JP5125919B2 - Waterproof connector - Google Patents

Description

The present invention relates to a waterproof connector.

  Conventionally, what was described in patent document 1 is known as an example of the waterproof connector which aimed at individual waterproofing. In this case, the wire barrel of the terminal fitting is crimped to the end of the core wire of the electric wire in which the metal core wire is covered with the insulation coating, and the rubber plug having the lip around the outer peripheral surface is provided on the end of the insulation coating. The insulation barrel of the terminal fitting is pressure-bonded to the fitting portion provided on the front end side of the rubber plug and the end of the insulation coating, and the terminal fitting is inserted into the cavity provided in the connector housing. Accordingly, a rubber plug is fitted into the rear end of the cavity, and the lip is sealed by elastically contacting the inner peripheral surface of the cavity. Further, in order to keep the insertion resistance of the rubber plug small, a guide portion having a tapered shape is provided at the rear end of the cavity.

By the way, in recent years, the demand for miniaturization of connectors has been severe, and for example, the margin of the rear end of the cavity, that is, the position of the lip of the rubber plug is displaced rearward to ensure the close contact with the inner peripheral surface of the cavity. There is a tendency to make the margin for sealing as short as possible. More specifically, as described above, the rubber plug is fitted to the end of the insulation coating of the electric wire and fixed by caulking the mounting portion provided on the front end side thereof with the insulation barrel of the terminal fitting. However, if the fitting position of the rubber plug stays behind the normal position, the rubber plug is fixed in a state of being shifted backward, that is, even if the terminal fitting is properly inserted into the cavity, the rubber plug is fixed. The stopper is fitted behind the normal position. Therefore, the above-described error in the fitting position of the rubber plug, particularly an error in the rear, is anticipated, and a margin length is secured so that the lip is positioned in front of the guide portion even if the rubber plug is displaced rearward. However, the margin length is shortened.
JP 2002-280108 A

  On the other hand, in the field of automobile wire harnesses, aluminum wires have been used for the purpose of reducing the weight of the wires. Aluminum wires have a core wire made of aluminum or aluminum alloy, but they don't like the formation of a strong oxide film on the surface of the core wire, and a wire barrel is crimped to the core wire to connect the terminal fitting to the terminal. In such a case, there is a concern that the contact resistance increases due to the presence of an oxide film between the two. For this reason, the oxide film is broken and peeled by crimping the wire barrel with high compression, and the exposed new surface of the core wire is brought into contact with the inner surface of the wire barrel so that the contact resistance is reduced, that is, the electrical performance is improved. Yes.

However, when the wire barrel is crimped with high compression in this way, the crimped portion and thus the entire terminal fitting extend in the axial direction, and the position of the rubber plug crimped to the insulation barrel is also protruded rearward. Therefore, especially in the case of an aluminum wire, when the fitting position of the rubber plug is shifted backward, even if it is within the error, the lip of the rubber plug may move back to the position of the guide part. There was a risk that the amount of lip rebound was insufficient and the sealing performance was impaired.
The present invention has been completed based on the above circumstances, and its purpose is to make it possible to visually determine whether or not the rubber plug is fitted in a position that can be properly sealed. is there.

In the waterproof connector of the present invention, a wire barrel of a terminal fitting is crimped to an end of the core wire in an electric wire in which a metal core wire is covered with an insulating coating, and a lip is provided on an outer peripheral surface of the end of the insulating coating. An insulation barrel of the terminal fitting is pressure-bonded to the mounting portion provided on the front end side of the rubber plug and the end of the insulating coating, and the terminal fitting is attached to the connector. As the rubber stopper is inserted into the cavity provided in the housing, the rubber plug is fitted to the rear end of the cavity so that the lip is in close contact with the inner peripheral surface of the cavity for sealing. in the waterproof connector that, while the rear of the lip on the outer peripheral surface of the rubber plug is Ru is formed indicator portion, contact the rear end surface of the cavity is a detection position of the indicator portion , Dimension between the lip and the indicator portion is set larger than the dimension between the detection position and the rear end position of the area where the lip of the inner peripheral surface of the cavity may be in close contact with the normal However, it has characteristics.

