A wire-to-board connector includes a plug attached to an electric wire and a receptacle mounted on a substrate. The plug and receptacle are formed by bending a metal plate. The electric wire is electrically connected to the substrate by fitting the plug with the receptacle. The receptacle includes an accommodating section formed in a tubular shape. The plug includes an insertion section to be inserted into the accommodating section. The insertion section has a claw and the accommodating section has an engaging surface. By inserting the insertion section into the accommodating section, the claw is engaged with the engaging surface and the plug is fitted with the receptacle. The claw and the engaging surface are configured so as to prevent a pull-out force acted on the electric wire from acting to disengage the engaged state between the claw and the engaging surface.

RELATED APPLICATIONS

This is the U.S. national stage application which claims priority under 35 U.S.C. §371 to International Patent Application No.: PCT/W2011/004527 filed on Aug. 10, 2011, which claims priority to Japanese Patent Application No. 2011-063640 filed on Mar. 23, 2011, the disclosures of which are incorporated by reference herein their entireties.

TECHNICAL FIELD

The present invention relates to a wire-to-board connector.

BACKGROUND ART

As this type of technique, patent literature 1 discloses a structure for connecting a wire-side fast-on tab terminal102, to which a wire101is attached, to a low-height type surface mounting fast-on tab terminal100, which is surface-mounted on a substrate as shown inFIG. 19of the present application.

CITATION LIST

Patent Literature

SUMMARY OF INVENTION

Technical Problem

However, in the structure disclosed in patent literature 1, when a pull-out force, i.e., a force that is acted so as to pull out the wire101from the low-height type surface mounting fast-on tab terminal100is acted on the wire101, the wire-side fast-on tab terminal102is sometimes pulled out from the low-height type surface mounting fast-on tab terminal100.

An object of the present invention is to provide a wire-to-board connector capable of maintaining the fitted state of the connector even when a pull-out force is acted on the electric wire.

Solution to Problem

According to an aspect of the present invention, a wire-to-board connector, which includes: a first terminal attached to an electric wire; and a second terminal mounted on a substrate, and in which the first and second terminals are entirely formed of metal, and the electric wire is electrically connected to the substrate by fitting the first terminal with the second terminal, has the following structure. That is, the second terminal includes an accommodating section formed into a tubular shape. The first terminal includes an insertion section to be inserted into the accommodating section. One of the accommodating section and the insertion section is provided with a claw section and the other of the accommodating section and the insertion section is provided with an engaging section with which the claw section engages. By inserting the insertion section into the accommodating section, the claw section is engaged with the engaging section and the first terminal is thereby fitted with the second terminal. The claw section and the engaging section are configured so as to prevent a pull-out force acted on the electric wire from acting to disengage the engaged state between the claw section and the engaging section.

Further, the claw section is preferably formed in the insertion section. The engaging section is formed in the accommodating section.

Further, the insertion section preferably includes a pair of mutually-opposed side plates and a cantilever-shaped lock spring strip formed in a place closer to one of the pair of side plates than to the other side plate. The claw section is formed in the lock spring strip.

Further, a lock hole is preferably formed in a peripheral wall of the accommodating section, and a blocking plate is preferably formed in an opened end of the accommodating section that is opposite to an opened end into which the insertion section is inserted. The engaging section is formed on an inner peripheral surface of the lock hole.

Further, an improper insertion prevention protrusion that, when the posture of the insertion section is not appropriate as the insertion section is inserted into the accommodating section, physically interferes the insertion section and thereby prevents the insertion section from being inserted into the accommodating section is preferably formed in the accommodating section.

Further, the improper insertion prevention protrusion is preferably formed by lancing when the lock hole is formed.

Further, the accommodating section preferably includes a cantilever-shaped contact spring strip.

Further, in a joint of the accommodating section, which is formed into the tubular shape by bending a metal plate, a shape retaining mechanism for retaining the tubular shape of the accommodating section is preferably formed.

Further, the shape retaining mechanism is preferably implemented by a shape retaining protrusion and a shape retaining protrusion accommodating hole in which the shape retaining protrusion is accommodated.

Further, the accommodating section is preferably formed into a rectangular-tube shape.

