JP2017208258A - Waterproof plug and electric wire having crimp contact with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a waterproof plug of a new structure which can prevent positional deviation with respect to an electric wire in the waterproof plug, and an electric wire having a crimp contact with the same.SOLUTION: A waterproof plug comprises: a cylindrical body 14 made of elastic material including an inner hole 12 through which an electric wire 38 can be inserted; an annular inner circumferential seal protrusion 20 and an annular outer peripheral seal protrusion 22 which are arranged in a base end side of the cylindrical body 14 through which the electric wire 38 is inserted and respectively protrude on the inner/outer circumferential surfaces 16, 18 of the cylindrical body 14; and a fixed cylinder part 24 arranged at a tip side of the cylindrical body 14 from which the electric wire 38 is derived and which is fixed to the electric wire 38. At least two position shift prevention ribs 30 are given protruding sandwiching the electric wire 38 and facing to each other in the inner hole 12 of the cylindrical body 14 in which the position shift prevention ribs are elastically deformable, length thereof in a peripheral direction is shorter than peripheral length of the inner hole 12, radial dimension thereof is larger than that of the inner circumferential seal protrusion 20, and they protrude in the inner peripheral side.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a waterproof plug to be attached to an electric wire with a crimp terminal that is required to be waterproof, and an electric wire with a crimp terminal including the waterproof plug.

  Conventionally, a wire with a crimp terminal in which a crimp terminal is crimped to a core wire exposed by peeling off an insulation coating of a wire end has been used by being housed and held in a housing region such as a terminal cavity of a connector, and is waterproof. When performance is required, a waterproof plug formed of a rubber elastic body or the like is attached around the electric wire with the crimp terminal. As described in JP-A-8-50955 (Patent Document 1), this waterproof plug is configured such that an electric wire can be inserted through an inner hole of a cylindrical main body made of a rubber elastic body. On the base end side, there are provided an annular inner peripheral seal protrusion and an outer peripheral seal protrusion that protrude from the inner and outer peripheral surfaces, while a crimped terminal covering crimp portion is provided on the distal end side that is the protruding side of the electric wire. There is provided a fixed cylinder portion to which is pressed. By attaching such a waterproof plug to the electric wire with the crimp terminal, the gap between the electric wire with the crimp terminal and the housing area is closed by sandwiching the outer peripheral seal protrusion of the waterproof plug, and the insulation coating of the electric wire and the waterproof plug The waterproofness of the electric wire with the crimp terminal can be secured by sandwiching and closing the gap between the inner peripheral seal protrusions.

  By the way, in order to fix the waterproof plug to the electric wire with the crimp terminal, in the crimping process of the crimp terminal to the electric wire, the fixing tube portion of the waterproof plug is inserted in advance into the portion where the covering crimp portion of the crimp terminal is crimped. It is necessary to place the crimp terminal on the wire terminal by crimping and fixing the core wire crimping portion and the covering crimp portion of the crimp terminal to the fixing tube portion of the core wire and the waterproof plug, respectively.

  However, if an external force is applied to the waterproof plug or the wire when moving to the caulking process, etc., even if the waterproof plug is inserted into the wire and the fixed tube portion of the waterproof plug is inserted into the predetermined position, the wire and the waterproof plug In some cases, the relative position changes and misalignment occurs. The diameter size of the electric wire inserted into the waterproof plug is various, and the problem is particularly noticeable when the electric wire diameter is small. When the caulking process is performed in such a state of being displaced, it is inevitable that a crimping failure occurs, and some countermeasure has been demanded.

JP-A-8-50955

  The present invention has been made in the background of the above-described circumstances, and the problem to be solved is a waterproof plug having a novel structure and a pressure-bonding unit having a waterproof plug, which can prevent the displacement of the waterproof plug with respect to the electric wire. It is to provide an electric wire with a terminal.

