Waterproof connector

The waterproof connector includes: a terminal having an electric wire; a housing body having a terminal insertion opening for inserting the terminal and a terminal receiving chamber for receiving the terminal; a waterproofing means having an electric wire insertion hole that is approximately coaxial with the terminal insertion opening of the housing body; and a rear holder which holds the waterproofing means and has a guide tube for guiding the terminal that is to be inserted into the terminal insertion opening, wherein a center axis of the guide tube is deviated from a center axis of the terminal insertion opening.

BACKGROUND OF THE INVENTION

(1) Field of the Invention

The present invention relates to a waterproof connector for use in electrical connection.

(2) Description of the Related Art

So far, a terminal having a bar-shaped tab has been used as a female connector for use in electrical connection.

FIG. 5shows a partially enlarged cross sectional view illustrating an intermediate state when a terminal having an electric wire is being inserted into a connector housing of such a conventional female connector.

A female connector α includes a connector housing α1and a terminal1′ to be inserted in the connector housing α1.

The connector housing α1includes a housing body2′, waterproofing means4′, and rear holder3′ as its primary components.

The housing body2′ has a terminal insertion opening2a′ to let the terminal1′ having an electric wire pass therethrough and holds and receives the terminal1′ having an electric wire inserted through the terminal insertion opening2a′.

The waterproofing means4′ is made of a soft material such as an elastomer, e.g. rubber to waterproof the circumference of the electric wire and includes an electric wire insertion hole4b′ which is approximately coaxial with a center axis of the terminal insertion opening2a′ of the housing body2′.

The rear holder3′ holds the waterproofing means4′ and has a guide tube3a′ for guiding the terminal1′, which is to be inserted into the terminal insertion opening2a′.

The terminal1′ includes: a bar-shaped tab1a′ for connecting the s terminal1′ to a female terminal in a mating connector (not shown in the figure) by being inserted in the female terminal in the mating connector when the female connector α is coupled with the mating connector, the tab1a′ being situated at an end of the terminal1′ in an insertion direction of the terminal1′ into the connector housing α1; an electric wire connecting part1b′ for connecting the terminal1′ to the electric wire; and a box part1c′ situated between the tab1a′ and the electric wire connecting part1b′, wherein a center axis of the tab1a′ is not aligned with that of the box part1c′.

The electric wire insertion hole4b′ of the waterproofing means4′ is approximately coaxial with the terminal insertion opening2a′ of the connector housing α1and an inner diameter of the electric wire insertion hole4b′ is thinner than an outer diameter of the electric wire. Therefore, when the terminal1′ passes through the electric wire insertion hole4b′, the terminal1′ presses and extends the electric wire insertion hole4b′ to pass therethrough.

However, since the center axis of the tab1a′ of the terminal1′ having an electric wire is not aligned with that of the box part1c′, therefore as shown inFIG. 5first an end of the bar-shaped tab1a′ of the terminal1′ abuts against a side surface of an electric wire sealing lip4a′, which is formed on an inner surface of the electric wire insertion hole4b′ together with another electric wire sealing lip4a′, then the terminal1′ presses and extends the electric wire insertion hole4b′ so as to pass through the electric wire insertion hole4b′ rubbing the side surface of the electric wire sealing lip4a′.

Due to such a rub, the electric wire insertion hole4b′ might be damaged, causing insecurity in a waterproof structure formed between the electric wire sealing lip4a′ and a coating layer of the electric wire.

Thus, a terminal of the type described in Japanese Patent Application Laid-Open No. 2002-184508, in which a center axis of the tab is not aligned with that of the box part, is hardly applicable to a waterproof connector of the type described in Japanese Patent Application Laid-Open No. H07-057815.

SUMMARY OF THE INVENTION

It is therefore an objective of the present invention to solve the above problem and to provide a high quality waterproof connector without a necessity of change in design of the tab even if the waterproof connector is a connector of the type, in which a center axis of the tab of the terminal is not aligned with a center axis of the box part of the terminal.

In order to attain the above objective, the present invention is to provide a waterproof connector including:

a terminal having an electric wire;

a housing body having a terminal insertion opening for inserting the terminal and a terminal receiving chamber for receiving the terminal;

a waterproofing means having an electric wire insertion hole that is approximately coaxial with the terminal insertion opening of the housing body; and

a rear holder which holds the waterproofing means and has a guide tube for guiding the terminal that is to be inserted into the terminal insertion opening,

wherein a center axis of the guide tube is deviated from a center axis of the terminal insertion opening.

Preferably, the terminal includes: a tab for connecting the terminal to a female terminal in a mating connector by being inserted in the female terminal in the mating connector; and a box part situated on an electric wire fixing side of the tab, the tab being situated at an end part of the terminal in an insertion direction of the terminal into the housing body, wherein a center axis of the tab is out of alignment with a center axis of the box part in a plane perpendicular to the insertion direction of the terminal into the housing body.

According to a waterproof connector of the present invention, upon insertion of the terminal, the tab is prevented from damaging the periphery of the electric wire insertion hole, so that deterioration in a waterproof characteristic between the electric wire sealing lip and a surface of the electric wire can be prevented. That is, even as for a connector using a terminal, in which a deviation of the center axis of the tab from that of the box part is large, such as in a case in which a tab is formed by extending one surface of the box part, a high quality waterproof connector can be attained.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the following, the preferred embodiments of the present invention will be explained with reference to the attached drawings.FIG. 1Ais a cross sectional view illustrating a connector housing A1constituting a waterproof connector (i.e. female connector) A according to the present invention.FIG. 1Bis a perspective view of a terminal1which is used by being connected to an electric wire.