Further, the second terminal preferably includes a pair of mutually-opposed side plates, and a guide strip that is formed in one of the pair of side plates and guides insertion of the insertion section into the accommodating section.

Advantageous Effects of Invention

According to the present invention, it is possible to maintain the fitted state of the wire-to-board connector even when a pull-out force is acted on the electric wire.

DESCRIPTION OF EMBODIMENTS

First Exemplary Embodiment

A first exemplary embodiment according to the present invention is explained hereinafter with reference toFIGS. 1 to 16.

As shown inFIG. 1, a wire-to-board connector1includes a plug3(first terminal) attached to an electric wire2and a receptacle5(second terminal) mounted on the surface of a substrate4. In this exemplary embodiment, each of the plug3and the receptacle5is entirely made of metal and is integrally formed by bending a metal plate. Further, as shown inFIG. 2, the electric wire2is electrically connected to the substrate4by fitting the plug3with the receptacle5.

Here, “connector insertion/pullout direction”, “connector height direction”, and “connector width direction” are defined. As shown inFIGS. 1 and 2, the “connector insertion/pullout direction” is a direction in which the plug3is pulled out from or inserted into the receptacle5. The “connector insertion/pullout direction” includes “insertion direction” and “pull-out direction”. The “insertion direction” is a direction in which the plug3is inserted into the receptacle5. The “pull-out direction” is a direction in which the plug3is pulled out from the receptacle5. The “connector height direction” is a direction perpendicular to the connector mounting surface4aof the substrate4. The “connector height direction” includes “mounting surface approaching direction” and “mounting surface receding direction”. The “mounting surface approaching direction” is a direction approaching to the connector mounting surface4aof the substrate4. The “mounting surface receding direction” is a direction receding from the connector mounting surface4aof the substrate4. The “connector width direction” is a direction perpendicular to both the “connector insertion/pullout direction” and the “connector height direction”.

As shown inFIGS. 3 to 8, the receptacle5includes an accommodating section6and a mounting section7.

The accommodating section6is formed into roughly a rectangular-tube shape. That is, the accommodating section6includes a bottom plate8, a pair of side plates9, and a top plate10. In other words, the peripheral wall of the accommodating section6is composed of a bottom plate8, a pair of side plates9, and a top plate10. The pair of side plates9are opposed to each other.

As shown inFIG. 3, a shape retaining mechanism E is formed in a joint11between the bottom plate8and one of the side plates9. The shape retaining mechanism E is a mechanism for retaining the shape of the accommodating section6, which has roughly a rectangular-tube shape. In this exemplary embodiment, the shape retaining mechanism E is implemented by a shape retaining protrusion12formed on the bottom plate8, and a shape retaining protrusion accommodating hole13formed in the side plate9. Further, the roughly rectangular-tube shape of the accommodating section6is retained by accommodating the shape retaining protrusion12in the shape retaining protrusion accommodating hole13.

As shown inFIGS. 4,6and7, a cantilever-shaped contact spring strip14is formed in the bottom plate8. As shown inFIGS. 4 and 6, the contact spring strip14is formed by lancing a central part of the bottom plate8. As shown inFIG. 7, the contact spring strip14is composed of a support spring strip14athat is supported in a cantilever shape by the bottom plate8, and a contact section14bformed at the free end of the support spring strip14a. The contact section14bprotrudes into internal space P of the accommodating section6in a state where no load is applied on the contact spring strip14shown inFIG. 7.

As shown inFIGS. 3,5and7, a lock hole15having roughly a rectangular shape is formed in the top plate10. As shown inFIG. 7, the lock hole15is formed at such a position in the connector height direction that the lock hole15is roughly opposed to the contact section14bof the contact spring strip14. An engaging surface16(engaging section), which serves as a surface facing in the connector insertion direction, is formed on the inner peripheral surface15aof the lock hole15. Further, as shown inFIGS. 5 and 8, a key17(improper insertion prevention protrusion) is formed in the top plate10. The key17connects to the top plate10. Further, as shown inFIG. 8, the key17protrudes into the internal space P from the top plate10toward the bottom plate8along the connector height direction (in mounting surface approaching direction). As shown inFIG. 5, the key17is formed by lancing when the lock hole15is formed. As shown inFIG. 8, the key17is formed in a position that is deviated in the connector width direction from the center line C in the connector width direction of the accommodating section6.

