JP7701606B2 - Engagement structure including seal member and dummy plug, and waterproof connector - Google Patents

Description

The present invention relates to a dummy plug and a waterproof connector.

Waterproof connectors are constructed using a sealing material to ensure waterproofing, but if the sealing material has excess sealing holes, the unused sealing holes are blocked with dummy plugs. Dummy plugs generally have a convex locking portion to prevent them from coming loose (see, for example, Patent Documents 1 to 3).

JP 2000-133368 A JP 2004-071200 A JP 2012-199004 A

In the case of a dummy plug with a convex locking portion, a member for locking the locking portion may be required on the waterproof connector side. In that case, it may lead to an increase in the size of the connector or an increase in the number of parts, which may lead to an increase in costs. Furthermore, if the locking portion is directly locked to the sealing member, there is a high risk of the sealing member being damaged during assembly, which may lead to a decrease in waterproof performance or a decrease in workability due to an increase in insertion force.

The present invention aims to provide a technology that can prevent the dummy plug from coming loose with a simple configuration and also provides sufficient waterproofing and other performance with the dummy plug.

According to one aspect of the present invention,
a seal member disposed in a terminal accommodating portion provided so as to penetrate a housing of the waterproof connector, the seal member having a seal hole and a lip portion formed in the seal hole ;
A dummy plug used to close the seal hole ,
The dummy plug is
a plug body portion that elastically deforms the lip portion when inserted into the seal hole and comes into close contact with the lip portion;
a fitting groove portion formed in a recessed groove shape to fit with the lip portion at a tip side of the plug body in the insertion direction ,
The fitting groove is formed so as to be continuous over the entire circumferential direction of the plug body,
The plug body has an axial length that allows it to come into close contact with the plurality of lip portions formed in the seal hole,
When the dummy plug is inserted into the seal hole, the single lip portion fits into the groove space of the fitting groove portion without interfering with the fitting groove portion over the entire circumference of the plug body in the circumferential direction.
A mating structure is provided.

The present invention provides a simple structure that prevents the dummy plug from coming loose, and also provides sufficient waterproofing and other performance.

1 is a side cross-sectional view showing an example of a main configuration of a waterproof connector according to an embodiment of the present invention. 1 is a side cross-sectional view showing an example of the configuration of a seal member used in a waterproof connector according to an embodiment of the present invention. 1A to 1C are explanatory diagrams showing an example of the configuration of a dummy plug according to one embodiment of the present invention, in which (a) is a side view, (b) is a view taken along the arrow A, and (c) is an enlarged view of part B. 1A to 1C are explanatory diagrams showing specific examples of usage of a dummy plug according to one embodiment of the present invention, in which (a) shows the state before insertion, (b) shows the state after insertion, and (c) shows the state in which the dummy plug is prevented from coming out.

Below, we will explain the dummy plug and waterproof connector according to one embodiment of the present invention with reference to the drawings.

(1) Configuration Example of Waterproof Connector First, a configuration example of the waterproof connector according to the present embodiment will be briefly described.
FIG. 1 is a side cross-sectional view showing an example of the main configuration of a waterproof connector according to the present embodiment.

The waterproof connector has a housing part 10 that houses terminal fittings (not shown). The housing part 10 can be mated with another housing part (not shown) that serves as a connection partner, and is configured to ensure electrical connection between the terminal fittings in each housing when the two housings are mated. Note that both housing parts need only have the same configuration, and the following explanation focuses on one of the housing parts, the housing part 10.

The housing portion 10 is formed by integral molding of an insulating resin material (e.g., polybutylene terephthalate: PBT), and is formed with a terminal accommodating portion 11 for accommodating terminal fittings (not shown). If the waterproof connector is compatible with multiple pins, the terminal accommodating portions 11 are formed so that the number of terminals corresponding to the number of pins is aligned, for example, in the depth direction in the figure.

The terminal accommodating portion 11 is provided so as to penetrate the housing portion 10, and has a lance portion 12 provided therein. The terminal metal fitting inserted from one end side of the terminal accommodating portion 11 is engaged with the lance portion 12, thereby fixing the position of the terminal metal fitting within the terminal accommodating portion 11. This allows the terminal metal fitting accommodated within the terminal accommodating portion 11 to be connected to the mating terminal metal fitting inserted from the other end side of the terminal accommodating portion 11.

