JP2019026027A - Seat sliding apparatus - Google Patents

Abstract

To provide a seat sliding apparatus having a structure capable of securing a sufficient strength as a stopper while maintaining a primary bracket function.SOLUTION: A seat sliding apparatus is equipped with: a lower rail; a slidable upper rail; a screw shaft 4; and a gear box having a gear screwing together with the screw shaft 4. A front side bracket 9 fixing the front end part of the screw shaft 4 to the lower rail has a bottom wall part 19 and a vertical wall part 20 on which an insertion hole 21 is formed. The lower half part of the vertical wall part 20 protrudes to a gear box side compared to the upper half part thereof to become a stopper surface 20a. The apparatus is configured so that the contact of a gear box holder to the vertical wall part 20 is carried out on the stopper surface 20a of a lower side of the screw shaft 4 at maximum advance of the upper rail.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a vehicle seat slide device, and more particularly to an improvement of a slide rail as a main element of an electric seat slide device called a power seat.

  As this type of seat slide device, for example, a device described in Patent Document 1 has been proposed.

  In the technique disclosed in Patent Document 1, a lower rail fixed to a vehicle body floor, an upper rail that is attached to a seat that is subject to front-rear position adjustment, and is slidably assembled in the longitudinal direction with respect to the lower rail; The basic structure includes a screw shaft fixed to the lower rail in a both-sided state, a worm wheel screwed to the screw shaft and a worm meshing with the screw shaft, and a gear box fixed to the upper rail.

  In particular, an L-shaped bracket is fixedly supported at the front end portion of the lower rail, and a screw shaft is inserted and supported in an insertion hole formed in the bracket, and a nut is attached from the front side of the bracket. . For example, the nut serves to bear a load in a direction in which the screw shaft comes out of the bracket in the event of a vehicle collision.

Japanese Patent Laying-Open No. 2015-67146

  By the way, it is possible to regulate the operating range of the seat slide device by causing the bracket to have a so-called mechanical stopper function and bringing the case of a gear box containing a worm gear screwed into the screw shaft into contact with the bracket. Done. In the above example, since the gear box is brought into contact with the vertical wall portion of the bracket bent in an L shape, a bending moment acts on the bracket at the time of contact.

  For this reason, when the bracket is used as a mechanical stopper that contacts the case of the gear box at the slide stroke end of the upper rail, there is a problem that it is difficult to maintain the strength as the stopper.

  The present invention has been made paying attention to such problems, and provides a structure capable of securing sufficient strength as a stopper while maintaining the original function of the bracket.

  The present invention includes a lower rail disposed along a front-rear direction on a vehicle floor surface, an upper rail that is slidable in a longitudinal direction with respect to the lower rail and on which a seat is assembled, and a longitudinal direction of both the rails. A screw shaft that is disposed and supported by one of the lower rail and the upper rail, and a gear that is provided on the other rail of the lower rail and the upper rail and is screwed to the screw shaft. And at least a front end portion of the screw shaft is fixedly supported on the one rail via an L-shaped bracket, and at the time of maximum advance of the upper rail with respect to the lower rail, A holder for housing the gear mechanism is in contact with the bracket. It is to have the seat slide apparatus adapted to.

  In addition, the bracket includes a bottom wall portion that is fixed to the one rail, and a vertical wall portion that has an insertion hole that rises from the bottom wall portion and into which the screw shaft is inserted. The contact of the holder with the vertical wall portion is performed at a position closer to the bottom wall portion than the screw shaft in the vertical wall portion.

  As a desirable mode, a portion closer to the bottom wall portion than a portion far from the bottom wall portion of the vertical wall portion protrudes toward the holder side, and the holder is located near the protruding bottom wall portion. It comes to contact.

  Similarly, as a desirable mode, in a state where the holder is in contact with a portion close to the bottom wall portion of the vertical wall portion, between the portion of the vertical wall portion far from the bottom wall portion and the case. A gap is set in.

