JP2009090799A - Power slide device for vehicular seat - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance load burden capacity by a load transmission member while maintaining the small diameter of a screw rod itself, in a power slide device for a vehicular seat provided with a lower rail fixed to a vehicle floor face, an upper rail fixed to the seat and slidably engaged with the lower rail, a nut member screwed to the screw rod rotatably supported by the upper rail and fixed to the lower rail, and the load transmission member supported by regulating the axial movement with respect to the screw rod fixed to the upper rail. <P>SOLUTION: In the power slide device for the vehicular seat, the load transmission member has an insertion part to which the screw rod is inserted, and the screw rod has a main nut screwing part to which the nut member is screwed and a crush nut screwing part inserted to the insertion part of the load transmission member and having a diameter smaller than that of the main nut screwing part. Crush nuts are screwed and secured to the crush nut screwing part so as to be positioned at least on one of front and rear sides of the insertion part of the load transmission member. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a power slide device that moves a vehicle seat in the front-rear direction by a motor-driven feed screw mechanism.

A vehicle seat slide device has a basic structure in which an upper rail fixed to a seat is slidably engaged with a lower rail fixed to a vehicle floor surface in a front-rear direction. In this vehicle seat slide device, a motor-driven screw rod is rotatably supported on the upper rail in the extension direction of the upper rail, and a nut member that is screwed to the screw rod is fixed to the upper rail. It has become. Furthermore, in order to receive a large load at the time of a vehicle collision, a load transmission member fixed to the upper rail is supported by restricting axial movement so as to be rotatable relative to the screw rod. In other words, a large load applied to the upper rail at the time of a collision is transmitted from the load transmission member to the screw rod, thereby preventing a large load from being applied to the rotation transmission mechanism (gear box) between the motor and the screw rod and preventing the damage. .
Japanese Unexamined Patent Publication No. 2000-158983 JP 2002-192996 A JP 2007-55557 A

  In this power sliding device for a vehicle seat, one of the technical problems is how to connect the screw rod and the load transmitting member. That is, as described above, the load transmission member fixed to the upper rail is connected to the screw rod so as to be relatively rotatable so that the axial movement is restricted, so that the power slide function is maintained and the collision load is received. Responsible for basic functions. However, in the conventional device, sufficient consideration is not given to the configuration around the screw rod and the load transmission member, and the required load bearing capacity is ensured without increasing the number of parts or achieving miniaturization. Was not done.

  It is an object of the present invention to obtain a vehicle seat power slide device that can increase the load bearing capacity of a load transmission member while maintaining the screw rod itself in a small diameter.

  The present invention relates to a lower rail fixed to a vehicle floor surface in the front-rear direction; an upper rail slidably engaged with the lower rail and fixed to a seat; A nut member screwed into the screw rod and fixed to the lower rail; and a load transmission member fixed to the upper rail and supported by restricting axial movement relative to the screw rod. In the power slide device for a vehicle seat, the load transmission member integrally has an insertion portion for inserting the screw rod and a fixing portion for fixing to the upper rail, and the screw rod is a main member to which the nut member is screwed. The nut screwing portion and the main nut screwing portion are in a position spaced apart in the axial direction, and the load transmitting member is inserted. A crush nut threaded portion having a diameter smaller than that of the main nut threaded portion that is inserted into the portion, and the crash nut threaded portion is positioned at least one of the front and rear of the insertion portion of the load transmitting member to crash. The nut is screwed and fixed.

  Although there is a degree of freedom in the manufacturing method of the screw rod, specifically, for example, it is practical that the main nut screwing portion is formed by feed rolling and the crush nut screwing portion is formed by rolling and rolling. .

  A serration portion that transmits rotational force to the screw rod can be formed at the end of the screw rod by rolling.

