JP5978952B2 - Feed screw support structure for vehicle seat - Google Patents

Description

  The present invention relates to a feed screw support structure for a vehicle seat. Specifically, the present invention relates to a feed screw support structure for a vehicle seat that supports the feed screw in a state in which the shaft can rotate.

  Conventionally, as a sliding device for a vehicle seat, an upper rail connected to the vehicle seat is slid in the front-rear direction with respect to the lower rail provided on the floor by the operation of an electric feed screw mechanism. Is known (Patent Document 1). Specifically, the feed screw mechanism includes a feed screw attached to the upper rail and a nut attached to the lower rail by being screwed to the feed screw, and the upper rail slides by rotating the feed screw. It is configured to be sent in the direction. The feed screw has a front end connected to the gear unit and rotatably supported, and a rear end is rotatably supported by the upper rail via a bracket. It is provided as a state. By supporting the both ends, the feed screw is rotated by a rotational driving force received from the gear unit, and a nut screwed to the feed screw is fed in the axial direction.

JP-A-9-109750

  However, in the above prior art, when a shaft misalignment occurs during rotation of the feed screw due to factors such as assembly errors of the feed screw, the shaft is strongly rubbed against the bracket at the rear end of the feed screw, resulting in torque fluctuation. The feed screw may not rotate smoothly. The present invention was devised as a solution to the above-mentioned problem, and the problem to be solved by the present invention is to strongly resist the support tool in the radial direction even if the feed screw is misaligned during rotational driving. It is to prevent rubbing.

In order to solve the above problems, the vehicle seat feed screw support structure of the present invention takes the following means.
1st invention is a feed screw support structure of the vehicle seat which supports a feed screw in the state which can be axially rotated, Comprising: The 1st support tool which supports one end of a feed screw, and the other end of a feed screw are supported And a second support tool. The first support is configured to support one end of the feed screw so that the shaft can rotate. The second support tool makes a point contact between the convex spherical surface formed in the other end of the feed screw and protruding in the axial direction with the concave spherical surface formed in the second support tool and recessed in the axial direction. The other end of the feed screw is supported in a rotatable state.

  According to the first aspect of the invention, the other end of the feed screw is supported in a point contact state by contact between the spherical surfaces with respect to the second support tool, so that even if the feed screw causes an axis deviation during rotational driving, The other end of the feed screw is always supported in a point contact state with respect to the second support. Therefore, even if the feed screw is misaligned, the feed screw can be prevented from being rubbed strongly against the second support in the radial direction.

  The second invention is the following configuration in the first invention described above. An electric drive unit is connected to one end of the feed screw, and the shaft is rotated by a driving force received from the drive unit.

  According to the second aspect of the present invention, even if the feed screw may move off-axis so that the other end swings with the drive unit driven, the other end of the feed screw is not supported by the second support. By the point contact structure with the tool, the second support tool is supported without being strongly rubbed in the radial direction. Therefore, it is possible to smoothly drive the shaft of the feed screw.

  The third invention is the following configuration in the first or second invention described above. The concave spherical surface formed on the second support is formed in a spherically concave shape drawn around one end of the feed screw.

  According to the third aspect of the present invention, the feed screw is constant without pressing the other end against the second support member with an unreasonable force, whether or not the other end of the lead screw is offset from its one end. In this manner, the state of point contact is maintained. Therefore, the shaft can be always driven to rotate smoothly without changing the torque of the feed screw.

It is the perspective view which showed schematic structure of the vehicle seat to which the slide apparatus of Example 1 was applied. It is a disassembled perspective view of a slide apparatus. It is the disassembled perspective view which expanded and showed one slide apparatus. It is the perspective view which expanded and showed the assembly | attachment state of the other slide apparatus. It is a front view of the other slide apparatus. FIG. 6 is a sectional view taken along line VI-VI in FIG. 5.

  EMBODIMENT OF THE INVENTION Below, the form for implementing this invention is demonstrated using drawing.