  Similarly, as a desirable mode, the insertion hole has a long hole shape in which the diameter through which the front end portion of the screw shaft can be inserted is a short diameter and the long diameter direction is directed in the vertical direction of the vertical wall portion. In addition, the insertion hole is fitted with an elastic holding member that holds the screw shuff and sandwiches the vertical wall portion from both the front and back sides.

  According to the present invention, the holder is in contact with the vertical wall portion at a position on the bottom wall portion side of the screw shaft in the vertical wall portion, so that the holder that accommodates the gear mechanism is pressed against the bracket. As well as stabilizing the position, the bending moment acting on the bracket can be reduced. In particular, even when the thickness of the bracket is reduced, sufficient strength as a stopper shared with the bracket can be secured.

  In addition, with the holder that houses the gear mechanism in contact with the portion of the vertical wall portion of the bracket that is close to the bottom wall portion, there is a gap between the portion of the vertical wall portion that is far from the bottom wall portion and the holder. Is secured, the impact acting on the screw shaft when the holder abuts can be reduced, the gear in the case meshing with the screw shaft can be protected, and the gear mechanism can be reversed. The operability at the start of driving is also good.

  Furthermore, the insertion hole formed in the vertical wall portion of the bracket is in the shape of a long hole, and the holding member made of an elastic body that sandwiches the vertical wall portion from the front and back both sides while holding the screw shaft in the insertion hole. When fitted, the vibration of the screw shaft accompanying the rotation of the gear can be suppressed, the impact at the time of contact with the holder can be further reduced, and the occurrence of a hitting sound can also be suppressed.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows 1st Embodiment of the seat slide apparatus which concerns on this invention, and sectional drawing in the state which has an upper rail in a retreat limit position. Sectional drawing of the state which has the upper rail shown in FIG. 1 in a forward limit position. The expanded sectional view along the AA line of FIG. The enlarged view of the principal part of FIG. FIG. 5 is a further enlarged view around the front bracket shown in FIG. 4. The front enlarged view which looked at the front bracket shown in FIG. 5 from the left side. The expansion perspective view of the bush with which the vertical wall part of the front side bracket shown in FIG. 5 is mounted | worn. FIG. 6 is a diagram showing a second embodiment of the seat slide device according to the present invention, and is an enlarged view of a portion equivalent to FIG. FIG. 9 is an explanatory diagram when an excessive input to the rear is applied to the front bracket shown in FIG. 8 via a screw shaft due to a collision, and (A) is an explanatory diagram before an input is applied to the vertical wall portion of the front bracket. (B) is explanatory drawing when the vertical wall part falls down, (C) is further explanatory drawing when the vertical wall part falls down.

  1 to 7 show a more specific first embodiment for carrying out the seat slide device according to the present invention. In particular, FIG. 1 shows the longitudinal direction of one slide rail 1 which is a main element of the seat slide device. FIG. 6 is a cross-sectional view taken along the line A and shows a state in which the upper rail 3 is most retracted relative to the lower rail 2 and is in the retreat limit position. 2 shows a state in which the upper rail 3 of FIG. 1 is most advanced to the forward limit position, and FIG. 3 is an enlarged sectional view taken along the line AA of FIG. Further, FIG. 4 shows an enlarged view of the main part of FIG.

  As is well known, in an electric seat slide device called a power seat, a pair of left and right slide rails 1 shown in FIGS. 1 to 3 is used as a pair so that each longitudinal direction is along the vehicle longitudinal direction, and It is arranged on the vehicle floor surface (floor surface) so as to be parallel to each other at a predetermined distance. Accordingly, the left side of FIGS. 1 and 2 is the front side of the vehicle, and the right side of FIG.

  The slide rail 1 is schematically composed of a lower rail 2 arranged along the front-rear direction on the floor surface of the vehicle, an upper rail 3 assembled to the lower rail 2 so as to be slidable in the longitudinal direction, and the upper rail 3 in the upper rail 3. A long male screw-like screw shaft 4 arranged along the longitudinal direction and a gear box 5 as a gear mechanism externally attached to the screw shaft 4 are configured.