  The present invention is a feed screw type vehicle seat power slide device including a screw rod rotatably supported by an upper rail and a nut member fixed to the lower rail and screwed to the screw rod. The main nut screwing portion into which the nut member is screwed, and the main nut screwing portion are spaced apart from each other in the axial direction and are inserted into the insertion portion of the load transmitting member and have a smaller diameter than the main nut screwing portion. The crush nut is screwed into and fixed to at least one of the front and rear of the insertion portion of the load transmitting member. Simply screw the crush nut into the joint, insert the insertion part of the load transmission member, and fix the crush nut. It can be coupled to the load transfer member. In addition, since the crush nut screwing portion has a smaller diameter than the main nut screwing portion, the insertion portion of the load transmission member can be made thicker by that amount, and the load transmission member can be maintained while maintaining the screw rod small in diameter. It is possible to increase the load bearing ability due to.

  As illustrated in FIG. 8, the vehicle seat slide device includes a pair of left and right seat tracks 10 that are positioned between the vehicle seat S and the floor surface F and extend in the vehicle front-rear direction. The left and right seat tracks 10 have the same (symmetric) structure, and have a lower rail 13 fixed to the floor F with front and rear brackets 11 and 12 and an upper rail 14 fixed to the seat S. The upper rail 14 is slidably fitted.

  As shown in FIG. 1, a nut member 16 whose axis is directed in the front-rear direction is fixed to the lower rail 13 via a fixing bolt 15. On the other hand, a screw rod 20 screwed into the nut member 16 is rotatably supported on the upper rail 14. That is, the upper rail 14 is provided with a gear box 30 and a bearing member 17 that rotatably support the front end portion and the rear end portion of the screw rod 20 at the front end portion and the rear end portion thereof. The gear box 30 is fixed to the upper rail 14 by a connection bracket 31, and the synthetic resin bearing member 17 is directly fixed to the upper rail 14. FIG. 1 shows a rearward movement end of the upper rail 14 (seat S) with respect to the lower rail 13.

  The screw rod 20 has a serration portion 21 formed at a front end portion thereof, and a worm wheel 32 having a serration hole 32a that engages with the serration portion 21 in a relatively non-rotatable manner in the gear box 30 in the shaft portion. It is supported rotatably. The worm wheel 32 is meshed with a worm 33 whose axis is directed in the vehicle left-right direction. When the worm 33 rotates in the forward and reverse directions, the worm wheel 32 rotates in the forward and reverse directions, and the serration portion 21 (screw rod 20) is in the normal direction. Reversely rotate.

  The worms 33 in the gear box 30 of the left and right upper rails 14 are rotated by an interlocking mechanism, and the screw rods 20 of the left and right upper rails 14 are rotated in the forward and reverse directions by this interlocking rotation. Then, since the screw rod 20 is screwed with the nut member 16 fixed to the lower rail 13, the upper rail 14 (seat S) moves back and forth.

  A load transmission member 40 is fixed to the upper rail 14 so as to be rotatable relative to the screw rod 20 and move together with the screw rod 20 in the axial direction (restricted in the axial movement). As apparent from FIGS. 2 to 4, the load transmission member 40 is fixed to the upper rail 14 and an annular portion (insertion portion) 41 having a screw insertion hole 41 a through which the screw rod 20 is inserted (slowly passed). A bolt part (fixed part) 42 and a flange part 43 between the annular part 41 and the bolt part 42 are integrally provided. As shown in FIG. 1, the bolt portion 42 is inserted into a fastening hole 31 a formed in the connection bracket 31 of the gear box 30 and a fastening hole 14 a formed in the upper rail 14, and then a fixing nut 44 is screwed into the protruding end. The load transmitting member 40 is fixed to the upper rail 14 (gear box 30) by tightening and tightening.

  Crush nuts 27 and 28 are fixed to the screw rod 20 in front of and behind the annular portion 41 of the load transmission member 40, and the axial direction of the load transmission member 40 with respect to the screw rod 20 is fixed by the crash nuts 27 and 28. Relative movement is restricted.

  In the seat slide device described above, when a collision load is applied, the upper rail 14 tends to move relative to the lower rail 13, and the load is transferred from the annular portion 41 of the load transmitting member 40 via the crash nut 27 or 28. To the screw rod 20. For this reason, the load applied to the gear box 30 portion can be reduced, and damage to the gear box 30 (worm wheel 32, worm 33) can be prevented.

