LIQUID-PROOF CONNECTOR Technical Field

The present invention relates to a liquid-proof connector which is liquid-proofed by filling a filling resin into a connector housing.

Background Art

In a related art, as a connector which is attached to a case or the like accommodating liquid such as oil and connectable to a mating terminal to prevent the liquid in the case from being leaked to the outside, a liquid-proof connector is used in which a terminal is accommodated and held in a connector housing having a liquid-proofing property. For example, a liquid-proof connector which is mounted to a vehicle automatic transmission case and used to electrically connect electrical parts in the vehicle automatic transmission case to an exterior electronic control unit has been suggested in PTL 1.

In the liquid-proof connector disclosed in PTL 1 , since a filling resin is filled into the connector housing so as to cover a connection part between a terminal and an electric wire, the liquid-proofing property is improved and therefore oil in the vehicle automatic transmission case is prevented from being leaked to the outside via the connector housing.

Citation List

Patent Literature

PTL 1 JP-A-2002-270283

Summary of Invention

Technical Problem

Meanwhile, as shown in Fig. 11 , a connector housing of such a liquid-proof connector includes a mating connector fit-in part 120 into which a mating connector is fitted and a terminal accommodation part 1 10 in which a terminal 10 is held via a terminal holder 130. The terminal accommodation part 110 is formed with a section enlarged area part 1 12. The section enlarged area part 112 is configured such that a cross section perpendicular to an insertion direction D of the terminal 10 is enlarged to a predetermined size toward an insertion opening 110a for the terminal 10 from a deep side position 111 of the terminal insertion direction communicated with the mating connector fit-in part 120. The section enlarged area part 1 12 is formed with a slanted surface 112a in order to prevent an air pocket from occurring when the filling resin 80 is filled into the connector housing 140.

Further, a locking part 131 for locking the terminal 10 in the terminal holder

130 is provided and a locking part protection rib 132 for protecting the locking part

131 is provided to protrude from the vicinity of the locking part 131 toward an inner surface of the connector housing 140 including the slanted surface 112a of the section enlarged area part 112.

However, in the liquid-proof connector 100 including the section enlarged area part 112 as described above, the cross section perpendicular to the insertion direction D of the terminal 10 is gradually varied in the insertion direction D of the terminal 10 to the connector housing 140 and also the locking part protection rib 132 is disposed in the vicinity of the slanted surface 112a. For this reason, the difference in the temperature transmitted to the filling resin 80 in the connector housing 140 becomes larger and therefore crack tends to occur in the filling resin 80 near the section enlarged area part 1 12 due to the difference in thermal expansion when a thermal shock is given. As a result, there was a matter that a liquid-proof performance is degraded.

The present invention has been made to solve the above-described problems and an object of the present invention is to provide a liquid-proof connector capable of preventing a liquid-proof performance from being degraded. Solution to Problem

[1] According to an aspect of the invention, a liquid-proof connector includes a connector housing including a mating connector fit-in part into which a mating connector is fitted and a terminal accommodation part in which a terminal holder locking a terminal connected to an electric wire is held and that includes a section enlarged area part. The connector housing is filled with a resin. An inner surface of the section enlarged area part has a round shape connecting a portion parallel to an insertion direction along which the terminal is inserted into the connector housing and a portion perpendicular to the insertion direction so that the cross section of the section enlarged area part is enlarged to a predetermined size.

[2] The liquid-proof connector according to [1], the terminal holder includes a locking part that locks the terminal in the terminal holder, and the terminal holder is formed so as not to protrude from a vicinity of the locking part toward an inner surface of the connector housing.

[3] The liquid-proof connector according to [1 ], wherein the terminal accommodation part further includes a cylindrical area part having a cylinder shape, and the section enlarged area part is formed at a downstream side of the cylindrical area part in the insertion direction.

[4] The liquid-proof connector according to [1 ], the terminal is connected to the electric wire in the cylindrical area part.

