ATTACHMENT STRUCTURE FOR CONNECTING MEMBER FOR SEAT AND ATTACHABLE MEMBER, AND SEAT STRUCTURE

An attachment structure for a connecting member for seat and an attachment member includes a connecting member for seat in a form of a pipe and an attachment member provided with an engaging part to engage with an end portion of the connecting member for seat. The engaging part includes a plurality of contact portions circumferentially arrayed with a predetermined interval to make contact with an inner circumferential surface of the connecting member for seat, and a plurality of non-contact portions, each provided between the contact portions, making no contact with the inner circumferential surface of the connecting member for seat. An adhesive is applied to the non-contact portion when the engaging part of the attachment member engages with the end portion of the connecting member for seat.

TECHNICAL FIELD

The present invention relates to an attachment structure for a connecting member for seat and an attachment member, and a seat structure.

BACKGROUND ART

In a conventional seat structure of vehicles, a connecting member in the form of a pipe extends between a pair of cushion frames. On an end of the connecting member, for example, a pin member for adjusting the distance between the pair of cushion frames or an attachment member, such as shaft member for pivotally supporting a link member, is inserted and fixed by welding (for example, see Patent Literature 1).

CITATION LIST

Patent Literature

Patent Literature 1: Japanese Unexamined Patent Application Publication No. 2012-136088 A

SUMMARY OF INVENTION

Technical Problem

Recently, a seat structure using a resin-made cushion frame has been developed. However, for a resin-made connecting member, welding cannot be actually used to fix an attachment member because the connecting member melts by welding.

The object of the present invention is to tightly join an attachment member to a resin-made connecting member.

Solution to Problem

To solve the problem, an attachment structure for a connecting member for seat and an attachment member according to claim1includes, a connecting member for seat in a form of a pipe; and an attachment member provided with an engaging part to engage with an end portion of the connecting member for seat, wherein the engaging part includes a plurality of contact portions circumferentially arrayed with a predetermined interval to make contact with an inner circumferential surface of the connecting member for seat, and a plurality of non-contact portions, each provided between the contact portions, making no contact with the inner circumferential surface of the connecting member for seat, and an adhesive is applied to the non-contact portion when the engaging part of the attachment member engages with the end portion of the connecting member for seat.

The invention of claim2is the attachment structure for a connecting member for seat and an attachment member according to claim1, wherein at least the three contact portions are provided, and a center of the connecting member for seat is positioned inside a polygonal area formed by connecting the at least three contact portions.

The invention of claim3is the attachment structure for a connecting member for seat and an attachment member according to claim1or2, wherein a notch is formed in the end portion of the connecting member for seat, and a protrusion which engages with the notch is provided on the engaging part of the attachment member.

The invention of claim4is the attachment structure for a connecting member for seat and an attachment member according to claim3, wherein the protrusion is formed on the non-contact portion.

The invention of claim5is the attachment structure for a connecting member for seat and an attachment member according to claim3or4, wherein an axial length of the contact portion is longer than an axial length of the protrusion.

The invention of claim6is the attachment structure for a connecting member for seat and an attachment member according to any one of claims3to5, wherein a plurality of the notches are provided in the end portion of the connecting member for seat, and a plurality of the protrusions, each of which configured to engage with each of the plurality of notches, are provided.

The invention of claim7is the attachment structure for a connecting member for seat and an attachment member according to any one of claims1to6, wherein the contact portion is tapered to have a height gradually decreasing toward a distal end.

The invention of claim8is a seat structure including a connecting member for seat in a form of a pipe extending between right-and-left cushion frames; and an attachment member, wherein the connecting member for seat is formed in a pipe, the attachment member includes an engaging part which engages with an end portion of the connecting member for seat, the engaging part includes a plurality of contact portions circumferentially arrayed with a predetermined interval to make contact with an inner circumferential surface of the connecting member for seat, and a plurality of non-contact portions, each provided between the contact portions, making no contact with the inner circumferential surface of the connecting member for seat, and an adhesive is applied to the non-contact portion when the engaging part of the attachment member engages with the end portion of the connecting member for seat.

Advantageous Effects of Invention

According to the invention of claim1, when an engaging part of an attachment member engages with an end portion of a connecting member for seat, an adhesive is applied to the non-contact portion so that a large amount of adhesive can be applied compared to a structure in which the entire periphery of the engaging part makes contact with the inner circumferential surface of the connecting member for seat. Since the adhesive strength increases as the amount of adhesive increases, the attachment member can tightly be joined to the resin-made connecting member for seat.

