JP2010257758A - Terminal waterproof structure of electric wire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To ensure waterproofness without degrading assembling work efficiency. <P>SOLUTION: A rubber plug 20 fitted to an electric wire 10 is inserted in a connector housing 60 to bring the outer peripheral surface of the rubber plug 20 into elastic contact with the inner peripheral surface of the connector housing 60 and to bring the inner peripheral surface of the rubber plug 20 into elastic contact with the outer peripheral surface of the electric wire 10. When the minimum inner diameter of the rubber plug 20 is set to D1 and the outer diameter of a conductor 11 of the electric wire 10 is set to D2, a relationship of D1>D2 is satisfied when the rubber plug 20 and the electric wire 10 exist independently of each other, and a relationship of D1<D2 is satisfied when the electric wire 10 exists independently and only the rubber plug 20 is inserted in the connector housing 60. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a terminal waterproof structure for electric wires.

  Patent Document 1 discloses a conventional wire terminal connection structure. This includes an electric wire in a form in which a conductor made of a stranded wire is surrounded by an insulating coating, and a cylindrical rubber plug that is externally attached to an end portion of the electric wire and elastically adhered to the outer peripheral surface of the electric wire. . The rubber plug is inserted into the cavity formed in the connector housing together with the electric wire, and the outer peripheral surface thereof is elastically adhered to the inner peripheral surface of the cavity.

JP 2006-147421 A

  By the way, when the electric wire is exposed to a high temperature environment or a low temperature environment, the insulation coating may be deformed to reduce its thickness. As a result, the difference between the minimum inner diameter of the rubber plug and the outer diameter of the electric wire is increased, and the compressive stress acting on the inner peripheral surface of the electric wire is reduced. As a result, the waterproof property between the electric wire and the rubber plug may be impaired. .

  On the other hand, in order to ensure waterproofness, for example, if the crushing margin of the rubber plug for the electric wire is set large, the insertion resistance when inserting the electric wire into the rubber plug becomes excessive, and the workability at the time of assembly deteriorates. is there.

  The present invention has been completed based on the above circumstances, and an object thereof is to ensure waterproofness without deteriorating assembly workability.

  As a means for achieving the above object, the invention of claim 1 comprises an electric wire in which a conductor is surrounded by an insulating coating, and a cylindrical rubber plug that is externally inserted into a terminal portion of the electric wire, and the electric wire The rubber plug fitted into the connector housing is inserted into the connector housing, the outer peripheral surface of the rubber plug is elastically adhered to the inner peripheral surface of the connector housing, and the inner peripheral surface of the rubber plug is the electric wire. A terminal waterproof structure of an electric wire that is elastically adhered to an outer peripheral surface of the wire, wherein the minimum inner diameter of the rubber plug is D1 and the outer diameter of the conductor is D2. When alone, the relationship of D1> D2 is satisfied, and when the wire exists alone and only the rubber plug is inserted into the connector housing, the relationship of D1 <D2 is satisfied. However, it has characteristics.

  According to a second aspect of the present invention, in the first aspect of the present invention, an outer peripheral lip that is in close contact with the inner peripheral surface of the connector housing and is elastically deformed is formed on the outer peripheral surface of the rubber plug. An inner peripheral lip that is brought into close contact with the outer peripheral surface of the electric wire and elastically deformed is formed on the inner peripheral surface of the electric wire, and the outer peripheral lip and the inner peripheral lip are portions that wrap around each other in the axial direction of the electric wire. It is characterized in that it is arranged to include.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, the inner peripheral surface of the rubber plug is formed with a plurality of inner peripheral lips that are brought into close contact with the outer peripheral surface of the electric wire and elastically deformed. The front end of the rubber plug in the direction of insertion into the connector housing is provided with a caulking region to which a terminal fitting is caulked, and among the plurality of inner circumferential lips located behind the caulking region, The inner peripheral lip located at least closest to the caulking area is characterized in that it has a minimum inner diameter of the rubber plug.

