JP4804795B2 - Support structure for the seat back table - Google Patents

Description

  The present invention relates to a support structure for a seat back table mounted on a seat of a railway vehicle or the like.

  Conventionally, on a seat of a railway vehicle, an aircraft, etc., on the back side of the seat back, as a table used by passengers on the rear seat, a storage position integrated with the seat back and a use position where the movable table body is held horizontally It is equipped with a seat back table that can be moved. In FIG. 8, the perspective view which looked at the three-seat seat for rail vehicles from the back was shown. In this vehicle seat, a seat-belt seat 14 and a seat back 15 for three persons are mounted on a seat frame 12 pivotally supported with respect to a leg base 11.

  A table is mounted on the back of each seatback 15. Each table includes a movable table main body 121 and a pair of table support plates (stays) 123 that pivotally support both end portions of the movable table main body 121 at the front end portion via a table shaft 122. Each table support plate 123 is pivotally supported by a shaft 117 whose lower end is fixed to the seat frame 12 (see FIG. 9). The movable table main body 121 and the table support plate 123 are stored in the storage recess 15a of the seat back 15 in a state where the movable table main body 121 faces the back of the seat back 15 and is integrated with the seat back 15 (see FIG. 8 and the movable table main body 121 at the center and the table support plate 123 rotate around the shaft 117 at the lower end, and the movable table main body 121 is pulled out to a horizontal position (see FIG. 8). It is formed to be movable to the leftmost movable table body 121). The movable table main body 121 is hooked by a table stopper 16 that is rotatably mounted on the seat back 15 at the storage position.

  The table support plate 123 is held in its use position when a stopper piece 123 a provided in the vicinity of the shaft 117 abuts on a stopper bolt 18 provided on the seat frame 12. In this use state, the movable table body 121 is also restricted in rotation so that the edge on the user side does not fall from the horizontal position. As a stopper structure for restricting the table support plate 123 at the use position, for example, a stopper piece 123a protruding in the vicinity of the bearing portion of the table support plate 123 is brought into contact with the head of the stopper bolt 18 etc. screwed to the seat frame 12. A stopper structure that abuts on a portion, a stopper structure that abuts on a tapered abutting portion fixed to a bolt screwed to a frame (Patent Document 1), and the like have been developed.

  Such a movable table main body 121 of the conventional seat back table is normally hooked so as not to move in the use position direction by the table stopper 16 at the storage position. When the latching by the table stopper 16 is released, the movable table main body 121 and the table support plate 123 rotate and move in the use position direction by their own weight. Therefore, when the user releases the latch by the table stopper 16 without pressing the movable table body 121, the movable table body 121 and the table support plate 123 are suddenly rotated to the use position, and the stopper piece of the table support plate 123 is released. When 123a collides with the stopper bolt 18 and the impact force is transmitted to the front seat, the front seat user is uncomfortable.

Accordingly, the applicant forms a through hole in the radial direction in the bearing boss 124 of the table support plate 123, inserts the buffer member 126 into the through hole, and further presses the buffer member 126 against the outer peripheral surface of the shaft 117 with the screw 127. Thus, there has been proposed a structure for supporting the table for the back of the seat that suppresses the rotation of the table support plate 123 by generating frictional resistance between the buffer member 126 and the shaft 117 when the table support plate 123 rotates (Patent Document). 2).
JP 2002-238697 A JP 2004-359084 A

  However, since the buffer member is in the shape of a rod inserted in a hole that penetrates the bearing in the radial direction, the contact area with the shaft is small, fine adjustment of the frictional resistance force is difficult, and adjustment of the rotation suppression force of the table body is not possible. There was a possibility that it was sufficient, or wear due to friction was early and the secular change was quick.

  The present invention has been made in view of such problems of the prior art, and when the movable table on the back of the seat is pulled out and stopped at the use position, no impact is generated, and the movable table is drawn out and stored smoothly and aged. It is an object of the present invention to provide a support structure for a table for a back surface of a sheet that can obtain a rotation suppressing force with little change.