  The lower rail 2 is fixed to the floor surface of the vehicle via foot brackets (not shown), for example, at two positions in the longitudinal direction. On the other hand, the upper rail 3 is fixed to a frame of a seat (seat cushion) (not shown). As shown in FIG. 3, the lower rail 2 has a substantially deformed channel shape with an open upper surface, and a flange portion 2a is bent downward from the upper opening edge, while the upper rail 3 has a lower surface. The open section has a substantially deformed channel shape, and a flange portion 3a is bent upward from the lower opening edge. And both flange parts 2a and 3a have overlapped.

  As shown in FIG. 3, a slide guide member 6 is interposed between the lower rail 2 and the flange portion 3 a on the upper rail 3 side, so that the upper rail 3 can slide smoothly with respect to the lower rail 2. ing. The slide guide member 6 has a known structure in which a plurality of steel balls 6b are held above and below the retainer 6a. For example, the slide guide member 6 is provided at two positions before and after the overlapping range in the longitudinal direction of the lower rail 2 and the upper rail 3. It is interposed and is not shown in FIGS.

  The front end portion of the screw shaft 4 is fixedly supported by an L-shaped front bracket 9 fixed to the front end portion of the lower rail 2 by a rivet 8 together with the reinforcing plate 7. On the other hand, the rear end portion of the screw shaft 4 is fixedly supported by a rear bracket 12 which is fixed to the rear end portion of the lower rail 2 by a bolt 11 together with the reinforcing plate 10. The rear end portion of the screw shaft 4 is directly fixed to the rear bracket 12 and is integrally fixed by, for example, welding. As a result, the screw shaft 4 is supported at both ends by the lower rail 2 through the front bracket 9 and the rear bracket 12 so as not to rotate. The details of the front bracket 9 will be described later.

  As shown in FIG. 4, the gear box 5 has a case 13 corresponding to the box body accommodated in a holder 14, and the holder 14 is fixed to the upper rail 3 by a rivet 16 together with a cover 15. A worm gear including a worm 17 and a worm wheel 18 meshing with the worm 17 is accommodated in the case 13. The inner peripheral surface of the worm wheel 18 is an internal thread portion that meshes with the external thread portion of the screw shaft 4. Therefore, when the worm 17 is rotationally driven in the forward or reverse direction by a motor (not shown), the worm wheel 18 meshing with the worm 17 rotates. Due to the screwing action based on the rotation of the worm wheel 18, the upper rail 3 slides in the forward or backward direction with respect to the lower rail 2.

  FIG. 5 shows a further enlarged view around the front bracket 9 shown in FIG. The front bracket 9 is formed by bending a metal plate having a predetermined thickness into an L shape. The front bracket 9 has a bottom wall portion 19 that is in close contact with the lower rail 2 and functions as a stopping point by the rivet 8, and a vertical wall portion 20 that stands up at a right angle from the bottom wall portion 19. An insertion hole 21 penetrating in the thickness direction is formed in the vertical wall portion 20. A front end portion of the screw shaft 4 is inserted into the insertion hole 21 via a bush 23 described later, and a nut 22 as a load receiving member is screwed. Accordingly, the front end portion is supported by the front bracket 9 in a manner that a predetermined tension is applied in the axial direction of the screw shaft 4. It should be noted that other members may be used instead of the nut 22 as the load receiving member as long as the function of preventing the screw shaft 4 from coming off is exhibited.

  Further, as shown in FIG. 5, the vertical wall portion 20 includes a lower half portion on the base side that is a portion close to the bottom wall portion 19 and an upper half portion that is a portion far from the bottom wall portion 19 of the screw shaft 4. They are offset from each other by a predetermined amount in the thickness direction at a position below the center. As a result, as shown in FIG. 4, the lower half side of the vertical wall portion 20 protrudes toward the gear box 5 with a step corresponding to the offset amount, and the protruding portion is the stopper surface. 20a.

