Contact structure

A contact structure causing a first electric device to be electrically connected to a second electric device includes first terminals and second terminals. The second terminals include contact projections to be electrically connected to the first terminals, and cleaning projections located closer to an opening side of a fitting part of the second electric device than the contact projections to be brought into contact with the first terminals. The contact structure is configured such that the contact projections are not in contact with a surface of an outer case of the first electric device or surfaces of the first terminals before the cleaning projections climb over the first terminals. The contact structure is also configured such that the contact projections are brought into contact with the surfaces of the first terminals after the cleaning projections climb over the first terminals.

CROSS REFERENCE TO RELATED APPLICATION

This application is based upon and claims the benefit of priority under 35 U.S.C. § 119 from Japanese Patent Application No. 2020-033300 filed on Feb. 28, 2020, the entire contents of which are incorporated herein by reference.

BACKGROUND

The present disclosure relates to a contact structure causing a first electric device to be electrically connected to a second electric device in a state in which the first electric device is fitted to a recessed fitting part of the second electric device.

A typical contact structure causing a first electric device such as a battery to be electrically connected to a second electric device such as a battery charger includes first terminals provided on an outer case of the first electric device, and second terminals provided on an inner wall of a fitting part of the second electric device to be brought into contact with the surfaces of the first terminals. The second terminals include projections projecting inward in the fitting part of the second electric device. The projections serve as contact points to be electrically connected to the first terminals, and further have a function of cleaning the first terminals and the second terminals.

The contact structure can scrape out dirt such as stains or dust adhering to the surfaces of the first terminals by rubbing between the projections of the second terminals and the surfaces of the first terminals upon the fitting of the first electric device to the fitting part of the second electric device. This enables the first electric device and the second electric device to be electrically connected to each other with the first terminals and the like cleaned, so as to reduce a contact failure (a connection failure) between the first electric device and the second electric device.

Japanese Utility Model Registration No. 3124613 is one of the related art.

Dirt scraped by the rubbing between the projections of the second terminals and the surfaces of the first terminals in the contact structure is sometimes gathered around the projections of the second terminals. The cleaning by the rubbing may cause a contact failure between the first electric device and the second electric device.

The contact structure disclosed in Japanese Utility Model Registration No. 3124613 includes elastic pieces having cleaning projections for cleaning the first terminals, in addition to the second terminals having the projections on the inner wall of the fitting part of the second electric device. The cleaning projections are located closer to the opening side of the fitting part of the second electric device than the projections of the second terminals, and project in the inward direction of the fitting part of the second electric device. The cleaning projections can scrape out the dirt adhering to the surfaces of the first terminals by the rubbing between the cleaning projections of the elastic pieces and the surfaces of the first terminals before the projections of the second terminals are brought into contact with the surfaces of the first terminals. The contact structure thus can reduce the dirt to be scraped by the rubbing between the projections of the second terminals and the surfaces of the first terminals, so as to avoid or reduce a contact failure between the first electric device and the second electric device caused by the cleaning accordingly.

The contact structure disclosed in Japanese Utility Model Registration No. 3124613, however, may cause the dirt to adhere to the projections of the second terminals due to the contact of the projections with the surface of an outer case (a first outer case) of the first electric device upon the fitting of the first electric device to the fitting part of the second electric device. The dirt, if adhering, may cause a contact failure between the first electric device and the second electric device because of the contact between the projections of the second terminals and the outer case of the first electric device.

SUMMARY

One or more embodiments provide a contact structure capable of sufficiently reducing a rate of occurrence of a contact failure between a first electric device and a second contact device.

An aspect of one or more embodiments provides a contact structure (a terminal structure) causing a first electric device to be electrically connected to a second electric device in a state in which the first electric device is fitted to a recessed fitting part of the second electric device, the contact structure including a first terminal provided at an outer case of the first electric device, and a second terminal provided on an inner wall of the fitting part of the second electric device to be electrically brought into contact with a surface of the first terminal. The second terminal includes a contact projection projecting in an inward direction of the fitting part of the second electric device to be brought into contact with the surface of the first terminal, and a cleaning projection located closer to an opening side of the fitting part of the second electric device than the contact projection and projecting in the inward direction to be brought into contact with the first terminal. The contact structure is configured such that the contact projection is not in contact with a surface of the outer case of the first electric device or the surface of the first terminal before the cleaning projection climbs over the first terminal in response to a movement of the first electric device in a fitting direction relative to the second electric device. The contact structure is also configured such that the contact projection is brought into contact with the surface of the first terminal after the cleaning projection climbs over the first terminal.