Advantageous Effects of Invention

In the liquid-proof connector according to [1 ] and [2], the terminal holder is formed so as not to protrude from the vicinity of the locking part for locking the terminal toward the inner surface of the connector housing and the inner surface of the section enlarged area part is curved in a round shape connecting a portion parallel to the insertion direction and a portion perpendicular to the insertion direction of the terminal so that a cross section thereof is enlarged to a predetermined size. Accordingly, the cross section is enlarged to a predetermined size in a short distance of the terminal insertion direction and therefore the filling resin is uniformly filled into the connector housing. Accordingly, a crack of the filling resin is prevented from occurring, so that it is possible to prevent a liquid-proof performance from being degraded.

In the liquid-proof connector according to [3], the terminal accommodation part includes the section enlarged area part and a cylindrical area part having a cylinder shape, which are sequentially formed from the deep side position of the terminal insertion direction to the insertion opening for the terminal. Accordingly, in a condition where the length of the terminal accommodation part in the terminal insertion direction is constant, the length of the cylindrical area part is increased by the shortened length of the section enlarged area part in the terminal insertion direction. By doing so, it is possible to widen an area where the filling resin filled into the connector housing is uniformly filled.

In the liquid-proof connector according to [4], the connection part between the terminal and the electric wire is disposed at the cylindrical area part. Accordingly, the connection part is covered with the filling resin uniformly formed and therefore it is possible to improve the liquid-proof performance of the connection part.

Brief Description of Drawings

Fig. 1 is a perspective view showing a liquid-proof connector according to an illustrative embodiment of the present invention.

Fig. 2 is a sectional view showing a main part of the liquid-proof connector shown in Fig. 1.

Fig. 3 is a side sectional view showing the main part of the liquid-proof connector shown in Fig. 1.

Fig. 4 is a sectional view showing a state where a terminal holder is mounted to a connector housing shown in Fig. 1.

Figs. 5A-5C are views showing an assembling procedure of the liquid-proof connector according to the illustrative embodiment of the present invention.

Figs. 6A and 6B are stress distribution diagrams showing the distribution of stress by a dotted line, which is applied to a liquid-proof connector and a connector housing of the liquid-proof connector in a related art and a liquid-proof connector and a connector housing of the liquid-proof connector according to the illustrative embodiment of the present invention.

Figs. 7A and 7B are stress distribution diagrams showing the distribution of stress by a dotted line, which is applied to a liquid-proof connector and a connector housing of the liquid-proof connector in a related art and a liquid-proof connector and a connector housing of the liquid-proof connector according to the illustrative embodiment of the present invention.

Figs. 8A and 8B are stress distribution diagrams showing the distribution of stress by a dotted line, which is applied to a liquid-proof connector and a connector housing of the liquid-proof connector in a related art and a liquid-proof connector and a connector housing of the liquid-proof connector according to the illustrative embodiment of the present invention.

Figs. 9A and 9B are stress distribution diagrams showing the distribution of stress by a dotted line, which is applied to a liquid-proof connector and a connector housing of the liquid-proof connector in a related art and a liquid-proof connector and a connector housing of the liquid-proof connector according to the illustrative embodiment of the present invention.

Figs. 10A and 10B are stress distribution diagram showing the distribution of stress by a dotted line, which is applied to a liquid-proof connector and a connector housing of the liquid-proof connector in a related art and a liquid-proof connector and a connector housing of the liquid-proof connector according to the illustrative embodiment of the present invention.

Fig. 11 is a view for explaining a related art.

Description of Embodiments

Hereinafter, a liquid-proof connector according to a preferred embodiment of the present invention will be described with reference to the drawings.

[Illustrative Embodiment]

Fig. 1 is a perspective view showing a liquid-proof connector 1 according to an illustrative embodiment of the present invention. Fig. 2 is a sectional view showing a main part of the liquid-proof connector 1 shown in Fig. 1. Fig. 3 is a side sectional view showing the main part of the liquid-proof connector 1 shown in Fig. 1. Fig. 4 is a sectional view showing a state where a terminal holder 30 is mounted to a connector housing 40 shown in Fig. 1.

The liquid-proof connector 1 includes the connector housing 40 which has a mating connector fit-in part 50 and a terminal accommodation part 60. A mating connector (not shown) is fitted to the mating connector fit-in part 50. A terminal 10 is held in the terminal accommodation part 60 via a terminal holder 30. A filling resin 80 is filled into the connector housing 40.