  A first aspect of the present invention relates to a waterproof plug, and is formed of an elastic material and has a cylindrical main body having an inner hole through which an electric wire can be inserted, and a proximal end of the cylindrical main body into which the electric wire is inserted. An annular inner peripheral seal protrusion and an outer peripheral seal protrusion that are provided on the side and project on the inner and outer peripheral surfaces of the cylindrical main body, respectively, and provided on the distal end side of the cylindrical main body from which the electric wire is led out. A fixed cylindrical portion fixed to the electric wire, and the inner hole of the cylindrical main body is elastically deformable and has a circumferential length shorter than a circumferential length of the inner hole. It is characterized in that at least two misalignment prevention ribs projecting toward the inner peripheral side with a larger radial dimension than the seal projection are provided so as to face each other with the electric wire in between.

  According to this aspect, in the waterproof plug formed of an elastic material that is externally inserted into the electric wire, it is elastically deformable from the inner hole of the cylindrical main body through which the electric wire is inserted, and has a larger radial dimension than the inner peripheral seal protrusion. Thus, at least two misalignment prevention ribs projecting toward the inner peripheral side are provided so as to face each other with the electric wire interposed therebetween. As a result, when inserting the electric wire into the inner hole of the cylindrical main body, the tip of the at least two misalignment prevention ribs extends forward in the direction of insertion of the electric wire from the inner peripheral seal protrusion. Is also in close contact with the surface of the electric wire from the outer side with the electric wire in between. Therefore, the reaction force against the load applied to the misalignment prevention rib from the surface of the electric wire as the electric wire is inserted into the waterproof plug is applied from the outer side sandwiching the electric wire, so that the electric wire against the cylindrical body The positioning stability in the insertion direction is improved, and the positional deviation between them is stably prevented. In particular, the tip portions of the at least two misregistration prevention ribs are in close contact with the surface of the electric wire from the outer side sandwiching the electric wire with a larger contact area than the inner peripheral seal protrusion, and therefore in the insertion direction of the electric wire. A large frictional resistance can be exhibited with respect to the movement of the electric wire with respect to the cylindrical main body, and the waterproof plug and the electric wire can be positioned and held more stably. Therefore, according to the waterproof plug of this aspect, since the waterproof plug can be stably held at a desired position with respect to the electric wire, it is possible to advantageously prevent the occurrence of crimping failure of the crimp terminal.

  Since each misalignment prevention rib is formed with a circumferential length shorter than the circumferential length of the inner hole of the cylindrical body, it is easier to elastically deform than the annular inner circumferential seal protrusion. Further, the excessive insertion resistance of the electric wire to the waterproof plug is prevented, and good workability can be ensured.

  Preferably, each misregistration prevention rib has a circumferential length that is 1/2 or less of the circumferential length of the inner hole, and at least two misregistration prevention ribs are provided at the same axial position and are radial. However, the present invention is not limited to this. For example, each misalignment prevention rib is provided with a circumferential length greater than ½ of the circumference of the inner hole and less than or equal to the circumference, and is provided at positions spaced apart from each other in the axial direction so as to face each other with the electric wire in between. You may do it.

  A second aspect of the present invention is the waterproof plug according to the first aspect, wherein each of the misalignment prevention ribs is inclined and extended from the proximal end side to the distal end side of the cylindrical main body. It is what.

  According to this aspect, since each misregistration prevention rib is inclined and extended toward the front end side from the base end side of the cylindrical main body, the radial dimension of each misregistration prevention rib is further ensured. be able to. Therefore, it is possible to secure a larger contact area between each misalignment prevention rib and the surface of the electric wire, and more stably prevent misalignment between the waterproof plug and the electric wire.

  According to a third aspect of the present invention, in the waterproof plug according to the first or second aspect, in the inner hole of the cylindrical main body, the at least two displacement prevention ribs face each other in the radial direction. Including a pair of the pair of misregistration prevention ribs provided so as to face each other in the two radial directions orthogonal to each other.

  According to this aspect, since the electric wire inserted into the inner hole of the cylindrical main body can be held and held by the pair of misalignment prevention ribs in two orthogonal radial directions, the waterproof plug can be more stably provided. It can be positioned and held with respect to the electric wire.