FIG. 2Ais an enlarged cross sectional view around a one-piece rubber plug4which is a waterproofing means of the connector housing A1.FIG. 2Bis a side view of a terminal1which is connected to an electric wire1d.

The female connector A includes the connector housing A1and the terminal1to be inserted into the connector housing A1.

The connector housing A1includes a housing body2, waterproofing means4, and rear holder3as its primary components.

The housing body2has a terminal insertion opening2afor inserting the terminal1having an electric wire and holds and receives the terminal1inserted through the terminal insertion opening2a.

The waterproofing means4is made of a soft material such as an elastomer, e.g. rubber to waterproof the circumference of the electric wire1dand includes an electric wire insertion hole4bwhich is coaxial or approximately coaxial with a center axis of the terminal insertion opening2aof the housing body2. In this example, a one-piece rubber plug4made of rubber is used.

The rear holder3holds the one-piece rubber plug4and has a guide tube3afor guiding the terminal1with an electric wire, which terminal1is to be inserted into the terminal insertion opening2a.

The terminal1includes: a bar-shaped tab1afor connecting the terminal1to a female terminal in a mating connector (not shown in the figure) by being inserted in the female terminal in the mating connector when the waterproof connector A is coupled with the mating connector, the tab1abeing situated at an end of the terminal1in an insertion direction of the terminal1into the connector housing A1; an electric wire connecting part1bfor connecting the terminal1to the electric wire1d; and a box part1csituated between the tab1aand the electric wire connecting part1b, wherein a center axis of the tab1ais not aligned with the center axis of the box part1c, that is, the center axis of the tab1ais out of alignment with the center axis of the box part1c. As shown inFIG. 2B, there is a distance t′ between the two center axes.

As shown inFIG. 2A, the one-piece rubber plug4is held by the rear holder3having the guide tube3aat a predetermined position in a receiving part2bfor receiving the one-piece rubber plug4in the housing body2. The rear holder3includes a hood part3bfor covering the terminal insertion side-end of the housing body2and is fixed to the housing body2by a locking means (not shown in the figure).

An outer circumference (outer side surface) of the one-piece rubber plug4is provided with: two outer lips4ceach pressure-contacting with an inner wall of the tube-shaped receiving part2bformed on the terminal-insertion side of the terminal insertion opening2aof the housing body2in a watertight manner; and a groove part4dformed between the two outer lips4c. The outer lips4cand the groove part4dimprove a sliding characteristic when the one-piece rubber plug4is slidingly set to a predetermined position (shown in the figure) of the receiving part2b, enabling an easy setting to the predetermined position. Also, after the setting, a high watertight property is attained between the inner wall of the receiving part2band the one-piece rubber plug4.

The electric wire insertion hole4bcommunicates with the terminal insertion opening2aand the guide tube3aand is approximately coaxial with the terminal insertion opening2aof the housing body2.

A center axis (shown by an alternate long and short dash line inFIG. 2A) of a section of the terminal insertion opening2ain a connecting direction of the terminal to a mating connector is not aligned with a center axis (shown by an alternate long and two short dashes line inFIG. 2A) of a section of the guide tube3ain a connecting direction of the terminal to a mating connector. That is, as shown inFIG. 2A, there is a distance t between the two center axes.

FIG. 3illustrates an intermediate state when the terminal1having an electric wire is being inserted into a terminal insertion opening2afrom the guide tube3aof the connector housing A1.

FIG. 3illustrates a state when an end part of the tab1aof the terminal1enters in the electric wire insertion hole4b.

Since an inner diameter of the electric wire insertion hole4bis smaller than an outer diameter of the electric wire1d, therefore when the terminal1passes through the electric wire insertion hole4b, the terminal1extends the electric wire insertion hole4bto pass therethrough.

As for the connector housing A1, within such an extent that an inner circumference of the guide tube3adoes not abut against an outer circumferential surface of the electric wire1dbeing pulled out of the guide tube3a, a center axis of the guide tube3ais formed being deviated from that of the terminal insertion opening2awith a deviation amount of t as shown inFIG. 2A. Therefore, the end part of the tab1ais guided into the electric wire insertion hole4bwithout abutting against the one-piece rubber plug4or, alternatively, even if the end part of the tab1aabuts against the one-piece rubber plug4, only very small friction takes place between the two, wherein the friction does not cause a problem since the one-piece rubber plug4is easily deformed so as to absorb the friction. Accordingly, the end part of the tab1ais prevented from damaging a certain portion (i.e. inner wall) of one-piece rubber plug4and therefore, a good waterproof characteristic between a surface of the electric wire and the electric wire sealing lip4acan be maintained.

FIG. 4illustrates a state when the terminal1having an electric wire is received in the connector housing A1.

When the terminal1having an electric wire is received in a predetermined space in the connector housing A1, the two electric wire insertion lips4aformed on the inner side surface of the electric wire insertion hole4bpressure-contact with the circumference of the electric wire1d, therefore a secure watertight characteristic can be attained.

In the waterproof connector A, the terminal1same as a terminal, which has been often used so far, can be used without a necessity of change in design thereof. The waterproof connector A according to the present invention, which includes the housing body2, one-piece rubber plug4and rear holder3as its primary components, is easily made since it can be made only by changing a position where the guide tube3ais formed in the rear holder3.

In the above embodiment, an example of the waterproof connector A of the type in which one terminal is received inside is explained. However, the present invention can be applicable to a waterproof connector of the type in which a plurality of terminals are received inside, that is, the present invention includes such a waterproof connector as well.

The aforementioned preferred embodiments are described to aid in understanding the present invention and variations may be made by one skilled in the art without departing from the spirit and scope of the present invention.