Further, a seal member 20 is disposed on one end of the terminal accommodating portion 11 to ensure waterproofing at the one end.
FIG. 2 is a side cross-sectional view showing an example of the configuration of the seal member 20. As shown in FIG.
The sealing member 20 is formed from an elastic material (e.g., silicone rubber) and, when installed in the terminal accommodating portion 11, serves to seal the space between the inner wall of the terminal accommodating portion 11 and an electric wire (not shown) that is connected to the terminal fitting accommodated in the terminal accommodating portion 11.
For this purpose, the seal member 20 is provided with a seal hole 21, which is a through hole having a circular planar shape. The electric wire to be connected to the terminal fitting is inserted into the seal hole 21, thereby sealing the gap between the inner wall of the terminal accommodating portion 11 and the electric wire.

The seal hole 21 has a lip portion 22 formed on its inner circumferential surface, the cross-sectional shape of which is continuous in the circumferential direction. The lip portion 22 is formed in a plurality of stripes (specifically, three stripes, for example) so as to be aligned along the axial direction of the seal hole 21. As a result, the inner circumferential surface of the seal hole 21 has an uneven surface portion in which a small diameter a portion due to the top of the lip portion 22 and a large diameter b portion due to the base of the lip portion 22 are alternately arranged. The small diameter a portion due to the top of the lip portion 22 is set to be smaller than the outer diameter of the electric wire inserted through the seal hole 21. By setting the diameter of the uneven surface portion in this way, each lip portion 22 comes into close contact with the outer periphery of the electric wire in an elastically deformed state, which is a preferable configuration for sealing the gap with the electric wire and ensuring waterproofness. Note that the "elastically deformed state" referred to here means a state in which elastic deformation occurs in the elastic material constituting the lip portion 22, and as long as at least the elastic material is elastically deformed, plastic deformation may occur in addition to the elastic deformation.

In addition to being formed inside the sealing hole 21, the sealing member 20 may also have multiple (specifically, three, for example) lip portions 23 formed on the outer periphery facing the inner wall of the terminal accommodating portion 11.

If the waterproof connector is compatible with multiple pins, then just like the terminal accommodating portion 11, the seal member 20 will have a number of seal holes 21 corresponding to the number of pins. In that case, depending on how the waterproof connector is used, excess seal holes 21 may be generated. The excess seal holes 21 will be unused seal holes 21 into which no electric wire is inserted, and waterproofing through close contact with the electric wire cannot be ensured. For that reason, dummy plugs 30 are inserted into the unused seal holes 21, as shown in FIG. 1, and the unused seal holes 21 are blocked by the dummy plugs 30.

(2) Configuration Example of Dummy Plug Next, a configuration example of the dummy plug 30 according to this embodiment will be described.
FIG. 3 is an explanatory diagram showing an example of the configuration of the dummy plug 30 according to this embodiment.

The dummy plug 30 is formed by integral molding of an insulating resin material (e.g., polybutylene terephthalate: PBT) and is configured with a plug body 31, a plug head 32, a plug tip 33, and a fitting groove 34 to block unused seal holes 21.

The plug body 31 is configured to elastically deform the lip portion 22 formed in the seal hole 21 when inserted into the seal hole 21, so as to come into close contact with the lip portion 22. For this purpose, the plug body 31 is formed in a cylindrical shape with an outer periphery having a diameter c (specifically, a diameter equivalent to that of an assumed electric wire) larger than the diameter a of the top of the lip portion 22. The plug body 31 is also formed in a cylindrical shape with an axial length d that comes into close contact with all of the multiple (specifically, three, for example) lip portions 22 formed in the seal hole 21. As a result, the plug body 31 comes into elastic contact with all of the multiple lip portions 22, which makes it possible to sufficiently ensure sealing between the plug body 31 and the seal member 20.

