JP2012124992A - Electronic apparatus, and grommet - Google Patents

Abstract

An object of the present invention is to provide an electronic device and a grommet that are excellent in assembling workability, do not hinder the reduction in thickness and weight of a housing, and can improve the durability and reliability of a product.
A grommet 50 is locked to an opening 14 of a housing 11 by a latch member 52 formed integrally with a seal portion 51. At this time, since the grommet 50 can be inserted and fixed by elastic deformation of the latch member 52, there is no need to use a fixing means such as a bolt or caulking.
Further, the elastically deformable latch member 52 absorbs a positional error between the connector 30 and the housing cover 13 in the direction along the surface of the circuit board 20. Further, the connector seal surface 51 a of the seal portion 51 of the grommet 50 has a certain length H in the insertion direction of the grommet 50 with respect to the connector 30, and absorbs misalignment between the grommet 50 and the connector 30 in the insertion direction of the grommet 50.
[Selection] Figure 2

Description

  The present invention relates to an electronic device that is required to be waterproof and a grommet used therefor.

2. Description of the Related Art In electronic devices that are required to be waterproof, such as on-vehicle components for automobiles, a circuit board on which the electronic components are mounted is housed in a waterproof casing. In order to connect the circuit board to an external circuit, a connector is mounted on the circuit board, and a part of the connector is exposed to the outside through an opening formed in the housing. The counterpart connector is connected to a connector that is partially exposed from the housing.
At this time, in order to ensure waterproofness in the gap between the connector and the opening, a configuration in which a rubber grommet is interposed in the gap between the connector and the opening of the housing has been conventionally employed (for example, Patent Documents). (See 1 and 2)

JP 2009-9845 A JP 2007-128715 A

  However, in the technique described in Patent Document 1, a plurality of bolts are used to fix the grommet to the housing side. Then, it takes time to fasten the bolts, and there is room for improvement in terms of assembly workability. Further, in order to form a screw hole for fixing a bolt, it is necessary to increase the thickness of the casing side to some extent, and it is assumed that the casing side is made of aluminum die cast. Accordingly, the manufacturing cost of the casing is increased, and the thickness and weight of the casing are hindered.

On the other hand, in the technique described in Patent Document 2, a tightening body is used to fix the grommet to the housing side, and although an improvement in efficiency can be expected as compared with a bolt, it takes time to crimp the tightening body. There is no change.
Furthermore, it is necessary to fit the convex part formed in the outer peripheral part of the connector to the concave part formed in the inner peripheral part of the grommet, and also in this respect, there is room for improvement in the assembly workability. In addition, if an operator applies force to the connector when fitting the grommet into the connector, the force acts on the soldered part between the circuit board and the connector in the housing and other surrounding parts, and the soldered part and circuit There is a possibility of damaging other components mounted on the board.
In addition, in the technique described in Patent Document 2, the positional deviation between the housing and the connector is absorbed in the bellows portion of the grommet. For this reason, a load due to the weight and vibration of the mating connector and wiring is applied to the bellows portion, the deterioration of the rubber material forming the grommet is likely to proceed, and there is room for improvement in terms of durability.

  The present invention has been made on the basis of such technical problems, and is excellent in assembling workability, does not hinder the thinning and weight reduction of the housing, and improves the durability and reliability of the product. An object of the present invention is to provide a grommet capable of electronic equipment.

An electronic device according to the present invention made for such a purpose includes a circuit board, a connector mounted on the circuit board, an opening for accommodating the circuit board inside and exposing a part of the connector to the outside. And a grommet mounted in the gap in order to ensure waterproofness of the gap between the connector and the opening of the housing, and the grommet is provided around the outer peripheral surface of the connector and the opening of the housing. An annular seal portion that abuts against the surface of the housing, and a latch portion that is inserted into a gap between the opening portion and the connector and locks the seal portion to the opening portion of the housing. The latch portion includes the opening portion and the connector. It is characterized by being elastically deformable in the direction of connecting
By locking the seal portion to the opening of the housing with such an elastically deformable latch portion, there is no need to use a screw or caulking to fix the grommet.
Further, due to the elastic deformation of the latch portion, it is possible to easily absorb variations in the size of the gap between the opening of the housing and the outer peripheral surface of the connector.

