EP2760087A1

EP2760087A1 - Waterproof structure for cable connector, plug connector using same and receptacle connector

Info

Publication number: EP2760087A1
Application number: EP20120833754
Authority: EP
Inventors: Someya Toshiyuki
Original assignee: Yamaichi Electronics Co Ltd
Current assignee: Yamaichi Electronics Co Ltd
Priority date: 2011-09-22
Filing date: 2012-09-21
Publication date: 2014-07-30
Also published as: EP2760087A4; WO2013042776A1; JP2013069550A; CN103891059A

Abstract

In a cable connector (16), guide pieces (20PA, 20PB) of lock piece portions (18RF, 18LF) of a cover member 18 are respectively locked to lock nibs (20RN1, 20RN4, 20LN1, and 20LN4) of a connector body (20), and lower end portions of the lock piece portions (18RF, 18LF) are respectively caught by lock nibs (20RN2, 20RN3, 20LN2, and20LN3) of the connector body (20). In this state, an upper surface portion of the cover member (18) placed substantially parallel to a bottom surface portion of the connector body (20) can be sucked and held by a component mounting machine, and a connecting end portion of a flexible wiring board (10) is made insertable into a cable housing portion (20A) through a cable slot.

Description

Technical Field

The present invention relates to a waterproof structure for a cable connector, and a plug connector and a receptacle connector using the same.

Background Art

Waterproof cable connectors are generally in practical use for electrically connecting between photovoltaic modules as well as a photovoltaic module and an electric switchboard. As shown in PATENT LITERATURE 1, for example, such a cable connector comprises : a male terminal lug as a contact terminal; a sealing tube which covers an electric wire crimp portion of the male terminal lug and an insulating jacket of a cable; and a housing joined to one end of the cable by molding.
One end of the cylindrical sealing tube molded from a heat shrinkable synthetic resin is attached to a distal end of the insulating jacket of the cable, while another end of the sealing tube is attached to the electric wire crimp portion of the male terminal lug. Hereby, the distal end of the insulating jacket of the cable and the electric wire crimp portion of the male terminal lug are sealed with the sealing tube.
In addition, the distal end of the insulating jacket of the cable and the electric wire crimp portion of the male terminal lug sealed with the sealing tube are buried into the above-mentioned housing by molding. Accordingly, a liquid from outside such as rain water is prevented from running down the insulating jacket of the cable and entering the male terminal lug and the electric wire crimp portion in the housing. Moreover, a connecting end portion of the cable is securely held in the housing with a sufficient holding force by molding.