  FIG. 6 is an enlarged front view of the front bracket 9 shown in FIG. 5 as viewed from the left side. As shown in FIG. 6, the insertion hole 21 formed in the vertical wall portion 20 has a long hole shape that is long in the vertical direction. Has become. That is, the insertion hole 21 has a short diameter that is slightly larger than the diameter of the screw shaft 4 so that the screw shaft 4 can be inserted, and the long diameter direction perpendicular to the short diameter direction is the vertical direction (the bottom wall portion 19 has It is formed as a long hole that points in the direction of heading.

  A bushing 23 as a holding member made of a rubber-based elastic body as shown in FIG. 7 is fitted into the insertion hole 21. The bush 23 includes an oval cylindrical portion 23a that fits into the long hole-shaped insertion hole 21, a substantially semicircular flange portion 23b that is integrally formed on one end side of the cylindrical portion 23a, and a cylindrical portion. A rectangular flange portion 23c formed integrally with the other end side of 23a. A shaft hole 23d through which the screw shaft 4 can be inserted is formed in the cylindrical portion 23a.

  Then, as shown in FIG. 5, both flange portions 23 b are positioned such that one flange portion 23 b is located on the front side of the vertical wall portion 20 and the other flange portion 23 c is located on the back side of the vertical wall portion 20. 23c, the cylindrical wall portion 23a of the bush 23 is fitted and held in the insertion hole 21 so that the vertical wall portion 20 is sandwiched from both the front and back sides. As a result, as shown in FIG. 5, the nut 22 screwed into the front end portion of the screw shaft 4 is indirectly seated on the vertical wall portion 20 via the flange portion 23 b of the bush 23. .

  Here, as is clear from FIG. 6, when attention is paid to the relationship between the nut 22 as the load receiving member and the insertion hole 21 in a front view of the front bracket 9, the long insertion hole 21 is formed from the lower end of the nut 22. The long diameter of the insertion hole 21 is set so that a part of the insertion hole 21 protrudes. That is, in FIG. 6, the insertion hole 21 having a long hole shape extends further to the bottom wall portion 19 side than the lower end of the nut 22 (here, for convenience, the lowermost point P1 of the flange attached to the nut 22). An extension is formed.

  Further, as is apparent from FIG. 5, the portion below the center of the screw shaft 4 between the vertical wall portion 20 of the front bracket 9 and the nut 22, more specifically, the diameter of the screw shaft 4. In a portion below the corresponding portion, a gap G1 corresponding to the offset amount between the lower half portion and the upper half portion of the vertical wall portion 20 is secured between the nut 22 and the cylindrical portion 23a of the bush 23. ing. Similarly, a gap G <b> 2 corresponding to the offset amount is secured between the upper half of the vertical wall portion 20 and the flange portion 23 c of the bush 23.

  Note that the general part of the screw shaft 4 (the part screwed with the internal threaded part of the inner periphery of the worm wheel 18) has an irregular cross section as shown in FIG. As shown in FIGS. 5 and 6, the portion supported by the side bracket 12 has a circular shape slightly smaller in diameter than the general portion.

  Therefore, in the seat slide device configured as described above, as described above, the worm gear composed of the worm 17 and the worm wheel 18 rotates in the forward rotation direction or the reverse rotation direction, so that the upper rail is moved with respect to the lower rail 2. 3 slides in the forward or backward direction.

  When the upper rail 3 slides to the retreat limit position, as shown in FIG. 1, the holder 14 that accommodates the gear box 5 contacts the rear bracket 12 and functions as a so-called mechanical stopper. On the other hand, when the upper rail 3 slides to the forward limit position, as shown in FIGS. 2 and 4, the holder 14 that accommodates the gear box 5 is connected to the vertical wall of the front bracket 9 via the flange portion 23 c of the bush 23. It abuts on the stopper surface 20a of the portion 20 and functions as a so-called mechanical stopper.

  In this case, as shown in FIG. 5, in the vertical wall portion 20 of the front bracket 9 with which the holder 14 that accommodates the gear box 5 comes into contact, the lower half portion has a gap G2 rather than the upper half portion. As described above, the stopper surface 20a protrudes toward the holder 14 by the amount. Therefore, when the holder 14 comes into contact with the front bracket 9 via the flange portion 23c of the bush 23, the holder 14 always comes into contact with the stopper surface 20a on the higher base portion side of the vertical wall portion 20 of the front bracket 9. Become.

