Vehicle seat frame structure

Abstract

To provide a frame structure of a vehicle seat which achieves improvement of strength around a gear mechanism with a small and light-weight structure.SOLUTION: A frame structure of a vehicle seat includes: a seat frame (14) that constitutes a seat surface part (11) of a vehicle seat (10); a pinion (33) that is rotatably attached to the seat frame and protrudes from an outer side to an inner side in a vehicle width direction; a drive input gear (22d) that is disposed on the inner side in the vehicle width direction with respect to the seat frame, is rotatable about a rotary shaft (16) at a position different from the pinion, and meshes with the pinion; a reinforcement member (25) that is disposed between the seat frame and the drive input gear in the vehicle width direction and is fixed to the seat frame; and support members (40, 47) that are disposed on the inner side in the vehicle width direction with respect to the seat frame with the drive input gear and the reinforcement member interposed therebetween, support a part (33a) of the pinion, and are fixed to the seat frame. A part of the support member (47) comes into contact with the seat frame through an insertion part (25b) provided at the reinforcement member.SELECTED DRAWING: Figure 10

Description

[Technical Field]

[0001] The present invention relates to a frame structure for a vehicle seat. [Background technology]

[0002] Vehicle seats are designed with various loads in mind, such as those that will be applied in the event of a vehicle collision. For example, in the case of a vehicle seat equipped with a gear mechanism that is involved in the operation of the seat, it is necessary to prevent the gear mechanism from failing to mesh or being damaged by an external impact.

[0003] One example of a vehicle seat equipped with a gear mechanism is one equipped with a lifter mechanism that changes the height of the seat cushion (see, for example, Patent Document 1). Specifically, a cushion frame (particularly, a side frame disposed on the side of the seat cushion) that forms the framework of the seat cushion is supported movably in the vertical direction relative to the floor of the vehicle (such as a seat track attached to the floor) via a lifter mechanism with a four-bar link structure. A sector gear provided in a part of the lifter mechanism is engaged with a pinion provided on the cushion frame side, and the lifter mechanism is operated in response to the rotational drive of the pinion, thereby moving the cushion frame up and down.

[0004] In conventional seats with lifter mechanisms, when a load is applied to the vehicle due to a rear-end collision (a rear-end collision), a load is applied to the cushion frame that moves the rotation centers of the pinion and sector gear apart (increasing the distance between the axes), which can cause poor meshing of the sector gear with the pinion (reduced meshing, etc.). This poor meshing can easily cause loads to concentrate locally, leading to chipped teeth on the sector gear. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-136439 Summary of the Invention [Problem to be solved by the invention]

[0006] In the seat with a lifter mechanism disclosed in Patent Document 1, the lifter mechanism is attached to one side of a cushion frame (side frame), and a support arm is attached to the cushion frame to suppress the inter-axial repulsive force acting between the pinion gear and the sector gear. One end of the support arm is fixed to the cushion frame, and a slide pin on the other end is fitted into an arc-shaped elongated hole formed in a rear link having a sector gear. An output shaft, which is the rotation center of the pinion, is inserted into the middle part of the support arm.

[0007] In Patent Document 1, the cushion frame is designed to bear the load generated on the support arm as well as the load generated on the cushion frame itself, and the cushion frame is responsible for ensuring the strength required to suppress the inter-axial repulsive force between the pinion gear and the sector gear. Therefore, the cushion frame needs to have high rigidity. However, if a thick metal plate is selected as the cushion frame's material and the overall thickness of the cushion frame is increased, although the rigidity is increased, problems arise, such as increased weight, poor workability, and increased costs due to a significant increase in material costs.

[0008] Furthermore, the support arm of Patent Document 1 has a structure in which the slide pin is fitted into the elongated hole of the rear link to directly restrict the movement of the rear link, which may hinder smooth movement of the rear link.

[0009] The present invention has been made in consideration of the above problems, and has an object to provide a frame structure for a vehicle seat that is small and lightweight and achieves improved strength around the gear mechanism. [Means for solving the problem]

[0010] The present invention provides a vehicle seat comprising: a seat frame that constitutes a seating surface of a vehicle seat; a pinion rotatably attached to the seat frame and protruding from the outside toward the inside in a vehicle width direction; a drive input gear that is arranged on the inside of the seat frame in the vehicle width direction, rotatable about a rotation axis that is positioned differently from the pinion and meshes with the pinion; a reinforcing member that is arranged between the seat frame and the drive input gear in the vehicle width direction and fixed to the seat frame; and a support member that is arranged on the inside of the seat frame in the vehicle width direction with the drive input gear and the reinforcing member between them, supports a part of the pinion, and is fixed to the seat frame, wherein a part of the support member abuts against the seat frame through an insertion portion provided in the reinforcing member. do.

[0011] It is preferable that the seat frame has a fixing member that fixes the pinion to the seat frame, and that the support member is also supported by the seat frame by the fixing member.

[0012] In one embodiment, The reinforcing member has a through hole through which a part of the pinion passes, a first extending portion extending from the through hole toward the rotation shaft of the drive input gear, and a second extending portion extending from the through hole toward the opposite side of the rotation shaft of the drive input gear, and the first extending portion is longer from the through hole than the second extending portion. stomach.

[0013] The insertion portion is preferably provided on the first extension portion.