Citation List

Patent Literature

PLT 1: Japanese Patent Laid-Open No. 2002-298656

Summary of Invention

In the case of performing installation work for photovoltaic modules using the above-described cable connectors, components are each prepared in advance by connecting the above-described connector to an end portion of each cable set to a predetermined length, and then the installation work is carried out.
However, in the installation work, there may be a case where the required length of a cable is changed on site by necessity due to a change in the location to install a photovoltaic module or the like. In this case, for the above-described cable connector, it is necessary to form a component by connecting the above-described connector to an end portion of a cable having the changed length by molding. Thus, since it is difficult to form the component on site by connecting the above-described connector to the end portion of the cable, there is a problem that the installation work may be suspended until the new cable is prepared.
In view of the above-described problem, the present invention aims to provide a waterproof structure for a cable connector, and a plug connector and a receptacle connector using the same. The waterproof structure for a cable connector and the plug connector and the receptacle connector using the same can attach a cable connector to an end portion of a cable easily with a sufficient holding force without requiring molding, and also securely prevent entry of a liquid into the cable connector.
For the purpose of achieving the foregoing object, a waterproof structure for a cable connector according to the present invention comprises: a housing configured to accommodate a contact terminal in a detachably and attachably manner, one end of a cable being connected; a sealing cylinder placed in the housing, having multiple pressing pieces and multiple engagement portions formed on a common circumference along outer peripheral portions of the pressing pieces, and configured to hold a sealing tube inside the multiple pressing pieces, the sealing tube being attached to an outer peripheral portion of the cable inserted in the housing; and a pressing member having a through-hole to accommodate the multiple pressing pieces of the sealing cylinder, and configured to press the multiple pressing pieces of the sealing cylinder and the sealing tube against the outer peripheral portion of the cable in the housing when the contact terminal to which the one end of the cable is connected is accommodated in the housing, wherein the multiple engagement portions of the sealing cylinder are movably engaged with portions being engaged formed on a periphery of the through-hole in the pressing member.
The through-hole of the pressing member may include: a large-diameter portion opened toward one end; a small-diameter portion formed in a wall portion of another end opposed to the one end; and a reducing portion formed between the large-diameter portion and the small-diameter portion and provided with a conical surface, with the large-diameter portion, the small-diameter portion and the tapered formed being provided on a common center axis. Each of the multiple engagement portions of the sealing cylinder may be a projection formed to project in a radial direction, and may be engaged with an extreme thread of a female thread portion formed in the large-diameter portion.
Each of the multiple pressing pieces of the sealing cylinder has a rake surface which is at a predetermined rake angle to a plane including a center line extending in a radial direction.
The sealing cylinder may include a contact receiving portion to accommodate the contact terminal. The contact terminal may include: a conductor connecting portion where an inner conductor of the cable is placed; and a clip piece rotational movably provided to the conductor connecting portion, and configured to take a locked position where the inner conductor of the cable is held on the conductor connection portion and an unlocked position where the inner conductor of the cable is released from the conductor connecting portion. The conductor connecting portion of the contact terminal may further include a lock nib portion configured to hold the inner conductor of the cable in cooperation with one end of the clip piece.
A plug connector according to the present invention comprises: a plug housing configured to accommodate a plug contact terminal in a detachably and attachably manner, the plug contact terminal including a rod-shaped contact end portion to which one end of a cable is connected; a sealing tube attached to an outer peripheral portion of the cable inserted in the plug housing; a sealing cylinder placed in the plug housing, having multiple pressing pieces and multiple engagement portions formed on a common circumference along outer peripheral portions of the pressing pieces, and configured to hold the sealing tube inside the multiple pressing pieces, the sealing tube being attached to the outer peripheral portion of the cable inserted in the plug housing; and a pressing member having a through-hole to accommodate the multiple pressing pieces of the sealing cylinder, and configured to press the multiple pressing pieces of the sealing cylinder and the sealing tube against the outer peripheral portion of the cable in the plug housing when the plug contact terminal to which the one end of the cable is connected is accommodated in the plug housing, wherein the multiple engagement portions of the sealing cylinder are movably engaged with portions being engaged formed on a periphery of the through-hole in the pressing member.
The through-hole of the pressing member may include: a large-diameter portion opened to one end; a small-diameter portion formed in a wall portion of another end opposed to the one end; and a reducing portion formed between the large-diameter portion and the small-diameter portion and provided with a conical surface, with the large-diameter portion, the small-diameter portion and the tapered formed being provided on a common center axis. Each of the multiple engagement portions of the sealing cylinder may be a projection formed to project in a radial direction, and may be engaged with an extreme thread of a female thread portion formed in the large-diameter portion.
Each of the multiple pressing pieces of the sealing cylinder may include a rake surface which is at a predetermined rake angle to a plane including a center line extending in a radial direction.
The sealing cylinder may include a contact receiving portion configured to accommodate the contact terminal. The contact terminal may include: a conductor connecting portion where an inner conductor of the cable is placed; and a clip piece rotational movably provided to the conductor connecting portion, and configured to take a locked position where the inner conductor of the cable is held on the conductor connection portion and an unlocked position where the inner conductor of the cable is released from the conductor connecting portion. The conductor connecting portion of the contact terminal may further include a lock nib portion configured to hold the inner conductor of the cable in cooperation with one end of the clip piece.
Furthermore, a receptacle connector according to the present invention comprises: a receptacle housing configured to accommodate a receptacle contact terminal in a detachably and attachably manner, the receptacle contact terminal including a cylindrical contact end portion to which one end of a cable is connected; a sealing tube attached to an outer peripheral portion of the cable inserted in the receptacle housing; a sealing cylinder including a through-hole to accommodate the multiple pressing pieces of the sealing cylinder, placed in the plug housing, including multiple pressing pieces and multiple engagement portions formed on a common circumference along outer peripheral portions of the pressing pieces, and configured to hold the sealing tube inside the multiple pressing pieces, the sealing tube being attached to the outer peripheral portion of the cable inserted in the receptacle housing; and a pressing member configured to press the multiple pressing pieces of the sealing cylinder and the sealing tube against the outer peripheral portion of the cable in the receptacle housing when the receptacle contact terminal to which the one end of the cable is connected is accommodated in the receptacle housing, wherein the multiple engagement portions of the sealing cylinder are movably engaged with portions being engaged formed on a periphery of the through-hole in the pressing member.
The through-hole of the pressing member may include: a large-diameter portion opened toward one end; a small-diameter portion formed in a wall portion of another end opposed to the one end; a reducing portion formed between the large-diameter portion and the small-diameter portion and provided with a conical surface, with the large-diameter portion, the small-diameter portion and the reducing portion formed being provided on a common center axis. Each of the multiple engagement portions of the sealing cylinder may be a projection formed to project in a radial direction, and may be engaged with an extreme thread of a female thread portion formed in the large-diameter portion.
Each of the multiple pressing pieces of the sealing cylinder may include a rake surface which is at a predetermined rake angle to a plane including a center line extending in a radial direction.
The sealing cylinder may include a contact receiving portion configured to accommodate the contact terminal. The contact terminal may include: a conductor connecting portion where an inner conductor of the cable is placed; and a clip piece rotational movably provided to the conductor connecting portion, and configured to take a locked position where the inner conductor of the cable is held on the conductor connection portion and an unlocked position where the inner conductor of the cable is released from the conductor connecting portion. The conductor connecting portion of the contact terminal may further include a lock nib portion configured to hold the inner conductor of the cable in cooperation with one end of the clip piece.
According to the present invention, each of the waterproof structure for a cable connector, and the plug connector and the receptacle connector using the same includes: the housing configured to accommodate the contact terminal to which the one end of the cable is connected in a detachably and attachably manner; the sealing cylinder configured to hold the sealing tube inside the multiple pressing pieces; and the pressing member. Since the multiple engagement portions of the sealing cylinder are movably engaged with the portions being engaged formed on the periphery of the through-hole in the pressing member, the cable connector can be attached easily to the end portion of the cable without requiring molding. Moreover, when the contact terminal to which the one end of the cable is connected is accommodated in the housing, the pressing member presses the multiple pressing pieces of the sealing cylinder and the sealing tube against the outer peripheral portion of the cable in the housing. Thus, it is possible to reliably prevent entry of a liquid into the cable connector in the state where the cable is attached with the sufficient holding force.