  According to the above configuration, when the rubber plug is fitted to the rear end portion of the cavity, if the index portion of the rubber plug is in front of the detection position set in the cavity, the lip of the rubber plug is properly adhered. If the index portion is located behind the detection position, the lip of the rubber plug is located behind the area where it can be properly adhered. That is, by visually observing the position of the indicator portion, it can be determined whether or not the rubber plug is fitted in a position where it can be properly sealed.

In addition, it is good also as following structures.
(1) The cavity has a structure in which a guide portion for leading in a taper shape with a front opening is continuously provided behind an equal-diameter portion where the lip of the rubber plug can be elastically compressed. The rear end position of the region where the lip of the rubber plug can be properly adhered is the rear end position of the equal-diameter portion, and the detection position is the rear end surface of the guide portion.
If the index part of the rubber plug is in front of the rear end face of the guide part of the cavity, the lip of the rubber plug is in the same diameter part of the cavity, and if the index part is behind the rear end face of the guide part, the rubber The stopper lip faces the guide. Since the detection position is the rear end surface of the guide portion, it is not necessary to change the shape of the cavity, and the relative position of the index portion of the rubber plug can be easily determined.

(2) The indicator portion of the rubber plug is an annular rib formed along the circumferential direction. Compared with the groove-shaped one, it is easier to visually check when the indicator part enters the cavity.
(3) The indicator portion of the rubber plug is formed by a plurality of protrusions protruding at intervals in the circumferential direction. Since the shape of the indicator portion is significantly different from the shape of the lip, the indicator portion can be easily recognized.

  (4) The said electric wire is an aluminum electric wire provided with the core wire made from aluminum or aluminum alloy. This is particularly useful when an aluminum electric wire that tends to jump out rearward of the rubber plug is used.

  According to the present invention, it is possible to visually determine whether or not the rubber plug is fitted in a position that can be properly sealed.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
<Embodiment 1>
A first embodiment of the present invention will be described with reference to FIGS.
In this embodiment, a female terminal fitting 20 (hereinafter referred to as a female terminal fitting 20) is connected to the terminal of the aluminum electric wire 10, and the female terminal fitting 20 is a cavity of the female connector housing 40 (hereinafter referred to as a female housing 40). A waterproof connector is illustrated which is inserted into 41 and sealed with a rubber stopper 30 closing the rear end of the cavity 41.
However, the female housing 40 is originally formed to accommodate the female terminal fitting 20 connected to the end of the copper wire.

  As shown in FIG. 1, the aluminum electric wire 10 has a core wire 11 formed of a twisted wire obtained by twisting a plurality of strands 12 made of aluminum or aluminum alloy, and an insulating coating 13 made of synthetic resin is formed around the core wire 11. The structure is covered with.

The female terminal fitting 20 is formed by pressing a copper alloy plate, and as shown in FIG. 2, has a substantially rectangular tube shape that is electrically connected to a mating male terminal fitting (not shown). A wire barrel 25 and an insulation barrel 26 are provided behind the terminal connection portion 21.
An elastic contact piece 23 is provided inside the terminal connection portion 21 so as to be folded back from the front edge of the bottom plate 22, and the tab of the mating male terminal fitting described above is connected to the terminal connection portion 21 from the front. By inserting and elastically contacting the elastic contact piece 23, the male terminal fitting and the female terminal fitting 20 are electrically connected. A lance hole (not shown) is formed on the bottom surface of the terminal connection portion 21.