[0014] In one embodiment, a fixing member for fixing the pinion to the seat frame, the drive input gear having an elongated hole in an arc shape centered on the rotation axis, the part of the support member being a vehicle width direction extending portion that is inserted through the elongated hole and the insertion portion and abuts against the seat frame, and a gap between the vehicle width direction extending portion and the insertion portion is smaller than a gap between the vehicle width direction extending portion and the elongated hole; stomach.

[0015] It is preferable that the fixing member is a screw, the vehicle width direction extension portion is cylindrical, and the screw that fastens and fixes the seat frame and the support member is inserted into the vehicle width direction extension portion. [Effects of the Invention]

[0016] According to the vehicle seat frame structure of the present invention, the reinforcing member reinforces the seat frame and also bears the load from the support member, so that the seat frame can be made thin and compact with a lightweight structure, thereby improving the strength around the gear mechanism. Furthermore, because the support member abuts against the seat frame through the insertion portion of the reinforcing member, movement of the support member in the fore-and-aft direction of the vehicle can be suppressed by the reinforcing member, and movement in the width direction of the vehicle can be suppressed by the seat frame. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a diagram showing a schematic configuration of a vehicle seat; [Figure 2] FIG. 2 is a perspective view showing a frame structure on one side of the vehicle seat. [Figure 3] FIG. 1 is a perspective view of one side of the frame structure excluding the support plate. [Figure 4] FIG. 2 is an exploded perspective view of one side of the frame structure. [Figure 5] FIG. 10 is a side view of one side of the frame structure as seen from inside the seat. [Figure 6] FIG. 1 is a side view of one side of the frame structure excluding the support plate. [Figure 7] FIG. 1 is a side view of one side of the frame structure excluding the support plate and the rear link. [Figure 8] FIG. 8 is an enlarged side view of a part of FIG. 7. [Figure 9] FIG. 6 is a cross-sectional view taken along line IX-IX in FIG. 5. [Figure 10] FIG. 10 is an enlarged cross-sectional view of a part of FIG. 9. DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, an embodiment to which the present invention is applied will be described with reference to the drawings. The vehicle seat 10 shown in Fig. 1 is a front seat for an automobile, and the front-rear, left-right, and up-down directions in the following description refer to directions based on the vehicle in which the vehicle seat 10 is installed. The left-right direction is also expressed as the vehicle width direction, and the center side of the vehicle seat 10 in the vehicle width direction is referred to as the seat inner side, and the left and right sides are referred to as the seat outer side. For example, of a pair of left and right side frames 14 described below, for the left side frame 14, the seat inner side is the right side and the seat outer side is the left side, and for the right side frame 14, the seat inner side is the left side and the seat outer side is the right side.

[0019] The vehicle seat 10 includes a seat cushion 11 serving as a seat surface and a seat back 12 serving as a backrest. The seat back 12 is supported near the rear end of the seat cushion 11 so as to be tiltable in the front-to-rear direction. A cushion frame 13 forming the framework of the seat cushion 11 has a pair of left and right side frames (seat frames) 14 spaced apart in the vehicle width direction and extending in the front-to-rear direction, and has a frame-like structure in which the pair of side frames 14 are connected by a cylindrical front pipe 15 and a rear pipe 16 extending in the vehicle width direction. The seat back frame forming the framework of the seat back 12 is not shown in the drawings.

[0020] The main parts of the cushion frame 13, including the side frames 14, are provided separately on the left and right sides of the vehicle seat 10, and Figures 2 to 10 show the frame structure on the left side. The basic parts of the frame structure are the same on both sides, but only the left frame structure has the drive unit 30 (details of which will be described later) which serves as the drive source and parts related to the drive unit 30. The right frame structure operates in conjunction with the left frame structure via the front pipe 15 and rear pipe 16.

[0021] The seat cushion 11 and the seat back 12 are supported by a pair of left and right seat tracks attached to the vehicle floor surface so as to be movable in the fore-and-aft direction. Each seat track has lower rails 17 fixed to the vehicle floor surface and upper rails 18 that are movable in the fore-and-aft direction relative to the lower rails 17. The fore-and-aft position of the vehicle seat 10 can be adjusted by sliding the lower rails 17 in the fore-and-aft direction relative to the upper rails 18. The position of the upper rails 18 relative to the lower rails 17 is fixed by a slide lock mechanism (not shown).

[0022] A pair of front and rear support brackets 19 are fixed to the upper surface near the front and rear ends of each upper rail 18. Each of the pair of left and right side frames 14 is supported on the support brackets 19 via a lifter mechanism 20. The lifter mechanism 20 has a four-link structure in which a front link 21 and a rear link 22, which are rotatable relative to the side frame 14 and the support bracket 19, are arranged spaced apart in the front-to-rear direction, and the height position of the vehicle seat 10 relative to the vehicle floor can be adjusted by operating the lifter mechanism 20.

[0023] The front link 21 has a connection portion 21a near one longitudinal end rotatably connected to the front support bracket 19, and a connection portion 21b near the other longitudinal end rotatably connected to the side frame 14. A pair of left and right front links 21 are connected by a front pipe 15. The front pipe 15 is connected to each front link 21 near its longitudinal center (the intermediate position between the connection portions 21a and 21b).