The latch part may have any shape. For example, the cantilever beam formed so as to be separated from the seal part in the direction connecting the opening part and the connector from the front to the rear in the insertion direction with respect to the gap between the opening part and the connector. It is preferable to make it into a shape.
Furthermore, it is preferable that the tip of the beam-shaped latch portion is abutted against the opening of the housing and is locked.

  Such latch portions are preferably provided at a plurality of locations in the circumferential direction of the seal portion.

Moreover, it is preferable that the seal portion has a contact surface that abuts against the outer peripheral surface of the connector, and the contact surface has a certain length along the insertion direction of the grommet with respect to the gap between the opening and the connector.
Thereby, even if there is a relative position error along the insertion direction of the grommet between the connector and the housing, the sealing performance between the connector and the grommet can be ensured.

  Further, the present invention provides a grommet that exhibits a sealing property between the first member and the second member by being mounted between the first member on the inner peripheral side and the second member on the outer peripheral side. And an annular seal portion and a latch portion that is formed integrally with the seal portion and engages the seal member with the second member, and the latch portion is elastically deformable in the radial direction of the seal portion. A grommet having a simple beam-shaped latch portion can also be provided.

According to the present invention, the seal portion is locked to the opening portion of the housing by the elastically deformable latch portion, so that it is not necessary to use a screw or caulking to fix the grommet. Therefore, assembly workability can be improved. In addition, since it is not necessary to ensure the strength against screws and caulking in the housing, the housing can be made thinner and lighter.
Further, due to the elastic deformation of the latch portion, it is possible to easily absorb variations in the size of the gap between the opening of the housing and the outer peripheral surface of the connector. Thereby, durability and reliability of the product can be improved without applying excessive force to each part.

It is a perspective view which shows the external appearance of the electronic device in this Embodiment. (A) is sectional drawing of an electronic device, (b) is an expanded sectional view of the part which attached the grommet. It is a perspective view which shows a connector. It is a figure which shows a grommet, (a) is the perspective view which looked at the grommet from the side which faces a housing | casing outer side, (b) is the perspective view which looked at the grommet from the surface which faces a housing inner side. It is a figure which shows the assembly process of an electronic device, and is sectional drawing which shows the state provided with the circuit board which mounted the connector in the housing | casing. 4A is a cross-sectional view of a state where a grommet is about to be inserted, and FIG. 4B is a cross-sectional view of a state where the grommet is inserted. It is sectional drawing which shows the mode of a deformation | transformation of the latch member when inserting a grommet.

Hereinafter, the present invention will be described in detail based on embodiments shown in the accompanying drawings.
1 and 2 are diagrams for explaining the configuration of an electronic device 10 according to the present embodiment.
As shown in FIGS. 1 and 2, the electronic device 10 includes a circuit board 20 in a housing (second member) 11, and a connector (first member) 30 mounted on the circuit board 20. A part of the housing 11 is exposed to the outside.

  As shown in FIG. 2A, the housing 11 includes a housing base 12 and a housing cover 13, and the outer peripheral portions of the housing base 12 and the housing cover 13 face each other and are assembled. A space for accommodating the circuit board 20 is provided inside.

  As shown in FIG. 2B, the housing cover 13 is formed with an opening 14 through which the connector 30 is inserted. A flange portion 15 that is bent and formed so as to extend in a direction orthogonal to the outer surface 13 a of the housing cover 13 is provided at the peripheral edge portion of the opening portion 14.

  As shown in FIG. 2A, the circuit board 20 is supported on a plurality of bosses 16 provided on the inner space side of the housing base 12, and is fixed to the bosses 16 by fixing means such as screws 17. It is fastened and fixed.

  As shown in FIGS. 2A and 3, the connector 30 includes a housing 31 and a plurality of contacts 32 held by the housing 31.