The plug head 32 is formed so as to be continuous with the plug body 31 at a rear end side in the insertion direction of the dummy plug 30 into the seal hole 21 from the plug body 31, in order to prevent over-insertion of the dummy plug 30 into the seal hole 21. For this reason, the plug head 32 is formed in a planar shape that is larger than the outer diameter c of the plug body 31. The planar shape of the plug head 32 is not particularly limited, but it is preferable that the plug head 32 has a planar shape with different sizes e, f in two perpendicular directions, as shown in the figure. Such a planar shape can be suitably adapted to seal holes 21 arranged at a narrow pitch.

The plug tip 33 is formed on the edge side of the plug body 31 opposite the plug head 32, and is the tip of the dummy plug 30. It is preferable that the plug tip 33 has a tapered portion that becomes smaller in diameter toward the tip in order to facilitate insertion of the dummy plug 30 into the seal hole 21.

The fitting groove 34 is disposed so as to be located between the plug body 31 and the plug tip 33, on the tip side of the plug body 31 in the insertion direction of the dummy plug 30 into the seal hole 21, and is formed in a concave groove shape that fits with the lip 22 in the seal hole 21 in a non-elastically deformed state. The "non-elastically deformed state" refers to a state in which no elastic deformation occurs in the elastic material constituting the lip 22, or a state in which the amount of elastic deformation is so small that it can be considered that no elastic deformation occurs. The concave groove shape that constitutes the fitting groove 34 is formed so as to be continuous over the entire circumference in the circumferential direction.
Further, the fitting groove portion 34 has a groove width that allows it to fit with the single lip portion 22 without interfering with the lip portion 22. In other words, the concave groove that constitutes the fitting groove portion 34 is formed with a groove width h that is larger than the width of one strip of the lip portion 22 so as to fit with the lip portion 22 in a non-elastically deformed state.
Furthermore, the fitting groove 34 has a groove depth greater than the protrusion amount of the mating lip portion 22. In other words, the recessed groove constituting the fitting groove 34 is formed with a groove bottom having a diameter g smaller than the diameter a of the top of the lip portion 22 so as to fit with the lip portion 22 in a non-elastically deformed state.
Here, the fitting groove 34 fits into the lip portion 22 in a non-elastically deformed state, but the present invention is not necessarily limited to this. For example, the fitting groove 34 may be formed to fit into the lip portion 22 in a state in which the elastic deformation is relaxed, rather than in a non-elastically deformed state. The "state in which the elastic deformation is relaxed" refers to a state in which the amount of elastic deformation is reduced and the elastic deformation is relaxed compared to the state in which the plug body 31 elastically deforms the lip portion 22, but the state is not completely non-elastically deformed and it is recognized that elastic deformation has occurred compared to the non-elastically deformed state.

The groove shape constituting the fitting groove 34 has, in addition to the groove bottom, a groove wall surface 34a at the leading end side in the insertion direction of the dummy plug 30 into the seal hole 21, and a groove wall surface 34b at the rear end side in the insertion direction. In the fitting groove shape having such a configuration, the groove wall surface 34a at the leading end side in the insertion direction and the groove wall surface 34b at the rear end side in the insertion direction are formed asymmetrically. More specifically, the groove wall surface 34b at the rear end side in the insertion direction has a larger inclination angle than the groove wall surface 34a at the leading end side in the insertion direction. In other words, the groove wall surface 34a at the leading end side in the insertion direction is formed to be approximately perpendicular to the groove bottom, while the groove wall surface 34b at the rear end side in the insertion direction is formed to have a larger inclination angle than the groove wall surface 34a. The dummy plug 30 having such a recessed groove-shaped fitting groove portion 34, as described in detail below, can easily insert the dummy plug 30 into the seal hole 21 while being unlikely to fall out of the seal hole 21. The magnitude of the inclination angle is not particularly limited and may be set as appropriate.

(3) Usage of the Dummy Plug Next, a usage of the dummy plug 30 according to this embodiment will be described.
FIG. 4 is an explanatory diagram showing a specific example of a usage mode of the dummy plug 30. As shown in FIG.

When using the dummy plug 30, first, as shown in FIG. 4(a), the dummy plug 30 is inserted into an unused seal hole 21 into which no electric wire is inserted, starting from the plug tip 33 (see arrow C in the figure). At this time, if the plug tip 33 has a tapered portion, it is easier to insert the dummy plug 30 into the seal hole 21.