  The fourth aspect of the present invention is a crimping with a waterproof plug, in which a waterproof plug is attached to a wire with a crimp terminal crimped to a core wire exposed by peeling off the insulation coating of the wire end. It is an electric wire with a terminal, and, as the waterproof plug, adopts the waterproof plug according to any one of the first to third aspects, while the fixed tube portion of the waterproof plug is extrapolated to the electric wire terminal. Is crimped and fixed to the electric wire by the cover crimping portion of the crimp terminal.

  According to this aspect, since the waterproof plug having the structure based on the present invention is adopted, the positional deviation between the electric wire and the waterproof plug is advantageously prevented. Therefore, it is possible to advantageously prevent the waterproof plug inserted on the end of the electric wire from being displaced with respect to the electric wire during the crimping process of the crimping terminal and causing a crimping failure.

  According to the present invention, in the waterproof plug formed of an elastic material that is externally inserted into the electric wire, it is elastically deformable from the inner hole of the cylindrical main body through which the electric wire is inserted, and has a larger radial dimension than the inner peripheral seal protrusion. Thus, at least two misalignment prevention ribs projecting toward the inner peripheral side are provided so as to face each other with the electric wire interposed therebetween. Thereby, the front-end | tip part of at least 2 position shift prevention rib is closely contacted to the electric wire surface from the outer side which pinched | interposed the electric wire in a contact area larger than an inner peripheral seal protrusion. Therefore, the reaction force against the load applied to the misalignment prevention rib from the surface of the wire as the wire is inserted into the waterproof plug is applied from the outside, and the mutual misalignment of the wire with respect to the cylindrical body is stabilized. Is prevented. Moreover, since the tip portions of the at least two misalignment prevention ribs are in close contact with the surface of the electric wire with a larger contact area than the inner peripheral seal protrusion, it is possible to exert a large frictional resistance against the movement of the electric wire with respect to the cylindrical body. Since the waterproof plug and the electric wire can be positioned and held more stably, it is possible to advantageously prevent the occurrence of crimp failure of the crimp terminal. In addition, since each misalignment prevention rib is formed with a circumferential length shorter than the circumferential length of the inner hole of the cylindrical body, it is easier to elastically deform than the annular inner circumferential seal protrusion, Good workability can be secured.

The side view which shows the waterproofing stopper as one Embodiment of this invention. The longitudinal cross-sectional view of FIG. The front view of FIG. It is sectional drawing for demonstrating the manufacturing procedure of the electric wire with a crimp terminal provided with the waterproof plug, Comprising: The figure ((a) state which attached the waterproof plug to the electric wire, (b) attached the waterproof plug) Crimp terminal attached to the wire). It is a front view which shows another aspect of the position shift prevention rib of this embodiment, Comprising: The figure corresponded in FIG.

  Embodiments of the present invention will be described below with reference to the drawings.

  First, FIGS. 1 to 3 show a waterproof plug 10 as an embodiment of the present invention. The waterproof plug 10 includes a cylindrical main body 14 having a substantially cylindrical inner hole 12 that can be inserted into an electric wire 38 to be described later and that opens in both length directions (left and right directions in FIGS. 1 and 2). For example, it is integrally formed of a rubber material which is an elastic material such as EPDM (ethylene propylene rubber) or SI (silicone rubber). The waterproof plug 10 is used in a state where the electric wire 38 is inserted into the inner hole 12 as will be described later, and on the proximal end side (right side in FIGS. 1 and 2) where the electric wire 38 is inserted, the cylindrical main body 14. On the inner peripheral surface 16 and the outer peripheral surface 18, there are provided three inner peripheral seal projections 20 and outer peripheral seal projections 22 that protrude substantially annularly over the entire circumference and are separated in the length direction. On the other hand, on the distal end side (the left side in FIGS. 1 and 2) of the tubular main body 14 of the waterproof plug 10 from which the electric wire 38 is led out, a fixed cylinder portion 24 that is crimped and fixed to the electric wire 38 is provided. In addition, as shown in FIG. 3, the distal end portion of the fixed cylinder portion 24 is substantially over the entire circumference except for the notch 26 on the lower end side (the lower end side in FIG. 3) of the outer peripheral surface 18. A retaining protrusion 28 that protrudes in an annular shape is provided. In the following description, “upper” refers to the upper side in FIGS. 1 to 3, “lower” refers to the lower side in FIGS. 1 to 3, and “front” refers to the left side in FIGS. The right side of 1-2 shall be said.