[0024] The rear link 22 has a connection portion 22a near one longitudinal end that is rotatably connected to the rear support bracket 19, and a circular through-hole 22b near the other longitudinal end. The rear link 22 has a linear arm portion 22c that extends from the connection portion 22a to the through-hole 22b, and a sector gear plate 22d that is fan-shaped and located above the arm portion 22c and spreads forward. A sector gear 22e is formed on the front edge of the sector gear plate 22d, with its center at the through-hole 22b. The sector gear 22e has multiple gear teeth that are arranged continuously in the circumferential direction. Note that the individual gear teeth of the sector gear 22e are not shown in the drawings. The rear link 22 also has an arc-shaped elongated hole 22f that is centered at the through-hole 22b and is located between the sector gear 22e and the through-hole 22b. The sector gear plate 22d is a drive input gear that can rotate around the rear pipe 16, which is the rotation axis, and meshes with a pinion 33 of the drive unit 30, which will be described later, to transmit the drive force from the drive unit 30 to the lifter mechanism 20.

[0025] Each side frame 14 is formed by pressing a metal plate or the like. The left side frame 14 has a base portion 14a whose thickness is oriented in the vehicle width direction and a flange portion 14b that protrudes from the periphery of the base portion 14a toward the inside of the seat. A front step portion 14c that protrudes toward the inside of the seat relative to the base portion 14a is formed near the front end of the side frame 14. A rear step portion 14d that protrudes toward the inside of the seat relative to the base portion 14a is formed behind the front step portion 14c. The flange portion 14b, the front step portion 14c, and the rear step portion 14d have shapes that protrude in the vehicle width direction relative to the base portion 14a, thereby increasing the cross-sectional strength of the side frame 14. The surfaces of the front step portion 14c and the rear step portion 14d facing the inside and outside of the seat are flat and serve as positioning references for each component assembled to the side frame 14.

[0026] 4, a support hole 14e is formed in the front step portion 14c, penetrating the front step portion 14c in the vehicle width direction. A connecting portion 21a of the front link 21 is rotatably supported by the support hole 14e.

[0027] As shown in Fig. 4, rear step portion 14d is formed with circular through-holes 14f and 14g, each of which penetrates in the vehicle width direction. Through-hole 14f is located near the rear end of rear step portion 14d, and through-hole 14g is disposed a predetermined distance forward from through-hole 14f. Rear step portion 14d is further formed with fastening hole 14h (see Fig. 10) located between through-hole 14f and through-hole 14g in the front-rear direction, and a pair of fastening holes 14i located forward of through-hole 14g.

[0028] The rear link 22 is disposed on the seat inner side of the side frame 14, and the rear pipe 16 is inserted through the through-hole 22b and the through-hole 14f. The rear pipe 16 is fixed to the through-hole 22b and rotatably supported by the through-hole 14f. As a result, the rear link 22 is connected to the side frame 14 so as to be rotatable about the rear pipe 16. In other words, the sector gear plate 22d is rotatably supported with the rear pipe 16 as the rotation axis.

[0029] The front portions of the pair of left and right side frames 14 are interlocked via front pipes 15 connected to the pair of left and right front links 21. The rear portions of the pair of left and right side frames 14 are also interlocked via rear pipes 16. As a result, the pair of left and right side frames 14 move integrally in the front-to-rear and up-and-down directions.

[0030] A reinforcing plate 25, which is a reinforcing member, is attached to the seat-inside surface of the rear step portion 14d of the side frame 14. As shown in FIGS. 9 and 10 , the reinforcing plate 25 is made of a metal plate material that is thicker in the vehicle width direction than the side frame 14. The reinforcing plate 25 is formed separately from the side frame 14 and then fixed to the side frame 14. In this embodiment, the reinforcing plate 25 is fixed to the side frame 14 by welding. The welding positions W (three positions) of the reinforcing plate 25 are shown in FIG. 8 . Note that it is also possible to weld positions other than the welding positions W, or to select a fixing method other than welding. Note that the reinforcing plate 25 may have the same thickness as the side frame 14 in the vehicle width direction, or may be thinner than the side frame 14. Furthermore, in this embodiment, the reinforcing plate 25 is made of metal and fixed to the side frame 14 by welding, but the reinforcing plate 25 may be made of resin and fixed to the side frame 14 by means other than welding, such as adhesive.

[0031] As shown in FIGS. 7 and 8, the reinforcing plate 25 has a shape that is elongated in the front-rear direction. The front end of the reinforcing plate 25 is located forward of the through-hole 14g and rearward of the fastening hole 14i. The rear end of the reinforcing plate 25 is located rearward of the fastening hole 14h and forward of the through-hole 14f. In other words, the reinforcing plate 25 is located in a range that overlaps with the through-hole 14g and the fastening hole 14h of the side frame 14. The reinforcing plate 25 is formed with a through-hole 25a that communicates with the through-hole 14g and a receiving hole (insertion portion) 25b that communicates with the fastening hole 14h, penetrating in the vehicle width direction (see FIGS. 4 and 10). As shown in FIG. 10, the through-hole 25a is a circular hole with approximately the same diameter as the through-hole 14g, and the centers of the through-hole 25a and the through-hole 14g are aligned. The receiving hole 25b is a circular hole having a larger diameter than the fastening hole 14h, and the centers of the receiving hole 25b and the fastening hole 14h are aligned.

[0032] 9 and 10, the reinforcing plate 25 is located between the side frame 14 and the rear link 22 in the vehicle width direction. In other words, the reinforcing plate 25 is arranged so as to fill the gap between the side frame 14 and the rear link 22 in the vehicle width direction. The reinforcing plate 25 and the rear link 22 are not in contact with each other in the vehicle width direction, and a gap is formed between them. The elongated hole 22f of the rear link 22 is located a predetermined distance inward from the receiving hole 25b of the reinforcing plate 25 on the seat inner side. As shown in FIG. 10, the width of the elongated hole 22f in the radial direction of the sector gear plate 22d is larger than the diameter (inner diameter) of the receiving hole 25b.