  First, “a feed screw support structure for a vehicle seat” of Example 1 will be described with reference to FIGS. 1 to 6. As shown in FIG. 1, the “seat feed screw support structure for a vehicle seat” of the present embodiment is configured to connect a seat 1 configured as a passenger seat of an automobile to a floor F so as to be slidable in the front-rear direction. Has been applied. The sliding device 10 is provided in a pair of left and right between the seat 1 and the floor F, and slides the seat 1 in the front-rear direction with respect to the floor F by an electric drive of a feed screw mechanism 20 described later. The position is adjusted. Here, the seat 1 includes a seat back 2 that serves as a backrest for a seated occupant and a seat cushion 3 that serves as a seating portion. The seat back 2 is in a state in which the lower end portions of the left and right sides thereof are connected to and supported by the rear end portions of the left and right sides of the seat cushion 3. Further, the seat cushion 3 is provided in a state in which a bottom surface portion thereof is connected to the floor F so as to be slidable back and forth via the pair of left and right slide devices 10 described above.

  Each of the above-described slide devices 10 can slide the seat 1 in the front-rear direction with respect to the floor F or can be fixed at each slide position by driving an electric motor M disposed therebetween. It can be done. Hereinafter, a specific configuration of each slide device 10 will be described in detail with reference to FIGS. As shown in FIGS. 2 to 4, each slide device 10 includes a lower rail 11, an upper rail 12, a bearing 13 (see FIG. 4) provided with a plurality of steel balls, and a feed screw mechanism 20. Yes.

  The lower rail 11 is formed by bending a sheet of steel sheet that is long in the longitudinal direction of the vehicle in several directions in the short side direction, and is provided in a state that is bolted and fixed integrally on the floor F. It has been. The lower rail 11 is formed in a rail shape whose cross-sectional shape is substantially uniform in the longitudinal direction. Specifically, as shown in FIG. 5, the lower rail 11 includes a bottom surface portion 11 </ b> A that is installed on the floor F with its surface facing upward, and extends upward from the left and right side portions of the bottom surface portion 11 </ b> A so as to inward each other. And a pair of left and right lower fin portions 11B and 11C that are bent back in an inverted U shape on the side to be formed.

  As shown in FIGS. 2 to 4, the upper rail 12 is formed by bending a sheet of steel sheet that is long in the vehicle front-rear direction in some directions in the lateral direction, like the lower rail 11 described above. It is. The above-described upper rail 12 is assembled into a state in which the upper rail 12 is slidable in the longitudinal direction with respect to the lower rail 11 by being inserted into the lower rail 11 from the opening end portion on either side in the longitudinal direction of the lower rail 11 described above. ing. Specifically, as shown in FIG. 5, the upper rail 12 has a pair of left and right vertical surface portions extending in the height direction through the gap 11 </ b> F between the left and right lower side fin portions 11 </ b> B and 11 </ b> C of the lower rail 11 described above. 12A, an upper surface portion 12B spanning between the upper end portions of these vertical surface portions 12A, and left and right extending from the lower end portions of the respective vertical surface portions 12A by being bent back so as to be warped outward in opposite directions. It is formed in the cross-sectional shape which has a pair of upper side fin part 12C, 12D.

  The above-described upper rail 12 has left and right upper fin portions 12C and 12D bent back in the U shape with respect to the lower rail 11, and the left and right lower sides of the lower rail 11 bent back in an inverted U shape. The fins 11B and 11C are inserted and assembled so as to engage with the inner sides of the fins 11B and 11C. By being inserted in this way, the upper rail 12 is moved by the bottom surface portion 11A of the lower rail 11 by the above-described hanging structure of the left and right upper side fin portions 12C, 12D and the lower side fin portions 11B, 11C with respect to the lower rail 11. While being supported from the lower side, it is assembled in a state of being prevented from coming off (preventing peeling) from the upper side.

