Buckle for connector, and method for assembling same

A buckle for a connector having a small simple structure and a favorable productivity, and a method for assembling the same. A buckle for connector of the present invention for supporting a tongue engageably/disengageably includes a base member, a latch member, an unlocking member, a latch spring, an ejector, an ejector spring, and cover members housing these members. The base member includes first and second plates. The ejector includes: two arms; a body section between the arms that includes a pushing/moving surface for the tongue to be pushed/moved by the tongue, a support section to support the latch member, and a pushing surface to be pushed by the ejector spring; and claws formed at ends of the arms and locked with an aperture at a terminal end of the base member, the terminal end being opposite to a starting end from which the tongue is inserted.

TECHNICAL FIELD

The present invention relates to a buckle for a connector used in conjunction with a seat belt of a vehicle, and a method for assembling the same.

BACKGROUND ART

With a three-point seat belt, a passenger constrains his/her body by pulling a seat belt tongue held at his/her shoulder to withdraw a shoulder belt and waist belt formed of one webbing simultaneously, and inserting the seat belt tongue into a seat belt buckle provided at a seat portion opposite to the position from where the waist belt is withdrawn in a manner to constrain the upper body and waist of the passenger.

The structure from which the waist belt is withdrawn is classified into a structure configured to fix one end of the waist belt to the seat or a surrounding member directly, and a structure configured to fix one end of the waist belt engageably and disengageably to the seat or a surrounding member via a buckle. The buckle in the latter structure is called a connector buckle, and used as engaged with a connector buckle tongue provided at the one end side of the waist belt. Except for such occasions as vehicle maintenance or the like, this connector buckle is usually kept engaged with the connector buckle tongue, so that it is possible to fasten the seat belt anytime by engaging a seat belt tongue into a seat belt buckle. A buckle structure of this type is disclosed in, e.g., PTL 1.

Connector buckles are required to have a smaller and simpler structure, because connector buckles are obstacles against utilization of the space inside the vehicles. Particularly, in the back seat, a large connector buckle would touch the waist of a passenger and give an uncomfortable feeling. In a type of a vehicle in which the seat belt device can be retracted inside the vehicle when nobody is sitting, a connector buckle left on the seat would become an obstacle against space utilization such as mounting of baggage on the seat, etc.

An example of a buckle structure that has been put into practical use as a connector buckle will be described with reference toFIG. 1.FIG. 1is an exploded perspective diagram of a structure of a conventional connector buckle.

The conventional connector buckle100is composed of a base member110, a latch member120, an unlocking member130, a leaf spring135, an ejector140, a coil spring145, a stopper member150, and cover members160aand160b.

Each member will be described. The base member110includes: an inner region111into which a tongue101having a locking groove102in a side thereof along an inserting direction I can be inserted; and slide grooves112formed in upper and lower facing surfaces of the base member110, respectively. The latch member120is inserted through the slide grooves112of the base member110and disposed such that both ends thereof stick out from the base member110. The unlocking member130is a squared-U-shaped member which, with an open mouth thereof ahead, is externally fitted over a side surface of the base member110, and includes locking support portions131aand131bconfigured to be locked with the both ends of the latch member120sticking out from the base member110such that the unlocking member130is supported in the externally fitted state. The leaf spring135is inserted between the base member110and the unlocking member130, and biased to slide the unlocking member130in a first sliding direction X1of the latch member120. The ejector140is provided in the inner region111of the base member110. The coil spring145is provided between the ejector140and the stopper member150, and biased to push out the ejector140in a releasing direction E opposite to the inserting direction I of the tongue101. The stopper member150is a member having a bracket shape in a plan view, and provided on the base member110such that locking portions151aand151bthereof formed at ends thereof are locked with claws113aand113bof the base member110. The upper and lower two cover members160aand160bhouse therein the base member110fitted with these members in the way described above in a manner to sandwich it, and are fixed in the housing state by means of a screw161.

