The present invention relates to a waterproof connector, particularly to a waterproof connector in which conductive members such as contacts and a shell are formed integrally with a housing.
In recent years, there is a strong demand for waterproof function in various electronic devices and accordingly, waterproof connectors having waterproof properties have been under development as connectors for establishing connections with external devices.
One example of such waterproof connectors is a connector in which conductive members such as contacts and a shell are formed inside a housing made of an insulating resin to be integral with the housing by, for example, insert molding. Owing to the integral molding, surfaces of the conductive members tightly adhere to the insulating resin at portions embedded in the housing because of a shrinking force of the insulating resin, and water is prevented from penetrating from the outside to the inside of the connector through boundary portions between the housing and the conductive members.
In general, however, a metal material making up the conductive members, such as contacts and a shell, and a resin material making up the housing are different in thermal expansion coefficient from each other, and therefore, when, for example, the connector is exposed to a high temperature environment during a soldering process such as reflow mounting in mounting the connector onto a circuit board of an electronic device, due to the different degree of expansion between the conductive members and the insulating resin, the insulating resin tightly adhering to surfaces of the conductive members may be separated therefrom. Once separated, the surfaces of the conductive members and the insulating resin are to have gaps therebetween, and water may disadvantageously enter the inside of the connector through the gaps even after the temperature falls to ambient temperature.
Aside from that, in a fitting process of a counter connector with the connector, the counter connector may be forcibly fitted in a direction oblique to the fitting axis, which is so-called “ill fitting,” and a high stress may be applied between the housing and the conductive members. In this case, again, the insulating resin of the housing may be separated from the surfaces of the conductive members, thereby damaging waterproof properties of the connector.
To cope with it, a waterproof connector in which a waterproof shaped section composed of grooves or protrusions is formed at the portion of a surface of a conductive member to be embedded in a housing to thereby improve waterproof properties, was filed by the present applicant and has been registered (JP 5433776 B).
In the waterproof connector of JP 5433776 B, for instance, as shown in
Owing to the grooves 3, even if the insulating resin constituting the housing 1 is separated from the surface of the conductive member 2 due to the difference between the thermal expansion coefficients of an insulating resin material and a metal material or due to so-called ill fitting, and water penetrates along the interface between the housing 1 and the conductive member 2, the penetrating water is blocked by the grooves 3.
Meanwhile, in recent years, as downsizing and densification of electric devices progress, a small connector is required, and use of a thin housing is desired accordingly. To minimize the decrease in strength of a connector caused by a thinner housing, for instance, JP 7-207151 A proposes a resin composition for connectors with higher shock resistance and heat resistance as obtained by mixing a resin material with an inorganic reinforcing material.
When, however, the housing 1 in the waterproof connector of JP 5433776 B is formed from the resin composition for connectors described in JP 7-207151 A in order to enhance both waterproof properties and strength, if an inorganic reinforcing material 4 contained in the resin composition for connectors enters the insides of the grooves 3 of the conductive member 2 as shown in
The present invention has been made to eliminate the conventional drawback as above and is aimed at providing a waterproof connector that can improve the strength without damaging waterproof properties.
A waterproof connector according to the present invention includes:
a housing made of a material in which reinforcing filler pieces are dispersed in an insulating resin; and
a conductive member formed integrally with the housing,
wherein the conductive member has a connector connecting section exposed from the housing and connected to a counter connector, a board connecting section exposed from the housing and connected to a board, and a fixed section connecting the connector connecting section and the board connecting section and embedded in the housing,
wherein a waterproof shaped section for blocking entry of water along an interface between the fixed section and the housing is formed at a surface of the fixed section, and
wherein the waterproof shaped section includes at least one groove having an opening width smaller than a size of each of the reinforcing filler pieces.
Embodiments of the present invention are described below based on the appended drawings.
