Vehicle seat and method for manufacturing vehicle seat

Abstract

To provide a configuration which can improve synchronism between both of reclining units without complicating coupling work.SOLUTION: A first reclining unit 21a and a second reclining unit 21b are arranged so that rotation centers of their shafts 24a and 24b are positioned on a predetermined rotation axis L, and their support parts 26 face each other along the rotation axis L. The support parts 26 are formed so that an end of a coupling member 22 is supported at an off-set position at a predetermined angle with a predetermined distance from the rotation center. In the coupling member 22, in the state along the rotation axis L, one end is welded and fixed in the state of being supported by the support part 26 of the shaft 24a in the first reclining unit 21a, and the other end is welded and fixed in the state of being supported by the support part 26 of the shaft 24b in the second reclining unit 21b.SELECTED DRAWING: Figure 11

Description

[Technical Field]

[0001] The present invention relates to a vehicle seat having a pair of reclining units that tilt a seat back relative to a seat cushion, and a method for manufacturing the same. [Background technology]

[0002] A conventional vehicle seat equipped with a pair of reclining units that tilt the seat back relative to the seat cushion is the vehicle seat disclosed in Patent Document 1. This vehicle seat is equipped with a right-side reclining unit and a left-side reclining unit that are configured in reverse, and a connecting rod (a long connecting member), and the hinge pin (shaft) of the right-side reclining unit and the hinge pin of the left-side reclining unit are connected by the connecting rod, so that the right-side reclining unit and the left-side reclining unit are synchronously locked off, etc. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2018-094990 Summary of the Invention [Problem to be solved by the invention]

[0004] In the process of connecting the shafts of the left and right reclining units to the long connecting member, each shaft is rotated to a predetermined rotation position (for example, a position rotated in the lock-off direction) and then welding or other work is performed to connect the components while maintaining the alignment of their rotation center axes. This is because connecting the shafts without aligning their rotation positions will result in misalignment of the lock-off timing of the left and right reclining units.

[0005] However, in the above-described work process of aligning the rotational positions of the shafts for welding, the equipment required is complicated, including jigs for aligning the rotational positions of each shaft, making it difficult to improve production takt time.

[0006] The present invention has been made to solve the above-mentioned problems, and its purpose is to provide a configuration that can improve the synchronization of both reclining units without making the connecting work complicated. [Means for solving the problem]

[0007] In order to achieve the above object, the invention of claim 1 described in the claims is as follows: a seat cushion and a seat back; one reclining unit and another reclining unit that control tilting of the seat back relative to the seat cushion; a long connecting member for connecting the one reclining unit and the other reclining unit so as to rotate synchronously; A vehicle seat comprising: The one reclining unit and the other reclining unit are a shaft and a locking member; a first plate attached to the seat cushion; a second plate attached to the seat back; Each equipped with The locking member is pushed and rotated by the rotating shaft, and the first plate and the second plate, which are in a relatively rotatable state, rotate relatively around the rotation center of the shaft in response to the rotation of the shaft, thereby tilting the seat back relative to the seat cushion, a rotation center of the shaft is located on a predetermined rotation axis, and support portions of the shaft that support the connecting member are arranged to face each other along the predetermined rotation axis; the support portion is formed so that an end of the connecting member is supported at a position offset by a predetermined angle and a predetermined distance from the rotation center, The connecting member is characterized in that one end is welded and fixed along the predetermined rotation axis while being supported by the support portion of the shaft in one of the reclining units, and the other end is welded and fixed along the predetermined rotation axis while being supported by the support portion of the shaft in the other reclining unit.

[0008] The invention of claim 2 is as follows: a seat cushion and a seat back; one reclining unit and another reclining unit that control tilting of the seat back relative to the seat cushion; a long connecting member for connecting the one reclining unit and the other reclining unit so as to rotate synchronously; A vehicle seat comprising: The one reclining unit and the other reclining unit are a shaft and a locking member; a first plate attached to the seat cushion; a second plate attached to the seat back; Each equipped with The locking member is pushed and rotated by the rotating shaft, and the first plate and the second plate, which are in a relatively rotatable state, rotate relatively around the rotation center of the shaft in response to the rotation of the shaft, thereby tilting the seat back relative to the seat cushion, the shaft of the one reclining unit is integrally molded with one end of the connecting member such that a rotation center of the shaft is located on a predetermined rotation axis, and the connecting member along the predetermined rotation axis is offset from the rotation center of the shaft by a predetermined angle and a predetermined distance; the shaft of the other reclining unit includes a support portion that supports the other end of the connecting member in a state where a rotation center of the shaft is positioned on the predetermined rotation axis and is offset from the rotation center of the shaft by the predetermined angle and the predetermined distance, The connecting member is characterized in that the other end portion is welded and fixed along the predetermined rotation axis in a state where it is supported by the support portion of the shaft of the other reclining unit.