  The basic functions of the power sliding device for a vehicle seat described above are already known. This embodiment is characterized by the configuration around the screw rod 20 in the power slide device described above, and one embodiment will be described with reference to FIGS. As shown in the lower stage of FIG. 5, the screw rod 20 includes the serration portion 21, the incomplete screw portion (or no screw portion) 22, the crush nut screw portion 23, and the incomplete screw portion in order from the front end portion. (Or a screwless part) 24, a main nut screwing part (nut screwing part) 25, and a screwless part (rear end bearing part, complete screwless part, circular cross section) 26. The unthreaded portion 26 at the rear end is a portion that is rotatably supported by the bearing member 17.

  The above screw rod 20 is produced in the following procedure. The round rod material 20S of the screw rod 20 is made of a material having a proper diameter (round rod material, for example, the original diameter D = 6...) In advance according to the diameter (for example, M8) of the main nut screwing portion 25 formed by rolling. 5 mmφ) is selected. The unthreaded portion 26 uses the material diameter of the round bar material 20S as it is and does not perform any post-processing.

  The main nut screwing portion 25 feeds and rolls the round bar material 20S (or rolling method in which the round bar material 20S moves in the axial direction while rotating around the axis during rolling and rolling). To form. Since rolling is a processing method in which a male thread is formed by moving the meat of a round bar material, the diameter D of the non-processed portion of the screw rod is a peak of the nut screwing portion 25 as shown in FIG. The diameter is between the diameter D1 and the valley diameter D2. Ideally, as D = (D1 + D2) / 2, the sum of the volumes of the concave portions inside the original diameter D of the round bar material 20S and the sum of the volumes of the convex portions outside can be matched. Feed rolling is a processing method capable of obtaining high screw accuracy even during rolling, and the main nut screwing portion 25 having a length corresponding to the moving stroke of the sheet S is maintained with high linearity. Can be formed.

  Next, the crush nut screwing portion 23 is rolled and rolled (a rolling method in which the round bar material 20S does not move in the axial direction during rolling). At this time, the diameter of the crush nut screwing portion 23 is processed to be smaller than the diameter of the main nut screwing portion 25 (for example, M7). In this rolling process, by extending the round bar material in the axial direction, it is possible to perform processing in which the total volume inside the original diameter D is smaller than the total volume outside.

  Finally, or simultaneously with the crush nut screwing portion 23, the serration portion 21 is processed by rolling. Serration processing by rolling is also the same as screw processing in principle, and as shown in FIG. 7, the total of the inner volume and the outer volume of the original diameter D are equal.

  The incomplete screw portion 24 between the main nut screwing portion 25 and the crush nut screwing portion 23 and the incomplete screw portion 22 between the crush nut screwing portion 23 and the serration portion 21 are the main nut screwing portion 25, Although it is a section formed when the crush nut screwing portion 23 and the serration portion 21 are rolled, this may be a non-threaded portion.

  Since the above screw rod 20 does not process at least the unthreaded portion 26 and uses the round bar material 20S as it is, the processing cost is low. The material diameter of the round bar material 20S is managed with high accuracy according to the intended rolling screw diameter, and there is no problem in terms of accuracy. For example, the machining cost, accuracy, and strength are superior to machining the unthreaded portion at the end of the screw shaft to form the unthreaded portion 26.

  Further, the crush nut screwing portion 23 is rolled into a smaller diameter screw than the main nut screwing portion 25, and the crush nuts 27 and 28 are screwed into the crush nut screwing portion 23, followed by caulking. Then, it is fixed to the crush nut screwing portion 23 (screw rod 20). For this reason, it is not necessary to partially increase the diameter of the screw rod 20 (form a flange portion), and the diameter of the screw rod 20 can be reduced. In addition, since the diameter of the screw insertion hole 41a can be reduced by an amount corresponding to the reduced diameter of the crush nut screwing portion 23 and the annular portion 41 can be thickened, the annular portion 41 and the crash nuts 27 and 28 collide with each other. The impact load at the time can be increased.

