Vehicle rail and vehicle seat apparatus

A vehicle rail fixed to a vehicle floor for relatively movably supporting a movable rail fixed to a seat includes a bottom wall member having a drawing portion at which the vehicle rail is fixed to the vehicle floor, and a guide member provided in a standing manner at both sides of the bottom wall member in a width direction for guiding a movement of the movable rail, the guide member being integrally formed with the bottom wall member by means of welding.

This application is based on and claims priority under 35 U.S.C. § 119 to Japanese Patent Application 2005-045891, filed on Feb. 22, 2005, the entire content of which is incorporated herein by reference.

FIELD OF THE INVENTION

This invention relates to a vehicle rail and a vehicle seat apparatus.

BACKGROUND

Conventionally, a seat apparatus is known, which includes a seat slide mechanism for adjusting a position of a seat. The seat slide mechanism includes a lower rail serving as a vehicle rail fixed to a vehicle floor, and an upper rail fixed to the seat. The upper rail is movably supported by the lower rail. One of the known seat apparatuses is disclosed in JP2002-254966A. According to the disclosed seat apparatus, a lower rail includes a bottom wall portion and guide wall portions, which are integrally formed by means of roll forming or press forming. The guide wall portions are provided in a standing manner at both sides of the bottom wall portion in a width direction for guiding an upper rail.

Further, the lower rail is provided with a bracket at which the lower rail is fixed to the vehicle floor by means of a bolt. The bracket is provided for stably mounting the lower rail on the vehicle floor in accordance with a shape of the floor, and is provided for preventing a head of the fixing bolt from being protruded from the lower rail and interfered with the upper rail.

However, because the lower rail according to the disclosed seat apparatus requires the bracket, the number of operating members is increased and manufacturing cost of the seat apparatus is increased. Moreover, because a space for housing the head of the bolt is required between the bottom wall portion of the lower rail and a bottom wall portion of the bracket, the seat apparatus is occasionally getting larger.

In order to avoid an increase of the number of the operating members, the bottom wall portion may be integrally formed with, by means of drawing, an operating member shaped similar to the bracket at which the lower rail is fixed to the vehicle floor. However, with the configuration of the lower rail, which includes the bottom wall portion and the guide wall portion integrally formed with each other and includes a complicated shape in a cross-section, distortion is provoked if the above-mentioned process is applied to form the operating member shaped similar to the bracket at the bottom wall portion by means of drawing. Accordingly, an accuracy of the seat rail may occasionally be lowered.

Further, in a condition where the guide wall portion of the lower rail includes a shape, which is folded inwardly in a width direction thereof, a width of an opening of the rail may be narrowed. On this occasion, in order to avoid interference between the head of the bolt for fixing the lower rail to the vehicle floor and the guide wall portion, the width of the opening may be required to be wider, and the cross-section of the rail may thereby occasionally be getting larger. Accordingly, in a condition where the seat rail is mounted on the vehicle, because of an enlargement of the opening in the width direction, an appearance may occasionally be detracted. Further, a protector may be required in order to shut out a foreign object, and the manufacturing cost of the seat apparatus may thereby be increased.

A need thus exists for a vehicle rail and a vehicle seat apparatus which can be downsized in totality while restraining the increase of the number of the operating members.

SUMMARY OF THE INVENTION

According to an aspect of the present invention, a vehicle rail fixed to a vehicle floor for relatively movably supporting a movable rail fixed to a seat includes a bottom wall member having a drawing portion at which the vehicle rail is fixed to the vehicle floor, and a guide member provided in a standing manner at both sides of the bottom wall member in a width direction for guiding a movement of the movable rail, the guide member being integrally formed with the bottom wall member by means of welding.

DETAILED DESCRIPTION

An embodiment of the present invention will be explained with reference to illustrations of drawing figures as follows. A framework portion illustrated inFIG. 1is arranged in a width direction of a seat (a direction perpendicular to a sheet ofFIG. 1) in pairs.

