape on the rear end side (upper side in FIG. 2) and a cylindrical mounting metal fitting 37 having a cylindrical shape on the front end side (lower side in FIG. 2). It is joined and integrated coaxially by welding. The outer metal fitting 31 is attached to the tube mounting portion 21 having the ground potential PVE and is set to the ground potential PVE.

  A grommet 39 made of fluoro rubber is attached to the inner side in the radial direction on the rear end side of the outer cylinder 35, and the coaxial cable 13, the first heater energization line 15, and the second heater energization line 17 are attached to the grommet 39. Are inserted in the axial direction (vertical direction in FIG. 2).

  Further, a cylindrical braided tube 19 made of, for example, stainless steel, which will be described later, is fitted on the radially outer side of the rear end side of the outer cylinder 35, and the braided tube 19 is fixed to the radially outer side of the braided tube 19. For example, a metal ring 41 made of stainless steel is fitted. The outer cylinder 35, the braided tube 19 and the metal ring 41 are integrally fixed by caulking from the outside in the radial direction.

  On the other hand, the inner metal fitting 33 is, for example, a stainless steel inner cylinder 43 disposed in the central portion in the axial direction, and a bottomed cylindrical metal stainless steel metal attached so as to cover the rear end side of the inner cylinder 43. A cap 45, a cylindrical metallic shell 47 made of, for example, stainless steel, coaxially joined to the distal end side of the inner cylinder 43 by laser welding, and an inner protector 49 made of, for example, stainless steel joined to the distal end side of the metallic shell 47; An outer protector 51 made of stainless steel, for example, is attached to the outer periphery of the inner protector 49 with a gap.

The inner protector 49 and the outer protector 51 are integrally joined to the metal shell 47 by laser welding on the rear end side.
Between the mounting metal fitting 37 and the inner metal fitting 33, a cylindrical sleeve 53 made of alumina and a first insulating spacer 55 are arranged. A cylindrical insulating second insulating spacer 57 is disposed between the mounting bracket 37 and the metal shell 47.

  Inside the inner metal fitting 33, as in the prior art (see, for example, Japanese Patent Application Laid-Open No. 2015-129711), a first separator 59, a second separator 61, and an insulation holder, which are members having electrical insulation from the rear end side. 63, a ceramic sleeve 65, a first powder filling layer 67, a second powder filling layer 69, and a ceramic holder 71 are arranged.

  A strip shape (that is, a width) is formed along the axial direction so as to penetrate the second separator 61, the insulating holder 63, the ceramic sleeve 65, the first powder filling layer 67, the second powder filling layer 69, and the ceramic holder 71. (Narrow plate-shaped) sensor element 73 is arranged.

<Configuration of braided tube>
The braided tube 19 is a tube in which a stainless thin wire is knitted into a cylindrical shape, and is separate from the coaxial cable 13, the first heater conducting wire 15, and the second heater conducting wire 17.

  The braided tube 19 extends from the outer cylinder 35 to the electronic device 9 (specifically, a metal container 75 of the electronic device 9: see FIG. 4), and is connected to the coaxial cable 13, the first heater conducting wire 15, and the second heater passage. The electric wire 17 is surrounded by a gap SK.

The braided tube 19 is electrically connected to the container 75.
Further, since the braided tube 19 is connected to the outer metal fitting 31 attached to the pipe mounting portion 21 of the exhaust pipe 5 that is set to the ground potential PVE, the braided tube 19 is set to the ground potential PVE. Accordingly, the container 75 described later is also set to the ground potential PVE.

<Configuration of sensor element>
The sensor element 73 includes a ceramic substrate 77 on which an insulating layer made of alumina is laminated. A heater (not shown) and a discharge electrode body 78 (see FIG. 3) that is sensor wiring are formed on the ceramic substrate 77. Has been.

The heater is connected to the first heater energization line 15 and the second heater energization line 17 through a terminal fitting (not shown) on the rear end side of the ceramic substrate 77.
The sensor element 73 has a leading end protruding into the inner protector 49 and a trailing end accommodated in the first separator 59.

A needle electrode portion 79 connected to the discharge electrode body 78 is provided on the front end side of the ceramic substrate 77 so as to extend to the front end side, and the discharge electrode body 78 is provided on the rear end side of the ceramic substrate 77. And connected to the coaxial cable 13 via the terminal fitting 81.