The present invention that solves such a problem includes a pair of left and right table support plates on the back side of the seat back, in which a shaft portion at the lower end is pivotally supported via a shaft fixed to a seat fixing structure. ; Pivotally supported between upper ends of the pair of table support plates , and with the rotation of the pair of table support plates , the storage position along the back of the seat back and the substantially horizontal when pulled out from the storage position; A seat back table support structure comprising : a movable table body held at a different use position, wherein the bearing communicates with at least one shaft portion of the pair of table support plates with a shaft hole of the shaft portion. A boss projectingly formed; the bearing boss is formed with a coaxial annular recess and an open portion formed by cutting away a part of the peripheral wall of the annular recess; the bearing boss includes the bearing boss An annular portion that fits into the annular recess of A tightening adjustment bracket having a pair of flanges extending in a radial direction from the circumferential edge of the annular portion and projecting from the open portion of the bearing boss is fitted; and A clamping force of a shaft fixed to the fixed structure of the seat can be adjusted by clamping a pair of flanges and adjusting a circumferential length or diameter of the annular portion of the clamping adjustment bracket; .

In a preferred embodiment of the present invention, a cylindrical bush having a variable circumferential length or a variable diameter is interposed between the shaft hole of the table support plate and the tightening adjustment bracket and the shaft fixed to the fixing structure of the seat. If a low friction layer is provided on at least one of the surfaces in which the cylindrical bush and the shaft are in sliding contact, the sliding becomes smooth and the rotation of the table support plate is suppressed with a smoother and more stable frictional resistance. And wear due to aging is reduced.

The seat back table support structure of the present invention has a bearing boss projectingly formed on at least one shaft portion of a pair of table support plates and communicating with the shaft hole of the shaft portion. An annular recess and an open portion formed by cutting a part of the peripheral wall of the annular recess are formed. The bearing boss has an annular portion that fits in the annular recess of the bearing boss, and the annular portion faces in the circumferential direction. A fastening adjustment bracket having a pair of flanges extending in a radial direction from the edge and projecting from the opening portion of the bearing boss is fitted, so that the pair of flanges of the fastening adjustment bracket is clamped to form a seat fixing structure. By adjusting the fastening force of the fixed shaft, a preferable rotation suppressing force of the movable table can be obtained, and a lightweight support structure for the table for seat back can be obtained without increasing the axial length.

  The seat back table to which the present invention is applied is the same as the structure shown in FIG. 8 when mounted on a vehicle seat. The structure around the bearing portion of the table support plate 23, which is a feature of the present invention, will be described with reference to FIGS. 1 is an exploded perspective view showing the periphery of the lower end shaft portion of the table support plate according to the first embodiment of the present invention, FIG. 2 is a front view of the periphery of the lower end portion after the assembly, and FIG. It is sectional drawing which follows the cutting line III-III.

  The movable table main body 121 is made of synthetic resin, and supports both side portions of the movable table main body 121 with the tip ends of a pair of table support plates (table stays) 23 via the table shaft 122. Although not shown in detail, the movable table body 121 is pivotally supported with respect to the table support plate 23 via the table shaft 122, and the upper surface can be stored opposite to the storage recess 15a of the seat back 15 in the storage position. Thus, when the table support plate 23 is rotated to the use position and the stopper piece 23a is in contact with the head of the stopper bolt 18 of the seat frame 12, the upper surface is regulated to be held substantially horizontally. ing. The structure that restricts the rotation of the table support plate 23 at the use position is such that the stopper bolt 18 is screwed into the end surface of the table support plate 23 so that the head of the stopper bolt 18 contacts the contact portion of the seat frame 12. It may be a structure.

  The table support plate 23 is in the shape of a bar made of metal such as aluminum, and is usually formed in a cross section H, I shape or the like in order to ensure rigidity strength. A shaft hole 24 and a bearing boss 25 that reinforces the shaft hole 24 are integrally formed at the lower end of the table support plate 23. Since the shape of the pair of table support plates 23 and the structure of supporting the pair of table support plates 23 so as to be swingable with respect to the seat frame 12 are symmetrical or the same, the structure relating to one table support plate 23 will be described below.

  On the outside of the bearing boss 25, an annular tightening adjustment bracket 30 having a C-shape in the axial direction is disposed in a state of being aligned with the shaft hole 24. The tightening adjustment bracket 30 includes a pair of flanges 32 that are bent from the circumferentially opposed edges of the annular portion 31 that is rounded into an annular shape and extend in the radial direction, and are opposed to each other in a natural state. Further, a fixing bracket 35 protruding in the radial direction is integrally formed on the outer peripheral surface of the annular portion 31. The fixed bracket 35 has a stepped shape that engages with the bearing boss 25, engages with the bearing boss 25, and the annular fastening surface 34 formed by the inner peripheral surface of the annular portion 31 and the shaft hole 24 are substantially formed. In the matched state, it is fastened and fixed to the table support plate 23 by a fixing screw 36 that passes through a through hole formed at the tip of the fixing bracket 35. By this screwing, the tightening adjustment bracket 30 rotates integrally with the table support plate 23.