  Since the above screw rod 20 does not process at least the unthreaded portion 26 and uses the round bar material 20S as it is, the processing cost is low. The material diameter of the round bar material 20S is managed with high accuracy according to the intended rolling screw diameter, and there is no problem in terms of accuracy. For example, the machining cost and accuracy are superior to machining the unthreaded portion at the end of the screw shaft to form the unthreaded portion 26.

  In the above embodiment, the pair of crush nuts 27 and 28 screwed to the crush nut screwing portion 23 are respectively screwed and fixed before and after the annular portion 41 of the load transmitting member 40. Even if it is fixed to either the front or rear of the annular portion 41, it can receive an impact load at the time of a rear collision or a front collision. In addition, the crush nut may be fixed to the crush nut screwing portion 23 by welding, bonding, or other fixing means in addition to the above-described caulking.

  In the above embodiment, the annular portion 41 of the load transmitting member 40 is an insertion portion that is inserted through the crush nut screwing portion 23. However, instead of the annular portion 41, for example, a U-shape may be used as the insertion portion. Further, the load transmitting member 40 may be fixed to the upper rail 14 by welding or other fixing means instead of the bolt portion 42.

  The processing method of the screw rod 20 of the above embodiment shows an example. In the present invention, a main nut screwing portion 25 and a crush nut screwing portion 23 having a smaller diameter than the main nut screwing portion are formed on the screw rod 20, and the load transmitting member 40 is connected to the crush nut screwing portion 23. The crush nut 27 or 28 is screwed and fixed at at least one of the front and rear of the annular portion 41, and the screw rod having the above structure may be formed by another processing method. .

It is a longitudinal cross-sectional view which shows one Embodiment of the power slide apparatus by this invention. It is sectional drawing which follows the II-II line of FIG. It is the perspective view which took out the structure around the screw rod made into the object of this invention from the power slide apparatus of FIG. It is the same side view. It is a top view which shows the formation step of the screw rod by this invention. It is a conceptual diagram of the screw formation by rolling. It is a conceptual diagram of serration part formation by rolling. 1 is a perspective view showing a general configuration of a vehicle seat slide device.

S Vehicle seat F Floor 10 Seat track 13 Lower rail 14 Upper rail 14a Fastening hole 15 Fixing bolt 16 Nut member 17 Bearing member 20S Round bar material 20 Screw rod 21 Serration portion 22 24 Non-threaded portion (or incomplete threaded portion)
23 Crash nut screwing part 25 Main nut screwing part 26 Screwless part (rear end bearing part)
27 28 Crash nut 30 Gear box 31 Connection bracket 31a Fastening hole 32 Worm wheel 32a Serration hole 33 Worm 40 Load transmitting member 41 Annular part (insertion part)
41a Screw insertion hole 42 Bolt part (fixed part)
43 Flange 44 Fixed nut

Claims (3)

Lower rail fixed to the vehicle floor in the front-rear direction;
An upper rail slidably engaged with the lower rail and fixed to the seat;
A screw rod supported on the upper rail so as to be rotatable in the extending direction of the upper rail;
A nut member screwed to the screw rod and fixed to the lower rail; and a load transmission member fixed to the upper rail and supported by restricting axial movement relative to the screw rod so as to be rotatable relative to the screw rod;
In a vehicle seat power slide device comprising:
The load transmission member integrally has an insertion portion for inserting the screw rod and a fixing portion for fixing to the upper rail,
The screw rod is inserted into the insertion portion of the load transmitting member at a position where the main nut screwing portion to which the nut member is screwed and the main nut screwing portion are spaced apart in the axial direction. It has a crush nut threaded part smaller in diameter than the main nut threaded part,
A power slide device for a vehicle seat, wherein the crash nut is screwed and fixed to the crash nut screwing portion at least one of the front and rear of the insertion portion of the load transmitting member. The power slide device for a vehicle seat according to claim 1, wherein the main nut screwing portion of the screw rod is formed by feed rolling, and the crash nut screwing portion is formed by rolling and rolling. Slide device. The power slide device for a vehicle seat according to claim 1 or 2, wherein a serration portion for transmitting a rotational force to the screw rod is formed at an end portion of the screw rod.

Images