Brief Description of Drawings

[Fig. 1] Fig. 1 is a cross-sectional view in which a contact terminal, a contact-sealing cylinder, and a stepped press nut member used in an example of a waterproof structure for a cable connector according to the present invention are illustrated together with a cable;
[Fig. 2] Fig. 2 is a cross-sectional view in which a plug connector and a receptacle connector to which the example of the waterproof structure for a cable connector according to the present invention is applied, are illustrated in a detached state;
[Fig. 3] Fig. 3 is an external view in which the plug connector and the receptacle connector to which the example of the waterproof structure for a cable connector according to the present invention is applied, are illustrated in a connected state;
[Fig. 4] Fig. 4 is an exploded front view of the plug connector shown in Fig. 2;
[Fig. 5] Fig. 5 is an exploded front view of the receptacle connector shown in Fig. 2;
[Fig. 6A] Fig. 6A is a perspective view showing the contact-sealing cylinder used in the example illustrated in Fig. 2;
[Fig. 6B] Fig. 6B is a front view of the example shown in Fig. 6A;
[Fig. 7] Fig. 7 is a cross-sectional view of the stepped press nut member used in the example illustrated in Fig. 2;
[Fig. 8A] Fig. 8A is a perspective view showing an external appearance of a receptacle contact terminal used in the example illustrated in Fig. 2;
[Fig. 8B] Fig. 8B is a cross-sectional view of the example illustrated in Fig. 8A;
[Fig. 9A] Fig. 9A is a perspective view showing an external appearance of a plug contact terminal used in the example illustrated in Fig. 2;
[Fig. 9B] Fig. 9B is a cross-sectional view of the example illustrated in Fig. 9A;
[Fig. 10] Fig. 10 is a perspective view made available for explaining assembly of the example illustrated in Fig. 2; and
[Fig. 11] Fig. 11 is a partial enlarged cross-sectional view made available for explaining the assembly of the example illustrated in Fig. 2.