  As is well known, the coaxial cable 13 includes a linear center conductor 83, a cylindrical inner insulating coating 85 covering the outer periphery of the central conductor 83, and an outer periphery knitted into a cylindrical shape covering the outer peripheral surface of the inner insulating coating 85. A conductor 87 and an outer insulating coating 89 covering the outer periphery of the outer conductor 87 are provided.

  In the coaxial cable 13, the center conductor 83 and the inner insulating coating 85 pass through the bottom 91 of the metal cap 45, and the center conductor 83 is electrically connected to the discharge electrode body 78 via the terminal fitting 81. Has been. On the other hand, the outer peripheral conductor 87 is fitted into a cylindrical portion 93 protruding from the bottom portion 91 of the metal cap 45 toward the front end side, and is electrically connected to the metal cap 45.

<Fine particle detection method>
Here, a particle detection method performed using the above-described particle sensor 7 will be described. However, since the basic principle is the same as that of the prior art, a simple description will be given.

  As shown in FIG. 3, the inner protector 49 is set to the first potential PV1 as the first floating potential by the electronic device 9 (detailed circuit portion 95: see FIG. 5), and the acicular electrode of the sensor element 73 The portion 79 is set to a second potential PV2 as a second floating potential that is a positive potential higher than the first potential PV1.

As a result, an air discharge (corona discharge) is generated between the inner protector 49 and the needle electrode portion 79 in accordance with voltage application, and positive ions CP such as N ³⁺ and O ²⁺ are generated.
On the other hand, the exhaust gas EG flowing through the exhaust pipe 5 is taken into the outer protector 51 from the gas inlet 51 a of the outer protector 51, and further taken into the inner protector 49 from the gas inlet 49 a of the inner protector 49. Then, in the vicinity of the front end portion of the sensor element 73, an air flow of the intake gas EGI from the rear end side toward the front end side is generated.

  Therefore, the generated ions CP adhere to the fine particles S in the intake gas EGI. Thereby, the fine particles S become positively charged charged particles SC and flow toward the gas discharge port 49b together with the intake gas EGI and are discharged to the exhaust pipe 5.

  The signal current corresponding to the charge amount of the discharged ions CPH adhering to the charged fine particles SC discharged from the gas discharge port 49 b is detected by the circuit unit 95. Thereby, the quantity (concentration) of the fine particles S contained in the exhaust gas EG can be detected.

  Specifically, a current (discharge current I1) corresponding to the charge released as the ions CP from the needle-shaped electrode portion 79 and a current corresponding to the charge of the ions CP collected by the inner protector 49 (received collection current I2). ) (Signal current Is) is considered to correspond to the amount of fine particles S, the circuit unit 95 can determine the amount of fine particles from the signal current Is.

The second potential V2 is a high potential of about 1 to 3 kV, for example, and the discharge current I1 is on the order of μA, but the signal current Is is a very weak current at the pA level.
[1-3. Electronic device]
Next, the electronic device 9 will be described.

As shown in FIG. 4, the electronic device 9 includes the container 75 having a substantially rectangular parallelepiped shape with a small thickness, and the circuit unit 95 is accommodated in the container 75.
The container 75 includes a box-shaped (that is, rectangular parallelepiped) metal case 101 in which one side in the thickness direction (above FIG. 4A) is opened, and an opening 103 (see FIG. 5) in which the metal case 101 is opened. And a rectangular metal lid 105 for covering. The metal case 101 and the lid 105 are made of a conductive material such as iron, stainless steel, aluminum, copper, or brass.

  Further, a sensor side mounting portion 106 that is an opening penetrating the metal case 101 is provided on the side of the metal case 101 (lower right direction in FIG. 4B). 7 is fitted in a sensor side connector 107 used for connection to the terminal 7.

  Further, a recess 101a is provided on the side of the bottom of the metal case 101 (the lower right direction in FIG. 4B), and a device side mounting portion that is an opening penetrating the metal case 101 in the stepped portion 101b of the recess 101a. 108 is provided. A device-side connector 109 used for connection with the vehicle electronic control device 23 and a heater is fitted in the device-side mounting portion 108.

  As shown in FIG. 5, a structure 111 (to be described later) is disposed inside the metal case 101, and the sensor-side connector 107 and the device-side connector 109 are assembled to the structure 111 and the like.