  The wire barrel 25 is an open barrel type, and a pair of left and right wide barrel pieces 25 </ b> A are formed to rise from the left and right side edges of the bottom plate 22. The wire barrel 25 is caulked and crimped to the end of the core wire 11 of the aluminum electric wire 10 described above, and both barrel pieces 25A hold the outer ends of the ends of the core wire 11 from both the left and right sides while abutting the protruding ends. In other words, it can be caulked into a so-called heart shape.

The insulation barrel 26 is also of an open barrel type, and a pair of left and right barrel pieces 26A that are narrower and taller than the barrel pieces 25A on the wire barrel 25 side are similarly connected to each other from the left and right side edges of the bottom plate 22. It is formed so as to face each other.
On the other hand, a rubber plug 30 which will be described in detail later is fitted to the end of the insulating coating 13 where the aluminum electric wire 10 is left, and the above-described insulation barrel 26 includes the terminal of the insulating coating 13 and the mounting portion 32 of the rubber plug 30. It is caulked and crimped over the entire area. The insulation barrel 26 can be caulked into a so-called overlap type, for example, by embedding the outer periphery of the mounting portion 32 of the rubber plug 30 from both the left and right sides while the two barrel pieces 26A overlap each other. Yes.

The rubber plug 30 is made of oil-impregnated silicon or the like, and is formed in a cylindrical shape that is long in the front-rear direction as a whole, as shown in FIG. The insulating coating 13 of the aluminum electric wire 10 is tightly inserted into the inner peripheral side of the rubber plug 30.
The rubber plug 30 has a main body portion 31 having an equal diameter at the rear half strength, while the front side has a tapered shape that is slightly thinner than the main body portion 31 and is gradually reduced in diameter toward the tip. An attachment portion 32 is provided. The insulation barrel 26 of the female terminal fitting 20 is caulked to the mounting portion 32 as described above.

A cavity lip that elastically adheres to the inner peripheral surface of the cavity 41 formed in the female housing 40 on the outer peripheral surface of the main body portion 31 of the rubber plug 30, specifically, on the outer peripheral surface of the front half portion of the main body portion 31. 34 protrudes. The cavity lip 34 is formed in a ring shape over the entire circumference with a mountain-shaped cross section, and is formed in two strips with a space in the front and rear. Of the two cavity lips 34, the rear cavity lip is particularly distinguished by attaching a reference numeral “34 </ b> A” for the convenience of describing the rear cavity lip alone. The rear cavity lip 34A corresponds to the lip of the present invention.
Further, at positions corresponding to the insides of the above-described cavity lips 34 on the inner peripheral surface of the main body 31, electric wire lips 36 that are elastically adhered to the outer peripheral surface of the insulating coating 13 of the aluminum electric wire 10 are formed. ing.

The procedure for crimping the female terminal fitting 20 and the rubber plug 30 to the end of the aluminum electric wire 10 is as follows.
The rubber plug 30 is passed through the end of the aluminum wire 10, and the end of the insulating coating 13 of the aluminum wire 10 is peeled in a state where the rubber plug 30 is once retracted to the rear, and the end of the core wire 11 has a predetermined length. It is made an exposure state over. After that, the rubber plug 30 is moved forward, and the rubber plug 30 is fitted on the outer periphery of the end of the insulating coating 13 where the mounting portion 32 is left.

  Then, the female terminal fitting 20 and the rubber plug 30 are crimped and connected to the end of the aluminum electric wire 10 using a crimping device. Specifically, the crimping device is provided with an anvil and a crimper, and the exposed end of the core wire 11 with respect to the wire barrel 25 of the female terminal fitting 20 and the insulation remaining with respect to the insulation barrel 26. The end of the covering 13 and the mounting portion 32 of the rubber plug 30 fitted thereto are set in a state where they are arranged, and both the barrels 25 and 26 are crimped between the anvil and the crimper. As a result, the female terminal fitting 20 and the rubber plug 30 are both crimped and fixed to the end of the aluminum electric wire 10.