Another aspect of one or more embodiments provides a contact structure (a terminal structure) causing a first electric device to be electrically connected to a second electric device in a state in which the first electric device is fitted to a recessed fitting part of the second electric device, the contact structure including a first terminal provided at an outer case of the first electric device, and a second terminal provided on an inner wall of the fitting part of the second electric device to be brought into contact with a surface of the first terminal. The second terminal includes a contact projection projecting in an inward direction of the fitting part of the second electric device to be brought into contact with the surface of the first terminal, and a cleaning projection located closer to an opening side of the fitting part of the second electric device than the contact projection and projecting in the inward direction to be electrically brought into contact with the first terminal. The contact structure is configured such that the contact projection is not in contact with a surface of the outer case of the first electric device or the surface of the first terminal in a state in which the cleaning projection is in contact with either the surface of the outer case of the first electric device or the surface of the first terminal. The contact structure is also configured such that the contact projection is brought into contact with the surface of the first terminal when the cleaning projection is shifted from the contact state to a non-contact state in response to a movement of the first electric device in a fitting direction relative to the second electric device.

DETAILED DESCRIPTION

Hereinafter, one or more embodiments are described with reference to the drawings fromFIG.1toFIG.5C.

As used in the specification and the claims according to the present disclosure, the term “fitting direction” refers to a direction in which a first electric device is fitted to a recessed fitting part of a second electric device. The term “inward direction of the fitting part” refers to a direction of approaching the middle of the fitting part. The term “outward direction of the fitting part” refers to a direction separating from the middle of the fitting part, which is opposite to the inward direction of the fitting part of the second electric device. In the drawings, a sign “FF” indicates a forward direction, a sign “FR” indicates a rearward direction, a sign “L” indicates a leftward direction, a sign “R” indicates a rightward direction, a sign “U” indicates an upward direction, and a sign “D” indicates a downward direction.

As illustrated inFIG.1toFIG.4B, a contact structure10according to an embodiment is a structure causing a battery12as a first electric device to be electrically connected to a battery charger14as a second electric device in a state in which the battery12is fitted to a recessed fitting part16of the battery charger14. Before explaining a specific configuration of the contact structure10, configurations regarding the battery12and the battery charger14other than the configuration of the contact structure10are briefly descried below.

The battery12is an electric device removably attached to a main body of a wireless mobile device (not illustrated), and is an example of the first electric device as described above. The battery12includes a battery outer case (a battery casing)18as a first outer case extending in the upper-lower direction. The battery outer case18is formed of synthetic resin, for example. A secondary battery such as a lithium ion secondary battery (not illustrated) is installed in the battery outer case18. The battery outer case18is provided inside with a thermistor (not illustrated) and a distinction resistor (not illustrated). The battery outer case18is also provided on the tip side with engagement grooves20extending in the longitudinal direction of the battery outer case18on both side surfaces in the short-side direction.

The battery charger14is an electric device for charging the battery12, and is an example of the second electric device as described above. The battery charger14includes a casing-shaped battery-charger outer case (a battery-charger casing)22as a second outer case. The battery-charger outer case22is formed of synthetic resin, for example. The battery-charger outer case22includes a rectangular bottom plate24, and a cover case26located on the upper side of the bottom plate24. The cover case26is provided in the middle with the recessed fitting part16described above. The fitting part16has a substantially rectangular shape in a plan view.

The battery-charger outer case22is provided inside with a circuit board28. A charge control circuit (not illustrated) for charging the battery12is mounted on the circuit board28. The battery-charger outer case22is also provided with an input connector30at an appropriate position on the rear side of the battery-charger outer case22. The input connector30is connected with a power supply cable (not illustrated) of an AC adaptor (not illustrated). DC power is supplied to the battery charger14via the AC adaptor. To place the battery12at a predetermined position in the fitting part16of the battery charger14, engagement guides32to be engaged with the engagement grooves20of the battery outer case18are provided on the inner wall on the right and left sides of the fitting part16of the battery charger14(the cover case26). The respective engagement guides32extend in the upper-lower direction.