In the connector buckle100configured as described above, when the tongue101is inserted along the inserting direction I, the latch member120slides in a second sliding direction X2once by being pushed and moved by a head of the tongue101, and when it is at the locking groove102of the tongue101, slides in the first sliding direction X1by means of the leaf spring135, to be thereby locked with the locking groove102of the tongue101. At the same time, the ejector140is pushed and moved by the head of the tongue101and thrust into the stopper member150by resisting being biased by the coil spring145. In this way, the tongue101is engaged with the connector buckle100.

On the other hand, disengagement of the connector buckle100and the tongue101is done by inserting a member such as a vehicle key into a cutout162formed in the cover member160bto push and move the unlocking member130in a manner to slide the latch member120in the second sliding direction X2to thereby release the latch member120from the locking groove102of the tongue101. When such a pushing/moving operation is given, the ejector140pushes out the tongue101in the releasing direction E by being biased by the coil spring145, and the tongue101is released from the connector buckle100.

The connector buckle100has the problems described below.

First, formation of the facing surfaces of the base member110is performed by folding the base member110at a folding position that is to become the side surface over which the unlocking member130is externally fitted. Specifically, sheet-metal working is performed using a sheet metal having a size corresponding to the inner region111as an insert member, to fold a flat-plate member to conform to the shape of the sheet metal and thereby form the base member110folded to have facing surfaces.

However, in the base member110formed in this way, the inner region111cannot have a height shorter than the thickness of the sheet metal, which leads to a problem that the base member110cannot avoid being thick. A conceivable way to overcome this problem may be to use a thin sheet metal. However, mechanical strength of a thin sheet metal is low, and the sheet metal may be torn during working.

Next, when the ejector140is to be assembled on the base member110, the ejector140is tied up with the coil spring145and the stopper member150beforehand, and in this state, inserted into the inner region111of the base member110. Because the stopper member150is to be held at a height that is above the inner region111, it is necessary to assemble the ejector140diagonally into the inner region111by holding the ejector140at a height lower than the stopper member150. That is, because the stopper member150is supposed to support the ejector140by enduring the tongue101to be inserted, the stopper member150is to be fixed on the base member110by a protrusion153thereof being inserted into a locking hole114formed in the base member110. Hence, the stopper member150is held at a height that is above the inner region111by an amount corresponding to the height of the protrusion153, which makes it necessary to perform the assembly diagonally. It is difficult to perform such diagonal assembly mechanically, which is a cause of reducing the productivity of the connector buckle100.

Hence, in the current circumstances, there is no satisfactory connector buckle available that has a small and simple structure and has a favorable productivity.

CITATION LIST

Patent Literature

SUMMARY OF INVENTION

Technical Problem

The present invention aims to solve the various conventional problems described above and achieve the object described below. That is, an object of the present invention is to provide a buckle for a connector that has a small and simple structure and has a favorable productivity, and a method for assembling the same.

Solution to Problem

A solution to the problems described above are as follows.

<1> A buckle for a connector, including:

a metallic base member including an inner region into which a tongue having a locking groove in a side thereof along an inserting direction can be inserted, and slide grooves formed in both of facing surfaces of the base member respectively;

a columnar latch member inserted through the slide grooves of the base member and disposed such that both ends thereof stick out from the base member, and configured to be locked with the locking groove of the tongue to be inserted, by, when it is at the locking groove of the tongue, sliding in a first sliding direction that is along a groove inward direction of the locking groove;

an unlocking member that is a squared-U-shaped member which, with an open mouth thereof ahead, is externally fitted over the base member, and that includes locking support portions in both of facing surfaces thereof respectively, the locking support portions being configured to be locked with the both ends of the latch member sticking out from the base member such that the unlocking member is supported in an externally fitted state, the unlocking member being configured to slide the latch member in a second sliding direction opposite to the first sliding direction when a pushing operation is given from outside, to unlock the tongue and the latch member from each other;

a latch spring inserted between the base member and the unlocking member, and configured to bias the unlocking member in the first sliding direction to support the tongue and the latch member in a locked state;

an ejector provided in the inner region of the base member, and configured to push out the tongue in a releasing direction opposite to the inserting direction during unlocking of the tongue inserted and the latch member, configured to support the latch member at a position reached by the pushing, and configured to be released from supporting the latch member by being pushed and moved by the tongue inserted, to enable the tongue and the latch member to be locked with each other;