A cavity 41 is formed in the female housing 40 so that the female terminal fitting 20 connected to the end of the aluminum electric wire 10 can be inserted from behind. The front wall 42 of the cavity 41 has a terminal insertion opening 43 into which a tab of a mating male terminal fitting is inserted, and a lance 44 that can be elastically displaced is provided on the front bottom wall.
Further, on the rear side of the cavity 41, a seal portion 45 having a circular cross section is formed over a region that is a little less than half of the entire length. Specifically, the seal portion 45 is constituted by an equal-diameter portion 46 having an inner diameter smaller than the outer diameter of the cavity lip 34 of the rubber plug 30 by a predetermined dimension. In addition, a guide portion 47 for guiding, which is tapered forward toward the opening edge, is formed at the rear end of the seal portion 45 in a form connected to the equal-diameter portion 46.

  The female terminal fitting 20 crimped to the end of the aluminum electric wire 10 as described above is inserted into the cavity 41 of the female housing 40 from the rear. When the female terminal fitting 20 is pushed in while elastically displacing the lance 44 and is inserted to a normal position where it hits the front wall 42, the female terminal fitting 20 is fitted and locked in the lance hole while the lance 44 is displaced backward. At the same time, the rubber plug 30 is fitted into the seal portion 45, and in detail, both the lip 34 for the cavities are in close contact with the inner peripheral surface of the equal-diameter portion 46 for sealing. .

  However, as described above, the female housing 40 is originally formed to accommodate the female terminal fitting 20 connected to the end of the copper wire. When the rubber plug 30 is fixed to the end of the copper wire together with the female terminal fitting 20, similarly, the rubber plug 30 is fitted to the end of the copper wire insulation coating 13 and provided on the front end side thereof. The mounting portion 32 is fixed by caulking with the insulation barrel 26 of the female terminal fitting 20, but as shown in FIG. 4, the fitting position of the rubber plug 30 remains behind the normal position. The rubber plug 30 is fixed in a state of being displaced rearward, that is, even if the female terminal fitting 20 is properly inserted into the cavity 41, the rubber plug 30 is fitted rearward from the normal position. It will be. Accordingly, the above-described error in the fitting position of the rubber plug 30, particularly an error in the rear, is anticipated so that the rear cavity lip 34 </ b> A stays at the equal diameter portion 46 even if the rubber plug 30 is displaced rearward, etc. The diameter portion 46 has a minimum margin length.

Now, in the rubber plug 30 of the present embodiment, the indicator portion 50 is formed at the rear position of the rear cavity lip 34 </ b> A on the outer peripheral surface of the main body portion 31. The index portion 50 is used to determine whether or not the rear cavity lip 34 </ b> A remains on the equal diameter portion 46 when the rubber plug 30 is fitted to the seal portion 45 as described above. Is.
The indicator portion 50 is formed by arranging a plurality of substantially hemispherical protrusions 51 around the entire circumference at predetermined intervals in the circumferential direction. As shown in FIG. 1, the dimension S between the index portion 50 and the rear cavity lip 34 is such that the rear cavity lip 34 is positioned at the rear end position of the equal-diameter portion 46 in the seal portion 45. Is set so that the indicator portion 50 comes to the rear end surface 47A (opening surface) of the guide portion 47 when it is at a position that is a small dimension before the boundary with the guide portion 47. Therefore, the rear end surface 47A of the guide portion 47 corresponds to the detection position of the present invention.

The operation of this embodiment will be described.
The female terminal fitting 20 is fixed to the end of the aluminum electric wire 10 together with the rubber plug 30 as described above. However, the aluminum electric wire 10 has an oxide film formed on the surface when the surface of the core wire 11 is in contact with the outside air. In order to peel off the oxide film, the wire barrel 25 is caulked with high compression, that is, crimped in order to peel off the oxide film. As a result, although the contact resistance between the core wire 11 and the wire barrel 25 can be reduced, on the other hand, the crimped portion of the wire barrel 25 extends in the axial direction, and consequently the total length of the female terminal fitting 20 increases. Then, even when the female terminal fitting 20 is properly inserted into the cavity 41, the rubber plug 30 is fitted to the seal portion 45 in a state of being relatively displaced rearward.