  As a result, the position where the holder 14 that accommodates the gear box 5 abuts against the front bracket 9 is stabilized, and the bending moment acting on the vertical wall portion 20 of the front bracket 9 is reduced. As a result, for example, even when the thickness of the front bracket 9 is limited, the front bracket 9 can ensure sufficient strength as a stopper, and the function as the front bracket 9 and the mechanical stopper It becomes possible to achieve both functions without difficulty.

  4 and 5, even if the holder 14 that accommodates the gear box 5 abuts the vertical wall portion 20 of the front bracket 9 via the flange portion 23c of the bush 23, the vertical wall portion still remains. A gap G2 is ensured between 20 and the flange portion 23c. Therefore, when the holder 14 that accommodates the gear box 5 comes into contact with the vertical wall portion 20, the gap G <b> 2 reduces the impact that acts on the screw shaft 4 that meshes with the worm gear in the gear box 5. It becomes possible to protect the worm gear in the box 5. In addition, the operability when starting to reversely rotate the worm gear in the gear box 5 is also good.

  Further, as is clear from FIG. 5, the bush 23 in which the screw shaft 4 is inserted into the shaft hole 23d is fitted and held in the insertion hole 21, and the vertical wall portion of the front bracket 9 in which the insertion hole 21 is formed. The flange part 23c which is a part of bush 23 is located in the upper half part side of 20 across the gap G2. Therefore, vibration of the screw shaft 4 meshing with the worm gear in the gear box 5 is absorbed and reduced by the bush 23, and as described above, the holder 14 comes into contact with the flange portion 23c of the bush 23. In addition, the cushioning effect of the bush 23 is exhibited, and the occurrence of sound hitting between metals can be prevented.

  Here, FIG. 8 shows a second embodiment of the seat slide device according to the present invention when the bush 23 shown in FIG. 5 is eliminated.

  In the second embodiment shown in FIG. 8, when an excessive input corresponding to the pulling force in the direction of arrow B is applied to the screw shaft 4 at the time of a vehicle collision, for example, the load is applied by the nut 22 that functions as a load receiving member. The load is applied to the vertical wall portion 20 of the front bracket 9 after being loaded.

  The vertical wall portion 20 to which such an excessive input is loaded causes the screw shaft 4 to move in the direction of arrow B, so that the screw shaft 4 is pressed against the upper end surface of the insertion hole 21, and FIG. As shown, a fall occurs between the root portion and the contact point P2 of the nut 22. At this time, since the flange lower end P1 of the nut 22 is not in contact with the vertical wall portion 20 by the gap G1, the force for bending the screw shaft 4 inserted and supported by the vertical wall portion 20 can be reduced. Furthermore, as shown in FIG. 9C, even when the vertical wall portion 20 is greatly tilted, the flange lower end P <b> 1 of the nut 22 enters the insertion hole 21 to try to bend the screw shaft 4. The power can be reduced. As a result, there is no possibility that the screw shaft 4 is broken.

  That is, in the second embodiment shown in FIG. 8, as shown in FIG. 6, in the front view of the front bracket 9, a long hole formed in the vertical wall portion 20 from the flange lower end P <b> 1 of the nut 22. Since the insertion hole 21 is formed so as to extend in the major axis direction so that a part of the insertion hole 21 protrudes, even if the vertical wall portion 20 falls down as shown in FIG. The flange lower end P <b> 1 does not directly contact the vertical wall portion 20. As a result, the bending moment applied to the screw shaft 4 is relaxed, the breaking (breaking) strength of the screw shaft 4 is relatively improved, and the conventional breakage of the screw shaft 4 can be prevented.

  As a result of experiments conducted by the present inventors under the second embodiment, it has been found that the breaking strength of the screw shaft 4 is improved by 60% or more compared to the conventional type.