  In the present embodiment, the rolling elements are respectively disposed between the bottom portions on both outer sides of the left and right upper fin portions 12C and 12D of the upper rail 12 and the outer corner portions of the bottom surface portion 11A of the lower rail 11. A plurality of bearings 13 each having a plurality of steel balls are provided. Moreover, it becomes a rolling element also between each upper part of the left and right upper side fin part 12C, 12D of the upper rail 12, and the upper corner part of both inner sides of the left and right lower side fin part 11B, 11C of the lower rail 11, respectively. A plurality of bearings 13 each having a plurality of steel balls are provided. By the arrangement of these bearings 13, the upper rail 12 is supported so as to be able to slide smoothly in the front-rear direction without largely rattling with respect to the lower rail 11 in the respective cross-sectional directions such as up, down, left, and right. Has been.

  As shown in FIG. 3, the feed screw mechanism 20 includes a round bar-shaped feed screw 21, a gear unit 22 that transmits the driving force from the electric motor M to the feed screw 21, and a metal screwed into the feed screw 21. And a nut 23. Here, the gear unit 22 corresponds to the “drive unit” of the present invention.

  The above-described feed screw 21 is in a state in which the axial direction extends along the sliding direction of the upper rail 12, and the front portion and the rear portion of the feed screw 21 with respect to the upper rail 12 by the bearing member 21A and the end cap 21B, respectively. Thus, it is assembled in a state where it is supported so as to be rotatable. Here, the bearing member 21A corresponds to the “first support member” of the present invention, and the end cap 21B corresponds to the “second support member” of the present invention. The above-described bearing member 21A includes a bearing 21A1 that rotatably supports the above-described feed screw 21 from the front end side, and an L-shaped bracket 21A2 that attaches the gear box 22C to the upper surface portion 12B of the upper rail 12. Yes.

  The bearing 21A1 is inserted so that a screw shaft portion 21A1a provided so as to protrude from the upper surface portion penetrates the bottom surface portion 21A2a facing the lower side of the L-shaped bracket 21A2 and the upper surface portion 12B of the upper rail 12 from the lower side. As a state where the upper rail 12 is protruded upward, the tip end portion of the upper rail 12 is fastened and fixed by the fastening nut 21A1b, so that the upper rail portion 12B is integrally coupled to the upper rail portion 12B. (See FIG. 6).

  The L-shaped bracket 21A2 is formed in an L-shaped plate shape having a bottom surface portion 21A2a whose surface is directed downward and a front surface portion 21A2b that is bent upward from the front edge of the bottom surface portion 21A2a and faces the front side. ing. In the L-shaped bracket 21A2, a gear box 22C of a gear unit 22 (described later) is assigned to the front surface portion 21A2b from the front side, and a bolt shaft 21A2c is passed from the front side between these to the gear box 22C. By being fastened together, the gear box 22C is integrally coupled. As described above, the L-shaped bracket 21A2 is fastened in a state in which the bottom surface portion 21A2a is sandwiched between the bearing 21A1 and the upper surface portion 12B of the upper rail 12, whereby the gear box 22C of the gear unit 22 is secured. The upper rail 12 is held integrally attached to the upper surface portion 12B (see FIG. 6).

  As shown in FIG. 6, the end cap 21 </ b> B is fitted and attached to the rear end portion of the upper rail 12 described above, and a claw portion (not shown) formed on the end cap 21 </ b> B is attached to the rear end of the upper rail 12. It is in a state where it is hooked on the part and integrally connected. When the end cap 21B is attached to the upper rail 12, the concave spherical surface 21B1 formed in the central portion of the front surface portion is applied to the rear end portion 212 of the feed screw 21, and the end cap 21B is fed. The rear end portion 212 of the screw 21 is supported in the axial direction.