As illustrated inFIG. 1, a lower rail11serving as a vehicle rail is directly fixed to a vehicle floor F and extends in a backward and forward direction of the vehicle. As illustrated inFIGS. 2-3, the lower rail11is provided with a pair of side wall portions12arranged in a standing manner at both sides thereof in a width direction, and is provided with a bottom wall portion13for connecting the side wall portions12with each other. Further, the lower rail11includes a substantially U-shaped cross-section. Each side wall portion12is continuously formed with, at an end portion (a top end portion), a first folded wall portion14. Each first folded wall portion14is inflected inwardly in the width direction of the lower rail11and further folded to a base portion side of the side wall portion12. The lower rail11includes an opening, which opens toward an upper side and has a width W1, between the first folded wall portions14. The side wall portions12and the first folded wall portions14together configure guide wall portions for guiding a movement of an upper rail31.

On this occasion, the lower rail11includes a bottom wall member21and a pair of guide members22, both of which are formed by rolling or pressing a plate material. The bottom wall member21forms a center portion of the bottom wall portion13in the width direction. The guide member22and a side end portion of the bottom wall portion13in the width direction together form the guide wall portion (the side wall portion12and the first folded wall portion14). The lower rail11is formed by integrally forming the bottom wall member21and the guide member22by means of laser welding, electronic beam welding, or the like. Connecting portions C (seeFIG. 3) of the bottom wall member21and the guide member22are configured to be perpendicular to a flat portion extending in the width direction of the bottom wall portion13. More particularly, the bottom wall member21and the guide member22are welded at end surfaces thereof facing with each other in the width direction. The bottom wall member21is formed with, by means of drawing, or the like, plural drawing portions21a,in a longitudinal direction thereof at regular intervals. Each drawing portion21ais protruded downward in a manner of table. According to the embodiment of the present invention, a cross-section of the drawing portion21ais substantially trapezoidal in a longitudinal direction and is substantially rectangular in a width direction.

The drawing portion21ais formed with a bolt insert hole (i.e., a hole)21bpenetrating through a center portion thereof in a substantially vertical direction. A shaft portion26aof a fixing bolt (i.e., a fixing member)26for fixing the lower rail11to the vehicle floor F is inserted through the bolt insert hole21b.The fixing bolt26is inserted through the bottom wall member21(the bottom wall portion13) from an opening side (an upper side) in such a manner that the head portion26bof the fixing bolt26is housed in a protrude length of the drawing portion21a.

The head portion26bof the fixing bolt26includes a width W2, which is smaller than a width of the drawing portion21aand larger than the width W1. The fixing bolt26is mounted in the lower rail11in such a manner that the fixing bolt26is preliminarily inserted through the bottom wall member21, which is preliminarily formed with the drawing portion21aand the bolt insert hole21bin a condition where the bottom wall member21is in a state of a single member, before the guide member22is connected to the bottom wall member21. More particularly, although the head portion26bof the fixing bolt26includes the width W2, which is wider than the width W1, an assembling of the fixing bolt26may not be disturbed because the fixing bolt26is mounted in the lower rail11before the guide member22is connected to the bottom wall member21. Further, the fixing bolt26(the head portion26b) is cramped by means of a jig (e.g. a driver), which is inserted from the opening in the substantially vertical direction, and the lower rail11is thereby fixed to the vehicle floor F. The present invention is applicable as long as the width W1ensures a width through which the jig can be inserted. On this occasion, the lower rail11(the bottom wall member21) is directly fixed to the vehicle floor in a stable manner while adjusting a height by means of the drawing portion21a.

The upper rail31serving as a movable rail extends in the backward and forward direction of the vehicle, and is fixed to a frame (not shown) serving as a framework of a seat cushion (the seat). As illustrated inFIGS. 2-3, the upper rail31is provided with support wall portions32and second folded wall portions33continuously formed from an end portion (a bottom end portion) of the support wall portions32. The support wall portions32are extended in the substantially vertical direction between the first folded wall portions14of the lower rail11. Each second folded wall portion33is inflected outwardly in the width direction and further folded so as to be enclosed between the side wall portion12and the first folded wall portions14. Further, the upper rail31includes a substantially inverted T-shaped cross-section.