First, the terminal 10 is described. As shown in Fig. 3, the terminal 10 is connected to an electric wire 20 and includes a rod-shaped connection part 1 1 having a rod shape and connected to a mating terminal (not shown) and a piece-shaped crimping part 12 crimped to a terminal portion 10a of the electric wire 20. The crimping part 12 is adapted to be crimped to an exposed conductive wire (not shown) of the terminal portion 10a of the electric wire 20. A connection part 13 of the terminal 10 and the electric wire 20 which are connected by the crimping part 12 is in a state where a portion of a conductive wire (not shown) is exposed to the outside. Accordingly, as the filling resin 80 is filled into the connector housing 40, the connection part 13 is covered with the filling resin 80.

Here, the terminal 10 of the present embodiment is a male-type terminal but is not limited to the male-type terminal. A female-type terminal may be used as the terminal 10.

Next, the terminal holder 30 is described.

The terminal holder 30 is adapted to hold a plurality of terminals 10 at predetermined positions in the connector housing 40. The terminal holder 30 is made of a synthetic resin and has a generally rectangular parallelepiped shape. The terminal holder 30 includes a plurality of terminal accommodation chambers 31.

Respective terminal accommodation chambers 31 are provided depending on the number of the terminals 10 held in the connector housing 40 and each terminal 10 is held in each terminal accommodation chamber 3 1 so as to be spaced apart and insulated from each other.

Further, each terminal accommodation chamber 31 includes an elastic piece-shaped locking part 32 for locking the terminals 10 in predetermined positions in the terminal accommodation chamber 31 and a terminal insertion hole 33 communicated with each terminal accommodation chamber 31. The rod-shaped connection part 1 1 of each terminal 10 is inserted into the terminal insertion hole 33.

The rod-shaped connection part 11 has a leading end protruding from the terminal insertion hole 33 and is connected to a mating terminal (not shown) in the mating connector fit-in part 50.

Further, as shown in Fig. 4, resin filling openings 34 are formed at positions corresponding to each terminal accommodation chamber 3 1 of the terminal holder 30 so that the filling resin 80 is filled into each terminal accommodation chamber 31 via the resin filling openings.

The terminal holder 30 is formed so that a rib or the like does not protrude from the vicinity of the locking part 32 toward an inner surface 40b of the connector housing 40. Accordingly, the filling resin 80 filled between the connector housing 40 and the terminal holder 30 is uniformly filled.

Next, the connector housing 40 is described.

The connector housing 40 includes the mating connector fit-in part 50 and the terminal accommodation part 60.

The mating connector fit-in part 50 is a part in which a mating connector (not shown) is fitted. The mating connector fit-in part 50 has a substantially elliptic cylindrical shape. As a male mating connector (not shown) is fitted in the mating connector fit-in part, each mating terminal (not shown) and each terminal 10 are connected to each other.

The terminal 10 is held in the terminal accommodating part 60 via the terminal holder 30. The terminal accommodation part 60 is formed with a section enlarged area part 63. The section enlarged area part is configured such that a cross section perpendicular to an insertion direction D of the terminal 10 is enlarged to a predetermined size toward an insertion opening 62 for the terminal 10 from a deep side position 61 of the terminal insertion direction communicated with the mating connector fit-in part 50.

More specifically, the terminal accommodation part 60 includes the section enlarged area part 63 and a cylindrical area part 64 having a cylinder shape, which are sequentially formed from the deep side position 61 of the terminal insertion direction toward the insertion opening 62 for the terminal 10. That is, the cylindrical area part 64 is a cylindrical part having a cross section which is enlarged to a predetermined size by the section enlarged area part 63.

An inner surface 60a of the section enlarged area part 63 is curved in a round shape connecting a portion parallel to the insertion direction D and a portion intersecting with the insertion direction D of the terminal 10 so that a cross section thereof is enlarged to a predetermined size. For this reason, the cross section of the section enlarged area part 63 is enlarged to a predetermined size in a short distance of the insertion direction D of the terminal 10. Accordingly, in a condition where the length of the terminal accommodation part 63 in the insertion direction D of the terminal 10 is constant, the length of the cylindrical area part 64 can be increased by the shortened length of the section enlarged area part 63 in the insertion direction D of the terminal 10. By doing so, it is possible to widen an area where the filling resin 80 filled into the connector housing 40 is uniformly filled.