[0033] A drive unit 30, which is a drive source for the lifter mechanism 20, is attached to the side frame 14 on the seat outer side. The drive unit 30 has a motor 31, a gear housing 32, and a pinion 33. The pinion 33 is rotatable around a pinion shaft 33a extending in the vehicle width direction. The rotation of the output shaft of the motor 31 is reduced through a gear train (not shown) arranged in the gear housing 32 and transmitted to the pinion shaft 33a, causing the pinion 33 to rotate around the pinion shaft 33a. The pinion 33 protrudes from the gear housing 32 toward the seat inner side. A cylindrical pinion base 34 with a diameter larger than that of the teeth of the pinion 33 is provided at the base end of the pinion 33. The pinion base 34 is integrally formed as part of the pinion 33.

[0034] A seat plate 35 is provided on the surface of the gear housing 32 facing inward from the seat, and when attaching the drive unit 30 to the side frame 14, the seat plate 35 is brought into contact with the surface of the rear stepped portion 14d facing outward from the seat (see FIGS. 9 and 10). At this time, the pinion 33 is inserted into the through holes 14g and 25a from the outside of the seat toward the inside of the seat. When the drive unit 30 is moved until the seat plate 35 comes into contact with the rear stepped portion 14d, the pinion base 34 is positioned inside the through holes 14g and 25a, and the pinion 33 protrudes further inward from the side frame 14 and the reinforcing plate 25. Then, the pinion 33 reaches the same position as the sector gear plate 22d in the vehicle width direction, and the sector gear 22e and the pinion 33 mesh with each other.

[0035] The drive unit 30 is fixed to the side frame 14 using a support plate 40. As shown in FIGS. 4 and 5, the support plate 40 has a base portion 41, a pinion cover portion 42, and a rear extension portion 43.

[0036] The base plate portion 41 overlaps the seat inner surface of the rear step portion 14d. The base plate portion 41 is long in the front-rear direction, and the area where the base plate portion 41 overlaps the side frame 14 is from near the front end of the rear step portion 14d to near the pair of fastening holes 14i.

[0037] The pinion cover portion 42 is located behind the base plate portion 41 and has a shape that protrudes further inward from the seat than the base plate portion 41 and covers the pinion 33.

[0038] The rear extension 43 is located on the seat inner side of the base plate 41 in the vehicle width direction, and is located behind the pinion cover 42 in the front-to-rear direction, and covers a part of the rear link 22 (mainly the sector gear plate 22d) from the seat inner side. The rear extension 43 and the rear link 22 are not in contact with each other in the vehicle width direction, and there is a gap between them.

[0039] As shown in Fig. 4, a pair of fastening holes 41a penetrating in the vehicle width direction are formed in the base plate portion 41 at positions close to the pinion cover portion 42. The pair of fastening holes 41a are provided at positions corresponding to the pair of fastening holes 14i of the side frame 14 (aligned in the vehicle width direction). The pinion cover portion 42 is formed with a pinion support hole 42a penetrating in the vehicle width direction. The pinion support hole 42a is provided at a position corresponding to the through hole 14g of the side frame 14 and the through hole 25a of the reinforcing plate 25 (aligned in the vehicle width direction), and the center position of the pinion support hole 42a coincides with the center positions of the through hole 14g and the through hole 25a. The rear extension portion 43 is formed with a fitting hole 43a penetrating in the vehicle width direction. The fitting hole 43a is provided at a position corresponding to the fastening hole 14h of the side frame 14 and the receiving hole 25b of the reinforcing plate 25 (aligned in the vehicle width direction), and the center position of the fitting hole 43a coincides with the center positions of the fastening hole 14h and the receiving hole 25b.

[0040] The rear extension portion 43 is located more inward than the rear link 22, and the support plate 40 is attached to the side frame 14 on the inner side of the seat so as to cover the rear link 22 and the reinforcing plate 25. The tip of the pinion shaft 33a, which is part of the pinion 33, is inserted into the pinion support hole 42a. The tip of the pinion shaft 33a and the pinion support hole 42a are both circular, and the pinion shaft 33a is rotatably supported relative to the pinion support hole 42a.

[0041] In this state, the drive unit 30 and the support plate 40 are fastened to the side frame 14 using a pair of fixing screws 44 and one fixing screw 45. The fixing screws 44 and 45 each have a shaft portion that protrudes from a large-diameter head, and a male thread is formed on the outer circumferential surface of the shaft portion. The shaft portion of the fixing screw 45 is longer than the shaft portion of the fixing screw 44.

[0042] The shank of each fixing screw 44 protrudes toward the inside of the seat through a through-hole 35a (FIG. 4) formed in the seat plate 35. The shank of each fixing screw 44 is inserted from the outside of the seat toward the inside of the seat through the fastening holes 14i and 41a, and protrudes toward the inside of the seat from the support plate 40. A nut 46 is threaded onto the protruding portion of this fixing screw 44 (see FIGS. 2 and 5).

[0043] 9 and 10, the reinforcing plate 25 and the rear link 22 (sector gear plate 22d) are arranged between the rear step 14d of the side frame 14 and the rear extension 43 of the support plate 40 in the vehicle width direction. The rear step 14d and the rear extension 43 face each other with a gap that is equal to or greater than the sum of the thicknesses of the reinforcing plate 25 and the rear link 22. A collar 47 is attached to the support plate 40 to fill this gap in the vehicle width direction and fasten the rear step 14d and the rear extension 43 together (see FIGS. 9 and 10).