Each flange 32 is formed with a hole 33 through which the adjustment screw 37a is inserted. A nut 37b is screwed into an adjustment screw 37a penetrating each hole 33, and the pair of flanges 32 are tightened in the approaching direction or loosened in the opposite direction by tightening with the adjusting screw 37a and the nut 37b. it can. That is, when the adjusting screw 37a is rotated in the tightening direction, the interval between the flanges 32 is narrowed, the circumferential length of the annular tightening surface 34 is shortened, the diameter of the annular tightening surface 34 is decreased, and the members in the annular tightening surface 34 Is tightened. Conversely, when the adjustment screw 37a is rotated in the relaxation direction, the circumferential length of the annular fastening surface 34 is increased, the diameter of the annular fastening surface 34 is increased, and the fastening of the members in the annular fastening surface 34 is relaxed.
The tightening adjustment bracket 30 is preferably formed of a metal plate rich in elasticity or flexibility.

  A cylindrical bush 40 having a C-shaped cross section is inserted into the shaft hole 24 through a space regulated by the annular fastening surface 34 of the fastening adjustment bracket 30. The bush 40 is formed with a cylindrical portion 41 and a flange 42 extending radially outward from one axial end of the cylindrical portion 41, and a slit 43 is formed by cutting the cylindrical portion 41 and the flange 42 in the axial direction. ing. The slit 43 is also a space left by cutting the cylindrical portion 41 and the flange 42 by a predetermined width in the circumferential direction. The presence of the slit 43 allows the bush 40 to be deformed so that the circumferential length or diameter of the inner peripheral surface (shaft hole regulated by the inner peripheral surface) of the cylindrical portion 41 can be extended / reduced or expanded / contracted. The bush 40 is inserted into the shaft hole 24 from a space in which the cylindrical portion 41 is restricted by the annular fastening surface 34 of the fastening adjustment bracket 30, and at this time, the gap between the slit 43 and the pair of flanges 32 coincides (overlaps). (State) is preferably inserted in the state.

  A cylindrical collar 50 as a hollow shaft is inserted into the cylindrical portion 41. The collar 50 includes a cylindrical hollow shaft portion 51 having a shaft hole 54 formed therein, a flange 52 projecting outward from one end portion of the hollow shaft portion 51, and the other end of the hollow shaft portion 51. A flat detent 53 is provided on the outer peripheral surface in the vicinity of the end. The collar 50 passes through the cylindrical portion 41 of the bush 40 and is inserted into a bearing hole 13 a formed at the tip end portion of the frame frame 13. The bearing hole 13a is formed with a flat rotation stopper 13b that is in close contact with the rotation stopper 53, and is supported by the bearing hole 13a and the rotation stopper 13b so as not to rotate. The underframe 13 is fixed to the seat frame 12.

  Further, a bolt 60 with a male screw 63 cut at the tip is inserted into the shaft hole 54 of the collar 50, and the male screw 63 is screwed into a female screw 13c formed at the bottom of the bearing hole 13a. A washer 65 is interposed between the shaft portion 61 of the bolt 60 and the head 62. By rotating the head 62 with a spanner, a wrench or the like, the flange 52 is tightened between the frame frame 13 and the head 62, and the collar The tip 50 is pressed against the bottom of the bearing hole 13a and fixed so as not to rotate (FIGS. 2 and 3). The collar 50 and the bolt 60 serve as a shaft that pivotally supports the table support plate 23 with respect to the frame frame 13. In addition, a margin is provided between the flange 52 and the bearing boss 25 so that the bearing boss 25 and the tightening adjustment bracket 30 can rotate.

