JP4672528B2 - Waterproof structure of the sensor - Google Patents

Description

  The present invention relates to a waterproof structure for a sensor used to detect the number of rotations of a rotating body such as a gear or a main shaft used in an engine or transmission of an automobile.

  As a conventional sensor, as shown in FIG. 5, a sensor housing 103 in which a sensor main body (not shown) is assembled and a pair of sensor terminals 102 protrudes outside is housed in a sensor case 101. A sensor 100 in which is sealed is known (see, for example, Patent Document 1).

JP 2003-214903 A

By the way, in the conventional sensor 100 disclosed in the above-mentioned Patent Document 1, when water enters the sensor housing 103 from outside through the sensor terminal 102, the pair of sensor terminals 102 are exposed in the sensor housing 103. If the sensor 100 is attached to the portion, a leak may occur between the sensor terminals 102 in the energized state of the sensor 100, and the output signal may not become a specified value, and an error may occur in the control circuit that monitors the signal of the sensor 100. There is.
On the other hand, in order to waterproof the inside of the sensor housing 103, it may be possible to fill the inside of the sensor housing 103 with an adhesive. However, the temperature inside the sensor housing 103 when the sensor cover 104 is thermally welded to the sensor case 101 is considered. Since the volume of the adhesive decreases or gas is generated due to the rise, the pressure in the sensor housing 103 may suddenly fluctuate and rupture. Can not be filled.

  The present invention has been made in view of the above-described circumstances, and an object of the present invention is to provide a waterproof structure for a sensor capable of improving waterproof characteristics with a simple structure.

1) The waterproof structure of the sensor according to the present invention includes a sensor body, a sensor case that houses the sensor body, a sensor terminal having one end connected to the sensor body and the other end connected to the outside, and the sensor A housing for housing a terminal and being joined to the sensor case and projecting the other end of the sensor terminal into the sensor case. Only one of the protruding pair of sensor terminals is covered with a covering portion , and the adhesive is filled in the sensor case up to a portion covering the tip of the covering portion .

According to the invention described in the above 1), one of the sensor terminals projecting from the housing in a sensor case is covered by the cover portion, in order not adhesive to a point which covers the front end of the covering portion is filled, the chance Even if water enters the sensor case, the sensor terminal is covered with the covering portion, so that no leak occurs in the sensor terminal, and no abnormality occurs in the sensor signal. Therefore, the waterproof property can be improved with a simple structure.

  2) Further, the waterproof structure of the sensor according to the present invention is the waterproof structure of the sensor according to the above 1), wherein the sensor case is filled with an adhesive while ensuring a space allowing pressure fluctuation. It is characterized by.

  According to the invention described in 2) above, since the adhesive is filled in the sensor case while ensuring a space allowing pressure fluctuation, the sensor case is filled without filling the adhesive in the entire sensor case. The remaining space excluding the covering portion and the adhesive in the case can sufficiently tolerate pressure fluctuations in the sensor case caused by joining means such as heat welding.

  3) The waterproof structure of the sensor according to the present invention is the waterproof structure of the sensor according to the above 1) or 2), wherein the covering portion is connected to the housing and is integrally formed with the housing. Features.

  According to the invention described in 3) above, since the covering portion is formed integrally with the housing, the covering portion is simultaneously formed when the housing is formed, and compared with the case where the covering portion is formed or assembled separately. Therefore, man-hours can be reduced, so that productivity can be improved and cost can be reduced.

  According to the waterproof structure of the sensor of the present invention, it is possible to solve problems such as leakage when water adheres to a terminal, an error occurs, and the entire inside of the sensor housing cannot be filled with an adhesive. An effect that the waterproof property can be improved by the structure is obtained.

  Hereinafter, a plurality of preferred embodiments according to the present invention will be described in detail with reference to the drawings.

(First embodiment)
FIG. 1 is a sectional view taken along the axial direction of a sensor terminal of a sensor for explaining a first embodiment of the waterproof structure of the sensor of the present invention, and FIG. 2 is a sectional view taken along the line AA of the sensor shown in FIG.

  As shown in FIG. 1, the sensor 10 using the waterproof structure of the sensor of the present invention is mainly composed of a sensor main body 11, a sensor case 12, a housing 13, and a pair of sensor terminals 14 and 15. .

  The sensor body 11 is a rotation detection semiconductor pickup sensor used to detect the number of rotations of a rotating body such as a gear incorporated in an automobile engine or transmission. The sensor body 11 includes a pair of lead portions 17 from a substantially cylindrical case 16. 17 is provided protruding.

  The sensor case 12 is made of an insulating resin, is formed in a bottomed cylindrical shape having an inner diameter larger than the outer diameter of the sensor body 11, and has a sensor housing portion 18 on the inner peripheral portion. The housing fixing portion 19 is provided at the end opening.

  The housing 13 is made of the same type of resin as the sensor case 12, and protrudes into the sensor case 12, a housing main body 20 having an outer diameter substantially equal to the outer diameter of the sensor case 12, a mounting flange portion 21, and the like. A sensor main body mounting portion 22.