  Thus, the container 75 is adjacent to the first chamber 113 in which the circuit unit 95 is accommodated, the second chamber 115 that is an air chamber adjacent to the first chamber 113, and the second chamber 115. For example, a strip-shaped space between the third chamber 117 filled with a resin J such as urethane, the fourth chamber 119 in which the device-side connector 109 is mounted on the outside, and the first chamber 113 and the fourth chamber 119. And the fifth chamber 120.

  Note that the outside of the second chamber 115 (upper side in FIG. 5) is a three-sided portion (right and left in FIG. The space 106a is surrounded by the first chamber 117, and the space 106a is a third chamber 117 filled with the filler J.

Hereinafter, each configuration will be described in detail.
<Structure>
As shown in FIGS. 6 and 7, the structure 111 is a terminal holder and is made of, for example, a resin such as PBT or PPS, and includes a rectangular frame-shaped frame portion 121. Further, on one end side (the upper side in FIG. 7) of the frame portion 121, along one side of the frame portion 121 (one side extending in the left-right direction in FIG. 7), the thickness direction of the frame portion 121 (the paper surface in FIG. 7). Wall portion 123 extending in the vertical direction).

  Furthermore, a bottomed box-like portion 125 (that is, a portion constituting the second chamber 115) extending upward in FIG. An opening 127 is provided on the upper surface (front side in FIG. 7) of the box-shaped portion 125, and a wall 128 is provided on the tip side (upper in FIG. 7) of the box-shaped portion 125. In 128, an oval through-hole 129 (see FIG. 6) penetrating the wall 128 is formed.

  In addition, as shown in FIG. 7, nine metal terminals 131, 133, 135, 137, 139, 141, made of, for example, brass, copper, or a copper alloy are provided on the wall 123 so as to penetrate the wall 123. 143, 145, 147 are arranged in parallel along the vertical direction of FIG. In addition, the front end side (lower side in FIG. 7) of each of the metal terminals 131 to 147 is electrically connected to the circuit unit 95.

Specifically, the first metal terminal 131 and the second metal terminal 133 having the shape shown in FIG. 8 are arranged so as to reach the second chamber 115 from the first chamber 113.
A metal ring 133a that covers the outer periphery of the first metal terminal 131 is connected to the second metal terminal 133 via a metal plate 133b. And between the 1st metal terminal 131 and the metal ring 133a, the insulation part 148 which is a resin member which has high electrical insulation (namely, higher electrical insulation than the structure 111) which consists of PTFE, PFA, for example is arrange | positioned. Yes.

  A third metal terminal 135 is disposed outside the second chamber 115 so as to be adjacent to the second metal terminal 133. The third metal terminal 135 is for electrically connecting the circuit portion 95 and the metal case 101 (that is, the portion maintained at the ground potential PVE).

The fourth to ninth metal terminals 137 to 147 electrically connect an external device via the circuit unit 95 and the device-side connector 109.
Specifically, the fourth metal terminal 137 electrically connects the circuit unit 95 and the first heater energization line 15. The fifth metal terminal 139 electrically connects the circuit unit 95 and the second heater conducting wire 17. The sixth and seventh metal terminals 141 and 143 electrically connect the circuit unit 95 and the vehicle electronic control device 23 via the cable 24 to form a communication line. The eighth and ninth metal terminals 145 and 147 electrically connect the circuit unit 95 and the power supply unit (not shown) via a cable (not shown).

<Circuit part>
As shown in FIG. 5, the circuit unit 95 includes a rectangular wiring board 149 disposed so as to close the opening of the frame unit 121 of the structure 111.

An electronic control circuit 150 such as a microcomputer for controlling the operation of the particle sensor 7 is mounted on the wiring board 149, and various wirings (not shown) are further formed.
In addition, the first to ninth metal terminals 131 to 147 are soldered to the wiring of the wiring board 149 and are electrically connected to each other.

<Sensor connector>
As shown in FIG. 9A, the sensor-side connector 107 includes a plate-like portion 151 exposed to the outside of the container 75 and a convex portion provided on one of the plate-like portions 151 (below FIG. 9A). 153, a rectangular cylindrical frame-shaped portion 155 provided on the surface of the convex portion 153, and a plate-shaped blocking portion 157 provided on one side of the frame-shaped portion 155 (below in FIG. 9A). ing. The blocking portion 157 is provided with a convex portion 157a on one side thereof (lower side of FIG. 9A), and an oval sealing material 159 is fitted on the convex portion 157a.