<Invention of Claim 1>
Even if the insulation coating of the wire is deformed in a high temperature environment or a low temperature environment and thinned to the limit, the relationship of D1 <D2 is satisfied when only the rubber plug is inserted into the connector housing. Therefore, the crushing cost of the rubber plug for the electric wire is surely secured. As a result, predetermined waterproofness is ensured.

  In addition, since the relationship of D1> D2 is satisfied before the rubber plug is inserted into the connector housing, the insertion resistance when inserting the electric wire into the rubber plug does not become excessive, and good assembly workability is achieved. Is secured.

<Invention of Claim 2>
When the rubber plug is inserted into the connector housing, the crushed portion of the rubber plug that is crushed between the outer peripheral surface of the electric wire and the inner peripheral surface of the connector housing increases by the wrap portion, so that higher waterproofness is obtained. Can do.

<Invention of Claim 3>
By satisfying the relational expression of the invention of claim 1 by the inner peripheral lip located closest to the caulking region, it is possible to effectively prevent the terminal fitting from being covered with water and impairing the waterproof property. .

The partially broken side view which shows the state which concerns on Embodiment 1 and the rubber plug is inserted in the terminal part of an electric wire, and the terminal metal fitting is connected to the crimping area | region of the rubber plug Sectional drawing which shows the state by which the rubber stopper was inserted by the terminal part of the electric wire Sectional drawing which shows the state in which the rubber stopper was inserted in the rubber stopper accommodating part Cross section of rubber stopper

<Embodiment 1>
A first embodiment of the present invention will be described with reference to FIGS. This embodiment exemplifies the terminal waterproof structure of the electric wire 10, and the rubber plug 20 is fitted to the terminal portion (front end portion) of the electric wire 10, and the terminal fitting 40 is caulked and connected to the rubber plug 20. Further, the terminal fitting 40 is inserted into the connector housing 60 together with the rubber plug 20 and the electric wire 10.

  The connector housing 60 is made of synthetic resin, and as shown in FIG. 3, a cavity 61 extending in the front-rear direction is formed therein. The rear part of the cavity 61 is a rubber stopper accommodating part 62 having a circular cross section, and the rubber stopper 20 is accommodated in a close contact state therewith.

  The electric wire 10 includes a conductor 11 having a circular cross section made of a stranded wire obtained by twisting a plurality of fine metal wires, and a resin insulating coating 12 surrounding the conductor 11. At the terminal portion of the electric wire 10, the insulating coating 12 is peeled off, and the front end portion of the conductor 11 is exposed. As the material of the conductor 11, copper or a copper alloy is used, and in some cases, aluminum or an aluminum alloy is used.

  The terminal fitting 40 is formed by bending a metal plate material punched into a predetermined shape, and as shown in FIG. 1, a cylindrical connecting portion 41 that receives a tab of a mating terminal (not shown) and is connected thereto. A wire barrel 42 located behind the connection portion 41, a first insulation barrel 43 located behind the wire barrel 42, and a second insulation barrel 44 located behind the first insulation barrel 43. have.

  The wire barrel 42, the first insulation barrel 43, and the second insulation barrel 44 have a pair of caulking pieces 46, 47, 48 extending from both side edges of the bottom plate 45. Both the caulking pieces 46 of the wire barrel 42 are wound around the exposed outer peripheral surface of the conductor 11 while abutting each other's protruding ends, and are connected to the conductor 11 in a conductive manner. The two caulking pieces 47 of the first insulation barrel 43 are wound around the outer peripheral surface of the insulating coating 12 while the projecting ends of the first insulation barrel 43 abut each other, and are held on the terminal portion of the electric wire 10. Further, both the caulking pieces 48 of the second insulation barrel 44 are wound around the outer peripheral surface of the rubber plug 20 while being displaced in the front-rear direction, and are held together with the rubber plug 20 at the terminal portion of the electric wire 10.