[0009] The invention of claim 3 is as follows: a seat cushion and a seat back; one reclining unit and another reclining unit that control tilting of the seat back relative to the seat cushion; a long connecting member for connecting the one reclining unit and the other reclining unit so as to rotate synchronously; A method for manufacturing a vehicle seat comprising: The one reclining unit and the other reclining unit are a shaft and a locking member; a first plate attached to the seat cushion; a second plate attached to the seat back; Each equipped with The locking member is pushed and rotated by the rotating shaft, and the first plate and the second plate, which are in a relatively rotatable state, rotate relatively around the rotation center of the shaft in response to the rotation of the shaft, thereby tilting the seat back relative to the seat cushion, a support portion of the shaft that supports the connecting member is formed so that an end of the connecting member is supported at a position offset by a predetermined angle and a predetermined distance from the rotation center, a step of disposing the one reclining unit and the other reclining unit such that rotation centers of the respective shafts are positioned on a predetermined rotation axis and the respective support portions face each other along the predetermined rotation axis; a step of supporting the connecting member, which is aligned with the predetermined rotation axis, at one end by the support portion of the shaft of the one reclining unit and at the other end by the support portion of the shaft of the other reclining unit; a step of welding and fixing the one end and the other end to the support portion while pressing the connecting member against the support portion; The present invention is characterized by comprising:

[0010] The invention of claim 4 is as follows: a seat cushion and a seat back; one reclining unit and another reclining unit that control tilting of the seat back relative to the seat cushion; a long connecting member for connecting the one reclining unit and the other reclining unit so as to rotate synchronously; A method for manufacturing a vehicle seat comprising: The one reclining unit and the other reclining unit are a shaft and a locking member; a first plate attached to the seat cushion; a second plate attached to the seat back; Each equipped with The locking member is pushed and rotated by the rotating shaft, and the first plate and the second plate, which are in a relatively rotatable state, rotate relatively around the rotation center of the shaft in response to the rotation of the shaft, thereby tilting the seat back relative to the seat cushion, the shaft of the one reclining unit is integrally molded with one end of the connecting member such that a rotation center of the shaft is located on a predetermined rotation axis, and the connecting member along the predetermined rotation axis is offset from the rotation center of the shaft by a predetermined angle and a predetermined distance; a step of positioning the one reclining unit and the other reclining unit so that the rotation centers of the shafts are positioned on the predetermined rotation axis line and the other end of the connecting member, which is aligned with the predetermined rotation axis line, is supported by a support portion of the shaft of the other reclining unit; welding and fixing the other end portion to the support portion while pressing the connecting member against the support portion; The present invention is characterized by comprising: The symbols in parentheses above indicate the correspondence with the specific means described in the embodiments to be described later. [Effects of the Invention]

[0011] In the invention of claim 1, one reclining unit and the other reclining unit are arranged so that the rotation centers of their respective shafts are located on a predetermined rotation axis and the support portions that support the connecting members of the shafts face each other along the predetermined rotation axis. The support portions are formed so that the ends of the connecting members are supported at positions offset from the rotation center by a predetermined angle and a predetermined distance. The connecting members are welded and fixed along the predetermined rotation axis with one end supported by the support portion of the shaft of one reclining unit and the other end supported by the support portion of the shaft of the other reclining unit.

[0012] As a result, the connecting members are welded and fixed in place while supported by the support portions of the shafts at positions offset by a predetermined angle and a predetermined distance from the predetermined rotation axis. Since the support portions are arranged opposite each other along the predetermined rotation axis, the shafts are rotated to a position where they can push and rotate the locking member by pressing the unwelded connecting members, whose ends are supported by the support portions, against the support portions. Therefore, simply by welding the pressed ends of the connecting members to the support portions as described above, the rotational positions of the two shafts can be aligned by welding, thereby improving the synchronization of the two reclining units without making the connection process complicated.