The housing 31 is formed with a plate-like terminal holding portion 33 into which a plurality of contacts 32 are press-fitted. The terminal holding portion 33 has an outer peripheral side surface 33 a that is continuous in a band shape and is orthogonal to the surface of the circuit board 20.
Each contact 32 press-fitted into the terminal holding portion 33 is provided so that its base end portion 32 a passes through a through hole formed in the circuit board 20. The base end portion 32a of the contact 32 is electrically connected to a wiring pattern around the through hole of the circuit board 20 by soldering or the like. In the present embodiment, the contact 32 has a straight shape extending in a direction orthogonal to the surface of the circuit board 20.

As shown in FIG. 3, a plurality of leg portions 34 for supporting the housing 31 on the circuit board 20 are formed on one surface side of the terminal holding portion 33. Each leg portion 34 is formed with a through hole 34 a, and the leg portion 34 is fixed to the boss 16 together with the circuit board 20 by inserting the screw 17 into the through hole 34 a.
Further, a terminal alignment plate 35 for aligning the contacts 32 at a predetermined position is provided between the leg portions 34. A plurality of through holes 35a are formed in the terminal alignment plate 35, and the contact 32 is inserted into each through hole 35a to position the base end portion 32a of the contact 32 with a predetermined positional accuracy.

  As shown in FIG. 2, a cylindrical hood portion 36 is formed on the other surface side of the terminal holding portion 33 so as to surround the contact 32. In the present embodiment, two hood portions 36 are formed, but there is no intention to limit the number thereof.

  The connector 30 thus mounted on the circuit board 20 is provided with the hood portion 36 protruding outward from the opening portion 14 of the housing cover 13. Here, the outer peripheral side surface 33a of the terminal holding portion 33 of the connector 30 faces the flange portion 15 of the opening 14 with a clearance therebetween.

A grommet 50 is provided between the opening 14 of the housing cover 13 and the outer peripheral side surface 33a of the terminal holding portion 33 of the connector 30 to ensure waterproofness.
As shown in FIGS. 2 and 4, the grommet 50 includes an annular seal portion 51 formed in accordance with the outer peripheral shape of the terminal holding portion 33 of the connector 30, and the seal portion 51 in the opening 14 of the housing cover 13. And a latch member 52 to be locked.

The seal portion 51 is formed from a rubber-based material having flexibility. The seal portion 51 has a connector seal surface (contact surface) 51 a that abuts on the outer peripheral side surface 33 a of the terminal holding portion 33 of the connector 30 on the inner peripheral side thereof. The connector seal surface 51a has an uneven shape that is continuous in the circumferential direction, and has a tapered shape whose inner diameter gradually increases as it goes to the tip on the side facing the circuit board 20.
The connector seal surface 51 a has a certain length H in the insertion direction of the grommet 50 with respect to the connector 30, that is, in the direction orthogonal to the surface of the circuit board 20. As a result, the grommet 50 and the connector 30 allow the displacement of the relative position within the range of a certain length H in the insertion direction of the grommet 50 (the arrow direction in FIG. 2B), and hold the terminal of the connector 30. The sealing performance between the portion 33 and the grommet 50 is maintained.

  Further, the seal portion 51 has a seal lip 51 b in contact with the outer surface 13 a of the housing cover 13 on the outer peripheral portion thereof. The seal lip 51b is formed to be inclined so as to approach the outer surface 13a of the housing cover 13 as it goes to the outer peripheral side, and is formed to become thinner according to the tip on the outer peripheral side. Thereby, even if the position of the grommet 50 in the insertion direction with respect to the housing cover 13 is shifted, the outer surface 13a of the housing cover 13 is reliably contacted.

  Further, the grommet 50 has a cylindrical sleeve portion 53 that is inserted into a gap between the opening portion 14 of the housing cover 13 and the connector 30.

The latch member 52 is integrally formed on the outer peripheral surface of the sleeve portion 53. In the present embodiment, the latch member 52 is provided at four locations in the circumferential direction of the sleeve portion 53, but the position and the number of installation are not limited.
The latch member 52 is formed into a beam shape that is folded back in a substantially J shape from the end portion in the insertion direction (side facing the circuit board 20) in the sleeve portion 53 and obliquely extends to the side away from the circuit board 20. ing. A stepped portion 52 a is formed at the tip of the latch member 52.
The latch member 52 and the sleeve portion 53 are formed of a material having higher rigidity and elasticity than the seal portion 51, for example, a resin material. The latch member 52 and the sleeve portion 53 are formed integrally with the seal portion 51 by two-color molding.