Moreover, with a plurality of contact portions making contact with the inner circumferential surface of the connecting member for seat, the attachment member is correctly positioned with respect to the connecting member for seat. So that, the gap between the non-contact portion and the connecting member for seat is stabilized, and a constant amount of adhesive can be applied to the non-contact portion411, thereby providing steady strength of joining the attachment member.

According to the invention of claim2, the center of the connecting member for seat is positioned inside a polygonal area formed by connecting at least three contact portions, so that the attachment member can be positioned in the connecting member for seat without eccentricity.

According to the invention of claim3, a protrusion of the attachment member engages with a notch of the connecting member for seat to restrict rotational motion between the connecting member for seat and the attachment member when the connecting member for seat and the attachment member almost rotate relatively. Hence, the relative rotational motion between the connecting member for seat and the attachment member can be restricted.

According to the invention of claim4, the protrusion is formed on the non-contact portion. Thus the protrusion can be separated from the contact portion. With the protrusion and the contact portion provided to be separated from each other, high rigidity of the attachment member can be provided compared to a structure with the protrusion and the contact portion adjoiningly or integrally provided.

According to the invention of claim5, the axial length of the contact portion is longer than that of the protrusion to provide a large area that contacts the connecting member for seat, thereby stably disposing the attachment member in the connecting member for seat.

According to the invention of claim6, each of a plurality of protrusions engages with each of a plurality of notches, thereby dispersing a load applied to each protrusion. Thus, the protrusion does not need to be made large in size, and the attachment member can be downsized.

According to the invention of claim7, the contact portion is tapered, having a height gradually decreasing toward the distal end, which allows the attachment member to be inserted smoothly in the end portion of the connecting member for seat without the attachment member sticking at the end portion.

According to the invention of claim8, the effect similar to that according to claim1can be provided. So that the rigidity of the joining portion of the connecting member for seat can be increased, thereby the rigidity of the seat itself being increased.

DESCRIPTION OF EMBODIMENTS

An embodiment of the present invention will be described below referring to the drawings. Though the embodiment preferably includes various technical limitations, the scope of the present invention is not limited by the embodiment or illustrative drawings.

FIG. 1is a side view illustrating a schematic configuration of a seat structure according to the embodiment. The seat structure according to the embodiment is used for a seat of vehicles. As illustrated inFIG. 1, the seat structure100includes a slide rail102, a bottom seat103, a back rest104, a reclining mechanism105, and other components. The reclining mechanism105connects the bottom end of the back rest104and the rear end of the bottom seat103, and the back rest104stands upright at the rear end of the bottom seat103. The reclining mechanism105allows the back rest104to swing forward and backward with respect to the bottom seat103. The reclining mechanism105can lock the back rest104to the bottom seat103, thereby restricting the swinging of the back rest104, and can release the lock to urge the back rest4to swing forward.

The bottom seat103includes a pair of right-and-left frames2and a connecting member6in the form of a pipe to connect the pair of right-and-left frames2. The frames2and the connecting member6are connected via pin members3and shaft members4, which will be described later.

FIG. 2is a sectional view illustrating a schematic configuration of a coupling structure for joining a connecting member for seat and an attachment member according to the embodiment.FIG. 3is a perspective view illustrating a schematic configuration of the coupling structure for joining the connecting member for seat and an attachment member. As illustrated inFIGS. 2 and 3, the coupling structure1for joining a connecting member for seat and an attachment member includes the frames2, the pin members3that each engages with the frames2, the shaft members4, that is, attachment (attachable) members each coaxially attached to the pin members3, a link members5each pivotally supported by the shaft members4so as to be disposed approximately parallel to the frames2, and the connecting member6which is in the form of a pipe and serves as a connecting member for seat.

Each of the frames2is formed of resin and provided as, for example, a cushion frame of a seat structure100. The frame2has a through hole21with which the pin member3engages.

Each of the pin members3includes a pin head31and a column-shaped projecting portion32which axially projects from the pin head31. The pin head31is provided with an engaging part33which engages with the through hole21of the frame2and a stepped portion34which seats on the frame2. The stepped portion34has a step-height H which is set substantially identical to the thickness of the frame2. A recessed portion35having an inner diameter larger than the outer diameter of the projecting portion32is formed in the pin head31on the side opposite to the projecting portion32.