Description of Embodiments

Fig. 3 shows an external appearance of cable connectors which apply for an example of a waterproof structure for a cable connector according to the present invention. Note that the cable connectors include a receptacle connector and a plug connector to be described later. Fig. 3 illustrates the receptacle connector and the plug connector in a connected state.
The cable connectors shown in Fig. 3 are attached to, for example, two end portions of a cable which connects between photovoltaic modules, end portions of a cable which connects a photovoltaic module and an electric switchboard, or end portions of a cable which connects a junction connector and a photovoltaic module.
In Fig. 3, each cable CA is a photovoltaic module connection cable (product type KSK-, manufactured by Kaneko Cord Co. , Ltd.), for example, which includes a single-core inner conductor, a cross-linked polyethylene insulator covering the inner conductor, and a flame-resistant cross-linked polyethylene sheath covering the inner conductor and the cross-linked polyethylene insulator. The flame-resistant cross-linked polyethylene sheath has an outside diameter of about 7 mm, for example. Moreover, the inner conductor has an outside diameter of about 2 to 3 mm, for example.
In Fig. 3, a plug connector 10 and a receptacle connector 30 are removably connected to each other. As shown in Fig. 2 and Fig. 4, the plug connector 10 comprises, as main constituents: a plug contact terminal 20 connected to the inner conductor on one end of the cable CA; a contact-sealing cylinder 14 in a cylindrical shape provided with a through-hole into which the one end of the cable CA is inserted, and configured to hold the plug contact terminal 20; a sealing tube 16 configured to seal the interstices between an outer peripheral portion on the one end of the cable CA and an inner peripheral portion of the contact-sealing cylinder 14; a plug housing 18 configured to accommodate the plug contact terminal 20 and the contact-sealing cylinder 14 with the sealing tube 16 inserted into the inside; and a stepped press nut member 12 provided with a female screw portion 12FS to be threaded into a male screw portion 18MS of the plug housing 18, and configured to press the contact-sealing cylinder 14 in one direction along the center axis of the plug contact terminal 20 and to press multiple pressing pieces 14Pi (see Fig. 6A) of the contact-sealing cylinder 14 against an outer peripheral portion of the sealing tube 16.
As shown in Fig. 9A and Fig. 9B, the plug contact terminal 20 is integrally molded from a thin metal sheet material by press working, for example. The plug contact terminal 20 comprises: a contact end portion 24 in a hollowed rod shape to be fitted into a hole 44a in a cylindrical contact end portion 44 of a receptacle contact terminal 40 to be described later; and a conductor connecting portion 26 configured to selectively press and hold, and connect the inner conductor on the one end of the cable CA as will be described later.
The conductor connecting portion 26 having a grooved shape has a conductor receiving portion in its inside, which is provided with an opening on one side in such a manner that the inner conductor on the one end of the cable CA is inserted from an end portion of the opening. The conductor receiving portion is formed between parallel wall portions that face each other.
In addition, the conductor connecting portion 26 rotational movably has a clip piece 28 so as to lock and unlock the inner conductor on the one end of the cable CA inserted into the conductor receiving portion to and from the conductor connecting portion 26. Note that a condition illustrated with solid lines in Fig. 9A and Fig. 9B shows the unlocked state of the clip piece 28. A lock nib portion 26N projects inward in a section forming a bottom portion of the conductor receiving portion located below the clip piece 28.
When the clip piece 28 is in the locked state, one end of the clip piece 28 serving as an elastically displaceable contact piece 28P and the lock nib portion 26N pinch and hold the inner conductor on the one end of the cable CA as illustrated with chain double dashed lines in Fig. 9B. Hereby, a holding force of the plug contact terminal 20 to hold the inner conductor on the one end of the cable CA is increased.
Moreover, the curved other end of the clip 28 and serving as an operating piece has a pair of engagement portions 28a formed substantially into a T-shape. The pair of engagement portions 28a are respectively engaged with hooked portions 26K formed on the each wall portion on the contact end portion 24 side of the conductor connection portion 26. Accordingly, the other end of the clip 28 including the engagement portions 28a is held in the locked state by an elastic force of the clip 28. Moreover, the inner conductor on the one end of the cable CA can be detached from between the one end of the clip piece 28 and the lock nib portion 26N by releasing the pair of engagement portions 28a on the other curved end of the clip 28 from the hooked portions 26K against the elastic force.
Accordingly, it is possible to connect the one end of the cable CA to the plug contact terminal 20 in a detachably and attachably manner by simple work without requiring soldering, swaging or the like.
The conductor connecting portion 26 of the plug contact terminal 20 is located in a contact receiving portion 14A of the contact-sealing cylinder 14. A pair of end portions 26E of the conductor connecting portion 26 are respectively inserted into slits 14C (see Fig. 4) of the contact-sealing cylinder 14 to be described later. In addition, nib portions 14NA (see Fig. 6A), which are respectively provided on both wall portions forming the contact receiving portion 14A, are engaged with peripheries of each cutout portion 26S (see Fig. 9B) adjacent to each hooked portion 26K of the wall portions of the conductor connecting portion 26. Hereby, the plug contact terminal 20 is fixed to the contact receiving portion 14A.
The contact-sealing cylinder 14 is integrally molded from a resin material, for example. As shown in Fig. 6A, the contact-sealing cylinder 14 comprises: the contact receiving portion 14A provided on one end of the contact-sealing cylinder 14 and configured to accommodate the conductor connecting portion 26 of the plug contact terminal 20; and a cable gripping portion 14B formed in a cylindrical shape on the other end thereof and configured to grip the one end portion of the cable CA in a detachably and attachably manner.
The cable gripping portion 14B having a through-hole 14H on its inside is provided with a plurality of pressing pieces 14Pi (i=1 to 12) arranged on the periphery of the through-hole 14H. As shown in Fig. 6B, the multiple pressing pieces 14Pi have substantially the same transverse sectional shape and are formed at equal intervals in a circumferential direction. A base end of each pressing piece 14Pi is formed integrally with a shared cylindrical portion. Each pressing piece 14Pi has a rake surface which is at a predetermined rake angle β to a plane including a center line extending in a radial direction. The adjacent pressing pieces 14Pi extend along the center axis of the through-hole 14H with predetermined equal clearances GA therebetween. In addition, each pressing piece 14Pi has an end surface which is at a predetermined angle α to the aforementioned rake surface in such a manner as to have a predetermined cross-sectional area. Hereby, when the pressing pieces 14Pi are pressed by the stepped press nut member 12 in such a manner that the pressing pieces 14Pi come close to one another as will be described later, the multiple pressing pieces 14Pi adjacent to one another are made capable of convergence in such a manner as to overlap one another while reducing an inner diameter formed therewith. Accordingly, as enlargedly shown in Fig. 11, tip end portion of each pressing piece 14Pi press the sealing tube 16 provided on the periphery of the through-hole 14H against an outer peripheral surface of the one end portion of the inserted cable CA, and bite into the outer peripheral portion on the one end portion of the cable CA so as to hold the cable CA.
Moreover, as shown in Fig. 6A and Fig. 6B, fixing projections 14Bn1, 14Bn2, 14Bn3, and 14Bn4 are formed on a common circumference along the base end portions of four pressing pieces 14Pi among the multiple pressing pieces 14Pi. The fixing projections 14Bn1 to 14Bn4 serving as engagement portions have mutually the same shape, and project radially outward in the radial directions. As described later, the fixing projections 14Bn1 to 14Bn4 are movably fitted into threads on the female screw portion 12FS of the stepped press nut member 12. Herewith, when the pressing pieces 14Pi are accommodated in a large-diameter portion 12b as shown in Fig. 1, the fixing projections 14Bn1 to 14Bn4 are fixed to an extreme thread 12fsb (see Fig. 7) of the female screw portion 12FS of the stepped press nut member 12 serving as the portion being engaged. Accordingly, the contact-sealing cylinder 14 and the stepped press nut member 12 do not come off easily unless they are rotated relative to each other. At that time, since it is unlikely that the contact-sealing cylinder 14 comes off the stepped press nut member 12, it is easy to operate insertion of the one end portion of the cable CA into the hole of the contact-sealing cylinder 14 and the hole of the nut member 12 at a time.
Note that the number of the pressing pieces 14Pi is not limited to the aforementioned example, and the number thereof may be less than twelve or more than twelve, for example. In addition, the number of the fixing projections 14n1 to 14n4 is not limited to the aforementioned example, and the number thereof may be two or three, or more than four, for example.