The specific configuration of the contact structure10according to the present embodiment is described below.

As illustrated inFIG.1toFIG.4B, the battery outer case18is provided at the bottom edge with a plurality of (four) battery terminals34as first terminals arranged at intervals in the short-side direction. As seen inFIG.2andFIG.5A, for example, the battery terminals34are each a flat metallic piece and recessed on the surface of the battery outer case18within corresponding recesses35. The four battery terminals34are a positive electrode terminal341, a negative electrode terminal342, an S-terminal as a battery distinction terminal343, and a T-terminal as a temperature detection terminal344. The positive electrode terminal341is connected to a positive electrode of the secondary battery, and the negative electrode terminal342is connected to a negative electrode of the secondary battery. The S-terminal343is connected to the distinction resistor, and the T-terminal344is connected to the thermistor. The surface of the battery outer case18adjacent to the respective battery terminals34is provided with indication marks36indicating the type of the respective battery terminals34.

The circuit board28is provided with a plurality of (four) charging terminals38as second terminals mounted at intervals in the right-left direction to be brought into contact with the plural battery terminals34. The respective charging terminals38project in the inward direction of the fitting part16of the battery charger14through slots40provided on the inner wall on the rear side of the fitting part16of the battery charger14. The four charging terminals38as the second terminals are arranged at intervals in the right-left direction on the inner wall on the rear side of the fitting part16of the battery charger14. The four charging terminals38are a positive electrode terminal381, a negative electrode terminal382, an S-terminal383, and a T-terminal384. The positive terminal381is connected to the charge control circuit, and is to be brought into contact with the surface of the positive electrode terminal341of the battery12. The negative electrode terminal382is connected to a ground potential, and is to be brought into contact with the surface of the negative electrode terminal342of the battery12. The S-terminal383is to be brought into contact with the surface of the S-terminal343of the battery12, and the T-terminal384is to be brought into contact with the surface of the T-terminal344of the battery12. The bottom surface of the fitting part16of the battery charger14adjacent to the respective charging terminals38is provided with indication marks42indicating the type of the respective charging terminals38.

As illustrated inFIG.4AandFIG.4B, the charging terminals38are each a plate spring, including an upstand part38amounted on the circuit board28, a bent part38bintegrally connected to the upper edge of the upstand part38a, and a flap part38cintegrally connected to the bent part38b. The upstand part38ais in contact with a rib26rof the cover case26with pressure. The flap part38cis elastically deformable in the inward direction and the outward direction of the fitting part16about a deforming center Ac on the bent part38bside. In a state before the battery12is fitted to the fitting part16of the battery charger14, the lower end (the tip) of the flap part38cis in contact with the bottom edge of the respective slots40with pressure. The respective charging terminals38may be a wire spring, instead of the plate spring.

The respective flap parts38cinclude a contact projection38cato be electrically brought into contact with the respective battery terminals34. The respective contact projections38caproject into a V-like shape in the inward direction of the fitting part16of the battery charger14. The flap parts38ceach include a cleaning projection38cbto be brought into contact with the respective battery terminals34so as to clean the battery terminals34and the respective charging terminals38. The respective cleaning projections38cbare located closer to the opening side of the fitting part16of the battery charger14(separate from the bottom of the fitting part16more) than the respective contact projections38ca, and project into a V-like shape in the inward direction of the fitting part16of the battery charger14. In the state before the battery12is fitted to the fitting part16of the battery charger14, the amount of projection of the respective cleaning projections38cbis set to be greater than the amount of projection of the respective contact projections38ca.

As illustrated inFIG.2andFIG.4B, the battery outer case18is provided, adjacent to the battery terminals34, with a recessed (groove-shaped) housing part44for housing the respective cleaning projections38cb. The housing part44extends in the short-side direction of the battery12. The battery outer case18may be provided with, instead of the single recessed housing part44, a plurality of recessed housing parts (not illustrated) for independently housing the respective cleaning projections38cb. The housing part44may have any stepped shape that can house the respective cleaning projections38cb, instead of the recessed shape.