As shown inFIGS. 3,4and7, a guide chamfering18is formed at an opened end of the accommodating section6into which an insertion section31is inserted. As shown inFIGS. 5 to 7, a blocking plate19is formed at an opened end of the accommodating section6that is opposite to the opened end into which the insertion section31is inserted. The opened end of the accommodating section6that is opposite to the opened end into which the insertion section31is inserted is blocked by the blocking plate19. As shown inFIGS. 5 to 7, the blocking plate19is perpendicular to the connector insertion/pullout direction and connects to the top plate10.

As shown inFIGS. 4 to 7, the mounting section7is composed of a pair of soldering legs20. Each of the soldering legs20connects to the bottom plate8. Further, the soldering legs20are arranged so that the bottom plate8is interposed therebetween in the connector insertion/pullout direction.

In this exemplary embodiment, the electric wire2is composed of a stranded wire25and an insulating covering26. The stranded wire25is covered by the insulating covering26. As shown inFIG. 9, the stranded wire25is exposed in a predetermined length.

As shown inFIGS. 9 to 11, the plug3is composed of an attachment section30, an insertion section31, and a connection section32.

As shown inFIGS. 9 and 10, the attachment section30is provided for attaching the electric wire2to the plug3. The attachment section30is composed of a conductor crimp section33that is crimped onto the stranded wire25of the electric wire2, and a covering crimp section34that is crimped onto the insulating covering26of the electric wire2.

As shown inFIG. 9, the insertion section31is composed of a bottom plate35, a pair of side plates36, and a lock spring strip37. The bottom plate35is formed so as to extend in the connector insertion/pullout direction. The pair of side plates36connect to the bottom plate35in such a manner that the bottom plate35is interposed therebetween in the connector width direction. The pair of side plates36are formed so as to protrude from the bottom plate35toward the mounting surface receding direction. The pair of side plates36are opposed to each other. Therefore, the bottom plate35and the pair of side plates36create roughly a U-shape as viewed in the connector insertion/pullout direction. The lock spring strip37is a cantilever-shaped spring strip supported by the bottom plate35of the insertion section31. The lock spring strip37connects to the tip of the bottom plate35of the insertion section31in the insertion direction and is formed so as to extend toward the pull-out direction. Therefore, as shown inFIG. 10, the bottom plate35and the lock spring strip37of the insertion section31are disposed on top of one another as viewed in the connector height direction. Further, the lock spring strip37is disposed in a place closer to one of the pair of side plates36than to the other side plate36, and a key insertion gap g is formed between the other side plate36and the lock spring strip37. Further, as shown inFIGS. 9 and 10, a claw section38that slightly protrudes in the mounting surface receding direction is formed at the tip of the lock spring strip37in the pull-out direction. A tip surface38aof the claw section38in the pull-out direction shown inFIG. 10is perpendicular to the connector insertion/pullout direction in a state where no load is applied on the lock spring strip37shown inFIG. 9. Further, as shown inFIG. 9, since the claw section38is formed in the lock spring strip37in such a manner that the claw section38slightly protrudes in the mounting surface receding direction, an inclined guide surface39that extends toward the mounting surface approaching direction as it extends towards the insertion direction is formed on the insertion direction side as viewed from the claw section38.

As shown inFIGS. 9 to 11, the connection section32is provided for connecting the attachment section30with the insertion section31.

Next, how to use the wire-to-board connector1is explained with reference toFIGS. 12 to 16.

Firstly, as shown inFIG. 12, the soldering legs20of the mounting section7of the receptacle5are soldered to respective electrodes pads40formed on the connector mounting surface4aof the substrate4.