One end of the contact receiving portion 14A of the contact-sealing cylinder 14 communicates with the through-hole 14H on the inside the multiple pressing pieces 14Pi. Moreover, the nib portions 14NA to hold the above-described conductor connecting portion 26 are formed in such a manner as to face each other on both wall portions 14W that constitute two side portions of the contact receiving portion 14A.
A groove 14G (see Fig. 4) into which an O-ring 22 is inserted is formed at a boundary portion between the cable gripping portion 14B and the contact receiving portion 14A. Hereby, as shown in Fig. 2, even when the female screw portion 12FS of the stepped press nut member 12 and the male screw portion 18MS of the plug housing 18, which will be described later, allows an undesired liquid to flow in through a gap therebetween, entering the undesired liquid into the inside the plug housing 18 is avoided.
In addition, as partial enlargedly shown in Fig. 11, an annular recessed portion 14b to which the sealing tube 16 is attached is formed in inner peripheral portions of the pressing pieces 14Pi.
For example, an inside diameter of the sealing tube 16 formed into the cylindrical shape from a rubber material is set slightly larger than an outside diameter of the cable CA so that the outer peripheral portion of the cable CA can be inserted. Moreover, an outside diameter of the sealing tube 16 is set substantially the same as the diameter of the annular recessed portion 14b of the contact-sealing cylinder 14 described above.
As enlargedly shown in Fig. 7, the stepped press nut member 12 having a hexagonal surface on one end of its outer peripheral portion is molded from a resin material, for example, and is provided with a through-hole 12A extending along its center axis. The through-hole 12A is formed from: the large-diameter portion 12b which is opened toward an open end on the other end of the stepped press nut member 12; a small-diameter portion 12e having a smaller inside diameter than an inside diameter of the large-diameter portion 12b; and a reducing portion 12d formed between the large-diameter portion 12b and the small-diameter portion 12e in such a manner that its inside diameter is gradually reduced toward the small-diameter portion 12e. The large-diameter portion 12b has the female screw portion 12FS having a predetermined length. The inside diameter of the large-diameter portion 12b is set substantially equal to a minor diameter of the female thread portion 12FS. The minor diameter of the female thread portion 12FS is set slightly larger than maximum outside diameter dimensions of the fixing projections 14Bn1 to 14Bn4 of the contact-sealing cylinder 14 described above. Hereby, because the fixing projections 14Bn1 to 14Bn4 of the contact-sealing cylinder 14 are made slidable on an inner peripheral surface of the large-diameter portion 12b and are fixed to the extreme thread 12fsb of the female screw portion 12FS, the contact-sealing cylinder 14 is unlikely to come off unless the contact-sealing cylinder 14 is rotated relative to the stepped press nut member 12. Moreover, as shown in Fig. 7, a dimension La from the root of the extreme thread 12fsb of the large-diameter portion 12b to an end of the reducing portion 12d is set larger than a dimension Lb (see Fig. 4) from tip ends of the pressing pieces 14Pi to the fixing projections 14Bn1 to 14Bn4 of the contact-sealing cylinder 14.
The reducing portion 12d has a conical surface so as to cause convergence of the tip ends of the multiple pressing pieces 14Pi of the inserted contact-sealing cylinder 14.
As shown in Fig. 2, the plug housing 18 is molded from a resin material, for example, and is provided with the male screw portion 18MS located on one end and configured to be threaded into the female screw portion 12FS of the stepped press nut member 12. The male screw portion 18MS is formed on an outer peripheral portion of the plug housing 18 in such a manner as to face the female screw portion 12FS. A small-diameter portion 18B into which a distal end of a connecting end portion 38B of a receptacle housing 38 of the receptacle connector 30 to be described later is inserted, and a large-diameter portion 18E into which a base end of the connecting end portion 38B is inserted, are formed inside another end of the plug housing 18. In the small-diameter portion 18B, the contact end portion 24 of the plug contact terminal 20 projects in the axial direction.
A conductor connecting portion receiving portion 18A for housing the contact receiving portion 14A of the contact-sealing cylinder 14 and the conductor connecting portion 26 of the plug contact terminal 20, is formed inside the male screw portion 18MS. A communicating portion 18C is formed between the conductor connecting portion receiving portion 18A and the small-diameter portion 18B. Moreover, slits 18DA and 18DB into which a pair of lock nib portions 38NA and 38NB of the receptacle connector 30 are respectively inserted are formed around the large-diameter portion 18E in such a manner as to face one another. Holes 18da and 18db are formed at end portions of the slits 18DA and 18DB, respectively. Hereby, when the receptacle connector 30 and the plug connector 10 are connected together, tip ends of the pair of lock nib portions 38NA and 38NB are fixed to peripheries of the holes 18da and 18db, as shown in Fig. 3. When the receptacle connector 30 and the plug connector 10 are pulled away from each other, the tip ends of the pair of lock nib portions 38NA and 38NB are detached from the peripheries of the holes 18da and 18db by inserting a given jig (not shown) into the holes 18da and 18db, and the unfixed state is thus established.
In the above-described configuration, when the plug contact terminal 20 including the conductor connecting portion 26 to which the one end of the cable CA is connected, is attached to the plug housing 18, the cable gripping portion 14B of the contact-sealing cylinder 14 to which the sealing tube 16 is attached is first fitted into the female screw portion 12FS of the stepped press nut member 12, and is then inserted into the large-diameter portion 12b. Hereby, the contact-sealing cylinder 14 and the stepped press nut member 12 are combined into a single component. Next, the conductor connecting portion 26 of the plug contact terminal 20 is secured to the contact receiving portion 14A of the contact-sealing cylinder 14. Subsequently, in the unlocked state of the clip piece 28, the inner conductor on the one end of the cable CA is inserted into the conductor connecting portion 26 via the hole 12A of the stepped press nut member 12, the hole of the sealing tube 16, and the hole 14H of the contact-sealing cylinder 14. Then, the clip piece 28 is set to the locked state. Subsequently, in the state where the cable CA is gripped, the plug contact terminal 20 connected to the one end of the cable CA is inserted through the conductor connecting portion receiving portion 18A and the communicating portion 18C of the plug housing 18. Hereby, as shown in Fig. 2, the contact end portion 24 of the plug contact terminal 20 projects into the small-diameter portion 18B. Then, the female screw portion 12FS of the stepped press nut member 12 is threaded into the male screw portion 18MS of the plug housing 18, and the assembly is hence completed.
Hereby, as partial enlargedly shown in Fig. 11, the reducing portion 12d of the stepped press nut member 12 presses the tip end portions of the pressing pieces 14Pi of the contact-sealing cylinder 14 in a converging manner against elastic forces thereof, and presses the entirety of the plug contact terminal 20 and the contact-sealing cylinder 14 toward the communicating portion 18C along the center axis. Thereby, an inner peripheral portion of the sealing tube 16 is brought into close contact with the outer peripheral portion of the cable CA, and the outer peripheral portion of the sealing tube 16 is brought into close contact with the inner peripheral surface that forms the displaced recessed portion 14b. Accordingly, an undesired liquid from outside is prevented by the sealing tube 16 from running down the outer peripheral portion of the cable CA and entering the inside the plug housing 18. Moreover, the tip end portions of the pressing pieces 14Pi of the contact-sealing cylinder 14 bite into the outer peripheral portion of the cable CA, thereby increasing a force with which the plug connector holds the cable CA.
Moreover, as shown in Fig. 2 and Fig. 5, the receptacle connector 30 comprises, as main constituents: a receptacle contact terminal 40 (see Fig. 8A and Fig. 8B) connected to an inner conductor on one end of a cable CA; a contact-sealing cylinder 14 in a cylindrical shape provided with a through-hole into which the one end of the cable CA is inserted, and configured to hold the receptacle contact terminal 40; a sealing tube 16 configured to seal a space between an outer peripheral portion on the one end of the cable CA and an inner peripheral portion of the contact-sealing cylinder 14; a receptacle housing 38 configured to accommodate the receptacle contact terminal 40 and the contact-sealing cylinder 14 with the sealing tube 16 inserted in the inside; and a stepped press nut member 12 provided with a female screw portion 12FS to be threaded into a male screw portion 38MS of the receptacle housing 38, and configured to press the contact-sealing cylinder 14 in one direction along the center axis of the receptacle contact terminal 40 and to press multiple pressing pieces 14Pi of the contact-sealing cylinder 14 against an outer peripheral portion of the sealing tube 16.
In Fig. 2 and Fig. 5, the same constituents as those constituting the example illustrated in Fig. 4 will be denoted by the same reference signs, and overlapping descriptions thereof will be omitted.