The shell 30 includes a hollow fitted section (shell-side connector connecting section) 31 that opens at a front surface 10A side of the housing 10. A space S is formed in the fitted section 31 for fitting with a counter connector. A contact section (contact-side connector connecting section) 21 provided at the front end of each contact 20 lies in the space S of the fitted section 31 of the shell 30. On the other hand, a contact-side board connecting section 22 provided at the rear end of each contact 20 is exposed from a rear surface 10B of the housing 10 to the outside of the housing 10.
The shell 30 includes a pair of shell-side board connecting sections 32 that are exposed from a bottom surface 10C of the housing 10 to the outside of the housing 10.
As shown in
The shell 30 includes a shell-side fixed section 33 connecting the fitted section 31 and the pair of shell-side board connecting sections 32. The shell-side fixed section 33 includes a rearward projecting section 33A that projects in the X direction from the middle of the upper rear end of the fitted section 31 along the central axis C1 of the fitted section 31, a pair of arm sections 33B that separately extend from the rear end of the rearward projecting section 33A in directions parallel to the top surface 31A of the flat fitted section 31 and perpendicular to the central axis C1, namely, in the Y and −Y directions, and a pair of leg sections 33C that separately extend downward, namely, in the Z direction from the tip ends of the arm sections 33B. The lower ends of the pair of leg sections 33C are separately connected to the shell-side board connecting sections 32. The pair of shell-side board connecting sections 32 are formed to extend from rear to front of the fitted section 31, i.e., in an XY plane and in the −X direction.
The rearward projecting section 33A, the pair of arm sections 33B and the pair of leg sections 33C of the shell-side fixed section 33 form a shell narrow section that is narrower than the fitted section 31. The shell-side fixed section 33 having the shell narrow section is embedded in the housing 10 when the housing 10 is formed by molding together with the shell 30.
A shell-side waterproof shaped section 34 is formed around the outer peripheral surface of each of the pair of arm sections 33B to block the entry of water along the interface between the arm section 33B and the housing 10. The shell-side waterproof shaped section 34 is formed so as to surround and enclose the periphery of the arm section 33B. A surface of the shell-side fixed section 33 is divided by the shell-side waterproof shaped section 34 into a portion containing the fitted section 31 and a portion containing the shell-side board connecting sections 32.
The shell 30 configured as above can be produced by cutting out a metal sheet 35 having conductivity into the shape shown in
As is evident from the development view of
In this case, the contacts 20 and the shell 30 are set in a mold (not shown) so that the contact sections 21 of the contacts 20 are positioned inside the fitted section 31 of the shell 30, the mold is closed, and a molten insulating resin material containing the dispersed reinforcing filler pieces is injected into the mold and cooled, whereby the housing 10 is formed integrally with the contacts 20 and the shell 30. The waterproof connector shown in
In
The contact-side waterproof shaped section 24 of the contact-side fixed section 23 has a plurality of grooves 25 of V shape in cross section formed in the surface of the contact-side fixed section 23. The grooves 25 each have a height difference H1 and an opening width W1. The height difference H1 of the groove 25 is preferably not less than 0.01 mm in order to block the entry of water along the interface between the contact-side fixed section 23 and the housing 10. The opening width W1 of the groove 25 is set smaller than the diameter D1 of the reinforcing filler piece F1 in advance.
Since the opening width W1 of the groove 25 is thus smaller than the diameter D1 of the reinforcing filler piece F1, the reinforcing filler pieces F1 contained in a molding material of the housing 10 do not enter the insides of the grooves 25 formed in the surface of the contact-side fixed section 23 during integral molding of the housing 10 with the contacts 20 in a mold. Therefore, the contact area between the insulating resin R and the inner surfaces of the grooves 25 is prevented from being reduced due to entry of the reinforcing filler pieces F1 to the insides of the grooves 25, while the flow of the molding material entering is not disturbed in molding so that the grooves 25 are filled up to their tip ends with the molding material, which allows the housing 10 to tightly and firmly adhere to the grooves 25 of the contact-side fixed section 23. Thus, it is possible to cause the housing 10 to tightly and firmly adhere to the grooves 25 of the contact-side fixed section 23 to ensure waterproof properties, while improving strength of the housing 10 using the insulating resin R containing the dispersed reinforcing filler pieces F1.