an ejector spring inserted between a stopper member and the ejector and configured to bias the ejector in the releasing direction of the tongue, the stopper member being a member defining the inner region at a deepest position in the inserting direction of the tongue; and

a cover member housing those described above,

wherein the buckle for a connector is configured to support the tongue engageably and disengageably,

wherein the base member includes: a bracket-shaped first plate, both side walls of which are formed along the inserting direction, and a planar surface of which has an opening; and a flat-plate-shaped second plate disposed to cover the opening of the planar surface of the first plate while forming an aperture along the inserting direction, and

wherein the ejector includes: two arms extending along the inserting direction and configured to be inserted into the base member from outside by being slid against the side walls; a body section held between the arms and including a pushing/moving surface for the tongue, which is to be pushed and moved by the tongue, a support section configured to support the latch member slid in the second sliding direction, and a pushing surface to be pushed by the ejector spring; and claws formed at ends of the arms and configured to be locked with the aperture at a terminal end of the base member, the terminal end being opposite to a starting end that is at a side from which the tongue is inserted.

<2> The buckle for a connector according to <1>,

wherein the claws of the arms are locked with terminal ends of the side walls of the first plate, respectively.

<3> The buckle for a connector according to <1> or <2>,

wherein the stopper member is formed integrally with a terminal end of the second plate.

<4> The buckle for a connector according to any one of <1> to <3>,

wherein the latch spring is a coil spring, and the first plate has a positioning groove at a side surface thereof that is at a side at which the unlocking member is externally fitted, the positioning groove being configured to be locked with one end of the coil spring.

<5> The buckle for a connector according to any one of <1> to <4>,

wherein the base member includes a position restricting portion facing a side surface of the first plate that is at a side at which the unlocking member is externally fitted, and configured to restrict a move, in each sliding direction, of the tongue inserted.

<6> The buckle for a connector according to <5>,

wherein the position restricting portion is formed by bending part of at least one of the first plate and the second plate toward a planer surface of the opposite plate.

<7> The buckle for a connector according to any one of <1> to <6>,

wherein the ejector includes a columnar gripping portion extending in the releasing direction from a base end of one of the two arms, the one arm being the arm inserted into the base member by being slid against a side surface opposite to a side surface at a side at which the unlocking member is externally fitted.

<8> A connector buckle assembling method for assembling the buckle for a connector according to any one of <1> to <7>, including:

an ejector assembling step of inserting the ejector internally into the base member substantially horizontally from the starting end toward the terminal end, such that the ejector supports one end of the ejector spring;

a latch member assembling step of disposing the latch member to be inserted through the slide grooves of the base member;

an unlocking member assembling step of externally fitting the unlocking member over the base member via the latch spring, and disposing the locking support portions of the unlocking member to be locked with the latch member; and

a cover member assembling step of disposing the cover member to house therein the base member over which the unlocking member is externally fitted.

Advantageous Effects of Invention

The present invention can solve the various problems of the conventional art described above, and can provide a buckle for a connector that has a small and simple structure and has a favorable productivity, and a method for assembling the same.

DESCRIPTION OF EMBODIMENTS

A buckle for a connector according to one embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 2Ais a plan view of a buckle for a connector according to one embodiment of the present invention.FIG. 2Bis a side elevation thereof.FIG. 2Cis a plan view of the buckle for a connector in a state of being engaged with a tongue.FIG. 2Dis a side elevation thereof.

As shown in these drawings, the buckle for a connector1is constructed such that the buckle structure thereof is housed in a cover member composed of an upper cover60aand a lower cover60b, and is engageable with and disengageable from a tongue101. The upper cover60aand the lower cover60bhave ring portions61aand61bin which a webbing extended from an arbitrary vehicle member is hooked to be passed around.

The buckle structure of the buckle for a connector1will be described with reference toFIG. 3.FIG. 3is an exploded perspective diagram of a buckle for a connector according to one embodiment of the present invention.

The buckle for a connector1is composed of; a base member10formed of a first plate13and a second plate15; a latch member20; an unlocking member30; a latch sprint35; an ejector40; an ejector spring45; and the upper cover60aand lower cover60bdescribed above.