Each of the shaft members4is attached to the each end portion of the connecting member6extending between the pair of frames2.FIG. 4is a perspective view illustrating a schematic configuration of the shaft member4, andFIG. 5is a front view of the shaft member4. As illustrated inFIGS. 2 to 5, the shaft member4includes an engaging part41which engages with the end portion of the connecting member6, a shaft42which pivotally supports the link member5, and a recessed portion43with which the projecting portion32of the pin member3engages.

The engaging part41includes a plurality of contact portions411circumferentially arrayed with a predetermined interval to make contact with the inner circumferential surface of the connecting member6and a non-contact portions412each of which is provided between the plurality of contact portions411and makes no contact with the inner circumferential surface of the connecting member6. In the embodiment, four contact portions411are evenly disposed as illustrated by example. The four contact portions411are evenly disposed by 90 degrees with each radial direction inclined from the position which is shifted 45 degree to the vertical line. The outer circumferential surfaces of the four contact portions411are formed along on a circumferential surface S1 that is substantially identical to the inner circumferential surface of the connecting member6. The center E of the connecting member6is positioned in a squared area F formed by connecting the center of contact portions411.

The outer circumferential surfaces of the non-contact portions412are formed along on a circumferential surface S2, which is concentric with and has smaller diameter than the circumferential surface S1. Thus, the step between the non-contact portion412and the contact portion411produces a gap, when the engaging part41engages with the connecting member6. An adhesive is applied to the outer circumferential surface of the engaging part41before engaging. The adhesive applied to the outer circumferential surface of the contact portion411is mostly removed by the inner circumferential surface of the connecting member6so that a very little portion remains. The most of the adhesive moves to the non-contact portion412to fill the non-contact portion412(hatched portion T inFIG. 5represents the adhesive).

FIG. 6is a sectional view taken along the line V-V inFIG. 5. As illustrated inFIG. 6, the contact portion411extends as far as to the vicinity of the distal end of the engaging part41. The contact portion411is tapered, having a height gradually decreasing toward the distal end.

First protrusions44are respectively provided between the two contact portions411on the upper part and between the two contact portions411on the lower part of the engaging part41. The first protrusion44on the upper part engages with a notch61provided on the top and the first protrusion44on the lower part engages with a notch61on the bottom of the end portion of the connecting member6to restrict circumferential rotation of the shaft member4. The first protrusion44is shorter, in the axial direction, than the contact portion411.

A rib45is provided on the proximal end of the engaging part41to extend in the circumferential direction. The rib45engages with the end portion of the connecting member6to correctly position the shaft member4. The first protrusion44and the contact portion411are respectively formed so as to extend to the rib45. Second protrusions46, each of which has a cross section with an arc-shaped contour, are protrudingly provided on the surface, opposite to the connecting member6, of the rib45. The second protrusion46is provide on the extended line in the axial direction of the connecting member6. The second protrusion46also is provided on the extended line in the axial direction of the contact portion411. That is, the second protrusion46and the contact portion411are respectively provided in the same plane passing in the axial direction of the connecting member6.

The column-shaped shaft42is formed to be coaxial with the engaging part41. The outer diameter of the shaft42is smaller than the outer diameter of the connecting member6and larger than the inner diameter of the through hole21of the frame2. The end face of the shaft42can thus make contact with the engaging part33of the pin member3and the frame2.

The recessed portion43is recessed from an end face of the shaft member4and extends along the axis of the engaging part41and the shaft42to form a cylindrical hollow. The recessed portion43passes through the link member5and extends further to the inside of the connecting member6through the end portion thereof. When the pin member3engages with the recessed portion43, the projecting portion32is positioned so as to penetrate the link member5and is disposed inside the end portion of the connecting member6. The boundary L, between the recessed portion43and the projecting portion32of the pin member3, is laser welded and a welding mark7is formed. Since a laser beam for welding is emitted from the outside of the frame2, the welding mark7is formed in a wedge-shape in cross-section, which becomes thicker toward the outside of the frame2and thinner toward the inside of the frame2. The welding mark7extends as far as to reach the link member5. Thus, the welding mark7, the stepped portion34and the frame2exist on the same vertical plane.