  Moreover, in the inner hole 12 of the cylindrical main body 14 located between the fixed cylinder part 24 and the inner peripheral seal projection part 20, as shown in FIGS. At four positions spaced at equal intervals, there are provided substantially band-shaped misregistration prevention ribs 30 that are inclined and extended from the proximal end side toward the distal end side (left side in FIG. 2). That is, the misregistration prevention rib 30 has two sets of a pair of misregistration prevention ribs 30 and 30 that are opposed to each other in the radial direction, and the two pairs of misregistration prevention ribs 30 and 30 are mutually connected. Are formed so as to be opposed to each other in two radial directions orthogonal to each other (in FIG. 3, the left-right direction and the up-down direction). Furthermore, the misalignment prevention rib 30 is elastically deformable and has a circumferential length L2 shorter than the circumferential length L1 of the inner hole 12, while the radial dimension of the inner circumferential seal protrusion 20 is: It protrudes inward with a radial dimension larger than H1: H2 (see FIG. 3).

  A procedure for manufacturing the electric wire 32 with the crimp terminal provided with the waterproof plug 10 using the waterproof plug 10 having such a structure will be described below. First, as shown in FIG. 4A, an electric wire 38 in which the insulation coating 34 of the electric wire end is peeled and the core wire 36 is exposed is prepared, and the electric wire end of the electric wire 38 is connected to the cylindrical main body of the waterproof plug 10. 14 is inserted into the inner hole 12 from the base end side so that the core wire 36 protrudes completely from the distal end side of the cylindrical main body 14. In this state, the inner peripheral seal protrusion 20 provided on the inner peripheral surface 16 of the cylindrical main body 14 and the misalignment prevention rib 30 are pressed against the surface of the insulating coating 34 of the electric wire 38. In particular, since the misalignment prevention ribs 30 are provided so as to face each other with the electric wire 38 interposed therebetween, the electric wire terminal of the electric wire 38 is distal to the inner hole 12 of the cylindrical main body 14 from the proximal end side. As it is inserted toward the side, it is elastically deformed toward the distal end side and the inner peripheral surface 16 side. As a result, the misalignment prevention rib 30 is pressed against the surface of the electric wire 38 from the outer side with the electric wire 38 sandwiched therebetween with a larger contact area than the inner peripheral seal projection 20. In addition, since the misalignment prevention rib 30 has a belt shape having a circumferential length L2 that is sufficiently shorter than the circumferential length L1 of the inner hole 12, it is easily deformed and increases the insertion resistance of the electric wire 38. Can be advantageously avoided.