  The bush 40 is formed, for example, by pressing a steel plate or the like, and further, a low friction layer that forms a low friction / oil-free bearing on the inner peripheral surface of the cylindrical portion 41 and the surface of the flange 42 connected to the inner peripheral surface, for example, It is preferable to form a fluororesin layer 44 by Teflon (registered trademark) processing or the like by coating (FIG. 4). By forming the fluororesin layer 44, the frictional resistance between the fluororesin layer 44 and the outer peripheral surface of the hollow shaft portion 51 of the collar 50 and the back surface of the flange 52 is such that the annular tightening surface 34 of the tightening adjustment bracket 30 and the bush 40. And the friction between the end surface of the tightening adjustment bracket 30 and the back surface of the flange 42 of the bush 40. Accordingly, when the table support plate 23 rotates, the bush 40 rotates together with the table support plate 23 and the tightening adjustment bracket 30 while the fluororesin layer 44 is in sliding contact with the outer peripheral surface of the hollow shaft portion 51 of the collar 50. In this manner, the fluororesin layer 44 of the bush 40 rotates in a sliding manner while being pressed against the outer peripheral surface of the hollow shaft portion 51 of the collar 50, thereby rotating smoothly while receiving a certain frictional resistance.

  In this manner, the table support plate 23 is supported by the tightening adjustment bracket 30, the bush 40, the collar 50 and the bolt 60 so as to be rotatable with respect to the frame frame 13. This state is the assembly completion state. In this assembled state, the bolt 60 and the collar 50 are fixed so as not to be rotatable with respect to the frame frame 13, and the tightening adjustment bracket 30 and the bush 40 are integrated with the table support plate 23 so that the bolt 60 and the collar 50 are integrated. It rotates about 50 as an axis.

  In this first embodiment, the cylindrical portion 41 of the bush 40 is inserted into the shaft hole 24 and is tightened by the tightening adjustment bracket 30 to reduce the diameter, so that the sliding resistance between the cylindrical portion 41 and the shaft hole 24 is small. . On the other hand, the cylindrical portion 41 of the bush 40 is reduced in diameter because the outer peripheral surface 45 is pressed toward the center by the reduced diameter of the annular fastening surface 34 of the fastening adjustment bracket 30, and the fluororesin layer 44 is the hollow shaft portion of the collar 50. 51 is pressed in the center direction with a cylindrical surface. Since the inner peripheral surface of the cylindrical portion 41 is coated with the fluororesin layer 44, the static / dynamic frictional resistance acting between the fluororesin layer 44 and the outer peripheral surface of the hollow shaft portion 51 is the annular clamping surface 34. And the static / dynamic friction resistance acting between the outer peripheral surface 45 and the outer peripheral surface 45. Therefore, when a force (rotational torque) for rotating the table support plate 23 in the storage position direction or the use position direction is applied, the table support plate 23 acts between the fluororesin layer 44 and the outer peripheral surface of the hollow shaft portion 51. It starts to rotate against the maximum static friction force and rotates against dynamic friction force. Thereafter, while the table support plate 23 was given a rotational torque of a certain level or more, the rotation of the table support plate 23 was suppressed by the dynamic friction force acting between the fluororesin layer 44 and the outer peripheral surface of the hollow shaft portion 51. Rotates smoothly in the state.

  As described above, in the first embodiment, since the static / dynamic friction resistance due to the surface contact between the tightening adjustment bracket 30 provided on the rotation shaft portion of the table support plate 23 and the bush 40 is received, the table support plate 23 is stable when rotating. The frictional resistance of the specified strength acts and rotates smoothly. That is, even if the movable table body 121 supported by the table support plate 23 is brought into a free state from the storage position, the table support plate 23 does not rotate suddenly by the weight of the movable table body 121, and the stopper piece 23a It does not collide with the stopper bolt 18 vigorously.

  In the first embodiment, the rotation restriction adjustment of the table support plate 23 is performed as follows. The adjustment screw 37a is rotated by a driver or the like. When the adjusting screw 37a is rotated in the fastening direction, the distance between the pair of flanges 32 is narrowed, the circumferential length of the annular portion 31 is shortened, the diameter of the annular fastening surface 34 is reduced, and the annular fastening surface 34 has an annular or cylindrical shape. The surface tightens the cylindrical portion 41 of the bush 40 from the entire circumference in the center direction indicated by the white arrow in FIG. 3 and increases the frictional resistance. When the adjustment screw 37a is rotated in the relaxation direction, the distance between the pair of flanges 32 is increased, the circumference of the annular portion 31 is increased, the diameter of the annular fastening surface 34 is increased, and the force for fastening the cylindrical portion 41 is increased. The table support plate 23 rotates with a weaker force.

  In the first embodiment, the fluororesin layer 44 is formed on the bush 40 in order to make the table support plate 23 swing smoothly. However, the fluororesin layer may be formed on the outer peripheral surface of the collar 50. Instead of the fluororesin layer, a member having a small frictional resistance may be used. Moreover, the structure which the metals suitable for an oil-free bearing contact may be provided, without providing a fluororesin layer. Alternatively, the bush 40 may be formed of a synthetic resin having low frictional resistance and high wear resistance.