The link member5constitutes a part of, for example, the reclining mechanism5of the seat structure100or a seat position adjusting mechanism. The link member5is pivotally supported by the shaft42of the shaft member4so as to pivot about the shaft42. A face of the link member5is in contact with the second protrusion46of the shaft member4. The second protrusion46creates a space between the link member5and the rib45. Filling the adhesive in the space ensures the amount of adhesive for attaching the link member5to the shaft member5, thereby increasing the strength of joining the link member5and the shaft member5.

According to the embodiment as described above, when the engaging part41of the shaft member4engages with the end portion of the connecting member6, a large amount of adhesive can be applied, with the adhesive applied to the non-contact portion412, compared to the structure where the entire periphery of the engaging part41makes contact with the inner circumferential surface of the connecting member6. Since the adhesive strength increases as the amount of adhesive increases, the structure can tightly join the shaft member4even to a resin-made connecting member6.

Furthermore, as a plurality of contact portions411makes contact with the inner circumferential surface of the connecting member6, the shaft member4is correctly positioned in the connecting member6. So that, the gap between the non-contact portion411and the connecting member6is set stably, and a constant amount of adhesive can be applied to a plurality of non-contact portions. Thus, the strength for joining the shaft member4can steadily be provided.

If the shaft member4can tightly be joined to the connecting member6, the rigidity of the joining portion of the connecting member6can be increased, thereby increasing the rigidity of the seat itself.

Since the center of the connecting member6is positioned inside the squared area formed by connecting four contact portions411, the shaft member4can be positioned in the connecting member6without eccentricity.

Further, the first protrusion44of the shaft member4engages with the notch61of the connecting member6to restrict the initial rotational motion between the connecting member6and the shaft member4when the connecting member6and the shaft member4almost rotate relatively. Thus, the relative rotational motion between the connecting member6and the shaft member4can be restricted.

The axial length of the contact portion411is longer than that of the first protrusion44to provide a large area that contacts the connecting member6, thereby stably disposing the shaft member4in the connecting member6.

Furthermore, the contact portion411is tapered, having a height gradually decreasing toward the distal end, which allows the shaft member4to be inserted smoothly in the end portion of the connecting member6without the contact portion411sticking at the end portion.

The first protrusion44, formed on the non-contact portion412, can be provided so as to be separated from the contact portion411. With the first protrusion44and the contact portion411provided to be separated from each other, high rigidity of the shaft member4can be obtained compared to a structure with the first protrusion44and the contact portion411adjoiningly or integrally provided.

Moreover, each of the plurality of first protrusions44engages with each of the plurality of notches61, thereby dispersing a load to reduce the load applied to each of the first protrusions44. Thus, the first protrusion44does not need to be made large in size, and the shaft member4can be downsized.

If the notch61and the first protrusion44are provided in the upper portion and the lower portion as described above, the engagement of the notches61with the first protrusions44can easily be checked.

The embodiment according to the present invention is not limited to the aforementioned embodiment, and modifications can optionally be made as required without departing from the spirit and scope of the present invention. Hereinafter, the same component as the aforementioned embodiment is appended with the same reference sign and the description thereof is omitted.

For example, although four contact portions411are provided in the aforementioned embodiment, the number of contact portions411may be three or more. In any case, it is preferable that the center of the connecting member6is located inside a polygonal area formed by connecting at least three contact portions411. In this manner, the shaft member4can be positioned in the connecting member6without eccentricity.

In the aforementioned embodiment, though the shaft member4, which pivotally supports the link member5, is provided as the attachment member, other form of attachment members may be a pin member that engages with the end portion of the connecting member6to adjust the distance between a pair of cushion frames.

In the aforementioned embodiment, though the outer circumferential surface of the non-contact portion412is formed to be concentric with the outer circumferential surface of the contact portion411, the non-contact portion412may be formed in any shape that avoids contact with the inner circumferential surface of the connecting member6.

In the aforementioned embodiment, the coupling structure for joining a connecting member for seat and an attachment member is described. It goes without saying that this structure can be used for a coupling structure for joining other connecting members and an attachment member.

INDUSTRIAL APPLICABILITY

The coupling structure for joining a connecting member for seat and an attachment member, and the seat structure can be used, for example, for a resin-made cushion frame mounted on vehicles.

REFERENCE SIGNS LIST