Similarly to the contact-side waterproof shaped section 24, the shell-side waterproof shaped sections 34 formed around the outer peripheral surfaces of the arm sections 33B of the shell-side fixed section 33 each have a plurality of grooves of V shape in cross section formed in the surface of the shell-side fixed section 33, with the grooves each having the height difference H1 and the opening width W1 smaller than the diameter D1 of the reinforcing filler piece F1.
Thus, also in the case of the shell 30, as with the contacts 20, the reinforcing filler pieces F1 contained in the molding material of the housing 10 do not enter the insides of the grooves formed in the surface of the shell-side fixed section 33 during integral molding of the housing 10 with the shell 30 in a mold, and therefore, the contact area between the insulating resin R and the inner surfaces of the grooves is prevented from being reduced, while the flow of the molding material entering is not disturbed in molding so that the grooves are filled up to their tip ends with the molding material, which allows the housing 10 to tightly and firmly adhere to the grooves of the shell-side fixed section 33. Thus, it is possible to cause the housing 10 to tightly and firmly adhere to the grooves of the shell-side fixed section 33 to ensure waterproof properties, while improving strength of the housing 10 using the insulating resin R containing the dispersed reinforcing filler pieces F1.
As described above, the contact-side waterproof shaped sections 24 are formed at the contact-side fixed sections 23 of the contacts 20 to be embedded in the housing 10 so as to surround and enclose the peripheries of the contact-side fixed sections 23. With this configuration, even if the insulating resin R of the housing 10 tightly adhering to the surfaces of the contact-side fixed sections 23 of the contacts 20 is separated from any of the contact-side fixed sections 23 and water penetrates along the contact section 21 exposed to the inside of the fitted section 31 of the shell 30 and then along the interface between the contact-side fixed section 23 and the housing 10, the penetrating water is blocked by the contact-side waterproof shaped section 24 and prevented from reaching the contact-side board connecting section 22 exposed from the rear surface 10B of the housing 10.
Likewise, the shell-side waterproof shaped sections 34 are formed at the shell-side fixed section 33 of the shell 30 to be embedded in the housing 10 so as to surround and enclose the peripheries of the arm sections 33B provided on the paths from the fitted section 31 to the shell-side board connecting sections 32. Therefore, even if the insulating resin R of the housing 10 tightly adhering to the surfaces of the shell-side fixed section 33 of the shell 30 is separated from the shell-side fixed section 33 due to, for instance, the difference between the thermal expansion coefficients of the insulating resin R of the housing 10 and the metal material constituting the shell 30 or due to so-called ill fitting in which the waterproof connector is forcibly fitted in a direction oblique to the fitting axis during fitting with a counter connector, and water penetrates from the fitted section 31 and along the interface between the shell-side fixed section 33 and the housing 10, the penetrating water is blocked by the shell-side waterproof shaped section 34 as soon as reaching the arm section 33B of the shell-side fixed section 33 and is prevented from reaching the shell-side board connecting section 32 exposed from the bottom surface 10C of the housing 10.
In particular, the arm sections 33B at which the shell-side waterproof shaped sections 34 are formed are constituent portions of the shell narrow section that is narrower than the fitted section 31, and accordingly, the entry path of water is so narrow as to limit the amount of penetrating water. Therefore, owing to the shell-side waterproof shaped sections 34, the waterproof function can work more effectively.
The waterproof properties between the housing 10 and the shell 30 and contacts 20 are thus improved so that water can be prevented from penetrating to the interior of a device, i.e., to the side at which a board having mounted thereon the waterproof connector is placed.