  The housing main body 20 insulates and fixes the pair of sensor terminals 14 and 15 from the upper side to the lower side in FIG. 1, and has an external connection portion 23 at one end of the sensor terminals 14 and 15 at the upper part. A bush fixing portion 25 that surrounds 24 and has a concave shape is provided. A bush 28 made of resin or rubber and fixed with external circuit connection leads 26 and 27 is fitted into the bush fixing portion 25, so that the external connection portions 23 and 24 of the sensor terminals 14 and 15 are connected to the external circuit. They are electrically connected to the connecting lead wires 26 and 27, respectively. An O-ring 29 is fitted near the lower end of the housing body 20.

  The flange portion 21 protrudes in a plate shape in the radial direction of the housing main body portion 20, and a metal ring-shaped fixing reinforcing member 30 is fixed near the distal end portion. In the flange portion 21, when the sensor 10 is fixed to the device, a fixing means such as a bolt is inserted into the fixing reinforcing member 30, and the sensor 10 is fixed to the device through the fixing means.

  The sensor mounting portion 22 has a pair of plate portions 31 and 32 protruding from the lower end portion of the housing main body portion 20 into the sensor case 12, and a pair of intermediate connection terminals at an intermediate portion of the plate portions 31 and 32. 33 and 34 are being fixed to the axial direction of the board parts 31 and 32, respectively. A concave sensor body fixing portion 35 is provided at the tip of the plate portions 31 and 32. The sensor main body 11 is assembled to the sensor main body fixing portion 35, and each lead portion 17, 17 of the sensor main body 11 is joined to one end portion of each intermediate connection terminal 33, 34 on each plate portion 31, 32 by joining means such as soldering. Are electrically connected to each other. Each of the intermediate connection terminals 33 and 34 is disposed on a connecting portion 36 having the other end portion spanning the plate portions 31 and 32 at the central portion of the sensor mounting portion 22. On the back side of the connecting portion 36, a disturbance preventing capacitor (resistor) 37 is electrically connected in parallel to the intermediate connection terminals 33 and 34.

  The sensor terminals 14 and 15 have sensor main body connection portions 38 and 39 at the other end protruding from the lower end portion of the housing main body portion 20 along the plate portions 31 and 32, respectively. On the connecting portion 36 in the sensor mounting portion 22, the other end portions of the intermediate connection terminals 33 and 34 are electrically connected to each other by a joining means such as soldering.

  A covering portion 40 is formed between the sensor terminals 14 and 15 protruding into the sensor case 12 and the vicinity of the connecting portion 36. The covering portion 40 is made of the same insulating resin as the housing main body portion 20 and covers the sensor terminals 14 and 15 with a substantially half length from the lower end surface 41 of the housing main body portion 20 to the connecting portion 36. The two plate portions 31 and 32 are connected to each other.

  As shown in FIG. 2, since the covering portion 40 insulates and covers part of the sensor main body connecting portions 38 and 39 of the sensor terminals 14 and 15, the sensor 10 should be Even if water or the like enters the case 12, the sensor terminals 14 and 15 are insulated from each other, so that trouble such as leakage does not occur.

  Such a sensor 10 has an adhesive filling range C (see FIG. 1) from the bottom plate 42 in the sensor case 12 to a predetermined position, and therefore the adhesive filling range C from the internal volume of the sensor case 12. When the volume of the adhesive up to and the volume of the covering portion 40 are subtracted, a space portion (see FIG. 1) 43 having a predetermined volume is provided between the sensor mounting portion 22 and the sensor case 12. And formed around the plate portions 31 and 32. And the housing fixing | fixed part 19 of the sensor case 12 is joined to the lower end surface 41 of the housing 13 by heat welding, for example. At this time, even if a pressure fluctuation occurs inside the sensor case 12, the space 43 can sufficiently withstand the pressure fluctuation by allowing the pressure fluctuation.

  The sensor 10 is fixed to a device (not shown) via a fixing reinforcing member 30 for the flange portion 21, and the sensor case 12 and the housing body 20 are accommodated in a sensor mounting portion received by the device via an O-ring 29. Fixed. In addition, external circuit connection leads 26 and 27 housed in the bush 28 are electrically connected to an external control circuit (not shown), and the bottom plate 42 of the sensor case 12 is connected to a rotating body built in the device. Arranged close to non-contact. When a predetermined potential is applied from the control circuit to one of the external circuit connection leads 26, one of the external circuit connection leads 26, one sensor terminal 14, one intermediate connection terminal 33, and one of the sensor body 11. Current is supplied through the lead portion 17, the sensor body 11, the other lead portion 17 of the sensor body 11, the other intermediate connection terminal 34, the other sensor terminal 15, and the other external circuit connection lead wire 27. When the sensor body 11 is operated, the rotational speed of the rotating body is converted into an electrical signal such as a pulse signal and supplied to the control circuit from the other external circuit connecting lead wire 27, and the rotating body rotates in the control circuit. The number is monitored.