[0044] As shown in Figure 10, the collar 47 has a cylindrical shape extending in the vehicle width direction, and is formed with an internal through-hole 47a that penetrates in the vehicle width direction. An engaging step 47b with a smaller diameter than the main body of the collar 47 is formed at the end of the collar 47 on the seat inner side. The engaging step 47b is inserted into and engaged with the engaging hole 43a of the rear extension 43, and the collar 47 is fixed to the rear extension 43. Before assembling the cushion frame 13, the support plate 40 and the collar 47 are joined in advance, and the combined support plate 40 and collar 47 are prepared as a support member (support plate assembly). The collar 47 constitutes a vehicle width direction extending portion that is part of this support member.

[0045] The shaft of the fixing screw 45 protrudes toward the inside of the seat through a through hole 35b (see FIGS. 4 and 10) formed in the seat panel 35. The shaft of the fixing screw 45 is inserted from the outside of the seat toward the inside of the seat through the fastening hole 14h and the internal through hole 47a (including the area where the collar 47 is inserted into the fitting hole 43a), and protrudes from the support plate 40 toward the inside of the seat. A nut 48 is threaded onto the protruding portion of this fixing screw 45. The thickness of the rear extension portion 43 is set slightly larger than the amount of protrusion of the fitting step portion 47b in the vehicle width direction, so that when the fixing screw 45 and the nut 48 are threaded together, the nut 48 comes into contact mainly with the surface of the rear extension portion 43 on the inside of the seat. The outer surface of the rear extension 43 contacts one end of the collar 47 (around the base end of the mating step 47b), and the other end of the collar 47 contacts the rear step 14d, so that the rear extension 43 and the collar 47 are sandwiched between the nut 48 and the side frame 14.

[0046] When a predetermined tightening torque is applied to the fixing screws 44 and nuts 46, the seat plate 35, the side frame 14 (rear step portion 14d), and the base plate portion 41 of the support plate 40 are sandwiched between the head of the fixing screw 44 and the nut 46, and these are stacked and fixed in the vehicle width direction. When a predetermined tightening torque is applied to the fixing screws 45 and nuts 48, the seat plate 35, the side frame 14 (rear step portion 14d), the collar 47, and the rear extension portion 43 of the support plate 40 are sandwiched between the head of the fixing screw 45 and the nut 48, and these are stacked and fixed in the vehicle width direction. Because the collar 47 functions as a spacer in the vehicle width direction, the fastening force of the fixing screws 45 and nuts 48 does not act on the sector gear plate 22d and the reinforcing plate 25. In this manner, the drive unit 30 is fastened and fixed to the side frame 14.

[0047] 9 and 10, the collar 47 is inserted into the elongated hole 22f of the rear link 22. The width of the elongated hole 22f in the radial direction of the sector gear plate 22d is set to be at least a predetermined value larger than the diameter of the collar 47 so as to provide a sufficient gap between the collar 47 and the elongated hole 22f. The elongated hole 22f is an arc-shaped groove centered on the through-hole 22b (rear pipe 16), and allows the rear link 22 to rotate (swing) about the rear pipe 16 without interference from the collar 47 when the lifter mechanism 20 is in operation.

[0048] 10, the collar 47 is further inserted into the receiving hole 25b of the reinforcing plate 25. The diameter (inner diameter) of the receiving hole 25b is smaller than the width of the elongated hole 22f, but is set to have a predetermined gap or more between the collar 47 and the receiving hole 25b. In other words, the collar 47 is designed so that when the support plate 40 (rear extension portion 43) and the drive unit 30 (seat plate 35) are fixed to the side frame 14 with the fixing screw 45 and the nut 48, the outer peripheral surface of the collar 47 does not come into contact with the inner peripheral surface of the receiving hole 25b, and some degree of precision error (assembly error) between the reinforcing plate 25 and the support plate 40 can be absorbed.

[0049] 9 and 10 , the main components of the left-side frame structure are arranged, in order from the side closest to the side frame 14, on the seat inner side, which is one side of the side frame 14 in the vehicle width direction. The reinforcing plate 25, the rear link 22 (particularly the sector gear plate 22d) constituting the lifter mechanism 20, and the support plate 40 are fixed to the side frame 14 on the seat inner side. The rear extension 43 of the support plate 40 is located away from the side frame 14 on the seat inner side, with the sector gear plate 22d and the reinforcing plate 25 between them. A collar 47 extending from the rear extension 43 in the vehicle width direction (outside the seat) is brought into contact with the side frame 14, and the support plate 40 is fastened to the side frame 14 using a fixing screw 45 and a nut 48. The sector gear plate 22d is supported rotatably about the rear pipe 16 relative to the side frame 14 without contacting the support plate 40 or the reinforcing plate 25.

[0050] A drive unit 30 is disposed on the other side of the side frame 14 in the vehicle width direction, that is, on the outer side of the seat. The drive unit 30 is fastened to the side frame 14 using fixing screws 45 and nuts 48, in a manner that the drive unit 30 is fastened together with a support plate 40 (rear extension portion 43) on the inner side of the seat. This makes it possible to reduce the number of fixing screws 45 that serve as fixing members. Furthermore, since it is possible to reduce the number of holes provided in the side frame 14 for inserting the fixing screws 45, it is possible to prevent a decrease in the strength of the side frame 14.

