JP5101928B2 - Sensor - Google Patents

Description

  The present invention relates to a sensor.

  Conventionally, a sensor disclosed in Patent Document 1 is known. This sensor includes a sensor body, a plurality of covered electric wires, a grommet, an annular body, and the like.

  Each covered electric wire has its one end connected to the sensor body and its other end connected to a connector connected to an external circuit. And the grommet is arrange | positioned between each covered conducting wire and the vehicle interior wall surface. The grommet has a cylindrical main body portion through which all of the plurality of covered conductors are inserted, and a cylindrical portion in which one insertion hole through which each covered electric wire is inserted is formed while protruding from one end of the main body portion. And have. In the sensor disclosed in Patent Document 1, the entire covered electric wire is covered with a tube, and the entire covered electric wire is inserted through the insertion hole together with the tube. The annular body is fixed by caulking on the outer peripheral side of the cylindrical portion.

  A conventional sensor having such a configuration is mounted on, for example, an automobile, and the sensor main body is attached to an intake system piping, an exhaust system piping, or the like of the engine outside the passenger compartment of the automobile. Further, the other end side of each covered electric wire led out from inside the sensor main body is inserted through the vehicle interior wall surface of the automobile through the grommet, and drawn to the vehicle interior side to be connected to the electrical equipment related device via the connector.

  In this way, this sensor can transmit an electric signal from the sensor main body for measuring a gas component, temperature, and the like to the electrical equipment related to the vehicle interior side by each covered electric wire.

Japanese Unexamined Patent Publication No. 7-72020

  By the way, the sensor attached to the outside of the passenger compartment is likely to be splashed with water (easy to get wet), and is concerned that the water on the outer side of the passenger compartment may enter the inside of the passenger compartment through the insertion hole in the cylindrical portion of the grommet. There must be. Specifically, the cylindrical portion of the grommet is deformed by receiving a force when the annular body is fixed by caulking, and further, due to this deformation, the insertion hole is also deformed to contract in the caulking direction. On the other hand, the covered electric wire is not easily deformed by caulking, and a gap is formed between the insertion hole and the covered conductive wire, and there is a possibility that water may enter from the gap when the sensor gets wet. In this case, the infiltrated water may adhere to the nearest connector and cause a problem such as a short circuit of the wiring.

  In this regard, in the above-described conventional sensor, the tube is inserted into the insertion hole, and the entire covered electric wire is present in the tube. For this reason, even if the cylindrical part of the grommet is deformed, the tube can also be deformed to follow this deformation, so that the adhesion between the tube and the insertion hole is sufficient, and a gap can be hardly formed. However, if water has entered the tube from the sensor body, the water is not easily deformed by caulking as described above, so that the water capillaries between the tube and each covered wire. There is also a risk of further moving to the vehicle interior side.

  The present invention has been made in view of the above-described conventional situation, and an object to be solved is to provide a sensor that can more reliably prevent water outside the vehicle interior from moving toward the vehicle interior side. .

The sensor of the present invention includes a sensor body that detects a measurement target;
A plurality of covered electric wires for connecting the inside of the sensor body and a connector connected to an external circuit;
A cylindrical main body portion through which all of the plurality of coated conducting wires are inserted, and a grommet having a cylindrical portion protruding in a cylindrical shape from one end of the main body portion;
An annular body that is caulked and fixed to the outer periphery of the cylindrical part,
In the cylindrical portion, a plurality of insertion holes for inserting each of the covered electric wires are formed to extend in the column direction,
When viewed in a plane perpendicular to the column direction of the cylindrical portion,
The annular body forms a protruding portion protruding in a first linear direction passing through the center of the cylindrical portion,
The insertion hole has an even number arranged circumferentially arranged through-holes in the circumferential direction near the outer periphery of the cylindrical portion,
Each circumferential direction arranged insertion hole, through the center of the cylindrical portion, without overlapping with and perpendicular second straight line to the first straight line,
Each of the first straight line and the second straight line is only one .

  The sensor of the present invention having such a configuration employs a grommet in which a plurality of insertion holes through which the respective covered electric wires are inserted are formed in a cylindrical portion. For this reason, even if the adhesion between each covered wire and each insertion hole is sufficient and a gap cannot be formed, there is a concern in a grommet that allows all covered wires to be inserted into the tube and the tube to be inserted into the insertion hole. Thus, it is possible to prevent water from moving from the insertion hole to the vehicle interior side due to the capillary phenomenon generated between the tube and the covered electric wire.