The first plate13is made of a bracket-shaped metal member having an opening in a planar surface thereof, and both side walls thereof are formed along an inserting direction I of the tongue101. The second plate15is made of a flat-plate-shaped metal member, and disposed to cover the opening of the first plate13. By constructing the base member as such a sandwich structure based on the two plate members, it is possible to make the base member on the whole thin, and as a result, to make the buckle for a connector1small.

An inner region11defined by the first plate13and the second plate15has a size into which the tongue can be inserted. The surfaces of the first plate13and second plate15facing each other have slide grooves12aand12brespectively, along which the latch20can slide.

The first plate13has a ring portion19in which a webbing extended from an arbitrary vehicle member is hooked to be passed around.

FIG. 4Ashows a perspective diagram showing a state of the unlocking member30being externally fitted over the base member10. As shown inFIG. 4A, the surfaces of the first plate13and second plate15facing each other are partially bent toward the opposite plates to have crushed portions16, respectively, which function as a position restricting portion for restricting moves of a tongue inserted. This enables a tongue inserted to be restricted from moving in the respective sliding directions (X1and X2directions, seeFIG. 3) of the slide grooves12aand12b. The crushed portions16may be formed on at least either one of the first plate13and the second plate15.

The surfaces of the first plate13and second plate15facing each other further have guide portions18, respectively, which are configured to guide the ejector spring45from the side from which the tongue101is inserted toward a stopper member50, in order to facilitate assembling of the ejector spring45. For the formation of the guide portions18, the surfaces of the first plate13and the second plate15facing each other are bent outward to match the diameter of the ejector spring. This makes it possible to assemble the ejector spring45easily by inserting it from the side from which the tongue101is inserted toward the stopper member50substantially horizontally while guiding it over the guide portions18. The guide portions18may be formed on at least either one of the first plate13and the second plate15.

FIG. 4Bshows a side elevation of the base member10. As shown inFIG. 4B, a side surface of the first plate13at a side at which the unlocking member30is externally fitted has a positioning groove17over which one end side of the latch spring35is externally fitted.

The stopper member50, which defines the inner region11at the deepest position in the inserting direction I of the tongue101, is formed integrally with the second plate15. The stopper member50has a protrusion52over which one end side of the ejector spring45is externally fitted. Integral formation of the stopper member50with the second plate15makes it possible to assemble a buckle for a connector easily, and to reduce the number of parts included to enable a simpler structure.

The latch member20is made of a columnar member, and disposed inserted through the slide grooves12aand12bsuch that both ends thereof stick out from the first plate13and the second plate15(seeFIG. 3). The latch member20is locked with the locking groove102of the tongue101inserted, by sliding in the first sliding direction X1that is along a groove inward direction of the locking groove102when it is at the locking groove102.

The unlocking member30is made of a member having substantially a squared-U shape as a whole, externally fitted over the base member10with an open mouth thereof ahead, and supported in the externally fitted state with locking support portions31aand31bthereof locked with the both ends of the latch member20sticking out from the base member10(seeFIG. 3andFIG. 4A), the locking support portions being formed in both of facing surfaces of the unlocking member, respectively. The locking support portions31aand31bare formed by machining the unlocking member30to match the shape of the latch member.

A surface of the unlocking member that faces a side surface of the base member10has a protrusion32on which one end of the latch spring35is supported (seeFIG. 7Ddescribed below).

The latch spring35is inserted between the base member10and the unlocking member30, and biases the unlocking member30in the first sliding direction X1. The latch spring35is not particularly limited, but is a coil spring, here. In this case, the latch spring35is installed on the buckle for a connector1in a stable state with the ends thereof supported on the positioning groove17of the first plate13and on the protrusion32of the unlocking member30, respectively (seeFIG. 3,FIG. 4A,FIG. 4B, andFIG. 7D).

The ejector40is disposed in the inner region11of the base member10by being inserted thereinto along the inserting direction I of the tongue101(seeFIG. 3). Here, the specific structure of the ejector40will be described with reference toFIG. 5.FIG. 5is a perspective diagram of the ejector40.