As the dummy plug 30 continues to be inserted into the seal hole 21, the fitting groove 34 in the dummy plug 30 passes through the position where the lip portion 22 is formed in the seal hole 21. If the groove wall surface 34b on the rear end side in the insertion direction of the fitting groove 34 is formed at an angle, the fitting groove 34 can easily pass through the position where the lip portion 22 is formed, which also makes it easier to insert the dummy plug 30 into the seal hole 21.

As shown in FIG. 4(b), the dummy plug 30 is inserted into the seal hole 21 until the plug head 32 reaches a predetermined position. The predetermined position is the position where the plug head 32 engages with another member (for example, the end face of the seal member 20 or the end face of a housing (not shown)). When the plug head 32 reaches the predetermined position, the fitting groove 34 reaches a position where it passes through the seal hole 21. The plug body 31 is then positioned within the seal hole 21. As a result, all of the lip portions 22 formed within the seal hole 21 are in close contact with the outer periphery of the plug body 31 in an elastically deformed state.

In this way, when the dummy plug 30 is inserted into the seal hole 21, the plug body 31 elastically contacts all of the multiple lip portions 22. Therefore, the dummy plug 30 can ensure sufficient sealing between the seal member 20. In other words, even if the seal hole 21 is unused and no electric wire is inserted, by inserting the dummy plug 30 into the seal hole 21, it is possible to ensure waterproofing through close contact with the dummy plug 30.

When the dummy plug 30 is inserted into the seal hole 21, the dummy plug 30 is held in the seal hole 21 by utilizing the frictional force with the seal member 20 (particularly the lip portion 22 inside the seal hole 21). Therefore, if an external force exceeding this frictional force is applied, the dummy plug 30 may move in the direction of coming out of the seal hole 21 (see arrow D in the figure), as shown in Figure 4(c).

However, even if the dummy plug 30 according to this embodiment moves in a direction that causes it to come out of the seal hole 21, the fitting groove portion 34 exerts a fall-prevention effect, which will be described below.

When the dummy plug 30 moves in the direction of coming out of the seal hole 21 and the fitting groove 34 reaches the formation position of the lip portion 22 in the seal hole 21, the lip portion 22 and the fitting groove 34 are fitted together at the time when the first lip portion 22 of the multiple rows is reached. More specifically, when the fitting groove 34 reaches the formation position of the first lip portion 22, the lip portion 22 is released from the outer peripheral surface of the plug body 31 into the groove space of the fitting groove 34 and is in a non-elastically deformed state or a state in which elastic deformation is relaxed (hereinafter referred to as a "non-elastically deformed state, etc."). Then, the lip portion 22 in a non-elastically deformed state, etc., fits into the groove space of the fitting groove 34, and the lip portion 22 and the fitting groove 34 are fitted together (see the enlarged view of part E in the figure).

In order for the lip portion 22 and the fitting groove portion 34 to fit together, it is preferable that the fitting groove portion 34 is formed so as to be continuous over the entire circumference in the circumferential direction. This allows the lip portion 22 to be in an inelastically deformed state over the entire circumference, and as a result, the inelastically deformed state of the lip portion 22 can be utilized to fully exert the slip-out prevention effect.
In order for the lip portion 22 to fit into the fitting groove portion 34, it is preferable that the fitting groove portion 34 has a groove depth greater than the protrusion amount of the mating lip portion 22. This makes it possible for the entire protrusion amount of the lip portion 22 to be in an inelastically deformed state, and as a result, the inelastically deformed state of the lip portion 22 can be utilized to fully exert the slip-out prevention effect.
Furthermore, for the lip portion 22 to fit into the fitting groove portion 34, it is preferable that the fitting groove portion 34 has a groove width that allows it to fit into at least one strip of the lip portion 22 without interfering with the lip portion 22. This makes it possible to put at least one strip of the lip portion 22 into an inelastically deformed state over the entire width, and as a result, the inelastically deformed state of the lip portion 22 can be utilized to fully exert the slip-out prevention effect.

When the lip portion 22 and the fitting groove portion 34 are engaged, the movement of the dummy plug 30 in the direction of removal from the seal hole 21 is restricted. In other words, in order for the dummy plug 30 to continue moving further, it is necessary to apply an external force sufficient to elastically deform the lip portion 22 so that it overcomes the groove wall surface 34a at the tip end side of the fitting groove portion 34 in the insertion direction. Therefore, when the lip portion 22 and the fitting groove portion 34 are engaged, a removal prevention effect is exerted on the dummy plug 30.