  The rubber plug 20 is made of rubber such as silicon rubber, and has a cylindrical main body 21 elongated in the front-rear direction as shown in FIG. An insertion hole 22 into which the electric wire 10 is inserted in close contact is formed in the main body 21 so as to penetrate in the front-rear direction. The front portion of the main body portion 21 is a caulking region 23 that is thinner than other portions. The outer circumferential surface of the caulking region 23 is a flat surface without unevenness, and both caulking pieces 48 of the second insulation barrel 44 are caulked thereto. The rear portion of the main body 21 is a thick body 24, and both the inner and outer surfaces are flat surfaces without any irregularities. The outer diameter of the body portion 24 is substantially the same as the inner diameter of the rubber plug housing portion 62.

  An intermediate portion of the main body 21 is a sealing region 25, and a plurality of outer peripheral lips 26 are formed on the outer peripheral surface, specifically, two outer peripheral lips 26. Each outer peripheral lip 26 forms a protrusion that goes around the outer periphery of the main body 21. The protruding end of each outer peripheral lip 26 is located on the outermost side in the rubber plug 20 and is arranged side by side at substantially the same height. Here, the outer peripheral surface of the seal region 25 is gradually reduced in diameter from the outer peripheral surface of the body portion 24 to the outer peripheral surface of the caulking region 23, so that the front outer peripheral lip 26 is axially more central than the rear outer peripheral lip 26. The proximal end is located closer to it.

  In addition, a plurality of inner circumferential lips 27 are formed on the inner circumferential surface of the intermediate portion of the main body 21, that is, the inner circumferential surface of the insertion hole 22 in the seal region 25. Each inner peripheral lip 27 forms a ridge that goes around the inner periphery of the main body 21. The protruding end of each inner peripheral lip 27 is located on the innermost side in the rubber plug 20 and is arranged side by side at substantially the same height.

  Among the inner peripheral lips 27, the innermost peripheral lip 27 located on the foremost side is disposed across the seal region 25 and the caulking region 23. And each outer periphery lip 26 and each inner periphery lip 27 are arrange | positioned so that the part which wraps about the front-back direction (axial direction of the electric wire 10) may be included. Specifically, the rear end portion of the inner peripheral lip 27 located at the frontmost side wraps with the front end portion of the outer peripheral lip 26 on the front side, and the front and rear end portions of the inner peripheral lip 27 located at the central portion respectively correspond to the front outer lip 26. The rear end portion and the front end portion of the rear outer peripheral lip 26 are wrapped, and the front end portion of the inner peripheral lip 27 located on the rearmost side is wrapped with the rear end portion of the rear outer peripheral lip 26. The wrap portion is thicker than the other portions.

  In the present embodiment, the minimum inner diameter of the rubber plug 20, that is, the inner diameter of the inner peripheral lip 27 is D1 (see FIG. 4), the outer diameter of the conductor 11 of the electric wire 10 is D2 (see FIG. 2), When the outer diameter of the insulating coating 12 of the electric wire 10 is D3, the relationship of D2 <D1 <D3 is satisfied in the natural state, that is, in the state where the rubber plug 20 and the electric wire 10 are present independently. On the other hand, when the electric wire 10 exists alone and the rubber plug 20 is inserted into the rubber plug housing portion 62 of the connector housing 60 alone, the relationship of D1 <D2 <D3 is satisfied. Of the inner peripheral lips 27, the innermost peripheral lip 27 located on the foremost side is also included in the caulking region 23 and is partially removed from the seal region 25. In the case of this embodiment, all the inner peripheral lips 27 including the inner peripheral lip 27 positioned at the foremost side are configured so as to satisfy the above relational expression. Therefore, the inner peripheral lip 27 located in the foremost side, which is also included in the caulking region 23, may not satisfy the above relational expression.