  Next, the crimp terminal 40 is attached to the electric wire 38 in which the waterproof plug 10 is extrapolated to the electric wire terminal as described above. More specifically, as shown in FIG. 4 (a), the crimp terminal 40 is coated on the insulation coating 34 of the electric wire terminal of the electric wire 38 from the proximal end side toward the distal end side. It includes a tightening portion 42, a core wire crimping portion 44 to which a core wire 36 exposed by peeling off the insulation coating 34 of the electric wire terminal is crimped, and a connection portion 46 that is conductively connected to an electrical connection target (not shown). It consists of Then, with respect to the crimping terminal 40 from above, the electric wire 38 to which the waterproof plug 10 is attached is placed on the core wire crimping portion 44 of the crimping terminal 40 and the fixed cylinder portion 24 of the waterproof plug 10. Is disposed so as to be placed on the cover crimping portion 42 of the crimp terminal 40. At this time, since the lower end side of the retaining projection 28 is flattened by the notch 26, the fixed cylinder portion 24 of the waterproof plug 10 is stably placed on the cover crimping portion 42. ing. Subsequently, by using a known crimping device, the core wire crimping portion 44 of the crimp terminal 40 is crimped to the core wire 36 of the electric wire 38, and the fixed cylinder portion 24 of the waterproof plug 10 is covered with the crimp terminal 40. The crimping part 42 is crimped and fixed to the insulating coating 34 of the electric wire 38. As a result, the core wire 36 of the electric wire 38 is crimped and connected to the crimping terminal 40, and the waterproof plug 10 is crimped and fixed to the crimping terminal 40 and the electric wire 38 at the cover crimping portion 42 of the crimping terminal 40. The electric wire 32 with a crimp terminal provided with the waterproof plug 10, in which the waterproof plug 10 is attached to the electric wire 32, is completed. In addition, in order to understand easily, in FIG. 4, the electric wire 38 and the crimp terminal 40 are described with the virtual line.

  By the way, the crimped terminal-equipped electric wire 32 having the waterproof plug 10 formed in this way is accommodated and disposed in a terminal cavity of a connector housing (not shown), for example, so that the outer peripheral seal protrusion 22 and the inner peripheral seal protrusion 20 A waterproof connector in which waterproofing between the electric wire 38 and the terminal cavity is realized is configured.

  According to the waterproof plug 10 having such a structure, the positional deviation prevention that protrudes from the inner peripheral surface 16 of the cylindrical main body 14 with a radial dimension: H2 larger than the radial dimension: H1 of the inner peripheral seal projection 20 is provided. The ribs 30 project so as to face each other with the electric wire 38 interposed therebetween. Thereby, as the electric wire terminal of the electric wire 38 is inserted from the proximal end side toward the distal end side with respect to the inner hole 12 of the cylindrical main body 14, the misalignment prevention rib 30 is formed on the distal end side and the inner peripheral surface 16. Since it is elastically deformed toward the side, it is pressed against the surface of the electric wire 38 from the outer side with the electric wire 38 sandwiched between them with a larger contact area than the inner peripheral seal projection 20. Therefore, a reaction force against a load applied to the misalignment prevention rib 30 from the surface of the electric wire 38 when the electric wire 38 is inserted into the waterproof plug 10 is applied from the outer side with the electric wire 38 interposed therebetween. Positioning stability of the cylindrical main body 14 in the insertion direction is improved, and mutual displacement between them is stably prevented. In addition, since the tip portion of the misalignment prevention rib 30 is pressed against the surface of the electric wire 38 with a larger contact area than the inner peripheral seal projection 20, a large amount of friction is generated against the displacement of the electric wire 38 in the insertion direction. Resistance can be exhibited, and the waterproof plug 10 and the electric wire 38 can be positioned and held more stably. Therefore, according to the waterproof plug 10 of the present invention, when the waterproof plug 10 is displaced with respect to the electric wire 38, for example, when the electric wire 38 is excessively protruded from the distal end portion of the waterproof plug 10, the core wire 36 of the electric wire 38 is added to the core wire. When the fastening portion 44 is crimped together with the insulating coating 34 to cause a connection failure, or when the core wire 36 of the electric wire 38 does not protrude sufficiently from the tip end portion of the waterproof plug 10, the core wire 36 is connected to the core wire crimping portion 44. In this case, it is possible to advantageously prevent the occurrence of crimping failure of the crimping terminal 40 such that it is easy to come out without being sufficiently crimped.