As shown in Fig. 8A and Fig. 8B, the receptacle contact terminal 40 is integrally molded from a thin metal sheet material by press working, for example. The receptacle contact terminal 40 includes: a contact end portion 44 in a cylindrical shape including a hole 44a into which the cylindrical contact end portion 24 of the plug contact terminal 20 described above is fitted; and a conductor connecting portion 46 configured to selectively press, and connect the inner conductor on the one end of the cable CA. A close contact sleeve 34 is fitted into an inner peripheral portion of the contact end portion 44. The conductor connecting portion 46 having a grooved shape includes a conductor receiving portion in its inside, which is provided with an opening on one side in such a manner that the inner conductor on the one end of the cable CA is inserted from an end portion of the opening. The conductor receiving portion is formed between parallel wall portions that face each other.
In addition, the conductor connecting portion 46 includes a clip piece 42 which is turnable so as to lock and unlock the inner conductor on the one end of the cable CA inserted into the conductor receiving portion to and from the conductor connecting portion 46. Note that a condition illustrated with solid lines in Fig. 8A and Fig. 8B shows the locked state of the clip piece 42. A lock nib portion 46N projects inward in a section forming a bottom portion of the conductor receiving portion located below the clip piece 42.
When the clip piece 42 is in the locked state, one end of the clip piece 42 serving as an elastically displaceable contact piece 42P and the lock nib portion 46N pinch and hold the inner conductor on the one end of the cable CA. Hereby, a holding force of the receptacle contact terminal 40 to hold the inner conductor on the one end of the cable CA is increased.
Moreover, the other end of the clip 42 curved and serving as an operating piece includes a pair of engagement portions 42a formed substantially into a T-shape. The pair of engagement portions 42a are respectively engaged with hooked portions 46K formed on the wall portions on the contact end portion 44 side of the conductor connection portion 46. Accordingly, the other end of the clip 42 including the engagement portions 42a is held in the locked state by an elastic force of the clip 42. Moreover, the inner conductor on the one end of the cable CA can be detached from the space between the one end of the clip piece 42 and the lock nib portion 46N by releasing the pair of engagement portions 42a on the other curved end of the clip 42 from the hooked portions 46K against the elastic force.
Accordingly, it is possible to connect the one end of the cable CA to the receptacle contact terminal 40 in a detachably and attachably manner by simple work without requiring soldering, swaging or the like.
The conductor connecting portion 46 of the receptacle contact terminal 40 is located in a contact receiving portion 14A of the contact-sealing cylinder 14. A pair of end portions 46E of the conductor connecting portion 46 are respectively inserted into slits 14C (see Fig. 4) of the contact-sealing cylinder 14 described above. In addition, nib portions 14NA (see Fig. 6A), which are respectively provided on two wall portions forming the contact receiving portion 14A, are engaged with peripheries of cutout portions 46S (see Fig. 8B) adjacent to the hooked portions 46K of the wall portions of the conductor connecting portion 46. Hereby, the receptacle contact terminal 40 is fixed to the contact receiving portion 14A.
As shown in Fig. 2 and Fig. 5, the receptacle housing 38 is molded from a resin material, for example, and is provided with the male screw portion 38MS located on one end and configured to be threaded into the female screw portion 12FS of the stepped press nut member 12. The male screw portion 38MS is formed on an outer peripheral portion of the receptacle housing 38 in such a manner as to face the female screw portion 12FS. The receptacle housing 38 includes the connecting end portion 38B on the other end thereof. The connecting end portion 38B projects in the axial direction from the other end toward the plug housing 18 of the plug connector 10. When the receptacle connector 30 is connected to the plug connector 10, the connecting end portion 38B is inserted into the small-diameter portion 18B of the plug housing 18 of the plug connector 10 described above. Moreover, the base end of the connecting end portion 38B is inserted into the large-diameter portion 18E of the plug housing 18. A groove in which to place an O-ring 36 is formed in an outer peripheral portion of the base end. Hereby, a liquid from outside is prevented by the O-ring 36 from entering the inside the receptacle housing 38 and the plug housing 18 through a gap between an end surface of the plug housing 18 and an end surface of the receptacle housing 38 in contact therewith.
Around the O-ring 36, the pair of lock nib portions 38NA and 38NB are formed parallel to the connecting end portion 38B and in such manner as to face each other. As described previously, the pair of lock nib portions 38NA and 38NB are inserted into the slits 18DA and 18DB of the plug housing 18.
A hole into which the contact end portion 44 of the receptacle contact terminal 40 is inserted is formed inside the connecting end portion 38B. Moreover, a hole 38b which the contact end portion 24 of the plug contact terminal 20 passes through is formed in an end of the aforementioned hole.
A conductor connecting portion receiving portion 38A for housing the contact receiving portion 14A of the contact-sealing cylinder 14 and the conductor connecting portion 46 of the receptacle contact terminal 40 described above, is formed inside the male screw portion 38MS. A communicating portion 38C is formed between the conductor connecting portion receiving portion 38A and the hole of the connecting end portion 38B.
In the above-described configuration, when the receptacle contact terminal 40 with the conductor connecting portion 46 to which the one end of the cable CA is connected, is attached to the receptacle housing 38, the cable gripping portion 14B of the contact-sealing cylinder 14 to which the sealing tube 16 is attached is first fitted into the female screw portion 12FS of the stepped press nut member 12, and is then inserted into the large-diameter portion 12b. Hereby, the contact-sealing cylinder 14 and the stepped press nut member 12 are combined into a single component. Next, as shown in Fig. 10, the conductor connecting portion 46 of the receptacle contact terminal 40 is fixed to the contact receiving portion 14A of the contact-sealing cylinder 14. Subsequently, in the unlocked state of the clip piece 46, the inner conductor on the one end of the cable CA is inserted into the conductor connecting portion 46 from the receptacle contact terminal 40 via the hole 12A of the stepped press nut member 12, the hole of the sealing tube 16, and the hole 14H of the contact-sealing cylinder 14. Then, the clip piece 42 is set in the locked state, as shown in Fig. 1. Subsequently, in the state where the cable CA is gripped, the receptacle contact terminal 40 connected to the one end of the cable CA is inserted through the conductor connecting portion receiving portion 38A and the communicating portion 38C of the receptacle housing 38. Hereby, as shown in Fig. 2, the contact end portion 44 of the receptacle contact terminal 40 projects into an inner peripheral portion of the connecting end portion 38B.
Then, the female screw portion 12FS of the stepped press nut member 12 is threaded into the male screw portion 38MS of the receptacle housing 38, and the attachment is hence completed. Hereby, a reducing portion 12d of the stepped press nut member 12 presses tip end portions of the pressing pieces 14Pi of the contact-sealing cylinder 14 in a converging manner against elastic forces thereof, and presses the entirety of the receptacle contact terminal 40 and the contact-sealing cylinder 14 against the communicating portion 38C along the center axis. Thereby, an inner peripheral portion of the sealing tube 16 is brought into close contact with the outer peripheral portion of the cable CA, and the outer peripheral portion of the sealing tube 16 is brought into close contact with a displaced inner peripheral surface that forms a recessed portion 14b. Accordingly, an undesired liquid from outside is prevented by the sealing tube 16 from running down the outer peripheral portion of the cable CA and entering the inside the receptacle housing 38. Moreover, the tip end portions of the pressing pieces 14Pi of the contact-sealing cylinder 14 bite into the outer peripheral portion of the cable CA, thereby increasing a force with which the receptacle connector 30 holds the cable CA.
In each cable connector to which the above-described example of the waterproof structure for a cable connector according to the present invention is applied, the fixing projections 14Bn1 to 14Bn4 of the contact-sealing cylinder 14 are designed to be locked to the extreme thread 12fsb of the female screw portion 12FS of the stepped press nut member 12. However, the present invention is not necessarily limited to this configuration. For instance, instead of the fixing projections 14Bn1 to 14Bn4 of the contact-sealing cylinder 14, a configuration may be used in which: an annular groove portion is formed in the contact-sealing cylinder 14; and a projection projecting radially inward so as to be releasably engaged with the annular groove portion is formed on the inner peripheral portion of the stepped press nut member 12 at a position adjacent to the extreme thread 12fsb of the female screw portion 12FS of the stepped press nut member 12.