[0051] As described above, by assembling the lifter mechanism 20 and the drive unit 30 to the side frame 14, the cushion frame 13 is provided with a lifter function. When the motor 31 is driven to rotate the pinion 33, the rear link 22 operates while changing the meshing position of the sector gear 22e with respect to the pinion 33, thereby changing the position of the rear pipe 16 relative to the connection portion 22a on the upper rail 18 (support bracket 19) side. Accordingly, the front link 21 also operates, changing the position of the connection portion 21b on the side frame 14 side relative to the connection portion 21a on the upper rail 18 (support bracket 19) side. As a result, the height position of the side frame 14 changes.

[0052] Unlike the left frame structure described above, the right frame structure does not have a drive unit 30 (see FIG. 1). Accordingly, for the rear link (not shown) that constitutes the lifter mechanism 20 in the right frame structure, a type that does not have a sector gear can be used.

[0053] Incidentally, when a vehicle equipped with the vehicle seat 10 is hit from behind by another vehicle or the like, the occupant seated in the vehicle seat 10 is pressed strongly against the seat cushion 11 and the seat back 12 due to inertia, and a rearward and downward load is applied to the frame structure of the vehicle seat 10. The force attempting to lower the vehicle seat 10 is received at the meshing portion between the pinion 33 and the sector gear 22e. If the countermeasure of this embodiment, which will be described later, is not implemented, when a strong load attempting to move the vehicle seat 10 rearward and downward is applied, meshing failure occurs between the pinion 33 and the sector gear 22e, and the teeth of the sector gear 22e or the pinion 33 may break due to inability to withstand the load.

[0054] As a result of research and experiments by the applicant, it was found that if an extremely strong rear-end collision load is applied without implementing the countermeasures of this embodiment, the rear portion of the side frame 14 will deform and extend rearward, increasing the axial distance between the pinion 33 and the sector gear plate 22d and reducing the amount of meshing between the pinion 33 and the sector gear 22e in the longitudinal direction. It was also found that an extremely strong rear-end collision load will cause either or both of the pinion 33 and the sector gear plate 22d to tilt in the vehicle width direction, causing the tooth flanks of the pinion 33 and the sector gear 22e to no longer face each other properly, and applying an irregular load that intersects with the vertical direction to the meshing point. It is assumed that these phenomena are the cause of the aforementioned poor meshing.

[0055] To prevent such problems, the frame structure of this embodiment improves the strength of the area around the gear mechanism as follows: First, a reinforcing plate 25 is attached to the rear region of the side frame 14, where the pinion 33 and sector gear plate 22d are located. Adding the thickness of the reinforcing plate 25 to the original thickness of the side frame 14 improves the cross-sectional strength, making the side frame 14 less likely to deform.

[0056] The reinforcing plate 25 is shaped to overlap the rear step portion 14d in the region between the rear pipe 16 (through hole 14f and through hole 22b), which is the rotation axis of the sector gear plate 22d, and the through hole 14g, which is the positional reference for the pinion 33. The thickness of the reinforcing plate 25 is greater than the thickness of the side frame 14. Therefore, the reinforcing plate 25 can effectively suppress deformation of the side frame 14 that would change the distance between the through hole 14f and the through hole 14g.

[0057] 7 to 10 , the reinforcing plate 25 has a first region 25c (first extending portion) extending toward the rear pipe 16 (rearward) and a second region 25d (second extending portion) extending away from the rear pipe 16 (forward), based on a through-hole 25a through which a pinion base 34, which is part of the pinion 33, passes. The first region 25c is longer from the through-hole 25a (longer in the front-rear direction) than the second region 25d, and the first region 25c overlaps the rear step portion 14d over nearly the entire area between the pinion 33 and the rear pipe 16 in the front-rear direction. In other words, the reinforcing plate 25 reinforces most of the area from the pinion 33 to the rear pipe 16 with the first region 25c. Furthermore, the reinforcing plate 25 has the second region 25d extending forward of the pinion 33, thereby improving the strength of the area around the pinion 33.

[0058] The receiving hole 25b of the reinforcing plate 25 is formed in the first region 25c. As described above, the diameter (inner diameter) of the receiving hole 25b is set to provide a predetermined gap or more with respect to the collar 47. When a strong rear-end collision load is applied to the vehicle seat 10 and the side frame 14 is slightly deformed, the gap between the collar 47 and the receiving hole 25b closes, and the outer peripheral surface of the collar 47 and the inner peripheral surface of the receiving hole 25b come into contact with each other. This contact provides a reinforcing effect between the reinforcing plate 25 and the support plate 40 that prevents further deformation of the side frame 14.

[0059] For example, if a load is applied in a direction that increases the axial distance between the pinion 33 and the sector gear 22e, the outer peripheral surface of the collar 47 abuts against the front portion of the inner peripheral surface of the receiving hole 25b, forming a portion that can withstand the load. Therefore, the reinforcing plate 25 has both the role of reinforcing the side frame 14 itself and the role of receiving the load on the support plate 40 and reducing the load on the side frame 14, and can effectively suppress an increase in the axial distance between the pinion 33 and the sector gear 22e (a decrease in the amount of meshing).

[0060] The reinforcing plate 25 prevents an increase in the distance between the axes of the pinion 33 and the sector gear 22e, and also serves to prevent both the sector gear plate 22d and the pinion 33 from tilting (leaning in the vehicle width direction).