In order to prevent the gap from being formed, the sensor of the present invention specifies the arrangement of the insertion holes. Specifically, when viewed in a plane perpendicular to the column direction of the cylindrical portion, the annular body forms a protruding portion that protrudes in a first linear direction passing through the center of the cylindrical portion, and the insertion hole is formed of the cylindrical portion. An even number of circumferentially arranged insertion holes are arranged near the outer periphery in the circumferential direction, and each circumferentially arranged insertion hole passes through the center of the cylindrical portion and does not overlap with a second straight line that is perpendicular to the first straight line. I have to. Each of the first straight line and the second straight line is only one. When the annular body is caulked and fixed to the cylindrical portion, the annular body is formed with a projecting portion that projects in a first linear direction that is a direction substantially perpendicular to the caulking direction. On the other hand, an even number of circumferentially arranged insertion holes arranged in the circumferential direction near the outer periphery of the cylindrical portion that is most easily deformed by caulking among the insertion holes are second straight lines that are perpendicular to the first linear direction. If it does not overlap in the direction (caulking direction), the circumferentially arranged insertion hole is not easily deformed by caulking. As a result, it is difficult to form a gap between the coated conductor and the insertion hole, and adhesion can be sufficiently maintained.

  Therefore, the sensor of the present invention can more reliably prevent water outside the vehicle interior from moving toward the vehicle interior. For this reason, even if this sensor is mounted on a vehicle or the like, problems such as short-circuiting of wiring due to intrusion of water hardly occur.

  In the sensor of the present invention, each insertion hole preferably has four circumferentially arranged insertion holes. In this case, this sensor can equalize the compressive force with respect to each circumferentially arranged insertion hole by caulking the annular portion, and can reliably exhibit the effects of the present invention.

The sensor of the present invention comprises a tube through which all the covered electric wires are inserted,
One end side of the tube may be sealed and fixed to the sensor body, and the other end side of the tube may be sealed and fixed to the grommet so as to be interposed between the cylindrical portion and the annular body.

  In this case, the internal space of the tube is a closed space in which both ends are sealed. For this reason, in this sensor, the situation where water is applied to the covered electric wire inserted into the tube is less likely to occur, and the problem that the water outside the passenger compartment moves toward the passenger compartment is less likely to occur.

  A first embodiment of the present invention will be described below with reference to the drawings.

  As shown in FIGS. 1 and 2, the sensor 1 of the first embodiment is a gas sensor mounted on an automobile, and includes a sensor body 10, four covered electric wires 21, 22, 23, 24, a grommet 30, and an annular body 40. It has. 1 and 3, the left side is the front end side, and the right side is the rear end side.

  The sensor main body 10 is attached to an intake system piping, an exhaust system piping, or the like of an engine outside the passenger compartment of an automobile, and measures a gas component, a temperature, and the like.

  The front end sides of the respective covered electric wires 21 to 24 are connected to the inside of the sensor body 10, and the rear end sides of the respective covered electric wires 21 to 24 are led out to the outside. And the connector 29 for connecting with the electrical equipment related apparatus by the side of a vehicle interior is mounted | worn with the rear end of each covered electric wire 21-24.

  As shown in FIGS. 3 and 4, the grommet 30 is an integrally molded product made of an elastic material such as fluorine rubber, and has a main body portion 31, a cylindrical portion 32, and a columnar portion 33.

  The main body 31 is formed in a flange shape, and a groove 31a that is recessed on the outer peripheral side is fitted to the inner peripheral edge (not shown) of the opening formed in the vehicle compartment wall surface. Closely fixed.

  The cylindrical portion 32 is formed so as to protrude in a cylindrical shape from the main body portion 31 toward the front end side, and the rear end sides of the respective covered electric wires 21 to 24 are inserted into the internal space.

  The columnar portion 33 is formed so as to protrude in a columnar shape from the cylindrical portion 32 toward the distal end side. As shown in FIG. 4, the cylindrical portion 33 has four circumferentially arranged insertion holes 51, 52 arranged at equal intervals on a circumference R centered on the axis L and parallel to the axis L. , 53 and 54 are provided. As shown in FIG. 3, the circumferentially arranged insertion hole 51 has an inner diameter slightly larger than the outer diameter of each covered electric wire 21 to 24, and in the middle, the inner diameter is larger than the outer diameter of each covered electric wire 21 to 24. Slightly smaller ribs 51a and 51b are formed. The other circumferentially arranged insertion holes 52, 53 and 54 are the same as the circumferentially arranged insertion holes 51.

  As shown in FIGS. 1 and 2, the circumferentially arranged insertion hole 51 has the rear end side of the covered electric wire 21 inserted through the cylindrical portion 32 into the main body portion 31 from the outside. The circumferentially arranged insertion hole 52 allows the rear end side of the covered electric wire 22 to be inserted from the outside into the main body portion 31 via the cylindrical portion 32. The circumferentially arranged insertion hole 53 allows the rear end side of the covered electric wire 23 to be inserted from the outside into the main body portion 31 via the cylindrical portion 32. The circumferentially arranged insertion hole 54 allows the rear end side of the covered electric wire 24 to be inserted from the outside into the main body portion 31 through the cylindrical portion 32.