Among these, the tip end side (below FIG. 9A) from the convex portion 153 is a portion that is fitted into the sensor side mounting portion 106 (see FIG. 4B) provided on the side of the metal case 101.
The sealing material 159 is a member that is fitted into the through hole 129 on the distal end side of the box-shaped portion 125 and seals (water-tight and air-tight) the fitting portion, and is made of rubber such as silicon. In addition, the following other sealing materials are also made of similar materials and have similar functions.

  An insertion hole 107a is provided in the sensor-side connector 107 (specifically, each of the plate-like portion 151, the convex portion 153, and the closing portion 157) so as to penetrate in the vertical direction of FIG. 9A. The coaxial cable 13 is disposed in the hole 107a.

The coaxial cable 13 is connected to the first metal terminal 131 and the second metal terminal 133 on the distal end side (that is, in the second chamber 115) from the sealing material 159 (see FIG. 5).
Specifically, an I-shaped first crimp terminal 163 is fixed to the distal end side of the central conductor 83 of the coaxial cable 13, and the first crimp terminal 163 and the first metal terminal 131 are connected (see FIG. 5). ). The first crimp terminal 163 and the first metal terminal 131 are integrated by laser welding.

  On the other hand, an L-shaped second crimp terminal 165 is fixed to the distal end side of the outer peripheral conductor 87 of the coaxial cable 13, and the second crimp terminal 165 and the second metal terminal 133 are connected (see FIG. 5). . The second crimp terminal 165 and the first metal terminal 131 are integrated by laser welding.

  As shown in FIG. 9B, a pair of cylindrical sealing materials 171 are disposed on the outer periphery of the coaxial cable 13, and the portion of the coaxial cable 13 where the sealing material 171 is disposed is the sensor. By inserting into the insertion hole 107a of the side connector 107, the coaxial cable 13 and the sensor side connector 107 are fixed in a watertight manner.

<Device side connector>
As shown in FIG. 10, a metal crimp terminal 189 is connected to the first heater energizing wire 15 and the second heater energizing wire 17 and the lead wires 181, 183, 185 and 187.

  Note that fourth and fifth metal terminals 137 and 139 are electrically connected to the first and second heater energization wires 15 and 17, respectively, and the lead wires 181, 183, 185 and 187 are respectively connected to the sixth to sixth heater terminals 15 and 17, respectively. The ninth metal terminals 141 to 147 are electrically connected.

  Further, a sealing material 191 is attached to the outer periphery of the first and second heater energization wires 15 and 17 and the lead wires 181 to 187 described above.

On the other hand, the device-side connector 109 is provided with a plurality of insertion holes (not shown) through which the first and second heater energization wires 15 and 17 and the lead wires 181 to 187 are respectively passed. By passing the first and second heater energization wires 15 and 17 and the lead wires 181 to 187 through the insertion holes, respectively, the apparatus-side connector 109, the first and second heater energization wires 15, 17 and the lead wires 181 to 187 are fixed.

An oval seal member 193 is attached to one side of the device-side connector 109 (the metal case 101 side: the left side in FIG. 10).
The device-side connector 109 to which the first and second heater energization wires 15 and 17 and the lead wires 181 to 187 are fixed is connected to the device-side mounting portion 108 of the metal case 101 (see FIG. 4B). The crimp terminals 189 are connected to the fourth to ninth metal terminals 137 to 147 by being fitted into the terminals. Each crimp terminal 189 and the fourth to ninth metal terminals 137 to 147 are joined by laser welding.

[1-4. Manufacturing method of electronic device]
Next, a method for manufacturing the electronic device 9 will be briefly described.
As shown in FIG. 5, the structure 111 to which the circuit portion 95 and the first to ninth metal terminals 131 to 147 are attached is fitted into the metal case 101.

  Next, the sensor-side connector 107 to which the coaxial cable 13 is attached is fitted into the sensor-side mounting portion 106 of the metal case 101. Note that the central conductor 83 side and the outer peripheral conductor 87 side on the distal end side of the coaxial cable 13 are separated.