Although the contact-side waterproof shaped section 24 shown in
Similarly, while the shell-side waterproof shaped section 34 can be composed of a single groove, the provision of the plurality of grooves leads to more excellent waterproof effect.
The shape of the grooves 25 of the contact-side waterproof shaped section 24 and the grooves of the shell-side waterproof shaped section 34 is not limited to the V-shaped cross section as long as those grooves each have the height difference H1 for blocking the entry of water and the opening width W1 smaller than the diameter D1 of the reinforcing filler piece F1 of the housing 10. For instance, grooves of U shape or rectangular shape in cross section may be employed.
While the beads having a spherical outer shape with the diameter D1 are used as the reinforcing filler pieces F1, the invention is not limited thereto, and use may be made of reinforcing filler pieces F1 having fibrous or bar-like outer shape such as glass fibers or carbon fibers. In this case, the grooves 25 of the contact-side waterproof shaped section 24 and the grooves of the shell-side waterproof shaped section 34 each preferably have the opening width W1 smaller than the cross-sectional diameter of the fibrous reinforcing filler piece F1.
Alternatively, use may be made of reinforcing filler pieces F1 having sheet- or laminate-like outer shape such as micas. In this case, the grooves 25 of the contact-side waterproof shaped section 24 and the grooves of the shell-side waterproof shaped section 34 each preferably have the opening width W1 smaller than the sheet length and sheet width of the reinforcing filler piece F1 measured along its surface.
In place of the pair of shell-side board connecting sections 32 exposed from the bottom surface 10C of the housing 10, the shell 30 may have a single shell-side board connecting section 32 or three or more shell-side board connecting sections 32. When a single shell-side board connecting section 32 is provided, the configuration may be applied in which a single arm section 33B is formed on the path from the fitted section 31 to the shell-side board connecting section 32 and the shell-side waterproof shaped section 34 is formed at the surface of the arm section 33B. When the shell 30 has three or more shell-side board connecting sections 32, the shell-side waterproof shaped section(s) 34 may be provided on any of the paths from the fitted section 31 to the respective shell-side board connecting sections 32, and the number of arm sections 33B at which the shell-side waterproof shaped section(s) 34 is formed may be equal to or smaller than the number of the shell-side board connecting sections 32.
While the fitted section 31 of the shell 30 has a flat cylindrical shape so as to cover the entire surrounding of the contact sections 21 of the contacts 20, the invention is not limited thereto. The fitted section 31 covering merely a part of the contact sections 21 of the contacts 20 can still bring about a shielding effect depending on the usage of the waterproof connector. When such a shielding effect is not required and a shell is used for the purpose of attaching the waterproof connector to a board via the shell-side board connecting sections 32, the shell need not cover the contact sections 21 of the contacts 20.
In Embodiment 1 above, the contact-side waterproof shaped section 24 has the plurality of grooves 25 of V shape in cross section formed in the surface of the contact-side fixed section 23, and each of the grooves 25 has the height difference H1 for blocking the entry of water along the interface between the housing 10 and the contact-side fixed section 23 and the opening width W1 smaller than the diameter D1 of the reinforcing filler piece F1; however, the invention is not limited thereto.
In a waterproof connector of Embodiment 2 shown in
The recesses 26 each have a height difference H2 and an opening width W2 larger than the diameter D2 of the reinforcing filler piece F2 of the housing 10. The height difference H2 of the recess 26 is preferably not less than 0.01 mm in order to block the entry of water along the interface between the housing 10 and the contact-side fixed section 23. The grooves 27 formed in the inner wall surfaces of the recesses 26 each have an opening width W3 smaller than the diameter D2 of the reinforcing filler piece F2 of the housing 10.