  Here, the rear end portion 212 of the feed screw 21 described above is formed in a shape protruding in a tapered manner in the axial direction toward the rear end side, and the tip end surface of the protruding tip is rounded into a hemispherical shape. The convex spherical surface 212A is formed. As a result, the rear end portion 212 of the feed screw 21 is placed in a state in which the above-described convex spherical surface 212A is in point contact with the concave spherical surface 21B1 of the end cap 21B and is axially rotatable by the concave spherical surface 21B1 of the end cap 21B. It has come to be supported. The concave spherical surface 21B1 described above is formed in a spherically concave shape drawn around the front end portion 211 of the feed screw 21 (the end portion directly connected to the worm wheel 22B of the gear unit 22 described later). Here, the front end portion 211 of the feed screw 21 corresponds to “one end” of the present invention, and the rear end portion 212 corresponds to “other end” of the present invention.

  The convex spherical surface 212 </ b> A is formed in a shape protruding in the axial direction from the rear end portion 212 of the feed screw 21 so that the center of the spherical surface coincides with the axis of the feed screw 21. As a result, the convex spherical surface 212A is always in point contact with the concave spherical surface 21B1 of the end cap 21B, and the rear end portion 212 of the feed screw 21 is swung by driving rotation based on the front end portion 211. Even if the shift occurs, the end cap 21B slides on the concave spherical surface 21B1 and is kept in a point-contacted state on the concave spherical surface 21B1. As a result, even if the rear end portion 212 swings from the front end portion 211 as a base point and causes an axis shift due to factors such as an assembly error of the gear unit 22 and the bearing member 21A described later, the feed screw 21 The rear end portion 212 of the feed screw 21 is not rubbed strongly against the end cap 21B in the radial direction, and is always kept in point contact with any location on the concave spherical surface 21B1. It can be rotated smoothly without causing fluctuations.

  Subsequently, as shown in FIG. 2, the gear unit 22 includes a worm 22A, a worm wheel 22B, and a gear box 22C. The worm 22 and the worm wheel 22B are assembled and held by the gear box 22C so as to mesh in directions orthogonal to each other. An end of a connecting rod Mr that rotates by driving of the electric motor M is inserted into the worm 22A and is connected to a state where power can be transmitted. The worm 22 </ b> A described above is in a state in which the axial direction is directed to the left and right direction of the slide device 10. The worm wheel 22B is assembled in a state of being engaged with the lower portion of the worm 22A, and is in a state where the axial direction is directed to the sliding direction of the sliding device 10 (the axial direction of the feed screw 21). The above-described worm wheel 22B has the front end portion 211 of the above-described feed screw 21 inserted therein and is integrally connected to the shaft, and the worm 22A is driven by the electric motor M via the connecting rod Mr. Thus, this rotational driving force is transmitted to the worm wheel 22B, and the feed screw 21 is driven.

  As shown in FIG. 3, the nut 23 is formed in a quadrangular prism shape, and is assembled to the bottom of the lower rail 11 via the holder 24 as a state assembled in the hat-type holder 24 via the rubber bush 25. It is in a state of being provided in a state of being bolted and fixed on the portion 11A. Specifically, the above-described holder 24 is bent so that a single steel sheet has a hat shape in a side view, and each seating surface portion 24A on the front and rear sides facing the surface below the seat, and each seating surface portion. Each of the standing surfaces 24B on the front and rear sides rising from the inner edge (rear side or front side) of 24A and the top plate surface portion 24C that connects between the upper edges of each of the standing surfaces 24B are formed in a form. ing. In the holder 24 described above, each seating surface portion 24A described above is placed on the bottom surface portion 11A of the lower rail 11, and each seating surface portion 24A is bolted to the bottom surface portion 11A of the lower rail 11 so as to be integrally coupled. (See FIG. 6).