[0013] In the invention of claim 2, the shaft of one reclining unit is integrally molded with one end of the connecting member so that the rotation center of the shaft is located on a predetermined rotation axis and the connecting member along the predetermined rotation axis is offset from the rotation center of the shaft by a predetermined angle and a predetermined distance. The shaft of the other reclining unit has a support part that supports the other end of the connecting member, whose rotation center is located on the predetermined rotation axis and is offset from the rotation center of the shaft by a predetermined angle and a predetermined distance. The connecting member is welded and fixed with its other end supported by the support part of the shaft of the other reclining unit along the predetermined rotation axis.

[0014] Even in this way, the other end of the connecting member pressed as described above can be welded and fixed to the support portion of the shaft in the other reclining unit so that the rotational positions of both shafts are aligned, thereby improving the synchronization of both reclining units without making the connecting work complicated.

[0015] In the invention of claim 3, one reclining unit and the other reclining unit are arranged so that the rotation center of each shaft is located on a predetermined rotation axis and the respective support parts that support the connecting members of the shafts face each other along the predetermined rotation axis, and the connecting member in a state aligned with the predetermined rotation axis is supported at one end by the support part of the shaft in one reclining unit and at the other end by the support part of the shaft in the other reclining unit, and with the connecting member pressed against the support parts, one end and the other end are welded and fixed to the support parts, respectively.

[0016] This allows the ends of the connecting member pressed as described above to be welded and fixed to the support part so that the rotational positions of both shafts are aligned, thereby improving the synchronization of the two reclining units without making the connecting work complicated.

[0017] In the invention of claim 4, the shaft of one reclining unit is integrally molded with one end of the connecting member so that the rotation center of the shaft is located on a predetermined rotation axis and the connecting member along the predetermined rotation axis is offset from the rotation center of the shaft by a predetermined angle and a predetermined distance. Then, one reclining unit and the other reclining unit are arranged so that the rotation centers of the respective shafts are located on the predetermined rotation axes and the connecting member along the predetermined rotation axis is supported at the other end by a support portion of the shaft of the other reclining unit, and the other end is welded to the support portion with the connecting member pressed against the support portion.

[0018] Even in this way, the other end of the connecting member pressed as described above can be welded and fixed to the support portion of the shaft in the other reclining unit so that the rotational positions of both shafts are aligned, thereby improving the synchronization of both reclining units without making the connecting work complicated. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a side view showing an outline of the configuration of a vehicle seat according to the present invention; [Figure 2] FIG. [Figure 3] FIG. [Figure 4] 4 is a view of the second reclining unit as seen from a cross section corresponding to line X1-X1 shown in FIG. 3. FIG. [Figure 5] FIG. 3 is a cross-sectional view of the first reclining unit. [Figure 6] 6 is a cross-sectional view taken along a line X2-X2 shown in FIG. 5. [Figure 7] 6 is a cross-sectional view taken along a line X3-X3 shown in FIG. 5. [Figure 8] FIG. 2 is a perspective view of a shaft of the first reclining unit. [Figure 9] 9(A) is a view of the shaft in FIG. 8 as seen from the support portion side, and FIG. 9(B) is a plan view of the shaft in FIG. [Figure 10] FIG. 10 is a perspective view of the shaft of the second reclining unit. [Figure 11] Figure 11(A) is an explanatory diagram illustrating the state before welding when the connecting member is not pressed against the support portion, and Figure 11(B) is an explanatory diagram illustrating the state when the connecting member is pressed against the support portion and welded. [Figure 12] FIG. 10 is a cross-sectional view of a reclining unit that is a main part of a vehicle seat according to a second embodiment. [Figure 13] FIG. 11 is a perspective view showing a shaft and a connecting member that are essential parts of a vehicle seat according to a third embodiment. BEST MODE FOR CARRYING OUT THE INVENTION

[0020] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a vehicle seat according to the present invention will now be described with reference to the drawings. As shown in FIG. 1, the vehicle seat 10 of the present invention mainly comprises a seat cushion 11, a seat back 12, and a reclining device 20, and a seat bracket (lower bracket) 11a is fixed to the seat cushion 11, and a seat back bracket (upper bracket) 12a is fixed to the seat back 12.

[0021] The lower bracket 11a and the upper bracket 12a are respectively fixed to the relative rotating portions of the pair of left and right round reclining units of the reclining device 20, and are connected to each other so as to be capable of rotating relative to each other. This makes it possible to adjust the tilt angle of the seat back 12 relative to the seat cushion 11.