In Embodiment 2, since the recesses 26 formed in the surface of the contact-side fixed section 23 each have the opening width W2 larger than the diameter D2 of the reinforcing filler piece F2, the reinforcing filler pieces F2 contained in a molding material of the housing 10 may enter the insides of the recesses 26 formed in the surface of the contact-side fixed section 23 during integral molding of the housing 10 with the contacts 20 in a mold. However, the grooves 27 formed in the inner wall surfaces of the recesses 26 each have the opening width W3 smaller than the diameter D2 of the reinforcing filler piece F2 and accordingly, the reinforcing filler pieces F2 do not enter the insides of the grooves 27. Therefore, the contact area between the insulating resin R and the inner surfaces of the grooves 27 is prevented from being reduced, while the flow of the molding material entering is not disturbed in molding so that the grooves 27 are filled up to their tip ends with the molding material, which allows the housing 10 to tightly and firmly adhere to the grooves 27 inside the recesses 26.
Thus, it is possible to cause the housing 10 to tightly and firmly adhere to the grooves 27 of the contact-side fixed section 23 to ensure waterproof properties, while improving strength of the housing 10 using the insulating resin R containing the dispersed reinforcing filler pieces F2, and to further improve waterproof properties by providing, in addition to the recesses 26 with the large opening width W2, the grooves 27 with the small opening width W3 in the inner wall surfaces of the recesses 26.
Likewise, the shell-side waterproof shaped sections 34 formed around the outer peripheral surfaces of the arm sections 33B of the shell-side fixed section 33 may be configured to include recesses having the opening width W2 larger than the diameter D2 of the reinforcing filler piece F2 and grooves formed in the inner wall surfaces of the recesses and having the opening width W3 smaller than the diameter D2 of the reinforcing filler piece F2.
Thus, the reinforcing filler pieces F2 contained in the molding material of the housing 10 do not enter the insides of the grooves formed in the inner wall surfaces of the recesses during integral molding of the housing 10 with the shell 30 in a mold, and therefore, the contact area between the insulating resin R and the inner surfaces of the grooves is prevented from being reduced, while the flow of the molding material entering is not disturbed in molding so that the grooves are filled up to their tip ends with the molding material, which allows the housing 10 to tightly and firmly adhere to the grooves of the shell-side fixed section 33. Thus, it is possible to cause the housing 10 to tightly and firmly adhere to the grooves of the shell-side fixed section 33 to ensure waterproof properties, while improving strength of the housing 10 using the insulating resin R containing the dispersed reinforcing filler pieces F2.
While a substance having a spherical outer shape with the diameter D2 is used for the reinforcing filler pieces F2, the invention is not limited thereto, and use may be made of reinforcing filler pieces F2 having fibrous or bar-like outer shape such as glass fibers or carbon fibers. In this case, the grooves 27 of the contact-side waterproof shaped section 24 and the grooves formed in the inner wall surfaces of the recesses of the shell-side waterproof shaped section 34 each preferably have the opening width W3 smaller than the cross-sectional diameter of the fibrous reinforcing filler piece F2.
Alternatively, use may be made of reinforcing filler pieces F2 having sheet- or laminate-like outer shape such as micas. In this case, the grooves 27 of the contact-side waterproof shaped section 24 and the grooves formed in the inner wall surfaces of the recesses of the shell-side waterproof shaped section 34 each preferably have the opening width W3 smaller than the sheet length and sheet width of the reinforcing filler piece F2 measured along its surface.
While the shell-side waterproof shaped section 34 is formed at the arm section 33B of the shell-side fixed section 33 in the shell 30 in Embodiment 1 above, the place to be formed is not limited to the arm section 33B but may be anywhere as long as it is a narrow section of the shell-side fixed section 33 that is to be embedded in the housing 10 and is provided on the path from the fitted section 31 to the shell-side board connecting section 32.
For instance, as in a shell 50 shown in
To reach from the fitted section 51 to the shell-side board connecting sections 52 along surfaces of the shell 50, it is necessary to pass the rearward projecting section 53A. Therefore, by forming the shell-side waterproof shaped section 54 around the outer peripheral surface of the rearward projecting section 53A, the entry of water along the interface between the shell-side fixed section 53 and the housing 10 can be blocked.