As illustrated inFIG. 2, the upper rail31is supported by the lower rail11by means of a bearing34, which is fixed at an outer surface of the second folded wall portion33and rotatably moves along the bottom wall portion13. Further, as illustrated inFIG. 3, the upper rail31is engaged with the lower rail11by means of a guide shoe35. The guide shoe35is fixed at the outer surface of the second folded wall portion33and slides along the side wall portion12and the first folded wall portion14(the guide wall portion). Thereby, because of a rotation of the bearing34along the side wall portion12, the upper rail31is slidably supported by the lower rail11in the longitudinal direction (the backward and forward direction of the vehicle) in such a manner that the guide shoe35is guided by means of the side wall portion12and the first folded wall portion14. On this occasion, because the head portion26bof the fixing bolt26is immersed in the drawing portion21a,the head portion26bof the fixing bolt26does not interfere with the upper rail31.

Next, a manufacturing process of the lower rail11and an assembling process of the lower rail11relative to the vehicle floor F will be explained hereinafter. In the manufacturing process of the lower rail11, the bottom wall member21and the guide member22are formed by rolling or pressing the plate material. On this occasion, formation of the drawing portion21aby means of the drawing and formation of the bolt insert hole21bare preliminarily be performed in a condition where the bottom wall member21is in the state of the single member. Further, the fixing bolt26is preliminarily inserted through the bolt insert hole21bin a condition where the bottom wall member21is in the state of the single member. Then, in a condition where the bottom wall member21and the guide member22are firmly held by mean of an appropriate fixing tool, the bottom wall member21and the guide member22are engaged by means of the laser welding, the electronic beam welding, or the like.

The lower rail11, through which the fixing bolt26is preliminarily inserted, is fixed to the vehicle floor F by cramping the fixing bolt26by means of the jig which is inserted from the opening in the substantially vertical direction. According to the embodiment of the present invention, the following effects can be obtained.

According to the embodiment of the present invention, because the bottom wall member21includes the drawing portion21aat which the lower rail11is fixed to the vehicle floor F, an extra operating member (e.g. a bracket) is not necessarily be added. Therefore, an increase of the number of operating members can be restrained. Further, the lower rail11can be downsized in totality relative to a condition where the extra operating member is added. Moreover, the lower rail11can be fixed to the vehicle floor F directly in a stable manner while adjusting the height by means of the drawing portion21a.

Further, in the manufacturing process of the lower rail11, the drawing portion21ais preliminarily formed in a condition where the bottom wall member21is in the state of the single member. Thereafter, the bottom wall member21and the guide member22are integrally formed by means of the welding. Accordingly, degradation of an accuracy of a shape of the guide member22can be restrained.

According to the embodiment of the present invention, because the fixing bolt26for fixing the lower rail11to the vehicle floor F is inserted through the bottom wall portion13, the extra operating member (e.g. the bracket) is not necessarily added. Therefore, the increase of the number of the operating members can be restrained and downsizing of the lower rail11in totality can be achieved relative to a condition where the extra operating member is added.

Further, in the manufacturing process of the lower rail11, the fixing bolt26is preliminarily inserted through the bottom wall member21in a condition where the bottom wall member21and the guide member22are separated. Thereafter, the separated operating members (the bottom wall member21and the guide member22) are integrally formed by means of the welding. Therefore, the guide wall portion folded inwardly in the width direction (the first folded wall portion14) is not required to ensure a width of the opening for preventing interference with the head26bof the fixing bolt26. Accordingly, a cross-section of the rail can be downsized.

According to the embodiment of the present invention, the separated operating members (the bottom wall member21and the guide member22) are not required to have an identical thickness or material with each other. Accordingly, the bottom wall member21and the guide member22can adopt the thickness or the material in accordance with a desirable amount of rigidity to each position of the lower rail11(e.g. a position where the lower rail11is fixed to the vehicle floor F and a position where the lower rail11guides the upper rail31). Therefore, a required strength can be ensured without improving quality of the material.

Generally, various types of the vehicle include various types of the vehicle floor F, respectively, and accordingly the various types of the vehicle include various shapes of the bottom wall portion13of the lower rail11(a shape, a position, or the like, of the drawing portion21afor adjusting a width or the height), respectively. In contrast, the guide wall portion of the lower rail11(the side wall portion12and the first folded wall portion14) is standardized among the various types of the vehicle, and thus each type of the vehicle includes a shape (cross-section) of the guide wall portion identical with each other. According to the embodiment of the present invention, because the bottom wall member21, which mainly forms the bottom wall portion13, and the guide member22, which forms the guide wall portion, are individually configured, a standardized operating member (the guide member22) can be used in part. Thereby, reduction of the number of the operating members and manufacturing cost can be performed. Further, the present invention can horizontally be developed to the various types of the vehicle by changing only the bottom wall member21.