  In addition, since the misalignment prevention rib 30 is formed with a radial dimension H2 larger than the radial dimension H1 of the inner peripheral seal protrusion 20, elastic deformation is easier than the inner peripheral seal protrusion 20. Thus, excessively increasing the insertion resistance of the electric wire 38 into the inner hole 12 of the waterproof plug 10 is prevented, and good workability can be secured. Further, since the misregistration prevention rib 30 extends while inclining from the proximal end side to the distal end side of the cylindrical main body 14, the radial dimension of the misregistration prevention rib 30 can be further ensured. . Therefore, since the contact area between the misalignment prevention rib 30 and the surface of the electric wire 38 can be ensured, the misalignment of the waterproof plug 10 and the electric wire 38 can be prevented more stably.

  As mentioned above, although embodiment of this invention has been described, this invention is not limited at all by the specific description in this embodiment. For example, in the above-described embodiment, the misregistration prevention rib 30 has a circumferential length of about 1/25 that is not more than half the circumference of the inner hole 12, and the four misregistration prevention ribs 30 have the same axial position. However, it is possible to arbitrarily set the circumferential length and the disposition position of the misregistration prevention rib 30. For example, as in the waterproof plug 48 according to another aspect of the present invention shown in FIG. 5, the circumferential length L2 of the two misalignment prevention ribs 50 is set to about half the circumferential length L1 of the inner hole 12. Alternatively, it may be provided with a circumferential length greater than half and less than or equal to the circumferential length, and may be provided at positions spaced apart from each other in the axial direction so as to face each other with the electric wire 38 interposed therebetween. Further, the number of the misalignment prevention ribs 30 and 50 can be set to an arbitrary value of 2 or more. Furthermore, in the above-described embodiment, the misalignment prevention ribs 30 and 50 are integrally formed with the waterproof plugs 10 and 48. However, they may be fixed after being molded separately. In addition, in the above embodiment, the waterproof plugs 10 and 48 are made of a rubber elastic body, but may be made of a thermoplastic elastomer (TPE) such as styrene or olefin other than the rubber elastic body. .

10, 48: waterproof plug, 12: inner hole, 14: cylindrical main body, 16: inner peripheral surface, 18: outer peripheral surface, 20: inner peripheral seal protrusion, 22: outer peripheral seal protrusion, 24: fixed cylinder portion, 30, 50: Misalignment prevention rib, 32: Electric wire with crimp terminal, 34: Insulation coating, 36: Core wire, 38: Electric wire, 40: Crimp terminal, 42: Cover crimping part

Claims (4)

A cylindrical body formed of an elastic material and having an inner hole through which an electric wire can be inserted;
An annular inner peripheral seal protrusion and an outer peripheral seal protrusion that are provided on the proximal end side of the cylindrical main body into which the electric wire is inserted and protrude on the inner and outer peripheral surfaces of the cylindrical main body,
A fixed cylinder portion provided on the distal end side of the cylindrical main body from which the electric wire is led out and fixed to the electric wire;
The inner hole of the cylindrical body is elastically deformable, has a circumferential length shorter than the circumferential length of the inner hole, and has a larger radial dimension than the inner circumferential seal protrusion on the inner circumferential side. A waterproof plug, characterized in that at least two projecting misalignment prevention ribs project so as to face each other with the electric wire in between.   2. The waterproof plug according to claim 1, wherein each of the misregistration prevention ribs is inclined and extended from the base end side to the tip end side of the cylindrical main body.   In the inner hole of the cylindrical main body, the at least two misregistration prevention ribs are two sets of a pair of misregistration prevention ribs facing each other in the radial direction, and two radial directions orthogonal to each other. The waterproof plug according to claim 1 or 2, including one provided so as to face each other. A wire with a crimping terminal equipped with a waterproof plug, with a waterproof plug attached to a crimped terminal-attached electric wire with a crimp terminal crimped to the exposed core wire after the insulation coating is peeled off,
While adopting the waterproof plug according to any one of claims 1 to 3, as the waterproof plug,
An electric wire with a crimping terminal provided with a waterproof plug, wherein the fixed cylindrical portion of the waterproof plug inserted around the electric wire terminal is crimped and fixed to the electric wire by a cover crimping portion of the crimp terminal.

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