Here, as described above, since the marginal length is secured in advance in the equal-diameter portion 46 of the seal portion 45, if the rubber plug 30 is fitted in the vicinity of the normal position, the extension of the female terminal fitting 20 is achieved. The rearward displacement of the rubber plug 30 is substantially absorbed by the marginal length portion of the equal-diameter portion 46, and the rear cavity lip 34 has a rear end of the equal-diameter portion 46 as shown in FIG. It remains in position and is in a state where it can exert its sealing function. At this time, the index portion 50 of the rubber plug 30 is at the position of the rear end surface 47A of the guide portion 47 or at the front (inside) position thereof.
In other words, if the position of the index portion 50 of the rubber plug 30 is in front (inside) of the rear end surface 47A of the guide portion 47, the lip 34 for both cavities of the rubber plug 30 is the inner peripheral surface of the equal diameter portion 46. It can be determined that the sealing function can be properly exhibited.

  On the other hand, as shown in FIG. 4, when the fitting position of the rubber plug 30 is greatly displaced backward from the normal position, when the rubber plug 30 is displaced backward due to the extension of the female terminal fitting 20. Therefore, the marginal length of the equal-diameter portion 46 can no longer be absorbed, so that the rear cavity lip 34A is retracted to the position of the guide portion 47, and the amount of retraction of the lip 34A is insufficient to provide a sealing function. It will be in a state where it cannot be demonstrated. At that time, the index portion 50 of the rubber plug 30 protrudes rearward (outside) from the position of the rear end surface 47A of the guide portion 47.

  In other words, if the position of the index portion 50 of the rubber plug 30 protrudes outside the rear end surface 47A of the guide portion 47, the cavity lip 34A at least on the rear side of the rubber plug 30 moves back to the position of the guide portion 47. Therefore, it can be determined that the seal function cannot be properly exhibited. In response to this, it is urged to replace the rubber plug 30 with a new one that is fitted and crimped in the proper position.

  As described above, according to the present embodiment, after the rubber plug 30 is fitted to the seal portion 45 of the cavity 41, the index portion 50 is viewed from the rear end surface 47 </ b> A of the guide portion 47. If there is, the rubber plug 30 is in a position where the sealing function can be properly exhibited, and conversely, if the index portion 50 is behind the rear end face 47A of the guide portion 47, it is determined that it is in a position where the sealing function cannot be exhibited. it can. What has been determined that the sealing function cannot be exhibited may be exchanged with a new one so that the sealing function can be exhibited. As a result, it is possible to prevent the sealing function by the rubber plug 30 from being incomplete.

  Further, since the detection position of the index portion 50 is the rear end face 47A of the guide portion 47, it is not necessary to change the shape of the cavity 41, and the relative position of the index portion 50 can be easily determined. Furthermore, the indicator portion 50 has a shape in which a plurality of hemispherical protrusions 51 are arranged over the entire circumference with a predetermined interval in the circumferential direction, and the shape of the lip forming an annular protrusion Since it is greatly different, it is easy to recognize as the index unit 50.

<Embodiment 2>
FIG. 5 shows a second embodiment of the present invention. In the second embodiment, the index portion 50A provided on the rubber plug 30A is constituted by an annular rib 53 extending over the entire circumference which is lower than the cavity lip 34.
Compared to the first embodiment, the structure of the mold is simplified to form the index portion 50A. Further, as compared with the groove-shaped one, it is easy to visually check when the index portion 50A enters the inside of the cavity 41.

<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, two lip cavities for rubber plugs are illustrated, but only one or three or more lips may be provided. When three or more strips are provided, the lip disposed on the rearmost side corresponds to the lip of the present invention.