[0022] As shown in FIGS. 1 to 3, reclining device 20 includes a pair of left and right round reclining units (hereinafter also referred to as first reclining unit 21a and second reclining unit 21b), a long connecting member 22 for connecting first reclining unit 21a and second reclining unit 21b so that they rotate synchronously, and a manual reclining operation lever 23. For convenience, reclining operation lever 23 is not shown in FIGS. 2 and 3. Furthermore, first reclining unit 21a can be an example of "one reclining unit," and second reclining unit 21b can be an example of "the other reclining unit."

[0023] Shaft 24a of first reclining unit 21a and shaft 24b of second reclining unit 21b are connected by connecting member 22 so as to rotate synchronously, and reclining operation lever 23 is attached to shaft 24a. Therefore, in response to operation of reclining operation lever 23, first reclining unit 21a and second reclining unit 21b operate synchronously.

[0024] Specifically, when the reclining operation lever 23 is pulled upward, the reclining device 20 enters an unlocked state, allowing adjustment of the tilt angle of the seat back 12. Here, the range of angle A shown in Fig. 1 when the seat back 12 is tilted backward is the tilt adjustment range in which the seat back 12 is locked at that angle position when the reclining operation lever 23 is released, and the range of angle B shown in Fig. 1 when the seat back 12 is tilted forward is the free rotation range corresponding to a lock-free state in which the unlocked state remains even when the reclining operation lever 23 is released. As can be seen from Fig. 1, the seat back 12 can be rotated from a forward-tilted position in which it contacts the seat cushion 11 to a backward-tilted position in which it is flat against the seat cushion 11.

[0025] Since the first reclining unit 21a and the second reclining unit 21b are basically symmetrical in shape, the first reclining unit 21a will be taken as an example for explanation. As shown in Figures 2, 3 and 5, the first reclining unit 21a is configured by overlapping an approximately circular base plate 30 and an approximately bowl-shaped gear plate 40 and assembling a cover bracket 50, so that the base plate 30 and the gear plate 40 are held so as to be able to rotate relative to each other and relative movement in the axial direction is suppressed.

[0026] A cavity (space) C is formed between the base plate 30 and the gear plate 40. As shown in Figures 5 to 7, this cavity C is provided with a total of four lock gears, namely, a pair of first lock gears 61 and a pair of second lock gears 62, a central cam 70, two biasing members 80, and a substantially disk-shaped cam lever 90, as well as other locking and unlocking components. For convenience, in Figures 6 and 7, only the area near the internal teeth 41 of the gear plate 40 is shown, and the cover bracket 50 is not shown.

[0027] The base plate 30 has a plurality of protrusions formed on its outer side, and is attached to the lower bracket 11a by engaging each of these protrusions with an engaging hole in the lower bracket 11a. The base plate 30 also has a guide surface formed on its side facing the gear plate 40 for guiding the lock gears 61, 62 in the radial direction. The base plate 30 can be an example of a "first plate" attached to the seat cushion 11.

[0028] Internal teeth 41 are formed around the entire inner peripheral surface of the gear plate 40. The gear plate 40 has a plurality of protrusions formed on its back surface (the surface on the other axial side), and is attached to the upper bracket 12a by engaging each of these protrusions with an engaging hole in the upper bracket 12a.

[0029] Furthermore, two arcuate stepped portions formed coaxially with the internal teeth 41 are arranged at 180° intervals on the inner peripheral surface of the gear plate 40. The arcuate stepped portions are intended to realize the above-mentioned lock-free state, and are formed so that the angular range in which a protrusion 61c (described later) of the first lock gear 61 abuts from the inner peripheral side corresponds to the above-mentioned free rotation range. The gear plate 40 can be an example of a "second plate" attached to the seat back 12.

[0030] As shown in Fig. 6, external teeth 61a, 62a that can mesh with the internal teeth 41 of the gear plate 40 are formed on the outer peripheries of both first lock gears 61 and both second lock gears 62. Each lock gear 61, 62 is assembled so as to be guided radially slidably using each guide surface of the base plate 30. Furthermore, protrusions 61b, 61c that are used to control the radial movement of the first lock gear 61 are formed on the gear plate 40 side of both first lock gears 61. Furthermore, protrusions 62b that are used to control the radial movement of the second lock gear 62 are formed on the gear plate 40 side of both second lock gears 62.