  As described above, according to the waterproof structure of the sensor according to the sensor 10 of the first embodiment, the sensor terminals 14 and 15 protruding from the housing 13 in the sensor case 12 are covered with the covering portion 40. Even if water or the like enters the sensor case 12, the sensor terminals 14 and 15 are covered with the covering portion 40, so that no leak occurs in the sensor terminals 14 and 15, and an abnormality occurs in the sensor signal. There is no. Further, without filling the whole of the sensor case 12 with the adhesive, the remaining space 43 excluding the covering portion 40 and the adhesive filling range C in the sensor case 12 is used for joining means such as heat welding. The pressure fluctuation in the sensor case 12 caused by the above can be sufficiently allowed. Thereby, the waterproof property can be improved with a simple structure. Further, since the sensor terminals 14 and 15 are covered with the covering portion 40, a structure that can withstand vibration can be created.

  Further, according to the waterproof structure of the sensor by the sensor 10 of the first embodiment, since the covering portion 40 is integrally formed with the housing 13, the covering portion 40 is simultaneously formed when the housing 13 is formed. Since the number of man-hours can be reduced as compared with those molded or assembled as a body, the productivity can be improved and the cost can be reduced.

(Second Embodiment)
Next, with reference to FIG.3 and FIG.4, 2nd Embodiment of the waterproof structure of the sensor of this invention is described. Note that in the second embodiment, members and the like having the same configurations and functions as those already described are denoted by the same or corresponding reference numerals in the drawing, and the description is simplified. FIG. 3 is a sectional view taken along the axial direction of a sensor terminal of a sensor for explaining a second embodiment of the waterproof structure of the sensor of the present invention, and FIG. 4 is a sectional view taken along the line BB of the sensor shown in FIG.

  As shown in FIG. 3, the sensor 50 using the waterproof structure of the sensor of the second embodiment is provided with the covering portion 51 only on the other sensor terminal 15 of the pair of sensor terminals 14 and 15. The site | part is the same as that of 1st Embodiment.

  As shown in FIG. 4, the covering portion 51 of the sensor 50 covers and insulates a part of the other sensor terminal 15 of the sensor terminals 14, 15. Even if water or the like enters the sensor case 12 and water adheres to one sensor terminal 14 not provided with the covering portion 51, the other sensor terminal 15 is insulated by the covering portion 51. Therefore, troubles such as leakage do not occur.

  Such a sensor 50 has an adhesive filling range C (see FIG. 3) C up to a predetermined position from the bottom plate 42 in the sensor case 12, and therefore the adhesive filling range C from the internal volume of the sensor case 12. When the volume of the adhesive up to and the volume of the covering portion 51 are subtracted, the space portion (see FIG. 3) 52 that is predetermined to be larger than the space portion 43 in the first embodiment is a sensor mounting portion. 22 and between the sensor case 12 and around and inside the plate portions 31 and 32. The housing fixing portion 19 of the sensor case 12 is joined to the lower end surface 41 of the housing 13 by heat welding or the like. At this time, even if a pressure fluctuation occurs inside the sensor case 12, the space portion 52 can sufficiently withstand the pressure fluctuation by allowing the pressure fluctuation.

  According to the waterproof structure of the sensor by the sensor 50 of the second embodiment, in addition to the operational effects of the first embodiment, the covering portion 51 is provided only on the other sensor terminal 15 of the pair of sensor terminals 14 and 15. As a result, it is possible to prevent leakage with one of the sensor terminals 14, and it is not necessary to make a large capital investment without a large-scale change of the conventional molding die.

  In addition, this invention is not limited to embodiment mentioned above, A deformation | transformation, improvement, etc. are possible suitably. For example, the sensor main body is not limited to the semiconductor sensor for detecting rotation, but may be a vibration sensor, an acceleration sensor, or the like.

  Further, as shown in the figure, the sensor terminal may be pulled out in the lateral direction by being bent at an intermediate portion instead of being linearly arranged from the upper side to the lower side.

It is sectional drawing along the axial direction of the sensor terminal of the sensor explaining 1st Embodiment of the waterproof structure of the sensor of this invention. It is the sectional view on the AA line of the sensor shown in FIG. It is sectional drawing along the axial direction of the sensor terminal of the sensor explaining 2nd Embodiment of the waterproof structure of the sensor of this invention. FIG. 4 is a cross-sectional view of the sensor shown in FIG. 3 taken along the line BB. It is sectional drawing of the conventional sensor.

Explanation of symbols

10, 50 Sensor 11 Sensor body 12 Sensor case 13 Housing 14, 15 Sensor terminal 40, 51 Covering portion

Claims (3)

A sensor body, a sensor case for housing the sensor body, a sensor terminal having one end connected to the sensor body and the other end connected to the outside, and housing the sensor terminal and joined to the sensor case A housing for projecting the other end of the sensor terminal into the sensor case, and a waterproof structure for the sensor,
Only one of the pair of sensor terminals protruding from the housing into the sensor case is covered with a covering portion ,
The waterproof structure for a sensor, wherein the sensor case is filled with an adhesive up to a portion covering the tip of the covering portion .   The waterproof structure for a sensor according to claim 1, wherein the sensor case is filled with an adhesive while ensuring a space allowing pressure fluctuation.   The waterproof structure for a sensor according to claim 1 or 2, wherein the covering portion is connected to the housing and is integrally formed with the housing.

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