  The annular body 40 is originally a metal cylinder whose inner diameter is slightly larger than the outer diameter of the cylindrical portion 33 as shown in FIG. The annular body 40 is caulked and fixed to the outer peripheral side of the cylindrical portion 33 by the following procedure.

  First, as shown in FIG. 6A, the annular body 40 is attached to the outer peripheral side of the cylindrical portion 33. In addition, one covered electric wire 21 to 24 is inserted through each circumferentially arranged insertion hole 51 to 54. And the annular body 40, the cylindrical part 33, and the covered electric wires 21-24 are pressed by a pair of caulking metal mold | die 90a, 90b. As a result, as shown in FIG. 6B, the annular body 40 is plastically deformed and fixed by caulking to the outer peripheral side of the cylindrical portion 33, and the circumferentially arranged insertion holes 51 to 54 are also compressively deformed. At this time, the annular body 40 is formed with a protruding portion 41 protruding in the first straight line K direction. Thus, in the sensor 1, the respective covered electric wires 21 to 24 and the circumferentially arranged insertion holes 51 to 54 are in close contact with each other.

At this time, in the sensor 1 of the first embodiment, as shown in FIG. 6A, the annular body is arranged so that the circumferentially arranged insertion holes 51 to 54 are not positioned on the second straight line N perpendicular to the first straight line K. 40 is caulked and fixed to the outer peripheral side of the cylindrical portion 33. More specifically, as shown in FIG. 4, the circumferentially arranged insertion holes 51 to 54 are arranged at equal intervals on the circumference R centering on the axis L, and are substantially in the same direction as the caulking direction. And the same distance from the second straight line N. For this reason, in this sensor 1, the compressive force with respect to the circumferentially arranged insertion holes 51 to 54 can be made substantially uniform.

  The sensor 1 according to the first embodiment having such a configuration is mounted on, for example, an automobile, and the sensor main body 10 is attached to an intake system piping, an exhaust system piping, or the like of the engine outside the passenger compartment of the automobile. Further, the rear end side of each of the covered electric wires 21 to 24 led out from the sensor body 10 is inserted through the wall surface of the vehicle compartment through the grommet 30 and pulled to the vehicle interior side to connect the connector 29 to the electrical equipment. Connected through.

  Thus, the sensor 1 can transmit an electrical signal from the sensor body 10 for measuring a gas component, a temperature, and the like to the electrical equipment related to the vehicle interior by the respective covered wires 21 to 24.

  Here, the sensor 1 of Example 1 employs a grommet 30 in which four circumferentially arranged insertion holes 51 to 54 through which the respective covered electric wires 21 to 24 are inserted are formed in the cylindrical portion 33. For this reason, if the adhesiveness between the respective covered electric wires 21 to 24 and the circumferentially arranged insertion holes 51 to 54 is sufficient and a gap cannot be formed, the entire covered electric wires 21 to 24 are inserted into the tube 70. Thus, there is no need to worry about the water moving to the vehicle interior side due to the capillary action that occurs in the tube 70 and the covered electric wires 21 to 24, which is concerned in the grommet 30 in which the tube 70 is inserted into the insertion hole.

And when it sees in the surface perpendicular | vertical to the column direction of the cylindrical part 33, the annular body 40 forms the protrusion part 41 which protrudes in the 1st linear direction K which passes along the center L of the cylindrical part 33, and circumferential direction arrangement | positioning penetration is carried out. The holes 51 to 54 pass through the center L of the cylindrical portion 33 and do not overlap with the second straight line N perpendicular to the first straight line K. Each of the first straight line K and the second straight line N is only one. Thereby, the circumferentially arranged insertion holes 51 to 54 are not easily deformed by caulking. As a result, it is difficult to form a gap between the coated conducting wires 21 to 24 and the circumferentially arranged insertion holes 51 to 54, and the adhesion can be sufficiently maintained.

  Therefore, the sensor 1 according to the first embodiment can more reliably prevent the water outside the vehicle interior from moving toward the vehicle interior. For this reason, even if this sensor 1 is mounted on a vehicle or the like, problems such as a short circuit of wiring due to intrusion of water hardly occur.

  Here, the sensor 1 of Example 1 was examined for the presence or absence of water in the grommet 30.

<Test Example 1>
In Test Example 1, a predetermined condition (injection pressure: 7 to 8 MPa, water amount: 10 ± 1 L / min, injection time: 5 seconds / cycle) is directed from the outside toward the cylindrical portion 33 of the grommet 30 of the sensor 1 of Example 1. ) To inject water into the grommet 30 to check whether water enters the internal space of the cylindrical portion 32. As Test Example 1, two sensors 1 were prepared.