Next, the effect | action of this embodiment is demonstrated with the significance of the said relational expression.
The terminal portion of the electric wire 10 is inserted into the insertion hole 22 of the rubber plug 20 from the rear. In the insertion process of the electric wire 10, the inner diameter D 1 of the inner peripheral lip 27 is larger than the outer diameter D 2 of the conductor 11 (D 2 <D 1). Workability is improved without increasing the size.

  In the state where the insertion operation of the electric wire 10 is completed, as shown in FIG. 2, substantially the entire inner peripheral surface of the trunk portion 24 and the caulking region 23 is in close contact with the outer peripheral surface of the electric wire 10, and the inner peripheral lip 27 is It is elastically deformed in close contact with the outer peripheral surface. At this time, the crushing margin of the inner peripheral lip 27 is within the thickness range of the insulating coating 12 because the inner diameter D1 of the inner peripheral lip 27 is larger than the outer diameter D2 of the conductor 11 (D2 <D1).

  Subsequently, the rubber plug 20 and the end portion of the electric wire 10 are placed on the bottom plate 45 of the terminal fitting 40, and the terminal fitting 40 and the like are set on an automatic machine including an anvil and a crimper (not shown), and the conductor 11 of the electric wire 10 is externally connected. The wire barrel 42 is crimped, the first insulation barrel 43 is crimped to the insulating coating 12 of the electric wire 11 from the outside, and the second insulation barrel 44 is crimped and connected to the caulking region 23 of the rubber plug 20 from the outside. To do.

  In this state, the electric wire 10 and the terminal fitting 40 with the rubber plug 20 are inserted into the cavity 61 of the connector housing 60 from the rear. As shown in FIG. 3, when the terminal fitting 40 is properly inserted, the substantially rear half portion of the body portion 24 of the rubber plug 60 protrudes rearward from the rear surface of the connector housing 60 and the outer periphery of the rubber plug 20 The lip 26 is brought into close contact with the inner peripheral surface of the rubber plug housing portion 62 and is elastically deformed. Along with this, the inner peripheral lip 27 is also displaced in the diameter-reducing direction and is brought into close contact with the outer peripheral surface of the rubber plug 20, so that the crushing margin of the inner peripheral lip 27 with respect to the electric wire 10 is greater than before insertion into the rubber plug accommodating portion 62. Will also increase. That is, the crushing margin of the inner peripheral lip 27 at this time is smaller than the outer diameter D2 of the conductor 11 because the inner diameter D1 of the inner peripheral lip 27 is smaller than before insertion into the rubber plug housing portion 62 (D1 <D2 For this reason, it extends beyond the thickness range of the insulating coating 12 to the conductor 11 side.

  Thereafter, the connector housing 60 is fitted into a mating connector housing (not shown), and the tab of the mating terminal attached to the mating connector housing is inserted into the connecting portion 41 of the terminal fitting 40 in accordance with the mating operation. Both terminal fittings are connected to each other.

  By the way, when the electric wire 10 is placed in a high temperature environment or a low temperature environment, the insulating coating 12 is deformed and its thickness is reduced, and accordingly, the crushing margin of the inner peripheral lip 27 is also reduced. There is a risk that the sealability of the can not be maintained.

  However, according to this embodiment, when the rubber plug 20 is inserted into the rubber plug housing portion 62, the inner diameter D1 of the inner peripheral lip 27 is smaller than the outer diameter D2 of the conductor 11 (D1 <D2). Since it is designed, even if the insulating coating 12 becomes extremely thin, a crushing margin is always ensured between the inner peripheral lip 27 and the conductor 11. As a result, a predetermined sealing property can be obtained.

  In addition, since the inner diameter D1 of the inner peripheral lip 27 is designed to be larger than the outer diameter D2 of the conductor 11 (D1> D2) before the rubber stopper 20 is inserted into the rubber stopper accommodating portion 62, Insertion resistance at the time of inserting the electric wire 10 into the insertion hole 22 of the rubber plug 20 does not become excessive, and good assembly workability is ensured.