  Next, a second embodiment of the present invention will be described with reference to FIG. 5, FIG. 6, and FIG. The same members and members having the same functions as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

In the second embodiment, a concave portion (annular concave portion) 252 and an opening portion 253 in which a part of the peripheral wall of the concave portion 252 is cut off are formed on the inner periphery of the bearing boss 251, and the concave portion 252 has a C-shape when viewed in the axial direction. A tightening adjustment bracket 301 having an annular portion 311 is accommodated. The length of the tightening adjustment bracket 301 in the axial direction is substantially the same as or slightly shorter than the depth of the recess 252. Each flange 321 of the tightening adjustment bracket 301 protrudes outward of the bearing boss 251 from the open portion 253, and an adjustment screw 37a passing through a hole 331 formed in each flange 321 and a nut screwed to the adjustment screw 37a. Tightened by 37b.

  A cylindrical bush 401 is inserted into the annular tightening surface 341 of the tightening adjustment bracket 301. This bush 401 is also formed with a slit extending in the axial direction, and has a variable circumferential length or a variable diameter. In this bush 401, the cylindrical portion 411 is press-fitted into the shaft hole 241 of the table support plate 23 from the tip portion through the annular fastening surface 341. A flange 421 projecting radially outward is formed at the rear end edge of the bush 401, and this flange 421 contacts the tightening adjustment bracket 301 to restrict the axial movement of the tightening adjustment bracket 301. Since the bush 401 is press-fitted into the shaft hole 241 as described above, the bush 401 rotates together with the shaft hole 241, that is, the table support plate 23.

  A collar 501 is inserted into a shaft hole 441 formed on the inner peripheral surface of the cylindrical portion 411 of the bush 401, and a bolt 601 is inserted into the shaft hole 541 of the collar 501. The collar 501 includes a hollow shaft portion 511 having an inner peripheral surface forming a shaft hole 541, a flange 521 projecting radially outward from the rear end portion of the hollow shaft portion 511, and the vicinity of the tip of the hollow shaft portion 511 A flat detent 531 formed on the outer peripheral surface of the portion is provided. The collar 501 is inserted into a bearing hole 13 a formed in the underframe frame 13 at a tip portion that penetrates the shaft hole 441 of the bush 401. The bearing hole 13a is formed with a flat rotation stopper 13b that is in close contact with the rotation stopper 531 and prevents the collar 501 from rotating, and is supported by the bearing hole 13a and the rotation stopper 13b so as not to rotate.

  At least one of the surfaces where the bush 401 and the collar 501 are in sliding contact, that is, the inner peripheral surface of the shaft hole 441 or the outer peripheral surface of the hollow shaft portion 511 is provided with a low friction layer, for example, a fluororesin layer by Teflon (registered trademark) processing or the like. It is preferable to coat.

  Further, a bolt 601 having a male screw 631 cut at the tip is inserted into the shaft hole 541 of the collar 501, and the male screw 631 is screwed into a female screw 13c formed at the bottom of the bearing hole 13a. A washer 651 is inserted between the shaft portion 611 of the bolt 601 and the head 621. By rotating the head 621 with a spanner, a wrench or the like, the flange 521 is fastened by the frame frame 13 and the head 621, and the collar 501 is fixed so that the front end surface is pressed against the bottom surface of the bearing hole 13a and cannot rotate. (FIGS. 6 and 7). The collar 501 and the bolt 601 serve as a shaft that pivotally supports the table support plate 23 with respect to the frame frame 13 and the seat frame 12. In addition, a margin is provided between the flange 521, the flange 421, and the bearing boss 251 so that the bearing boss 251 can rotate.

  In this manner, the table support plate 23 is rotatably supported with respect to the frame frame 13 by the tightening adjustment bracket 301, the bush 401, the collar 501 and the bolt 601. This state is the assembly completion state. In this assembled state, the bolt 601 and the collar 501 are fixed to the underframe 13 so as not to be rotatable, and the tightening adjustment bracket 301 and the bush 401 are integrated with the table support plate 23 so that the bolt 601 and the collar 501 are integrated. Rotate around the axis.