Instead of the rearward projecting section 53A, the shell-side waterproof shaped sections 54 may be formed at surfaces of the pair of leg sections 53C in the same manner.
Even with the configuration above, by forming the housing 10 from the material in which a large number of the reinforcing filler pieces F1 are dispersed in the insulating resin R and forming the shell-side waterproof shaped section 54 with the grooves having the opening width W1 smaller than the diameter D1 of the reinforcing filler piece F1 as in Embodiment 1, it is possible to cause the housing 10 to tightly and firmly adhere to the grooves of the shell-side waterproof shaped section 54 to ensure waterproof properties.
Likewise, by forming the housing 10 from the material in which a large number of the reinforcing filler pieces F2 are dispersed in the insulating resin R and forming the shell-side waterproof shaped section 54 including the recesses with the opening width W2 larger than the diameter D2 of the reinforcing filler piece F2 and the grooves with the opening width W3 smaller than the diameter D2 of the reinforcing filler piece F2 as in Embodiment 2, the housing 10 can be caused to tightly and firmly adhere to the grooves of the shell-side waterproof shaped section 54 to ensure waterproof properties.
In the shells 30 and 50 used in Embodiments 1 and 3 above, the shell-side waterproof shaped sections 34 and 54 are respectively formed at the leg sections 33C and the rearward projecting section 53A, which are the narrow sections, but are not necessarily formed at such a narrow section.
As shown in
The fitted section 61 covers the surrounding of the contact sections 21 provided at the front ends of the contacts 20 with its inner surface portion being exposed from the housing 10. The inner and outer surface portions of the shell-side fixed section 63 are fully embedded in the housing 10.
A shell-side waterproof shaped section 64 is formed at the outer peripheral surface of the shell-side fixed section 63, while a shell-side waterproof shaped section 65 is also formed at the inner peripheral surface of the shell-side fixed section 63. The shell-side waterproof shaped section 64 is formed so as to surround and enclose the outer periphery of the shell-side fixed section 63, while the shell-side waterproof shaped section 65 is formed so as to surround and enclose the inner periphery of the shell-side fixed section 63.
To reach from the fitted section 61 to the shell-side board connecting sections 62 along surfaces of the shell 60, it is necessary to go across the shell-side waterproof shaped section 64 or 65. Thus, owing to the shell-side waterproof shaped sections 64 and 65, the entry of water along the interface between the shell-side fixed section 63 and the housing 10 can be blocked.
Even with the configuration above, by forming the housing 10 from the material in which a large number of the reinforcing filler pieces F1 are dispersed in the insulating resin R and forming the shell-side waterproof shaped sections 64 and 65 with the grooves having the opening width W1 smaller than the diameter D1 of the reinforcing filler piece F1 as in Embodiment 1, it is possible to cause the housing 10 to tightly and firmly adhere to the grooves of the shell-side waterproof shaped sections 64 and 65 to ensure waterproof properties.
Likewise, by forming the housing 10 from the material in which a large number of the reinforcing filler pieces F2 are dispersed in the insulating resin R and forming the shell-side waterproof shaped sections 64 and 65 including the recesses with the opening width W2 larger than the diameter D2 of the reinforcing filler piece F2 and the grooves with the opening width W3 smaller than the diameter D2 of the reinforcing filler piece F2 as in Embodiment 2, the housing 10 can be caused to tightly and firmly adhere to the grooves of the shell-side waterproof shaped sections 64 and 65 to ensure waterproof properties.
Number | Date | Country | Kind |
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2014-218249 | Oct 2014 | JP | national |
Number | Date | Country | |
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Parent | PCT/JP2015/067597 | Jun 2015 | US |
Child | 15479025 | US |