Further, when an interior of the connector housing 40 is divided in the insertion direction D of the terminal 10, the section enlarged area part 63 is deviated from a zone C in which the connection part 13 between the terminal 10 and the electric wire 20 is disposed, as shown in Fig. 3. That is, the connection part 13 is disposed in the cylindrical area part 64. Accordingly, since the connection part 13 is covered with the filling resin 80 which is uniformly formed so that crack is difficult to occur, a sealing property of the connection part 13 is improved.

Further, the terminal accommodation part 60 includes a seal member placement part 65 in which a seal member 65a for plugging the insertion opening 62 for the terminal 10 is placed.

In this seal member placement part 65, an inner peripheral edge 62a of the insertion opening 62 is formed corresponding to an outer shape of the seal member 65a so that the seal member 65a is disposed in close contact with the inner peripheral edge 62a.

In the liquid-proof connector 1 of such a configuration, the filing resin 80 such as epoxy resin is filled into the connector housing 40 so as to cover the connection part 13 between the terminal 10 and the electric wire 20 and therefore oil in a case which is a mounting destination such as a vehicle automatic transmission case is prevented from being leaked to the outside via the connector housing 40.

Next, an assembling procedure of the liquid-proof connector 1 according to the illustrative embodiment of the present invention is described with reference to Fig. 5. Figs. 5 A to 5C are views showing an assembling procedure of the liquid-proof connector 1 according to the illustrative embodiment of the present invention.

First, a plurality of terminals 10 is inserted into the connector housing 40 through the insertion opening 62 for the terminal 10 and thus each terminal 10 is set in each terminal accommodation chamber 31 of the terminal holder 30 which is mounted in the connector housing 40 (see Fig. 5 A). In this way, each terminal 10 is locked in the terminal accommodation chamber 31 by the locking^art 32.

And then, the seal member 65a is mounted to the connector housing 40 (see Fig. 5B). In this way, the insertion opening 62 is in a sealed state.

And then, the filling resin 80 is filled into the connector housing 40 and the assembling of the liquid-proof connector 1 is completed (see Fig. 5C). When filing the filling resin 80, the filling resin 80 is injected into the connector housing 40 from the mating connector fit-in part 50, for example. Meanwhile, the connection part 13 between the terminal 10 and the electric wire 20 is covered with the filling resin 80 which is filled into the terminal accommodation chamber 31 through the resin filling opening 34 of the terminal holder 30.

Here, a stress analyzing test is carried out in order to analyze the stress applied to the connector housing 140 of the liquid-proof connector 100 in a related art and the connector housing 40 of the liquid-proof connector 1 according to the illustrative embodiment of the present invention and a result of the stress analyzing test is described with reference to Figs. 6A to 10.

Meanwhile, assuming that the liquid-proof connector 1 is installed in an engine room and the temperature in the engine room is in a range from -30°C to 120°C, the stress analyzing test is carried out under a temperature condition of -30°C . Figs. 6 to 10 are stress distribution diagrams showing the distribution of stress by a dotted line, which is applied to the liquid-proof connector 100 and the connector housing 140 of the liquid-proof connector 100 in a related art and the liquid-proof connector 1 and the connector housing 40 of the liquid-proof connector 1 according to the illustrative embodiment of the present invention. Here, an upper part of the drawings represents the liquid-proof connector 100 in a related art, a lower part thereof represents the liquid-proof connector 1 according to the illustrative embodiment of the present invention and a sectional view of the connectors is represented in an upper left part of each stress distribution diagram. Further, a paint-out area represents an area to which a relatively high stress is applied. Here, the pain-out area of the stress distribution diagrams in the upper and lower part represents the same degree of stress.

As shown in Figs. 6 to 10, comparing the stress distribution diagram of the liquid-proof connector 100 in a related art with that of the liquid-proof connector 1 according to the illustrative embodiment of the present invention, it is found that the liquid-proof connector. 1 according to the illustrative embodiment of the present invention has a stress high area which is smaller than a stress high area of the liquid-proof connector 100 in a related art.