[0061] First, by disposing the reinforcing plate 25 between the side frame 14 and the sector gear plate 22d in the vehicle width direction, the space between the side frame 14 and the sector gear plate 22d is filled. Therefore, when the sector gear plate 22d tries to tilt significantly toward the outside of the seat, the sector gear plate 22d abuts against the side surface of the reinforcing plate 25, and the reinforcing plate 25 can prevent the sector gear plate 22d from tilting further.

[0062] Furthermore, the abutment of the collar 47 with the receiving hole 25b and the side frame 14 suppresses the movement and tilt of the support plate 40 in the front-rear direction relative to the side frame 14 and the reinforcing plate 25. Because the support plate 40 supports the pinion shaft 33a via the pinion support hole 42a, suppressing the movement and tilt of the support plate 40 in the front-rear direction also contributes to suppressing the movement and tilt of the pinion 33 in the front-rear direction. In addition, the abutment of the inner circumferential surface of the through hole 25a with the outer circumferential surface of the pinion base 34 is also effective in suppressing the movement and tilt of the pinion 33 in the front-rear direction.

[0063] Because the gap between the collar 47 and the receiving hole 25b is set smaller than the gap between the collar 47 and the elongated hole 22f, the collar 47 and the receiving hole 25b come into contact with each other preferentially, and the collar 47 and the elongated hole 22f remain separated from each other. In other words, the load can be reliably transferred between the collar 47 and the reinforcing plate 25 without affecting the positional accuracy of the sector gear plate 22d or the operation of the rear link 22.

[0064] Due to the above-described configuration and action, the frame structure of this embodiment can suppress the relative positional change between the pinion 33 and the sector gear plate 22d when a rear-end collision load is input, and the load-bearing performance around the gear mechanism is significantly improved compared to existing frame structures.

[0065] Because the reinforcing plate 25 is attached only to a portion of the side frame 14 that requires high strength against a rear-end collision load, there is no need to increase the thickness of the entire side frame 14. This allows for a compact, lightweight structure without increasing the weight of the side frame 14, while still achieving improved strength of the frame structure. Furthermore, because a thick side frame 14 is not used, the side frame 14 is easy to process and material costs are low, thereby reducing manufacturing costs. The reinforcing plate 25 has a simple structure based on a flat plate shape that fits along the rear step portion 14d of the side frame 14, with through holes 25a and receiving holes 25b that penetrate in the plate thickness direction, and can be obtained at low cost.

[0066] The collar 47 serves both as a spacer for filling the gap between the rear extension 43 of the support plate 40 and the rear step 14d of the side frame 14 and fastening them together, and as a load transfer device between the support plate 40 and the reinforcing plate 25. This allows the simple configuration to contribute to improving the strength of the frame structure without complicating the structure of the support plate 40.

[0067] While the above description focuses on loads that increase the axial distance between the pinion 33 and the sector gear plate 22d, the frame structure of this embodiment is equally effective against loads that decrease the axial distance between the pinion 33 and the sector gear plate 22d. The reinforcing plate 25, which has the first region 25c positioned between the through holes 14g and 14f, has the effect of suppressing deformation of the side frame 14 in a direction that decreases the distance between the through holes 14g and 14f (i.e., decreases the axial distance between the pinion 33 and the sector gear plate 22d). In addition, the outer peripheral surface of the collar 47 abuts against the rear portion of the inner peripheral surface of the receiving hole 25b, making it possible to withstand loads that decrease the axial distance between the pinion 33 and the sector gear 22d.

[0068] The position of the receiving hole 25b, which is the insertion portion in the reinforcing plate 25, is set under the conditions that it can exert an effect of suppressing changes in the axial distance between the pinion 33 and the sector gear plate 22d, and that the periphery of the receiving hole 25b has a structure (area and thickness) that is sufficient to withstand the load from the collar 47. The first region 25c, which is located between the pinion 33 and the rear pipe 16 and is longer (i.e., has a larger area) than the second region 25d, satisfies these conditions, and therefore the receiving hole 25b is formed in the first region 25c.

[0069] As long as the above conditions are satisfied, there is a degree of freedom in determining the position where the receiving hole 25b is formed. For example, in this embodiment, because the welding position W is located near the rear end of the reinforcing plate 25, the receiving hole 25b is located at a position some distance forward from the welding position W (near the center of the first region 25c in the front-to-rear direction). However, if there are no restrictions such as the welding position W, the receiving hole 25b may be located further rearward (near the through hole 14f). By locating the load receiving point of the receiving hole 25b and the collar 47 closer to the rear and closer to the through hole 14f, it becomes easier to suppress deformation (elongation) of the side frame 14 in a direction that increases the axial distance between the pinion 33 and the sector gear plate 22d.

[0070] FIG. 8 shows an imaginary line P1 connecting the center of the pinion shaft 33a of the pinion 33 and the center of the rear pipe 16 as viewed from the side. The meshing position of the sector gear 22e with the pinion 33 is located approximately on the imaginary line P1. By setting the load receiving point of the receiving hole 25b and the collar 47 on or close to the imaginary line P1 as viewed from the side, it is possible to enhance the effect of preventing changes in the distance between the pinion 33 and the rear pipe 16 (i.e., changes in the center distance between the pinion 33 and the sector gear plate 22d). In this embodiment, the receiving hole 25b is located very close to the imaginary line P1, which satisfies this condition. As a modified example, the receiving hole 25b can be positioned even closer to the imaginary line P1 than in this embodiment, so that the receiving hole 25b overlaps with the imaginary line P1.