  As described above, in the second embodiment, since the frictional rotation is restricted by the surface contact between the bush 401 tightened by the tightening adjustment bracket 301 and the collar 501 at the rotation shaft portion of the table support plate 23, the rotation of the table support plate 23 is performed. When moving, a stable frictional force acts and rotates smoothly. That is, even if the movable table body 121 supported by the table support plate 23 is brought into a free state from the storage position, the table support plate 23 does not rotate suddenly by the weight of the movable table body 121, and the stopper piece 23a It does not collide with the stopper bolt 18 vigorously.

  Furthermore, in the second embodiment, the tightening adjustment bracket 301 is housed in the recess 252 formed in the bearing boss 251. Therefore, the axial length is shorter than that of the first embodiment, and the overall size is reduced. . Further, the fixing bracket 35 and the fixing screw 36 are not required, and the lengths of the bush 401, the collar 501 and the bolt 601 are shortened, so that the weight is reduced as a whole as compared with the first embodiment.

  In the first and second embodiments, members such as the adjusting screw 37a and nut 37b of the shaft portion, the stopper bolt 18 and the like are covered with a cover (not shown), and are stored in the cover in a normal use state. And hidden from the user.

It is a perspective view which decomposes | disassembles and shows the lower end axial part periphery of the table support plate which is the 1st Embodiment of this invention. It is a front view of the lower end part periphery after the said assembly of the said 1st Embodiment. FIG. 3 is a cross-sectional view taken along a cutting line III-III in FIG. 2. It is sectional drawing which shows the cross-section of the bush of the 1st embodiment. It is a perspective view which decomposes | disassembles and shows the lower end axial part periphery of the table support plate which is the 2nd Embodiment of this invention. It is a front view of the lower end part periphery after the assembly of the 2nd embodiment. It is sectional drawing which follows the cutting line VII-VII of FIG. It is the perspective view which looked at the three-seat seat for rail vehicles from the back. It is sectional drawing which shows the principal part of the support structure of the conventional seat back table.

Explanation of symbols

13 frame frame 13a bearing hole 13b detent 13c female screw 23 table support plate 24 shaft hole 25 bearing boss 30 tightening adjustment bracket 31 annular portion 32 flange 34 annular tightening surface 35 fixing bracket 36 fixing screw 37a adjusting screw 37b nut 40 bush 41 cylinder Portion 42 Flange 43 Slit 44 Fluorine resin layer 45 Outer peripheral surface 50 Collar 51 Hollow shaft portion 52 Flange 53 Detent 54 Shaft hole 60 Bolt 61 Shaft portion 62 Head 63 Male screw 65 Washer 251 Bearing boss 252 Recess 253 Opening portion 301 Tightening adjustment bracket 321 Flange 341 Annular tightening surface 401 Bush 411 Cylindrical portion 421 Flange 441 Shaft hole 501 Collar 511 Hollow shaft portion 521 Flange 531 Rotation stop 541 Shaft hole 601 Bolt 611 Shaft portion 621 Head 631 Male thread 651 Washer

Claims (2)

A pair of left and right table support plates pivotally supported on the back side of the seat back by a shaft portion at the lower end via a shaft fixed to a seat fixing structure;
It is pivotally supported between the upper ends of the pair of table support plates. As the pair of table support plates rotate, the storage position along the back of the seat back and the substantially horizontal position when pulled out from the storage position are provided. A movable table body held in a use position;
A support structure for a table on the back side of the seat,
A bearing boss communicating with the shaft hole of the shaft portion is formed to protrude from at least one shaft portion of the pair of table support plates;
The bearing boss is formed with a coaxial annular recess and an open portion obtained by cutting away a part of the peripheral wall of the annular recess;
The bearing boss includes an annular portion that fits in the annular recess of the bearing boss, and a pair of flanges that extend radially from opposite circumferential edges of the annular portion and project from the open portion of the bearing boss. Fitted with a tightening adjustment bracket having; and
The tightening adjustment bracket is capable of adjusting the tightening force of the shaft fixed to the fixed structure of the seat by adjusting the circumferential length or diameter of the annular portion of the tightening adjustment bracket by clamping the pair of flanges. thing;
The seat back table support structure characterized by the above. The support structure for the seat back table according to claim 1 , wherein a variable circumferential length or a variable diameter is provided between the shaft hole of the table support plate and the tightening adjustment bracket and the shaft fixed to the fixed structure of the seat. A support structure of a seat back table, wherein a cylindrical bush is interposed, and a low friction layer is provided on at least one of surfaces where the cylindrical bush and the shaft are in sliding contact.