A conventional lower rail, the operating members of which are integrally formed at the same time by means of roll forming or press forming, may occasionally be difficult to change the cross-section thereof in part in the longitudinal direction. It is because a strength of a punch dies may be deficient because of a constraint of a size of a form structure and the cross-section of the lower rail in case of the roll forming. Further, it is because the manufacturing process is constrained in case of the press forming. According to the embodiment of the present invention, because the bottom wall member21and the guide member22are individually formed from the plane material, they can be formed in a simple process relative to a condition where the whole operating member of the lower rail is formed at the same time. Further, the lower rail can adopt the shape (the cross-section), which was difficult to be manufactured by means of the roll forming or the press forming. Therefore, a degree of freedom of a product design can be expanded.

According to the embodiment of the present invention, the bottom wall member21including the bolt insert hole21bcan be formed by means of the press forming without difficulty. Accordingly, the bottom wall member21can be formed into almost any shape by means of the press forming, and an overall manufacturing expense can thereby be reduced.

According to the embodiment of the present invention, because the separated operating members (the bottom wall member21and the guide member22) configure the lower rail11, the material corresponding to a function of the cross-section of the lower rail11can be adopted in part. Further, a special process, such that the guide member22guiding the upper rail31is provided with a film having a smaller degree of friction coefficient, can relatively readily be performed in a condition where the guide member22is in a state of a single member.

According to the embodiment of the present invention, because the pair of guide members22is symmetric with each other, they can be formed in an identical process. Further, in a condition where the guide member22is formed by means of the roll forming, a size of the cross-section of the lower rail11becomes less than, or equal to, half relative to a condition where the whole operating member of the lower rail11is formed at the same time. Accordingly, downsizing of a facility and the form can be achieved, and the reduction of the manufacturing cost can thereby be achieved.

According to the embodiment of the present invention, because the bottom wall member21and the guide member22are integrally formed by means of the welding (the laser welding or the electronic beam welding), which has a smaller degree of thermal distortion, the degradation of the accuracy of the shape (the cross-section) of the rail can be restrained.

According to the embodiment of the present invention, the vehicle seat apparatus can be downsized in totality while restraining the increase of the number of the operating members. However, the present invention is not limited to the embodiment disclosed above. Variations and changes will be explained hereinafter.

According to a variation of the present invention, a lower rail (i.e., a vehicle rail)51corresponding to an upper rail (i.e., movable rail)41illustrated inFIGS. 4A-4Bmay be adopted. More particularly, the upper rail41includes support wall portions42, which have a substantially U-shaped cross-section and opens toward lower side, and a folded wall portion43continuously formed from each opening end of the support wall portion42. The folded wall portion43includes a shape similar to the second folded wall portion33of the aforementioned embodiment of the present invention. Accordingly, relative to the aforementioned embodiment, the upper rail41may be wider in a width direction corresponding amount of an opening width of the support wall portion42. Further, the lower rail51is formed by integrally forming a bottom wall member52, which is enlarged corresponding amount of the opening width of the support wall portion42, and the guide member22by means of the laser welding, the electronic beam welding, or the like. The bottom wall member52includes a drawing portion52a,a width of which is wider than that of the drawing portion21aof the embodiment disclosed above. The drawing portion52ais formed with a bolt insert hole52bthrough which the fixing bolt26is inserted. According to the variation of the present invention, the guide member22, which is common to the embodiment disclosed above, is used and only the configuration of the bottom wall member52is changed for corresponding to the upper rail41having a different shape from the upper rail31of the aforementioned embodiment.

Another variation of the present invention will be explained hereinafter with reference toFIG. 5. A lower rail (i.e., a vehicle rail)56may include a bottom wall member57and a guide member58, which have a thickness different from each other. More particularly, a thickness of the bottom wall member57is greater than that of the guide member58to some degree. Accordingly, a required strength can be ensured without improving the quality of the material because the material (plate material), the thickness of which is corresponding a desirable amount of rigidity to a function of a cross-section of the lower rail56, is used in part. Further, the increase of the manufacturing cost can be restrained.