[0071] In this embodiment, a collar 47 through which the fixing screw 45 is inserted is used as the portion of the support plate 40 that is inserted into the receiving hole 25b of the reinforcing plate 25. As described above, the collar 47 serves multiple functions, which makes it possible to simplify the configuration of the support plate 40 while improving the strength of the frame structure. However, as a modified example different from this embodiment, it is also possible to use a portion other than the collar through which the fixing screw is inserted as part of the support member (support plate 40) that is inserted into the insertion portion (receiving hole 25b) of the reinforcing member (reinforcing plate 25).

[0072] The above embodiment illustrates a frame structure equipped with a lifter mechanism 20 for lifting and lowering a seat and a drive unit 30, but the present invention can also be applied to a frame structure equipped with a gear mechanism for purposes other than lifting and lowering a seat. Therefore, the drive input gear in the present invention may be a gear other than a sector gear for lifting and lowering a seat.

[0073] Furthermore, the embodiments of the present invention are not limited to the above-described embodiments and their modifications, and may be variously changed, substituted, or modified within the scope of the spirit of the technical idea of ​​the present invention. Furthermore, if the technical idea of ​​the present invention can be realized in a different way due to technological advances or other derived technologies, it may be implemented using that method. Therefore, the claims cover all embodiments that may fall within the scope of the technical idea of ​​the present invention. [Explanation of symbols]

[0074] 10 Vehicle seats 11 Seat cushion (seat part) 12 Seat back 13 Cushion Frame 14 Side frame (seat frame) 14c Front step 14d Rear step 14f through hole 14g through hole 14h Fastening hole 14i Fastening hole 15 Front pipe 16 Rear pipe (rotating shaft of drive input gear) 20 Lifter mechanism 21 Front link 22 Rear link 22b Through hole 22c Arm part 22d Sector gear plate (drive input gear) 22e Sector gear (drive input gear) 22f long hole 25 Reinforcement plate (reinforcement member) 25a through hole 25b Receiving hole (insertion part) 25c 1st area (1st extension part) 25d 2nd area (2nd extension part) 30 Drive Unit 31 Motor 32 Gear housing 33 Pinion 33a Pinion shaft (part of the pinion) 34 Pinion base (part of the pinion) 35 Seat plate 40 Support plate (support member) 42 Pinion cover part 42a Pinion support hole 43 Rear extension 43a Fitting hole 44 fixing screws 45 Fixing screw (fixing member) 46 Nut 47 Collar (part of support member, extension in vehicle width direction) 47a Internal through hole 47b Fitting step 48 Nut

Claims

1. a seat frame that constitutes a seat surface portion of the vehicle seat; a pinion rotatably attached to the seat frame and protruding from an outer side toward an inner side in a vehicle width direction; a drive input gear that is disposed inside the seat frame in a vehicle width direction, is rotatable about a rotation axis that is positioned differently from the pinion, and meshes with the pinion; a reinforcing member disposed between the seat frame and the drive input gear in the vehicle width direction and fixed to the seat frame; a support member that is disposed on an inner side of the seat frame in a vehicle width direction with the drive input gear and the reinforcing member interposed therebetween, supports a portion of the pinion, and is fixed to the seat frame; Equipped with a portion of the support member passes through an insertion portion provided in the reinforcing member and abuts against the seat frame; The reinforcing member is a through hole through which a portion of the pinion passes; a first extending portion extending from the through hole toward the rotation shaft of the drive input gear; a second extending portion extending from the through hole to a side opposite the rotation shaft of the drive input gear; and A frame structure for a vehicle seat, wherein the first extension portion has a greater length from the through hole than the second extension portion.

2. a fixing member that fixes the pinion to the seat frame, 2. The frame structure of claim 1, wherein the support member is also supported by the seat frame through the fixing member.

3. 3. The frame structure for a vehicle seat according to claim 1, wherein the insertion portion is provided in the first extension portion.

4. A seat frame that constitutes a seat surface portion of a vehicle seat; a pinion rotatably attached to the seat frame and protruding from an outer side toward an inner side in a vehicle width direction; a drive input gear that is disposed inside the seat frame in a vehicle width direction, is rotatable about a rotation axis that is positioned differently from the pinion, and meshes with the pinion; a reinforcing member disposed between the seat frame and the drive input gear in the vehicle width direction and fixed to the seat frame; a support member that is disposed on an inner side of the seat frame in a vehicle width direction with the drive input gear and the reinforcing member interposed therebetween, supports a portion of the pinion, and is fixed to the seat frame; Equipped with a portion of the support member passes through an insertion portion provided in the reinforcing member and abuts against the seat frame; a fixing member that fixes the pinion to the seat frame, the drive input gear has an arc-shaped slot centered on the rotation shaft, the portion of the support member is a vehicle width direction extending portion that is inserted through the elongated hole and the insertion portion and abuts against the seat frame, A frame structure for a vehicle seat, wherein a gap between the vehicle width direction extending portion and the insertion portion is smaller than a gap between the vehicle width direction extending portion and the elongated hole.

5. the fixing member is a screw, The frame structure of a vehicle seat according to claim 4, characterized in that the vehicle width direction extension portion is cylindrical, and the screw that fastens and fixes the seat frame and the support member is inserted into the interior of the vehicle width direction extension portion.

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