At this time, the first of the multiple lip portions 22 engages with the engagement groove 34, but the remaining lip portions 22 (e.g., the other two) of the multiple lip portions 22 maintain their elastically deformed state in close contact with the outer periphery of the plug body 31. Therefore, the engagement groove 34 exerts a slip-out prevention effect while the other lip portions 22 maintain their sealing ability, ensuring sufficient waterproofing.

In this way, the fitting groove 34 exerts a slip-out prevention effect by utilizing the fitting of the lip portion 22 in a non-elastically deformed state, etc. For this reason, in the fitting groove 34, it is preferable that the groove wall surface 34a at the leading end side in the insertion direction of the fitting groove 34 is formed so as to be approximately perpendicular to the groove bottom, without having an inclination angle like the groove wall surface 34b at the trailing end side in the insertion direction. This is because not inclining it makes it difficult for the lip portion 22 to climb over the groove wall surface 34a.

On the other hand, as described above, it is preferable that the groove wall surface 34b of the fitting groove portion 34 has an inclination angle to facilitate insertion of the dummy plug 30. In other words, in the fitting groove portion 34, the groove wall surface 34a at the leading end side in the insertion direction and the groove wall surface 34b at the trailing end side in the insertion direction are formed asymmetrically, and if the groove wall surface 34b has a larger inclination angle than the groove wall surface 34a, it is possible to both facilitate insertion of the dummy plug 30 into the seal hole 21 and provide a good retention effect for the dummy plug 30 inserted into the seal hole 21.

(4) Effects Obtained by the Present Embodiment According to the present embodiment, one or more of the following effects can be obtained.

(a) In this embodiment, the dummy plug 30 for blocking the seal hole 21 is formed with a recessed fitting groove 34 on the tip side of the plug body 31 in the insertion direction, which fits with the lip portion 22 in a non-elastically deformed state, and is configured to exert a fall-off prevention effect by utilizing the fitting of the fitting groove 34 with the lip portion 22. As a result, in order to prevent the dummy plug 30 from falling off, it is not necessary to provide the dummy plug 30 with, for example, a convex-shaped locking portion, and the fall-off prevention effect of the dummy plug 30 can be exerted with an extremely simple configuration.
Therefore, according to this embodiment, it is possible to suppress an increase in cost due to an increase in the size of the connector or an increase in the number of parts, etc. In addition, since the convex locking portion does not damage the seal member 20, the risk of damage to the seal member 20 during assembly can be reduced, and there is no risk of a decrease in waterproof performance or a decrease in workability due to an increase in insertion force.
Moreover, according to this embodiment, even with a simple configuration, the lip portion 22 is in elastic contact with the plug body portion 31, making it possible to ensure sufficient waterproofing.
That is, according to this embodiment, the effect of preventing the dummy plug 30 from coming off can be achieved with a very simple configuration, and the dummy plug 30 also provides sufficient waterproof performance, etc.

(b) If the fitting groove 34 is formed so as to be continuous around the entire circumference as in this embodiment, it is possible to fully exert the anti-removal effect by utilizing the inelastic deformation state of the lip portion 22. In other words, this is extremely preferable for exerting the anti-removal effect of the dummy plug 30 with a simple configuration.

(c) As in this embodiment, if the plug body 31 has an axial length that allows it to fit tightly with the multiple lip portions 22, and the engagement groove 34 has a groove width that allows it to engage with the single lip portion 22 without interfering with it, then it will be possible to fully exert the anti-slip effect by utilizing the inelastic deformation state of the lip portion 22 while ensuring sufficient waterproofing. In other words, it is extremely preferable for the dummy plug 30 to have an anti-slip effect with a simple configuration and to obtain sufficient waterproofing performance, etc., from the dummy plug 30.

(d) As in this embodiment, if the mating groove portion 34 has a groove depth greater than the protrusion amount of the mating lip portion 22, the non-elastic deformation state of the lip portion 22 can be utilized to fully exert the anti-removal effect. In other words, this is extremely preferable for exerting the anti-removal effect of the dummy plug 30 with a simple configuration.