  As shown in FIG. 3, the holder 24 described above has a shape in which the standing surface portions 24 </ b> B on the front and rear sides thereof are opposed to each other with a certain width in the front and rear direction. The rubber bush 25 with the nut 23 mounted therein is pushed into the space between the upright surface portions 24B and mounted from below, so that the nut 23 is elastically attached to the holder 24 via the rubber bush 25. It is in the state assembled | attached to the state supported in general. The rubber bush 25 described above is formed in a rectangular box shape having an open bottom, and the nut 23 is pushed upward from the bottom opening and attached to the outer surface of the nut 23. The surface is assembled in a state where the surface is in wide contact.

  Then, the rubber bush 25 with the nut 23 mounted therein is pushed into the space between the standing surface portions 24B of the holder 24 described above from the lower side and mounted, whereby the rubber bush 25 on the front and rear sides of the rubber bush 25 is mounted. Each wall portion and the upper wall portion are pressed against the inner surface of each standing surface portion 24B and the inner surface of the top plate surface portion 24C of the holder 24, respectively, and are pushed into the holder 24. It is supposed to be assembled.

  Here, through the front and rear wall portions of the rubber bush 25 and the standing surface portions 24B of the holder 24, through holes 25A for opening the female screw holes 23A of the nuts 23 assembled therein in the axial direction. , 24B1 are formed penetrating in the axial direction (see FIG. 6). Among these, the through holes 24B1 formed in the standing surface portions 24B of the holder 24 are formed in a shape having a larger diameter than the female screw holes 23A formed in the nut 23, and the nut 23 is generated between the respective assembly parts. Even if the assembly position is displaced or the shaft is displaced when the feed screw 21 is rotationally driven, the shaft of the feed screw 21 can be moved even if the holder 24 is displaced in the vertical or horizontal direction or the shaft is inclined. It is in the state formed so that it may not interfere with a part. As a result, the nut 23 flexes the rubber bush 25 in the vertical direction and the horizontal direction by causing the holder 24 elastically supported through the rubber bush 25 described above to cause various deviations between the nut 23 and the feed screw 21. It is in a state provided so that it can be absorbed or released.

  Thus, the “feed screw support structure for vehicle seat” of this embodiment supports the bearing member 21A that supports the front end portion 211 of the feed screw 21 in a state in which the front end portion 211 of the feed screw 21 is rotatable. The end cap 21B that supports the rear end portion 212 of the feed screw 21 has a convex spherical surface 212A that is formed in the rear end portion 212 of the feed screw 21 and protrudes in the axial direction. The rear end portion 212 of the feed screw 21 is supported so as to be axially rotatable by making point contact with the concave spherical surface 21B1 that is recessed in the direction. Since the rear end portion 212 of the feed screw 21 is supported in a point contact state by contact between the spherical surfaces with respect to the end cap 21B, the rear end portion of the feed screw 21 even if the feed screw 21 is misaligned during rotational driving. 212 is always supported in a point contact state with respect to the end cap 21B. Therefore, even if the feed screw 21 is misaligned, the feed screw 21 can be prevented from being rubbed strongly against the end cap 21B in the radial direction.

  The concave spherical surface 21B1 formed on the end cap 21B is formed in a spherically concave shape drawn around the front end portion 211 of the feed screw 21, so that the feed screw 21 is based on the front end portion 211. Whether or not the rear end portion 212 is off-axis, the rear end portion 212 is always kept in point contact with the end cap 21B in a certain manner without being pressed against the end cap 21B. Therefore, the feed screw 21 can always be driven to rotate smoothly without changing the torque.

  As mentioned above, although the embodiment of the present invention has been described using one example, the present invention can be implemented in various forms in addition to the above example. For example, the configuration of the present invention can be applied to a seat other than a passenger seat of an automobile, and can also be widely applied to a seat provided for a vehicle other than an automobile such as a railway. It is. Moreover, in the said Example, although the feed screw 21 was provided in the upper rail 12 and the nut 23 was provided in the lower rail 11, the rail assembled | attached may be reverse. In addition, the length relationship between the rail lengths of the upper rail 12 and the lower rail 11 may be longer.