Reference Signs List

10: plug connector
12: stepped press nut member
14: contact-sealing cylinder
14Pi: pressing piece
14Bn1, 14Bn2, 14Bn3, 14Bn4: fixing projection
14A: contact receiving portion
16: sealing tube
18: plug housing
20: plug contact terminal
30: receptacle connector
38: receptacle housing
40: receptacle contact terminal
CA: cable

Claims

A waterproof structure for a cable connector, characterized in that
the waterproof structure comprises:
a housing configured to accommodate a contact terminal detachably and attachably, one end of a cable being connected to the contact terminal;

a sealing cylinder placed in the housing, having a plurality of pressing pieces and a plurality of engagement portions formed on a common circumference along outer peripheral portions of the pressing pieces, and configured to hold a sealing tube inside the plurality of pressing pieces, the sealing tube being attached to an outer peripheral portion of the cable inserted in the housing; and

a pressing member having a through-hole to accommodate the plurality of pressing pieces of the sealing cylinder, and configured to press the plurality of pressing pieces of the sealing cylinder and the sealing tube against the outer peripheral portion of the cable in the housing when the contact terminal to which the one end of the cable is connected is accommodated in the housing, wherein the plurality of engagement portions of the sealing cylinder are movably engaged with portions being engaged formed on a periphery of the through-hole in the pressing member.
The waterproof structure for a cable connector according to claim 1, characterized in that
the through-hole of the pressing member comprises:
a large-diameter portion opened to one end;

a small-diameter portion formed in a wall portion of another end opposed to the one end; and

a reducing portion formed between the large-diameter portion and the small-diameter portion and provided with a conical surface,

the large-diameter portion, the small-diameter portion, and the reducing portionformed are provided on a common center axis, and