Next, as shown inFIG. 12, the posture of the plug3with respect to the receptacle5is adjusted so that the lock spring strip37of the insertion section31of the plug3is positioned on the opposite side to the substrate4with the bottom plate35of the insertion section31of the plug3is interposed therebetween. Then, as shown inFIGS. 13 to 15, the insertion section31of the plug3is inserted into the accommodating section6of the receptacle5. In this process, the insertion section31of the plug3shown inFIG. 14presses down the contact spring strip14of the accommodating section6of the receptacle5in the mounting surface approaching direction. Further, in this process, the lock spring strip37of the insertion section31of the plug3is pressed down in the mounting surface approaching direction by the reciprocal action between the inclined guide surface39of the lock spring strip37of the insertion section31of the plug3shown inFIG. 9and the guide chamfering18of the top plate10of the accommodating section6shown inFIG. 7. Then, when the claw section38of the lock spring strip37of the insertion section31of the plug3shown inFIG. 14reaches the lock hole15of the top plate10of the accommodating section6of the receptacle5, the claw section38of the lock spring strip37moves into the lock hole15due to the self elastic restoring force of the lock spring strip37. This movement makes the claw section38of the plug3engage with the engaging surface16of the receptacle5(see alsoFIG. 15). Then, as shown inFIG. 15, the plug3and the receptacle5fit together by this engagement. As a result, the wire-to-board connector1provides an electric connection as a connector.

Note that in the fitted state of the plug3and the receptacle5shown inFIG. 15, even if a pull-out force F is acted on the electric wire2, the fitted state of the plug3and the receptacle5is never disengaged. This is because the claw section38of the plug3and the engaging surface16of the accommodating section6are configured so as to prevent the pull-out force F acted on the electric wire2from acting to disengage the engaged state between the claw section38of the plug3and the engaging surface16of the receptacle5. Specifically, in the fitted state of the plug3and the receptacle5shown inFIG. 15, the tip surface38aof the claw section38shown inFIG. 10and the engaging surface16shown inFIG. 7are both perpendicular to the connector insertion/pullout direction.

Further, the electrical conduction between the plug3and the receptacle5is implemented by all the contact points at which the plug3is in contact with the receptacle5inFIG. 15. In addition, in this exemplary embodiment, in the fitted state of the plug3and the receptacle5, the contact section14bof the contact spring strip14is in strong contact with the bottom plate35of the insertion section31of the plug3shown inFIG. 11by the self elastic restoring force of the contact spring strip14shown inFIG. 7. Therefore, this contact point ensures reliable electrical conduction.

Further, as shown inFIGS. 13 and 15, when the insertion section31of the plug3is inserted into the accommodating section6of the receptacle5, the key17of the receptacle5shown inFIGS. 5 and 8is inserted into a key insertion gap g formed between the lock spring strip37and the side plate36as indicated by a bold arrow G inFIG. 10. Therefore, the presence of the key17of the receptacle5does not obstruct the insertion of the insertion section31of the plug3into the accommodating section6of the receptacle5under a normal circumstance. However, for example, when the insertion section31of the plug3is attempted to be inserted into the accommodating section6of the receptacle5while the insertion section31is in an upside-down state as shown inFIG. 16, the key17of the receptacle5shown inFIGS. 5 and 8physically interferes with the connection section41between the bottom plate35and the lock spring strip37of the insertion section31of the plug3shown inFIG. 11. Therefore, when the insertion section31of the plug3is attempted to be inserted into the accommodating section6of the receptacle5in an improper posture, the presence of the key17of the receptacle5obstructs the insertion of the insertion section31of the plug3into the accommodating section6of the receptacle5.

Further, the blocking plate19of the receptacle5shown inFIG. 5prevents the insertion section31of the plug3from being inserted into the accommodating section6of the receptacle5from a wrong direction. The blocking plate19also serves as a stopper that prevents excessive insertion of the insertion section31.

Note that when the plug3needs to be pulled out from the receptacle5, the claw section38shown inFIG. 15is pressed down by using a jig having a sharp tip. By doing so, the engaged state between the claw section38of the plug3and the engaging surface16of the receptacle5is temporarily disengaged.

A preferable first exemplary embodiment according to the present invention has been explained above. To sum up, the first exemplary embodiment has following characteristics.

That is, as shown inFIGS. 1 to 15, the wire-to-board connector1includes the plug3(first terminal) attached to the electric wire2and the receptacle5(second terminal) mounted on the substrate4. Each of the plug3and the receptacle5is formed by bending a metal plate. The electric wire2is electrically connected to the substrate4by fitting the plug3with the receptacle5. The receptacle5includes the accommodating section6formed into a tubular shape. The plug3includes the insertion section31to be inserted into the accommodating section6. The insertion section31is provided with the claw section38and the accommodating section6is provided with the engaging surface16(engaging section). The claw section38is engaged with the engaging surface16and the plug3is thereby fitted with the receptacle5by inserting the insertion section31into the accommodating section6. The claw section38and the engaging surface16are configured so as to prevent a pull-out force F acted on the electric wire2from acting to disengage the engaged state between the claw section38and the engaging surface16. With the structure described above, it is possible to maintain the fitted state of the wire-to-board connector1even when a pull-out force F is acted on the electric wire2.