The ejector40includes: two arms41aand41bthat extend in the inserting direction1, and are inserted into the base member13from outside by being slid against the side walls of the first plate13, respectively; and a body section42held between the arms41aand41b, and including a pushing/moving surface43ato be pushed and moved by the tongue101, a support section43bconfigured to support the latch member20slide in the second sliding direction X2(seeFIG. 3), and a pushing surface43cto be pushed by the ejector spring45. Claws are formed at ends of the arms41aand41bso as to be locked with terminal ends of the both side walls of the first plate13, respectively, the terminal ends being opposite to a starting end that is at a side from which the tongue101is inserted. The ejector40having this shape can be assembled on the base member10easily, and once assembled, can be maintained in the assembled state because the claws are locked with the terminal ends of the both side walls of the first plate13by resisting being biased by the ejector spring45.

The pushing surface43chas a protrusion43dover which one end of the ejector spring45is supported.

As in the present embodiment, by forming the claws of the arms41aand41bso as to be locked with the terminal ends of the both side walls of the first plate13respectively, it is possible to insert and assemble the ejector40internally into the inner region of the base member10easily, and to realize a locked state stable against an external force with a simple structure, because the locked state after the assembly is not unlocked easily.

However, the present invention is not limited to the example of the present embodiment as long as the effect of the present invention is not spoiled, and the structure of the claws may be changed such that they are locked with an arbitrary aperture of the base member that is positioned at the terminal end side. For example, they may be constructed such that the claw of the arm41ais locked with a terminal end of the second plate15and the claw of the arm41bis locked with the terminal end of the side wall of the first plate13. Alternatively, they may be constructed such that the claw of the arm41ais locked with the terminal end of the side wall of the first plate13and the claw of the arm41bis locked with the terminal end of the second plate15.

The ejector40also includes a columnar gripping portion44that extends in a releasing direction E (seeFIG. 3) of the tongue from a base end of the arm41a, which is one of the arms41aand41bthat is inserted internally into the base member10by being slid against such a side surface of the first plate that is opposite to a side surface thereof at a side at which the unlocking member30is externally fitted. It is possible to perform the assembling work more efficiently, by gripping the gripping portion44and inserting the ejector40internally into the inner region of the base member10.

The ejector spring45is inserted between the stopper member50of the second plate15and the pushing surface43cof the ejector40, and biases the ejector40in the releasing direction E of the tongue101in a state of being disposed in the inner region11of the base member10. Here, the ejector spring45is a coil spring, which provides stable support of the coil spring because both ends of the coil spring are supported on the protrusion52of the stopper member50and on the protrusion43dof the pushing surface43c, respectively.

Next, operations of engaging the tongue101with and disengaging it from the buckle for a connector1will be described.

FIG. 6Ais a cross-sectional diagram ofFIG. 2Ataken along a line A-A.FIG. 6Bis a cross-sectional diagram ofFIG. 2Btaken along a line B-B, showing a state of a cover member being removed.FIG. 6Cis a cross-sectional diagram ofFIG. 2Ctaken along a line C-C.FIG. 6Dis a cross-sectional diagram ofFIG. 2Dtaken along a line D-D, showing a state of a cover member being removed.

First, an initial state (a disengaged state) of the tongue101before inserted will be described with reference toFIG. 6AandFIG. 6B.

In the initial state, the latch member20is supported by the support section43bof the ejector40in a state of being biased in the first sliding direction X1of the slide groove12bby the unlocking member30biased by the latch spring35. The position of the latch member20in this state is the initial position of the latch member20.

Further, the ejector40is supported by the claws of the arms41aand41bbeing locked with the terminal ends of the side walls of the first plate13in a state of being biased in the releasing direction E of the tongue101by the ejector spring45. The position of the ejector40in this state is the initial position of the ejector40.

When the tongue101is inserted along the inserting direction I from this initial state, the pushing/moving surface43aof the ejector40is pushed and moved by the leading end of the tongue101, which moves the ejector40from the initial position thereof to a position closer to the stopper member50along the inserting direction I.