(e) As in this embodiment, in the fitting groove portion 34, if the groove wall surface 34a at the leading end side in the insertion direction and the groove wall surface 34b at the trailing end side in the insertion direction are formed asymmetrically, and the groove wall surface 34b has a larger inclination angle than the groove wall surface 34a, it is possible to achieve both easy insertion of the dummy plug 30 into the sealing hole 21 and a good anti-removal effect for the dummy plug 30 inserted into the sealing hole 21. Therefore, it is very preferable that the anti-removal effect of the dummy plug 30 can be achieved with a simple configuration, and that sufficient waterproof performance, etc. can be obtained by the dummy plug 30.

(f) As in this embodiment, if the plug head 32 has a planar shape with different sizes e, f in two perpendicular directions, it can be used effectively with seal holes 21 arranged at a narrow pitch. In other words, for example, if there are multiple unused seal holes 21 arranged at a narrow pitch, the plug heads 32 can be arranged along the direction of the smaller size f, so that the plug heads 32 of the dummy plugs 30 inserted into each seal hole 21 do not interfere with each other, and each dummy plug 30 can be inserted into the seal hole 21. Moreover, even in this case, the plug heads 32 extend in the direction of the larger size e, so that the planar area of the plug heads 32 can be sufficiently secured, which is preferable for obtaining sufficient waterproof performance, etc., of the dummy plugs 30.

(5) Modifications, etc. Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments and can be modified as appropriate without departing from the spirit of the present invention.

In the above embodiment, the dummy plug 30 has been mainly described, but the present invention is not limited thereto, and it is also possible to configure a waterproof connector including the dummy plug 30. Specifically, the waterproof connector may be configured by inserting the dummy plug 30 into the seal hole 21 of the seal member 20 attached to the housing portion 10 of the waterproof connector. A waterproof connector configured in this way is suitable for multi-pin compatibility, and even if, for example, an excess seal hole 21 occurs depending on the usage mode, sufficient waterproof performance can be obtained by using the dummy plug 30 for that seal hole 21. Moreover, the configuration related to the dummy plug 30 does not become complicated as a result.

10...Housing portion, 11...Terminal accommodating portion, 12...Lance portion, 20...Sealing member, 21...Sealing hole, 22...Lip portion, 30...Dummy plug, 31...Plug body portion, 32...Plug head portion, 33...Plug tip portion, 34...Fitting groove portion, 34a...Groove wall surface, 34b...Groove wall surface

Claims (5)

a seal member disposed in a terminal accommodating portion provided so as to penetrate a housing of the waterproof connector, the seal member having a seal hole and a lip portion formed in the seal hole ;
A dummy plug used to close the seal hole ,
The dummy plug is
a plug body portion that elastically deforms the lip portion when inserted into the seal hole and comes into close contact with the lip portion;
a fitting groove portion formed in a recessed groove shape to fit with the lip portion at a tip side of the plug body in the insertion direction ,
The fitting groove is formed so as to be continuous over the entire circumferential direction of the plug body,
The plug body has an axial length that allows it to come into close contact with the plurality of lip portions formed in the seal hole,
When the dummy plug is inserted into the seal hole, the single lip portion fits into the groove space of the fitting groove portion without interfering with the fitting groove portion over the entire circumference of the plug body in the circumferential direction.
Interlocking structure . The fitting structure according to claim 1 , wherein the fitting groove portion has a groove depth larger than a protrusion amount of the lip portion that fits therewith. The fitting groove portion has a groove wall surface at a front end side in the insertion direction and a groove wall surface at a rear end side in the insertion direction that are formed asymmetrically,
The fitting structure according to claim 1 or 2 , wherein a wall surface of the groove at a rear end side in the insertion direction has a larger inclination angle than a wall surface of the groove at a front end side in the insertion direction. a plug head portion formed so as to be continuous with the plug main body portion at a rear end side of the plug main body portion in the insertion direction,
The fitting structure according to claim 1 , wherein the plug head has a planar shape whose sizes in two perpendicular directions are different from each other. A waterproof connector comprising the fitting structure according to any one of claims 1 to 4 .

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