(2) The shape of the indicator portion is not limited to those exemplified in the above-described embodiments, and a plurality of arc-shaped protrusions may be arranged in a circle at intervals, or may be in a groove shape. Furthermore, it may be provided only in a part of the entire circumference, and the point is that it can display the position behind a predetermined distance from the lip.
(3) The detection position for detecting the position of the index part of the rubber plug is not limited to the rear end surface of the guide part, and may be set to other positions such as a position within a predetermined dimension in the guide part.

(4) In the above embodiment, the female terminal fitting is exemplified as the terminal fitting to be connected to the end of the aluminum wire with the rubber plug. However, the male terminal fitting having the male tab, the LA terminal having the eyeball-shaped connecting portion, etc. Other terminal fittings may be used.
(5) The present invention is also effective when other wires such as copper wires are used in addition to the aluminum wires exemplified in the above embodiment. Even if the terminal fitting does not stretch as much as when using an aluminum wire, if the fitting position of the rubber plug itself is greatly displaced, there is a possibility that the seal will be deficient. Can be prevented.

Sectional drawing which shows the state by which the rubber stopper which concerns on Embodiment 1 of this invention was fitted by the appropriate range Perspective view of female terminal fitting Longitudinal section of rubber stopper Sectional drawing which shows the state by which the rubber stopper was inserted in the improper position Side view of rubber plug according to Embodiment 2

Explanation of symbols

10 ... Aluminum wire (wire)
DESCRIPTION OF SYMBOLS 11 ... Core wire 13 ... Insulation coating 20 ... Female terminal metal fitting (terminal metal fitting)
25 ... Wire barrel 26 ... Insulation barrel 30,30A ... Rubber plug 31 ... Body part 32 ... Mounting part 34A ... Rip for cavity on the rear side (lip)
40. Female housing (connector housing)
41 ... Cavity 45 ... Seal part 46 ... Equal diameter part 47 ... Guide part 47A ... Rear end face (of the guide part 47) (detection position)
50, 50A ... indicator portion 51 ... protrusion 53 ... rib

Claims (5)

A wire barrel of a terminal fitting is crimped to the end of the core wire in an electric wire in which a metal core wire is covered with an insulation coating, and a rubber plug having a lip around the outer peripheral surface is fitted to the end of the insulation coating. An insulation barrel of the terminal fitting is pressure-bonded to the mounting portion provided on the front end side of the rubber plug and the end of the insulating coating, and the terminal fitting is placed in a cavity provided in the connector housing. In the waterproof connector, the rubber plug is fitted to the rear end of the cavity as it is inserted into the cavity, and the lip is sealed by elastically contacting the inner peripheral surface of the cavity.
While said rearward lip Ru is formed indicator portion on the outer peripheral surface of the rubber plug, the rear end surface of the cavity has a detection position of the indicator portion,
The dimension between the lip and the indicator portion is set to be larger than the dimension between the rear end position of the region where the lip can be properly adhered to the inner peripheral surface of the cavity and the detection position. Waterproof connector featuring. The cavity has a structure in which a guide portion for leading in a tapered shape is continuously provided behind an equal diameter portion where the lip of the rubber plug can be elastically compressed. 2. The waterproofing according to claim 1, wherein a rear end position of the region where the lip can be properly adhered is a rear end position of the equal-diameter portion, and the detection position is a rear end surface of the guide portion. connector. The waterproof connector according to claim 1, wherein the indicator portion of the rubber plug is a ring-shaped rib formed along a circumferential direction. The waterproof connector according to claim 1, wherein the indicator portion of the rubber plug is formed by a plurality of protrusions protruding at intervals in the circumferential direction. The waterproof connector according to claim 1, wherein the electric wire is an aluminum electric wire having a core wire made of aluminum or an aluminum alloy.

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