  As a result, in the sensor 1 of Example 1, water did not enter the internal space of the cylindrical portion 32 after two cycles. In addition, water did not penetrate into the internal space of the cylindrical portion 32 after both of three cycles.

<Comparative Example 1>
On the other hand, as shown in FIGS. 7A and 7B, the annular body 40 is fixed by caulking by changing the circumferentially arranged insertion holes 51 and 54 of the sensor 1 of Example 1 so as to overlap the second straight line N. This was prepared as a sensor for Comparative Example 1. The other conditions and configuration were the same as in Test Example 1, and the presence or absence of water intrusion into the grommet 30 was examined for the sensor of Comparative Example 1. As Comparative Example 1, two sensors 1 were prepared.

  As a result, in the sensor of Comparative Example 1, after one cycle, water did not enter the internal space of the cylindrical portion 32 for one, but water entered the internal space of the cylindrical portion 32 for the other. Invaded. In addition, after three separate cycles, water entered the internal space of the cylindrical portion 32 in both cases.

  From the results of Test Example 1 and Comparative Example 1, it is clear that the sensor 1 of Example 1 has the above-described effects.

  In the sensor of the second embodiment, the tip 70a of the tube 70 through which all of the covered electric wires 21 to 24 shown in FIG. 1 are inserted is extended and sealed and fixed to the sensor body 10, and the rear end 70b of the tube 70 is extended. The grommet 30 is sealed and fixed so as to be interposed between the cylindrical portion 33 and the annular body 40. Since other configurations are the same as those of the sensor 1 of the first embodiment, description thereof is omitted.

  In the sensor of Example 2 having such a configuration, the internal space of the tube 70 is a closed space in which both ends 70a and 70b are sealed. For this reason, in this sensor, the situation where water is applied to the covered electric wires 21 to 24 inserted into the tube 70 is less likely to occur, and the problem that the water outside the vehicle interior moves toward the vehicle interior side is less likely to occur.

  In the above, the present invention has been described with reference to the first and second embodiments. However, the present invention is not limited to the first and second embodiments, and can be appropriately modified and applied without departing from the spirit of the present invention. Needless to say.

  The present invention is applicable to sensors.

It is a side view of the gas sensor of Example 1. It is sectional drawing which concerns on the gas sensor of Example 1, and shows the II-II cross section of FIG. 1 is a side view (partial cross-sectional view) of a grommet according to a gas sensor of Example 1. FIG. FIG. 4 is a front view of the grommet according to the gas sensor of Example 1 (viewed from the direction A in FIG. 3). 1 is a perspective view of an annular body according to a gas sensor of Example 1. FIG. (A) is sectional drawing which shows the process of crimping and fixing an annular body to the outer peripheral side of a cylindrical part, (b) is sectional drawing which shows the cylindrical part by which the annular body was fixed by crimping, concerning the gas sensor of Example 1. is there. (A) is sectional drawing which shows the process of crimping and fixing an annular body to the outer peripheral side of a cylindrical part, (b) is sectional drawing which shows the cylindrical part by which the annular body was fixed by crimping, regarding the gas sensor of the comparative example 1. is there.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Sensor 10 ... Sensor main body 21, 22, 23, 24 ... Covered electric wire 29 ... Connector 30 ... Grommet 31 ... Main body part 32 ... Cylindrical part 33 ... Cylindrical part 40 ... Annular body 41 ... Protrusion part 51, 52, 53, 54 ... Insertion holes (circumferentially arranged insertion holes)
70 ... Tube K ... First straight line N ... Second straight line L ... Center (axial center)

Claims (3)

A sensor body for detecting an object to be measured;
A plurality of covered electric wires connecting the sensor body and a connector connected to an external circuit;
A grommet having a cylindrical main body portion through which all of the plurality of covered conducting wires are inserted, and a cylindrical portion protruding in a cylindrical shape from one end of the main body portion;
An annular body that is caulked and fixed to the outer periphery of the cylindrical part,
In the cylindrical portion, a plurality of insertion holes for inserting each of the covered electric wires are formed to extend in the column direction,
When viewed in a plane perpendicular to the column direction of the cylindrical portion,
The annular body forms a protruding portion protruding in a first linear direction passing through the center of the cylindrical portion,
The insertion hole has a circumferentially arranged insertion hole arranged in an even number in the circumferential direction near the outer periphery of the cylindrical portion,
Each circumferentially arranged insertion hole does not overlap a second straight line that passes through the center of the cylindrical portion and is perpendicular to the first straight line ,
Each of the first straight line and the second straight line is only one sensor.   The sensor according to claim 1, wherein the insertion hole has four circumferentially arranged insertion holes. A tube through which all the covered electric wires are inserted;
The one end side of the tube is sealed and fixed to the sensor body, and the other end side of the tube is sealed and fixed to the grommet so as to be interposed between the cylindrical portion and the annular body. The sensor according to 1 or 2.

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