Alternatively, or in addition, the material of the bottom wall member may have a tensile strength different from that of the guide member. Even in such condition, the required strength can be ensured without improving the quality of the material because the material having the tensile strength corresponding to the desirable amount of rigidity to the function of the cross-section of the lower rail is used in part. Further, because of the material having the tensile strength, the thickness of the panel material can be reduced, and the lower rail can be downsized in totality.

Alternatively or in addition, the material of the bottom wall member may have friction coefficient different from that of the guide member. More particularly, the guide member, which forms a contact surface with the guide shoe when the upper rail slides relative to the lower rail, may be formed from the material having the friction coefficient smaller than that of the bottom wall member. On this occasion, because the material, which has the friction coefficient corresponding to a desirable smoothness or lower friction to the function of the cross-section of the lower rail, is used in part, a required smoothness, or the like, can be ensured without improving the quality of the material. For example, if the guide member is formed from mirror finished stainless, which is a general-purpose item, the required smoothness, or the like, can be ensured without adding an extra process.

Further, the special process, such that the guide member is provided with the film having the smaller degree of the friction coefficient, can relatively readily be performed in a condition where the guide member is in the state of the single member. Further, productivity of the vehicle rail is not disturbed.

Alternatively or in addition, a shape of the pair of guide wall portions (the side wall portion12and the first folded wall portion14) may not necessarily be identical with each other. For example, a protruding length of a first guide wall portion in a substantially vertical direction may be shorter degree than that of a second guide wall portion in the substantially vertical direction.

The present invention is applicable even when the guide member22is made of several pieces of the operating member. Alternatively, or in addition, the drawing portion21amay be omitted. On this occasion, the lower rail11can be made of any number of the operating members as long as the lower rail11includes an operating member through which the fixing bolt26can be inserted.

Alternatively or in addition, the fixing member may include a caulking pin. Further, the seat apparatus according to the embodiment of the present invention may include more than two lower rails11and upper rails31. Moreover, alternatively or in addition, the seat apparatus according to the embodiment of the present invention may include a single lower rail11and upper rail31as long as a sufficient strength and stability are ensured.

Alternatively or in addition, a moving direction of the seat in response to a relative movement of the lower rail and the upper rail may be a width direction of the vehicle.

According to the embodiment of the present invention, because the bottom wall member includes the drawing portion at which the lower rail is fixed to the vehicle floor, the extra operating member (e.g. the bracket) is not necessarily be added. Therefore, the increase of the number of the operating members can be restrained. Further, the vehicle rail can be downsized in totality relative to a condition where the extra operating member is added. Moreover, the lower rail can be fixed to the vehicle floor directly in the stable manner while adjusting the height by means of the drawing portion.

Moreover, in the manufacturing process of the vehicle rail, the drawing portion is preliminarily formed in a condition where the bottom wall member is in the state of the single member. Thereafter, the bottom wall member and the guide member are integrally formed by means of the welding. Thereby, the degradation of the accuracy of the shape of the guide member can be restrained.

According to the embodiment of the present invention, because the fixing member for fixing the vehicle rail to the vehicle floor is inserted through the bottom wall portion, the extra operating member (e.g. the bracket) is not necessarily be added. Therefore, the increase of the number of the operating members can be restrained and downsizing of the vehicle rail in totality can be achieved relative to a condition where the extra operating member is added.

Further, in the manufacturing process of the vehicle rail, the fixing member is preliminarily inserted through the operating member forming the bottom wall portion in a condition where the operating members of the vehicle rail are separated. Thereafter, the separated operating members are integrally formed by means of the welding. Thereby, the guide wall portion, which is folded inwardly in the width direction, is not required to ensure the width of the opening for preventing the interference with the head of the fixing member. Therefore, the cross-section of the rail can be downsized.

According to the embodiment of the present invention, because each operating member adopts the thickness or the material in accordance with the desirable amount of rigidity to each position of the vehicle rail (e.g. the position where the lower rail is fixed to the vehicle floor and the position where the lower rail11guides the upper rail), the required strength can be ensured without improving the quality of the material.

According to the embodiment of the present invention, the vehicle seat apparatus can be downsized in totality while restraining the increase of the operating member.