each of the plurality of engagement portions of the sealing cylinder is a projection formed to project in a radial direction and is engaged with an extreme thread of a female thread portion formed in the large-diameter portion.
The waterproof structure for a cable connector according to claim 1, characterized in that each of the plurality of pressing pieces of the sealing cylinder has a rake surface which is at a predetermined rake angle to a plane including a center line extending in a radial direction.
The waterproof structure for a cable connector according to claim 1, characterized in that
the sealing cylinder has a contact receiving portion to accommodate the contact terminal,
the contact terminal has:
a conductor connecting portion where an inner conductor of the cable is placed; and

a clip piece rotational movably provided to the conductor connecting portion, and configured to take a locked position where the inner conductor of the cable is held on the conductor connection portion and an unlocked position where the inner conductor of the cable is released from the conductor connecting portion, and
the conductor connecting portion of the contact terminal further comprises a lock nib portion configured to hold the inner conductor of the cable in cooperation with one end of the clip piece.
A plug connector characterized in that
the plug connector comprises:
a plug housing configured to accommodate a plug contact terminal in a detachably and attachably manner, the plug contact terminal having a rod-shaped contact end portion to which one end of a cable is connected;

a sealing tube attached to an outer peripheral portion of the cable inserted in the plug housing;

a sealing cylinder placed in the plug housing, having a plurality of pressing pieces and a plurality of engagement portions formed on a common circumference along outer peripheral portions of the pressing pieces, and configured to hold the sealing tube inside the plurality of pressing pieces, the sealing tube being attached to the outer peripheral portion of the cable inserted in the plug housing; and

a pressing member having a through-hole to accommodate the plurality of pressing pieces of the sealing cylinder, and configured to press the plurality of pressing pieces of the sealing cylinder and the sealing tube against the outer peripheral portion of the cable in the plug housing when the plug contact terminal to which the one end of the cable is connected is accommodated in the plug housing,

wherein the plurality of engagement portions of the sealing cylinder are movably engaged with portions being engaged formed on a periphery of the through-hole in the pressing member.
The plug connector according to claim 5, characterized in that
the through-hole of the pressing member has:
a large-diameter portion opened to one end;

a small-diameter portion formed in a wall portion of another end opposed to the one end; and

a reducing portion formed between the large-diameter portion and the small-diameter portion and provided with a conical surface,

the large-diameter portion, the small-diameter portion, and the reducing portion formed are provided on a common center axis, and

each of the plurality of engagement portions of the sealing cylinder is a projection formed to project in a radial direction and is engaged with an extreme thread of a female thread portion formed in the large-diameter portion.
The plug connector according to claim 5, characterized in that each of the plurality of pressing pieces of the sealing cylinder has a rake surface which is at a predetermined rake angle to a plane including a center line extending in a radial direction.
The plug connector according to claim 5, characterized in that
the sealing cylinder has a contact receiving portion configured to accommodate the contact terminal,
the contact terminal has:
a conductor connecting portion where an inner conductor of the cable is placed; and

a clip piece rotational movably provided to the conductor connecting portion, and configured to take a locked position where the inner conductor of the cable is held on the conductor connection portion and an unlocked position where the inner conductor of the cable is released from the conductor connecting portion, and
the conductor connecting portion of the contact terminal further comprises a lock nib portion configured to hold the inner conductor of the cable in cooperation with one end of the clip piece.
A receptacle connector characterized in that
the receptacle connector comprises:
a receptacle housing configured to accommodate a receptacle contact terminal in a detachably and attachably manner, the receptacle contact terminal having a cylindrical contact end portion to which one end of a cable is connected;

a sealing tube attached to an outer peripheral portion of the cable inserted in the receptacle housing;

a sealing cylinder having a through-hole to accommodate the plurality of pressing pieces of the sealing cylinder, placed in the receptacle housing, having a plurality of pressing pieces and a plurality of engagement portions formed on a common circumference along outer peripheral portions of the pressing pieces, and configured to hold the sealing tube inside the plurality of pressing pieces, the sealing tube being attached to the outer peripheral portion of the cable inserted in the receptacle housing; and

a pressing member configured to press the plurality of pressing pieces of the sealing cylinder and the sealing tube against the outer peripheral portion of the cable in the receptacle housing when the receptacle contact terminal to which the one end of the cable is connected is accommodated in the receptacle housing, wherein the plurality of engagement portions of the sealing cylinder are movably engaged with portions being engaged formed on a periphery of the through-hole in the pressing member.
The receptacle connector according to claim 9, characterized in that
the through-hole of the pressing member has:
a large-diameter portion opened to one end;

a small-diameter portion formed in a wall portion of another end opposed to the one end; and

a reducing portion formed between the large-diameter portion and the small-diameter portion and provided with a conical surface,

the large-diameter portion, the small-diameter portion, and the tapered formed are provided on a common center axis, and

each of the plurality of engagement portions of the sealing cylinder is a projection formed to project in a radial direction and is engaged with an extreme thread of a female thread portion formed in the large-diameter portion.
The receptacle connector according to claim 9, characterized in that each of the plurality of pressing pieces of the sealing cylinder has a rake surface which is at a predetermined rake angle to a plane including a center line extending in a radial direction.
The receptacle connector according to claim 9, characterized in that
the sealing cylinder has a contact receiving portion configured to accommodate the contact terminal,
the contact terminal has:
a conductor connecting portion where an inner conductor of the cable is placed; and

a clip piece rotational movably provided to the conductor connecting portion, and configured to take a locked position where the inner conductor of the cable is held on the conductor connection portion and an unlocked position where the inner conductor of the cable is released from the conductor connecting portion, and
the conductor connecting portion of the contact terminal further comprises a lock nib portion configured to hold the inner conductor of the cable in cooperation with one end of the clip piece.