  In the above embodiment, the front end portion (one end) of the feed screw is supported by the bearing member (first support member) and is directly connected to the gear unit (drive unit) to be rotationally driven. The part (the other end) is illustrated as having a structure in which the spherical surfaces are in point contact with each other by the end cap (second support tool). It may be. Further, the first support that supports one end of the feed screw is a configuration in which the drive unit corresponds to the first support when one end of the feed screw also serves as a support by being directly connected to the drive unit. It becomes.

  Further, the feed screw may be configured to be rotationally driven by a user's manual operation instead of electric drive. In addition, the concave spherical surface formed on the second support member does not necessarily have to be formed in a spherically concave shape drawn around one end of the feed screw. It can be set as the structure which carries out point contact with the convex spherical surface formed in the other end of the screw.

  Further, in the above-described embodiment, the configuration in which the “feed screw support structure for vehicle seat” of the present invention is applied to the slide device is illustrated. However, the “feed screw support structure for vehicle seat” of the present invention is a feed screw. It can be applied to a wide range of mechanisms equipped with. Specifically, a mechanism for folding the seat back by driving the feed screw, a mechanism for moving the ottoman by driving the feed screw, a mechanism for adjusting the seat height by driving the feed screw, and the like.

  Further, in the case where a plurality of slide devices are provided between the vehicle seat and the floor, the feed screw mechanism 20 may not be provided in all the slide devices. However, if the driving force for operating the slide device is configured so that the left and right sides act equally between the vehicle seat and the floor, the slide operation will not stick and the slide operation can be performed smoothly. it can. The slide device may be arranged to slide the vehicle seat in the seat width direction with respect to the floor.

  Moreover, in the said Example, although the slide device 10 illustrated the structure which interposed the bearing 13 used as a rolling element between both so that the upper rail 12 could be slid smoothly with respect to the lower rail 11, rolling element was illustrated. Alternatively, a roller may be used, or a resin shoe having good slidability may be interposed instead of the rolling element.

DESCRIPTION OF SYMBOLS 1 Seat 2 Seat back 3 Seat cushion 10 Slide apparatus 11 Lower rail 11A Bottom surface part 11B Lower side fin part 11C Lower side fin part 11F Clearance 12 Upper rail 12A Vertical surface part 12B Upper surface part 12C Upper side fin part 12D Upper side fin part 13 Bearing 20 Feed Screw mechanism 21 Feed screw 211 Front end (one end)
212 Rear end (other end)
212A Convex spherical surface 21A Bearing (first support)
21A1 Bearing 21A1a Screw shaft 21A1b Fastening nut 21A2 L bracket 21A2a Bottom surface 21A2b Front surface 21A2c Bolt shaft 21B End cap (second support)
21B1 concave spherical surface 22 gear unit (drive unit)
22A Worm 22B Worm wheel 22C Gear box 23 Nut 23A Female screw hole 24 Holder 24A Seat surface portion 24B Standing surface portion 24B1 Through hole 24C Top plate surface portion 25 Rubber bush 25A Through hole M Electric motor Mr Connecting rod F Floor

Claims (2)

A feed screw support structure for a vehicle seat that supports the feed screw in a state in which the shaft can rotate.
A first support for supporting one end of the feed screw;
A second support for supporting the other end of the feed screw;
The first support is configured to support one end of the feed screw so that the shaft can rotate.
The second support tool is a point contact between a convex spherical surface formed in the other end of the feed screw and protruding in the axial direction, and a concave spherical surface formed in the second support tool that is recessed in the axial direction. And is configured to support the other end of the feed screw in a rotatable state .
The feed screw support structure for a vehicle seat, wherein the concave spherical surface formed on the second support member is formed in a spherical concave shape drawn around one end of the feed screw. A feed screw support structure for a vehicle seat according to claim 1,
A feed screw support structure for a vehicle seat, wherein an electric drive unit is connected to one end of the feed screw and the shaft is rotated by a driving force received from the drive unit.

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