Note that in the first exemplary embodiment, the claw section38is disposed in the insertion section31and the engaging surface16(engaging section) is disposed in the accommodating section6. However, instead of using this structure, the engaging section may be disposed in the insertion section31and the claw section may be disposed in the accommodating section6.

Further, the insertion section31includes a cantilever-shaped lock spring strip37. The claw section38is formed in the lock spring strip37. With the structure described above, it is possible to secure a large movable area in which the claw section38can be displaced.

Further, the lock hole15is formed in the top plate10(peripheral wall) of the accommodating section6. The engaging surface16is formed on the inner peripheral surface15aof the lock hole15. With the structure described above, it is possible to implement the engaging surface16with a simple structure.

Further, the key17(improper insertion prevention protrusion) that, when the posture of the insertion section31is not appropriate as the insertion section31is inserted into the accommodating section6, physically interferes the insertion section31and thereby prevents the insertion section31from being inserted into the accommodating section6is preferably formed in the accommodating section6. With the structure described above, it is possible, when the posture of the insertion section31is not appropriate as the insertion section31is inserted into the accommodating section6, to prevent the insertion section31from being inserted into the accommodating section6.

Further, the key17is formed by lancing when the lock hole15is formed. With the structure described above, it is possible to form the key17at a low cost.

Further, the accommodating section6includes the cantilever-shaped contact spring strip14. The contact spring strip14comes into contact with the insertion section31, which is inserted into the accommodating section6, by the self elastic restoring force. With the structure described above, it is possible to ensure reliable contact between the plug3and the receptacle5.

Further, in the joint11of the accommodating section6, which is formed into a tubular shape by bending a metal plate, the shape retaining mechanism E for retaining the tubular shape of the accommodating section6is formed. With the structure described above, it is possible to retain the tubular shape of the accommodating section6.

Further, the shape retaining mechanism E is implemented by the shape retaining protrusion12and the shape retaining protrusion accommodating hole13in which the shape retaining protrusion12is accommodated. With the structure described above, the shape retaining mechanism E is implemented with a simple structure, even when the insertion section31is forcefully inserted into the accommodating section6so that the accommodating section6is deformed.

Although a preferable first exemplary embodiment according to the present invention has been explained above, the first exemplary embodiment can be modified as described below.

That is, as shown inFIG. 9, although the electric wire2is connected to the plug3by crimping by using the conductor crimp section33and the covering crimp section34in the above-described first exemplary embodiment, the electric wire2may be connected to the plug3by using other techniques such as soldering instead of using the crimping.

Second Exemplary Embodiment

Next, a second exemplary embodiment according to the present invention is explained with reference toFIGS. 17 and 18. In this exemplary embodiment, the differences of this exemplary embodiment from the above-described first exemplary embodiment are mainly explained and duplicated explanations are omitted as appropriate. Further, components corresponding to respective components of the above-described first exemplary embodiment are basically denoted by the same symbols.

In this exemplary embodiment, as shown inFIGS. 17 and 18, the side plate9adjacent to the joint11extends toward the pull-out direction. As a result, an insertion guide strip50(guide strip) is formed. That is, an insertion guide strip50is formed in one of the pair of the side plates9of the accommodating section6of the receptacle5. In short, the receptacle5includes an insertion guide strip50. This insertion guide strip50is a guide strip that guides the insertion of the insertion section31into the accommodating section6. The presence of this insertion guide strip50makes the task of inserting the insertion section31of the plug3into the accommodating section6of the receptacle5easier even further in comparison to the above-described first exemplary embodiment. That is, it makes the task of fitting the plug3with the receptacle5easier.

This application is based upon and claims the benefit of priority from Japanese patent application No. 2011-063640, filed on Mar. 23, 2011, the disclosure of which is incorporated herein in its entirety by reference.

REFERENCE SIGNS LIST