It is estimated that the reason is due to the fact that the filling resin 80 is uniformly formed in the insertion direction D of the terminal 10 since the terminal holder 30 is not provided with a lock part protection rib protruding from the vicinity of the locking part 32 for locking the terminal 10 toward the inner surface 40b of the connector housing 40 and the section enlarged area part 63 is curved in a round shape connecting a portion parallel to the insertion direction D an a portion perpendicular to the insertion direction D of the terminal 10 so that a cross section thereof is enlarged to a predetermined size.

That is, it is estimated that the reason is due to the fact that stress occurring due to the difference in thermal expansion is reduced since the difference in the temperature transmitted to the filling resin 80 in the connector housing 40 becomes smaller.

In the liquid-proof connector 1 according to the illustrative embodiment of the present invention, the terminal holder 30 is formed so as not to protrude from the vicinity of the locking part 32 for locking the terminal 10 toward the inner surfaces 40b, 60a of the connector housing 40 and the inner surface 63a of the section enlarged area part 63 is curved in a round shape connecting a portion parallel to the insertion direction D and a portion perpendicular to the insertion direction D of the terminal 10 so that a cross section thereof is enlarged to a predetermined size. Accordingly, the cross section is enlarged to a predetermined size in a short distance of the insertion direction D of the terminal 10 and therefore the filling resin 80 can be uniformly filled into the connector housing 40. Accordingly, crack of the filling resin 80 is prevented from occurring, so that it is possible to prevent a liquid-proof performance from being degraded.

Further, in the liquid-proof connector 1 according to the illustrative embodiment of the present invention, the terminal accommodation part 31 includes the section enlarged area part 63 and the cylindrical area part 64 having a cylinder shape, which are sequentially formed from the deep side position 61 of the terminal insertion direction toward the insertion opening for the terminal. Accordingly, in a condition where the length of the terminal accommodation part 60 in the insertion direction D for the terminal 10 is constant, the length of the cylindrical area part 64 can be increased by the shortened length of the section enlarged area part 63 in the insertion direction D of the terminal 10. By doing so, it is possible to widen an area where the filling resin 80 filled into the connector housing 40 is uniformly filled.

Further, in the liquid-proof connector 1 according to the illustrative embodiment of the present invention, the connection part 13 between the terminal 10 and the electric wire 20 is disposed at the cylindrical area part 64. Accordingly, the connection part 13 is covered with the filling resin 80 uniformly formed and therefore it is possible to improve the liquid-proof performance of the connection part 13.

Although the liquid-proof connector 1 according to the illustrative embodiment of the present invention includes the cylindrical area part 64 having a cylinder shape in the foregoing description, the present invention is not limited to this configuration. That is, other shapes than the cylinder shape may be used, as long as the cross section thereof perpendicular to the insertion direction D of the terminal 10 is formed to have a predetermined size. For example, a square cylindrical shape may be employed.

Further, although the liquid-proof connector 1 according to the illustrative embodiment of the present invention holds a plurality of terminals 10 in the foregoing description, the present invention is not limited to this configuration. One or more terminals 10 may be held.

Hereinabove, although the invention realized by the present inventors has been described on the basis of the above-described illustrative embodiment, the present invention is not limited to the above-described illustrative embodiment and the illustrative embodiments may be variously modified without departing a spirit and a scope of the present invention.

The present application is based on Japanese Patent Application No. 2012-021564, filed on February 3, 2012, the entire contents of which are incorporated herein by reference.

Industrial Applicability

There is provided a liquid-proof connector capable of preventing a liquid-proof performance from being degraded.

Reference Signs List

1 liquid-proof connector

10 terminal

10a terminal portion

11 rod-shaped connection part

12 crimping portion

13 connection part

20 electric wire

30 terminal holder

31 terminal accommodation chamber

32 locking part

33 terminal insertion hole

34 resin filling openings

40 connector housing

40a circumference surface

40b inner surface

50 mating connector fit-in part

60 terminal accommodation part

60a inner surface 61 deep side position of terminal insertion direction

62 insertion opening

62a inner peripheral edge

63 section enlarged area part

63a inner surface

64 cylindrical area part

65 seal member placement part

65a seal member

80 filling resin

100 liquid-proof connector

110 terminal accommodation portion

110a insertion opening

111 deep side position

1 12 section enlarged area part

112a slanted surface

120 mating connector fit-in part

130 terminal holder

131 locking part

132 locking part protection rib

140 connector housing

D insertion direction