As a result, the sealing material 159 of the sensor-side connector 107 is fitted into the insertion hole 129 of the box-shaped portion 125 of the structure 111, and the center conductor 83 and the first crimp terminal 163, the outer conductor 87 and the second conductor of the coaxial cable 13. A crimp terminal 165 is disposed in the second chamber 115.
At the same time, the second chamber 115 configured by the box-shaped portion 125 of the structure 111 and the third chamber 117 configured by the space 106a including the frame-shaped portion 155 of the sensor-side connector 107 are connected via the blocking portion 157 and the like. Are adjacent to each other.

  A space 106a surrounded by the metal case 101, the wall portion 128 on the distal end side (upper side in FIG. 5), the closing portion 157, the plate-like portion 151, and the convex portion 153 (see FIG. 9A). Is the third chamber 117 (the region indicated by the dots in FIG. 5) in which the filler J is filled.

  Then, in the second chamber 115, the first crimp terminal 163 and the first metal terminal 131 of the center conductor 83 are connected, and the second crimp terminal 165 and the second metal terminal 133 of the outer peripheral conductor 87 are connected. Further, the first crimp terminal 163 and the first metal terminal 131 of the center conductor 83 are joined by laser welding, and the second crimp terminal 165 and the second metal terminal 133 of the outer conductor 87 are joined.

  Separately, the device-side connector 109 with the first and second heater energization wires 15 and 17 and the lead wires 181 to 187 and the like is fitted into the device-side mounting portion 108 of the metal case 101. Thereby, the 4th-9th metal terminals 137-147 and each crimp terminal 189 are connected.

Furthermore, the 4th-9th metal terminals 137-147 and each crimp terminal 189 are joined by performing laser welding through the 5th chamber 120 which is a hole.
Further, the resin J is filled into the third chamber 117 (that is, the space 106a) including the frame-shaped portion 155, and the resin J is also filled into the fifth chamber 120.

  Next, as shown in FIG. 11, the second chamber 115 (ie, the opening 127 on the near side in FIG. 11) is closed with a lid 195, and the third chamber 117 (ie, the space 106a) is similarly closed with a lid 197. To do. Similarly, the fifth chamber 120 is closed with a lid 199. Each of the lids 195, 197, and 199 is made of, for example, resin, and is bonded to the structure 111 with, for example, an adhesive.

  Thereafter, a liquid gasket (not shown) is disposed on the outer peripheral portion 101d surrounding the opening 103 of the metal case 101, the opening 103 and the outer peripheral portion 101d are closed with a lid 105, and a bolt 105a (FIG. 4A). Fix with reference). Thereby, the electronic device 9 is completed.

[1-5. effect]
Next, the effect of this 1st Embodiment is demonstrated using the schematic diagram of FIG.
(1) As shown in FIG. 12, the electronic device 9 according to the first embodiment includes a first chamber 113 that houses a circuit unit 95 in a container 75, and air inside the first chamber 113 adjacent to the first chamber 113. A filled second chamber 115 and a third chamber 117 filled with resin J inside are provided adjacent to the second chamber 115. The resin molded portion JS is configured by filling the resin J.

  Further, the first and second metal terminals 131 and 133 extend from the circuit portion 95 in the first chamber 113 into the second chamber 115, and pass through the third chamber 117 from the outside of the container 75 to pass through the second chamber 115. A coaxial cable 13 is extended.

  In the air in the second chamber 115, the central conductor 83 and the outer peripheral conductor 87 of the coaxial cable 13 are exposed from the inner insulating coating 85 and the outer insulating coating 89, respectively. Further, the center conductor 83 and the outer conductor 87 are electrically connected to the first metal terminal 131 and the second metal terminal 133 via the first crimp terminal 163 and the second crimp terminal 165, respectively. .

  Thus, in the first embodiment, the center conductor 83 and the outer conductor 87 of the coaxial cable 13 are respectively insulated on the inside and outside in the air in the second chamber 115 (that is, the air chamber) where air exists. It is exposed from the coverings 85 and 89 and is electrically connected to the first metal terminal 131 and the second metal terminal 133, respectively.