In order to assemble such an electronic device 10, first, as shown in FIG. 5, the circuit board 20 and the connector 30 are set on the boss 16 in the housing base 12, and these circuit board 20 and The connector 30 is fixed to the boss 16.
Then, the housing cover 13 is put on the housing base 12 so that the hood portion 36 of the connector 30 is passed through the opening 14. And the housing | casing 11 is comprised by joining the outer peripheral part of the housing | casing cover 13 and the housing | casing base 12 by joining means, such as a volt | bolt.
In this state, in the connector 30, the hood portion 36 projects to the outside from the opening portion 14 of the housing cover 13, and the outer peripheral side surface 33 a of the terminal holding portion 33 faces the flange portion 15 of the opening portion 14 with a clearance therebetween. Yes. At this time, the clearance between the outer peripheral side surface 33a of the terminal holding portion 33 and the flange portion 15 of the opening portion 14 is not uniform in the circumferential direction of the terminal holding portion 33 due to molding errors, assembly errors, and the like of each component. There is. Further, the positional relationship between the outer peripheral side surface 33a of the terminal holding portion 33 and the outer surface 13a of the housing cover 13 in the direction orthogonal to the surface of the circuit board 20 may cause an error for the same reason.

Next, as shown in FIGS. 6A, 7 </ b> A, and 7 </ b> B, the grommet 50 is inserted into the gap between the outer peripheral side surface 33 a of the terminal holding portion 33 and the flange portion 15 of the opening portion 14. At this time, the grommet 50 is inserted into the gap from the folded portion of the latch member 52 at the distal end portion of the sleeve portion 53. The latch member 52 gradually moves away from the sleeve portion 53 as it goes from the folded portion to the tip portion, that is, the tip portion of the sleeve portion 53 is the narrowest. Therefore, the grommet 50 can be easily inserted into the gap between the outer peripheral side surface 33 a of the terminal holding portion 33 and the flange portion 15 of the opening 14.
Then, as the grommet 50 is inserted, the latch member 52 that gradually separates from the sleeve portion 53 contacts the flange portion 15 of the opening portion 14. At this time, the latch member 52 is elastically deformed to the side (the inner peripheral side of the seal portion 51) where the tip end side approaches the sleeve portion 53. Thereby, the dispersion | variation in the clearance between the outer peripheral side surface 33a of the terminal holding part 33 and the flange part 15 of the opening part 14 can be absorbed.

Further, as shown in FIGS. 6B and 7C, the grommet 50 is inserted, and the latch member 52 is restored and deformed to the side where the tip end side is separated from the sleeve portion 53 (the outer peripheral side of the seal portion 51). As shown in FIG. 7D, the step 52 a formed at the tip of the latch member 52 is engaged with the opening 14, whereby the grommet 50 is engaged with the opening 14.
In this state, the connector seal surface 51 a of the seal portion 51 of the grommet 50 is in contact with the outer peripheral side surface 33 a of the terminal holding portion 33 of the connector 30. At this time, since the connector seal surface 51a has a certain length H in the insertion direction of the grommet 50 with respect to the connector 30, the grommet 50 and the connector 30 are within the range of the certain length H in the insertion direction of the grommet 50. For example, the displacement of the relative position is allowed, and the sealing performance between the terminal holding portion 33 of the connector 30 and the grommet 50 is maintained.
In this state, the seal lip 51b of the seal portion 51 is pressed against the outer surface 13a of the housing cover 13 and is in an elastically deformed state so as to make a reliable contact, and between the grommet and the outer surface 13a of the housing cover 13. Sealing performance is ensured.