  In addition, since each inner peripheral lip 27 and each outer peripheral lip 26 have a portion that wraps in the front-rear direction, when inserted into the connector housing 60, the crushed portion of the rubber plug 20 increases at the wrap portion. Higher waterproofness can be obtained.

  Further, since the above relational expression is established by all the inner peripheral lips 27 including the inner peripheral lip 27 located closest to the caulking region 23, good sealing performance is secured at a position close to the connection portion 41 of the terminal fitting 40. The Rukoto. As a result, the connection part 41 is prevented from getting wet, and the connection reliability between the two terminal fittings is improved.

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention.
(1) In the above embodiment, the rubber plugs individually corresponding to the respective electric wires are exemplified. However, according to the present invention, the rubber plugs having a plurality of insertion holes through which the electric wires pass are provided. Also good.
(2) Either one or both of the inner peripheral lip and the outer peripheral lip may be omitted.
(3) The number of inner peripheral lips and outer peripheral lips is arbitrary.
(4) The height position of the protruding end of each outer peripheral lip may be different. Moreover, what differs in the height position of the protrusion end of each inner peripheral lip may be included. Further, in this case, among the inner lips located behind the caulking region, the inner peripheral lip located at the foremost end, that is, the inner peripheral lip located closest to the caulking region has the minimum inner diameter of the rubber plug. It is preferable that the relational expression of the first invention is satisfied. If it carries out like this, it can prevent effectively that a terminal metal fitting gets wet and waterproofness is impaired.
(5) The present invention can also be applied to a rubber plug that does not have a caulking region to which a terminal fitting is caulked.

DESCRIPTION OF SYMBOLS 10 ... Electric wire 11 ... Conductor 12 ... Insulation coating 20 ... Rubber plug 23 ... Caulking area 26 ... Outer peripheral lip 27 ... Inner peripheral lip 40 ... Terminal metal fitting 60 ... Connector housing D1 ... Minimum inner diameter of rubber plug D2 ... Outer diameter of conductor

Claims (3)

An electric wire that surrounds the conductor with an insulating coating; and a cylindrical rubber plug that is externally attached to a terminal portion of the electric wire, and the rubber plug that is fitted to the electric wire is inserted into a connector housing, A waterproof structure for a terminal of an electric wire, wherein an outer peripheral surface of a rubber plug is elastically adhered to an inner peripheral surface of the connector housing, and an inner peripheral surface of the rubber plug is elastically adhered to an outer peripheral surface of the electric wire. And
When the minimum inner diameter of the rubber plug is D1, and the outer diameter of the conductor is D2,
When the rubber plug and the electric wire are present alone,
The relationship D1> D2 is satisfied,
When the electric wire is present alone and only the rubber plug is inserted into the connector housing,
A terminal waterproof structure for electric wires, wherein the relationship of D1 <D2 is satisfied. An outer peripheral lip is formed on the outer peripheral surface of the rubber plug to be elastically deformed in close contact with the inner peripheral surface of the connector housing. The inner peripheral surface of the rubber plug is in close contact with the outer peripheral surface of the electric wire. An inner lip that is elastically deformed is formed,
The terminal waterproof structure for an electric wire according to claim 1, wherein the outer peripheral lip and the inner peripheral lip are arranged so as to include portions that wrap with each other in the axial direction of the electric wire. The inner peripheral surface of the rubber plug is formed with a plurality of inner peripheral lips that are in close contact with the outer peripheral surface of the electric wire and elastically deformed,
A caulking region to which a terminal fitting is caulked is provided in the insertion direction into the connector housing on the outer circumferential surface of the rubber plug, and at least of the plurality of inner circumferential lips positioned rearward of the caulking region The end waterproof structure for an electric wire according to claim 1 or 2, wherein an inner peripheral lip located closest to the caulking region has a minimum inner diameter of the rubber plug.

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