When the ejector40is moved closer to the stopper member50, the support section43bof the ejector40is released from supporting the latch member20, which enables the latch member20to move from the initial position thereof more into the first sliding direction X1, and to slide in the groove inward direction (i.e., a direction along the sliding direction X1) when it is at the locking groove102of the tongue101inserted, to be locked with the locking groove102.

Next, an engaged state of the tongue101that is inserted will be described with reference toFIG. 6CandFIG. 6D. As shown in these drawings, the latch member20is locked with the locking groove102of the tongue101, which brings the tongue101and the buckle for a connector1into an engaged state. Here, the tongue101is restricted, by a side surface of the first plate13and the crushed portions16formed at a position facing this side surface, from moving in any sliding direction, which keeps the tongue101and the buckle for a connector1in the engaged state even when a large external force is applied.

When the tongue101and the buckle for a connector1are to be released from the engaged state, first, a vehicle key, a tongue of an adjacent seat, or the like is inserted through a manipulation hole62(seeFIG. 3) formed in the lower cover, and a pushing operation is given with this vehicle key or the like to slide the unlocking member30along the second sliding direction X2to thereby slide the latch member20locked and supported by the unlocking member30more into the second sliding direction X2of the slide groove12bbeyond the initial position thereof.

When the latch member20is slid in the sliding direction X2, it is released from the state of being locked with the locking groove102of the tongue101.

When the latch member20and the tongue101are released from being locked, the tongue101is pushed out in the releasing direction E by the ejector40biased by the ejector spring45, and the latch member20comes to be supported by the support section43bof the ejector40at the position at which the tongue is pushed out (i.e., the initial position of the ejector40).

Through this, the tongue101and the buckle for a connector1are disengaged, and the buckle for a connector1returns to the initial state described above.

The buckle for a connector1configured as described above can provide a buckle for a connector having a small and simple structure that is easy to assemble.

Finally, a method for assembling the buckle for a connector1will be described.FIG. 7AtoFIG. 7Hare process drawings (1) to (8) showing the steps of assembling the buckle for a connector.

First, the ejector spring45is inserted into the inner region11of the base member10composed of the first plate13and the second plate15(seeFIG. 7A). Here, the ejector spring45can be inserted from the side from which the tongue is inserted, substantially horizontally from the starting end of the base member toward the terminal end thereof. Further, when the base member10has the guide portions18, it is easier to insert the ejector spring.

Next, the ejector40is inserted into the inner region11of the base member10(seeFIG. 7B). Here, the ejector40is inserted with its arms41aand41bslid against the side walls of the first plate13respectively, and is assembled with the claws at the ends of the arms41aand41blocked with the terminal ends of the both side walls of the first plate13. When assembled in this way, the ejector40can be inserted from the side from which the tongue is inserted, substantially horizontally from the starting end of the base member10.

Here, the ejector40and the ejector spring45are assembled separately. However, in such a case as when there are no guide portions18, the ejector40in a state of supporting the ejector spring45on the protrusion43dthereof may be assembled on the base member10(hereinbefore, an ejector assembling step).

Next, the latch member20is disposed to be inserted through the slide grooves12aand12bof the base member10(a latch member assembling step, seeFIG. 7C).

Next, the latch spring35is attached on the protrusion32of the unlocking member30(seeFIG. 7D).

Next, the unlocking member is externally fitted over the base member10via the latch spring35, and the locking support portions31aand31bof the unlocking member30are locked with the latch member20(hereinbefore, an unlocking member assembling step, seeFIG. 7E).

Next, the base member10is set in the lower cover60b(seeFIG. 7F).

Then, the upper cover60ais fitted with the lower cover60bsuch that the base member10is housed thereinside (hereinbefore, a cover member assembling step, seeFIG. 7G).

In this way, the assembly of the buckle for a connector1is completed (seeFIG. 7H). According to such an assembling method, it is possible to insert and assemble the ejector40and the ejector spring45into the inner region11of the base member10substantially horizontally from the side from which the tongue is inserted, which facilitates the assembly. Particularly, with diagonal assembling eliminated, it is easy to introduce a mechanical assembly device, and a significant improvement in the productivity can be expected.

REFERENCE SIGNS LIST