  Therefore, even if moisture enters the second chamber 115 from between the central conductor 83 of the coaxial cable 13 and the inner insulating coating 85 or between the outer peripheral conductor 87 and the outer insulating coating 89, the central conductor of the coaxial cable 13 is used. It is possible to suppress a decrease in electrical insulation between the terminal 83 and the outer peripheral conductor 87 or between the first metal terminal 131 and the second metal terminal 133.

  Even if moisture (humidity) enters from the interface between the coaxial cable 13 and the plate-like portion 151 of the sensor-side connector 107, the moisture can be stopped by the resin J in the third chamber 117. At this time, since the outer conductor 87 and the like of the coaxial cable 13 are not exposed in the third chamber 117 and the outer insulating coating 89 of the coaxial cable 13 is exposed, even if the resin J absorbs moisture, the coaxial cable The electrical insulation property at 13 or the like does not deteriorate.

  Furthermore, although the moisture is stopped by the resin J in the third chamber 117, there is a risk that moisture (humidity) may enter the second chamber 115 from the third chamber 117 due to the moisture absorption of the resin J. However, even in that case, since the second chamber 115 is a hollow space, the resin J is not in a humidified state as in the prior art. Therefore, the electrical insulation between conductive members such as between the center conductor 83 and the outer peripheral conductor 87 is not lowered by the humidified resin J.

  As a result, even when the particulate sensor 7 or the electronic device 9 is used in a harsh environment where there is a lot of moisture (that is, the humidity is high), the coaxial cable 13 and thus the circuit unit 95 of the electronic device 9 are less susceptible to moisture. There is an effect that appropriate signal processing can be executed over a long period of time. That is, it is possible to suppress the occurrence of malfunction of the circuit unit 95 due to an increase in humidity.

  (2) In the first embodiment, the first metal terminal 131 and the second metal terminal 133 are disposed so as to penetrate the wall portion 123 and are provided integrally with the wall portion 123. Thereby, there exists an effect that the structure of the electronic device 9 can be simplified. Moreover, there exists an advantage that the sealing performance which suppresses permeation of water improves.

  (3) Further, in the first embodiment, when detecting the fine particles S, the circuit unit 95 receives a weak signal having a current value of 10 μA or less from the fine particle sensor 7 through the coaxial cable 13.

In the circuit unit 95 that receives such a weak signal, there is a possibility that the weak signal cannot be normally received even if a relatively small insulation drop occurs due to an increase in humidity.
In contrast, in the first embodiment, the center conductor 83 and the outer conductor 87 of the coaxial cable 13 are respectively connected to the first metal terminal 131 and the second metal in the air in the second chamber 115 which is an air chamber. Since it is electrically connected to the terminal 133, it is possible to reduce the possibility that the circuit unit 95 cannot normally receive a weak signal even when used in a high humidity environment, and the signal processing in the circuit unit 95 is abnormal. The possibility of becoming can be reduced.

[1-6. Correspondence of wording]
Here, the correspondence between words will be described.
In the first embodiment, the fine particle sensor 7, the central conductor 83 and the outer peripheral conductor 87, the inner insulating coating 85 and the outer insulating coating 89, the coaxial cable 13, the electronic device 9, the first chamber 113, the second chamber 115, the resin J, the first Three chambers 117, first and second metal terminals 131, 133 are external devices, conductors, electrical insulating materials, cables, first chamber, second chamber, resin, third chamber, circuit side of the present invention, respectively. This corresponds to an example of a conductor.

[2. Second Embodiment]
Next, the second embodiment will be described, but the description of the same contents as the first embodiment will be omitted.

In addition, the same number is attached | subjected to the structure similar to 1st Embodiment.
As shown in FIG. 13A, the container 75 of the electronic device 201 according to the second embodiment includes a first chamber 113 in which the circuit unit 95 is disposed and a second chamber that is an air chamber, as in the first embodiment. 115 and a third chamber 117 filled with resin J.

  In the second embodiment, not a coaxial cable but a pair of single cables 203 are arranged so as to penetrate the third chamber 117 from the outside to reach the second chamber 115 as in the first embodiment.

  The conductor 205 of the pair of cables is exposed in the second chamber 115 and connected to the first metal terminal 131 and the second metal terminal 133 via the crimp terminals 207 in the air in the second chamber 115, respectively. Has been.

The second embodiment has the same effects as the first embodiment.
[3. Third Embodiment]
Next, a third embodiment will be described, but a description of the same content as that of the first embodiment will be omitted.