As described above, the grommet 50 is locked to the opening portion 14 of the housing 11 by the latch member 52 formed integrally with the seal portion 51. At this time, since the grommet 50 can be inserted and fixed by elastic deformation of the latch member 52, it is not necessary to use fixing means such as bolts and caulking, and the mounting operation of the grommet 50 is completed with one touch. Thereby, the assembly workability is improved. Furthermore, the housing cover 13 can also be made thinner because it is only necessary to engage the stepped portion 52a formed at the tip of the latch member 52 of the latch member 52 without using a bolt or the like. This can contribute to reducing the thickness and weight of the electronic device 10. Further, when the grommet 50 is attached, no great force acts on the connector 30 or the circuit board 20, and the reliability of the product is not impaired.
In addition, the elastically deformable latch member 52 can absorb position errors between the connector 30 and the housing cover 13 in the direction along the surface of the circuit board 20. Further, the connector seal surface 51a of the seal portion 51 of the grommet 50 has a certain length H in the insertion direction of the grommet 50 with respect to the connector 30, and absorbs the positional deviation between the grommet 50 and the connector 30 in the insertion direction of the grommet 50. can do. Thereby, the position error between the connector 30 and the housing cover 13 by the grommet 50 can be absorbed, and the sealing performance can be ensured reliably. In addition, since the load due to the weight and vibration of the mating connector and wiring does not occur particularly, deterioration of the rubber material forming the grommet 50 can be suppressed and durability can be improved.

In the above embodiment, the contact 32 of the connector 30 extends in a direction orthogonal to the surface of the circuit board 20, and the mating connector is inserted into the connector 30 from the direction orthogonal to the surface of the circuit board 20. Although configured, it is not limited to this. The contact 32 may be substantially L-shaped, and the mating connector may be inserted into the connector 30 from a direction parallel to the surface of the circuit board 20.
Further, the shape and configuration of the housing 11 are not limited to those described above, but may be other configurations as appropriate.
In addition to this, as long as it does not depart from the gist of the present invention, the configuration described in the above embodiment can be selected or changed to another configuration as appropriate.

  DESCRIPTION OF SYMBOLS 10 ... Electronic device, 11 ... Housing | casing (2nd member), 14 ... Opening part, 20 ... Circuit board, 30 ... Connector (1st member), 31 ... Housing, 32 ... Contact, 33 ... Terminal holding part, 33a ... outer peripheral side surface, 50 ... grommet, 51 ... seal part, 51a ... connector seal surface (contact surface), 51b ... seal lip, 52 ... latch member, 52a ... step part, 53 ... sleeve part

Claims (6)

A circuit board;
A connector mounted on the circuit board;
A housing having an opening for accommodating the circuit board inside and exposing a part of the connector to the outside;
In order to ensure waterproofness of the gap between the connector and the opening of the housing, the grommet mounted in the gap,
The grommet has an annular seal portion that abuts against an outer peripheral surface of the connector and a surface around the opening of the housing;
A latch portion that is inserted into a gap between the opening portion and the connector and locks the seal portion to the opening portion of the housing;
The electronic device according to claim 1, wherein the latch portion is elastically deformable in a direction connecting the opening and the connector.   The latch portion is in the form of a cantilever beam formed so as to be separated from the seal portion in a direction connecting the opening and the connector from the front to the rear in the insertion direction with respect to the gap between the opening and the connector. The electronic apparatus according to claim 1, wherein the electronic apparatus is provided.   The electronic device according to claim 2, wherein the latch portion is locked with a tip portion abutting against the opening of the housing.   The electronic device according to claim 1, wherein the latch portion is provided at a plurality of locations in the circumferential direction of the seal portion.   The seal portion has a contact surface that abuts against the outer peripheral surface of the connector, and the contact surface has a certain length along the insertion direction of the grommet with respect to the gap between the opening and the connector. The electronic device according to any one of claims 1 to 4. A grommet that exhibits sealing properties between the first member and the second member by being mounted between the first member on the inner peripheral side and the second member on the outer peripheral side,
An annular seal,
A latch part formed integrally with the seal part and locking the seal part to the second member;
The grommet characterized in that the latch portion has a beam shape that is elastically deformable in a radial direction of the seal portion.

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