As illustrated inFIG.5AandFIG.5B, the contact structure10is configured such that the cleaning projections38cbare brought into contact with the surface of the battery outer case18in association with the movement of the battery12relative to the battery charger14in the fitting direction PB, so as to lead the contact projections38cato move in the outward direction of the fitting part16of the battery charger14against the elastic force of the respective flap parts38c. The contact structure10is also configured such that, before the cleaning projections38cbclimb over the battery terminals34upon the movement of the battery12relative to the battery charger14in the fitting direction PB, the respective contact projections38caare not brought into contact with the surface of the battery outer case18or the surface of the respective battery terminals34. Namely, the contact structure10is configured such that the respective contact projections38caare in the non-contact state of not being in contact with the surface of the battery outer case18or the surface of the respective battery terminals34in the state in which the respective cleaning projections38cbare in contact with the surface of the battery outer case18or the surface of the respective battery terminals34.

As illustrated inFIG.5BandFIG.5C, the contact structure10is configured such that the cleaning projections38cbclimb over the battery terminals34to be housed in the housing part44, so as to lead the contact projections38cato move in the inward direction of the fitting part16of the battery charger14by the elastic force of the flap parts38cof the charging terminals38and to be brought into contact with the surface of the respective battery terminals34. Namely, the contact structure10is configured such that the contact projections38caare brought into contact with the surface of the respective battery terminals34when the respective cleaning projections38cbare shifted from the state of being in contact with the respective battery terminals34to the non-contact state in association with the movement of the battery12relative to the battery charger14in the fitting direction PB.

The functional effects according to one or more embodiments are described below.

As described above, the flap parts38cof the charging terminals38include the cleaning projections38cbfor cleaning the respective battery terminals34and the respective charging terminals38, in addition to the contact projections38cato be electrically connected to the battery terminals34. The cleaning projections38cbare located closer to the opening side of the fitting part16of the battery charger14than the contact projections38ca. The rubbing between the cleaning projections38cbof the charging terminals38and the surfaces of the battery terminals34before the contact between the contact projections38caof the charging terminals38and the surfaces of the battery terminals34, can scrape out dirt such as stains or dust adhering to the surfaces of the battery terminals34. This structure can reduce the dirt to be scraped by the rubbing between the contact projections38caof the charging terminals38and the surfaces of the battery terminals34, so as to avoid or reduce a contact failure between the battery12and the battery charger14caused by the cleaning.

As described above, the contact structure10is configured such that the cleaning projections38cbare brought into contact with the surface of the battery outer case18in association with the movement of the battery12relative to the battery charger14in the fitting direction PB, so as to lead the contact projections38cato move in the outward direction of the fitting part16of the battery charger14. The contact structure10is also configured such that, before the cleaning projections38cbclimb over the battery terminals34, the respective contact projections38caare not in contact with the surface of the battery outer case18or the surface of the respective battery terminals34. The contact structure10is configured such that the cleaning projections38cbclimb over the battery terminals34to be housed in the housing part44, so as to bring the contact projections38cainto contact with the surfaces of the battery terminals34. This structure enables the contact projections38caof the charging terminals38to be brought into contact with the surfaces of the battery terminals34with no contact with the surface of the battery outer case18of the battery12. The contact structure10thus can avoid a contact failure between the battery12and the battery charger14caused by the contact between the contact projections38caof the charging terminals38and the battery outer case18of the battery12.

One or more embodiments described above can greatly reduce a rate of occurrence of a contact failure between the battery12and the battery charger14accordingly.

The present disclosure can sufficiently reduce a rate of occurrence of a contact failure between the first electric device and the second electric device.

The present disclosure is not intended to be limited to one or more embodiments described above, and can be applied to various modes, such that the technical idea applied to the contact structure10described above is applied to another contact structure causing a first electric device other than the battery12to be electrically connected to a second electric device other than the battery charger14. It should be understood that the scope of the present disclosure covers any contact structure for electrically connecting a first electric device other than the battery12with a second electric device other than the battery charger14, in addition to the contact structure10for electrically connecting the battery12with the battery charger14.