In addition, the same number is attached | subjected to the structure similar to 1st Embodiment.
As shown in FIG. 13B, the container 75 of the electronic device 211 of the third embodiment is similar to the first embodiment in the first chamber 113 in which the circuit unit 95 is arranged and the second chamber which is an air chamber. 115 and resin J
And a third chamber 117 filled with.

In the third embodiment, as a coaxial cable, a triaxial coaxial cable 213 instead of a biaxial is arranged in the same manner as in the first embodiment.
That is, the center conductor 215 of the coaxial cable 213, the first outer conductor 217 inside the pair of outer conductors, and the second outer conductor 219 outside are exposed in the second chamber 115, and in the second chamber 115 These are connected to each of the three metal terminals 223 through the respective crimp terminals 221.

The third embodiment has the same effects as the first embodiment.
[4. Other Embodiments]
As mentioned above, although embodiment of this invention was described, this invention is not limited to the said embodiment, In the range which does not deviate from the summary of this invention, it is possible to implement in various aspects.

(1) For example, a single-wire cable and a coaxial cable may be disposed in the second chamber and the third chamber, and may be connected to the metal terminal via a crimp terminal in the air in the second chamber. .
(2) In each embodiment, the number of cables to be used is not limited. Furthermore, a coaxial cable having two or more axes can be used. In addition, you may electrically connect the conductor of a cable and the circuit side conductor, without using a crimp terminal.

(3) The resin filled in the second chamber is not limited to the urethane resin and the epoxy resin. For example, other materials may be adopted as long as moisture (humidity) is difficult to permeate.
(4) In the above embodiment, the electronic device in which the sensor to be connected is a particle sensor has been described, but the sensor to be connected is not limited to the particle sensor. For example, the present invention is applied to an electronic device connected to various sensors for detecting a physical quantity, a chemical quantity, or a concentration of a specific component in a fluid, such as a gas sensor (oxygen sensor, NOx sensor, hydrogen sensor, etc.), a temperature sensor, etc. You may apply.

  (5) It should be noted that the functions of one component in each of the above embodiments may be distributed as a plurality of components, or the functions of a plurality of components may be integrated into one component. Moreover, you may abbreviate | omit a part of structure of each said embodiment. In addition, at least a part of the configuration of each of the above embodiments may be added to or replaced with the configuration of each of the above other embodiments. In addition, all the aspects included in the technical idea specified from the wording described in the claims are embodiments of this patent.

DESCRIPTION OF SYMBOLS 7 ... Fine particle sensor 9, 211 ... Electronic device 13, 201, 213 ... Coaxial cable 75 ... Container 83, 215 ... Center conductor 85 ... Inner insulation coating 87 ... Outer periphery conductor 89 ... Outer insulation coating 95 ... Circuit part 113 ... First chamber 115 ... second chamber 117 ... third chamber 131 ... first metal terminal 133 ... second metal terminal J ... resin

Claims (6)

A circuit unit for performing signal processing is housed in a container, and the circuit unit and an external device are electrically connected by a cable whose conductor is covered with an electrical insulating material,
The container is provided with a first chamber that houses the circuit portion, a second chamber in which air is present, and a third chamber that is filled with resin.
A circuit-side conductor extends from the circuit portion in the first chamber to the second chamber, and the cable extends from the outside of the container to the second chamber through the third chamber.
In the air in the second chamber, the conductor of the cable is exposed from the electrical insulating material and is electrically connected to the circuit-side conductor.
Electronic equipment. The first chamber and the second chamber are adjacent via a wall portion, and the second chamber and the third chamber are adjacent via another wall portion,
The electronic device according to claim 1. The cable is a coaxial cable;
The electronic device according to claim 1 or 2. The conductor is a center conductor and an outer conductor of the coaxial cable, and a pair of circuit side conductors extending from the circuit portion are connected to the center conductor and the outer conductor, respectively.
The electronic device according to claim 3. In the wall section that separates the first chamber and the second chamber, a part of the circuit side conductor penetrates the wall section and is provided integrally with the wall section.
The electronic device as described in any one of Claims 1-4. The circuit unit receives a weak signal having a current value of 10 μA or less via the cable.
The electronic device according to any one of claims 1 to 5.