  In addition, as shown in FIG. 5, since the gap G1 is set in advance between the flange lower end P1 of the nut 22 and the vertical wall portion 20, the point where the nut 22 and the vertical wall portion 20 contact during deformation is Since the contact point P2 does not change, the contact point becomes stable, the bending moment applied to the screw shaft 4 can be reduced and stabilized, and the breaking (breaking) strength of the screw shaft 4 is further improved. This is further advantageous in preventing breakage.

  As described above, the first embodiment shown in FIG. 5 differs from the second embodiment shown in FIG. 8 only in that a bushing 23 as a holding member is added. The bush 23 is formed of a rubber elastic body. In this case, for example, as shown in FIG. 9, when the vertical wall portion 20 of the front bracket 9 falls down, the second embodiment shown in FIG. 8 is also used in the first embodiment shown in FIG. It can be easily understood that the same behavior as that of the embodiment is performed. Therefore, in the first embodiment shown in FIG. 5, in addition to the unique effects described above, the same effects as those in the second embodiment shown in FIG. 8 can be obtained.

  Here, in each of the above-described embodiments, the screw shaft 4 is supported at both ends on the lower rail 2 side, while the gear box 5 incorporating a worm gear is supported on the upper rail 3 side. Instead of this, for example, according to required specifications such as various layouts, the screw shaft 4 is supported at both ends on the upper rail 3 side, while the gear box 5 with a built-in worm gear is supported on the lower rail 2 side. Of course it is possible.

  Moreover, the shape of the long hole-shaped insertion hole 21 formed in the vertical wall part 20 shown in FIG. 6 is only an example, and if it is a shape that can exhibit an equivalent function, for example, a so-called daruma hole shape or other shapes May be.

2 ... Lower rail 3 ... Upper rail 4 ... Screw shaft 5 ... Gear box (gear mechanism)
DESCRIPTION OF SYMBOLS 9 ... Front side bracket 13 ... Case 14 ... Holder 19 ... Bottom wall part 20 ... Vertical wall part 20a ... Stopper surface 21 ... Insertion hole 23 ... Bush (holding member)
23b, 23c ... Flange G1, G2 ... Gap

Claims (4)

A lower rail disposed along the front-rear direction on the vehicle floor;
An upper rail that is slidable in the longitudinal direction with respect to the lower rail and on which a seat is assembled;
A screw shaft that is arranged along the longitudinal direction of the two rails and is supported at both ends by either one of the lower rail and the upper rail;
A gear mechanism having a gear which is provided on the other rail of the lower rail and the upper rail and is screwed to the screw shaft;
With
At least a front end portion of the screw shaft is fixedly supported by the one rail via an L-shaped bracket, and the gear mechanism is accommodated with respect to the bracket when the upper rail advances maximum with respect to the lower rail. A seat slide device in which the holder comes into contact,
The bracket has a bottom wall portion fixed to the one rail, and a vertical wall portion in which an insertion hole is formed to stand from the bottom wall portion and the screw shaft is inserted.
The seat slide device according to claim 1, wherein the contact of the holder with the vertical wall portion is performed at a position of the vertical wall portion closer to the bottom wall portion than the screw shaft.   Of the vertical wall portion, a portion closer to the bottom wall portion than a portion far from the bottom wall portion protrudes toward the holder, and the holder comes into contact with a portion close to the protruding bottom wall portion. The seat slide device according to claim 1, wherein the seat slide device is provided.   In a state where the holder is in contact with a portion of the vertical wall portion close to the bottom wall portion, a gap is secured between the vertical wall portion and a portion far from the bottom wall portion and the holder. The seat slide device according to claim 2, wherein the seat slide device is configured. The insertion hole has a long hole shape in which the diameter through which the front end of the screw shaft can be inserted is a short diameter and the long diameter direction is directed in the vertical direction of the vertical wall part,
The seat slide device according to claim 3, wherein a holding member made of an elastic body, which holds the screw shaft and sandwiches the vertical wall portion from both front and back sides, is fitted in the insertion hole.

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