[0031] The movable guide 37 is formed in a wedge shape so that its width gradually narrows from one end to the other end, and is disposed so as to be slidable between the first lock gear 61 and the guide surface of the base plate 30. Each movable guide 37 is formed with an engagement hole 37a for engaging one end of a biasing member 80. By engaging one end of the biasing member 80 with the engagement hole 37a, the biasing member 80 biases each movable guide 37 inwardly of the base plate 30. As a result, the movable guide 37 is always wedged between the first lock gear 61 and the guide surface of the base plate 30, and the first lock gear 61, the guide surfaces of the base plate 30, and the movable guide 37 are tightly fitted together (fitted together), eliminating any gap in the rotation direction between each component. This eliminates backlash in the front-rear direction of the seat back 12.

[0032] A plate-shaped cam 70 having a through-hole 71 for engagement formed in its center is rotatably disposed in the center of the base plate 30. The cam 70 is formed so that when rotated in the unlocking direction, it abuts against the lock gears 61, 62 from the radially inner side, thereby causing the external teeth 61a, 62a to mesh with the internal teeth 41 of the gear plate 40. The cam 70 also has two engagement holes 73 with which the other ends of both biasing members 80 engage, and two cylindrical protrusions 74 for assembling the cam lever 90.

[0033] As shown in Fig. 7, the cam 70 is strongly urged in the locking direction (clockwise in Figs. 6 and 7) by engaging with each of the two urging members 80. As a result, the cam surface on the outer circumferential side of the cam 70 abuts against the inner end surfaces of the lock gears 61, 62, and the urging forces in the locking direction from the two urging members 80 strongly urge the lock gears 61, 62 radially outward.

[0034] The fitting portion 25a of the shaft 24a is inserted into the through-hole 71 of the cam 70, and by rotating this shaft 24a, the cam 70 can be rotated in the unlocking direction (counterclockwise in FIGS. 6 and 7) against the biasing forces of both biasing members 80. The cam 70 can be an example of a "locking member."

[0035] 7, the cam lever 90 is provided with a through hole 91 into which both protrusions 74 of the cam 70 are fitted, two cam holes 92, and two cam holes 93. The cam lever 90 is assembled to the gear plate 40 side of the cam 70 in a state in which both through holes 91 are fitted into both protrusions 74, respectively, the protrusion 61b is inserted into both cam holes 92, and the protrusion 62b is inserted into both cam holes 93, respectively.

[0036] As a result, when the cam lever 90 rotates in the unlocking direction together with the cam 70, the inner peripheral edge of the cam hole 92 abuts against the protrusion 61b of the first lock gear 61, and the inner peripheral edge of the cam hole 93 abuts against the protrusions 62b of both second lock gears 62. When the cam lever 90 further rotates in the unlocking direction, the protrusions 61b and 62b are urged radially inward by the inner peripheral edges of the cam holes 92 and 93, causing the lock gears 61 and 62 to move radially inward in conjunction with each other, thereby releasing the meshing between the external teeth 61a and 62a and the internal teeth 41 of the gear plate 40. In other words, the locked state and the unlocked state are controlled according to the rotational states of the cam 70 and the cam lever 90. The cam lever 90 may be an example of a "releasing member" that can release the meshing between the external teeth 61a and 62a and the internal teeth 41 by rotating the cam 70 against the biasing force of the biasing member.

[0037] 8 and 9, shaft 24a is formed to have fitting portion 25a and support portion 26. Fitting portion 25a is formed to fit with the rotation center aligned with through-hole 71 of cam 70, and its tip side is formed to be exposed to the outside from base plate 30 so that reclining operation lever 23 can be assembled thereto.

[0038] The support portion 26 is used to position and support the end of the connecting member 22 during welding, and is formed so as to be exposed to the outside from the gear plate 40 when the fitting portion 25a is fitted into the through-hole 71 of the cam 70. The support portion 26 has four support pieces arranged in a cross shape, and is formed so that adjacent pairs of long and short support pieces among the four support pieces clamp and support the end of the connecting member 22 (see FIG. 4). Each support piece is formed so that the end of the connecting member 22 is supported at a position offset by the same predetermined distance from the rotation center for each pair of long and short support pieces. Note that the support portion 26 having four support pieces can be an example of a "support portion" formed so that the end of the connecting member 22 is supported at a position offset by a predetermined angle and a predetermined distance from the rotation center.

[0039] Second reclining unit 21b is formed to have a shape that is basically the same as that of first reclining unit 21a, except for shaft 24b. As shown in Figure 10, shaft 24b is formed to have fitting portion 25b, whose axial length is shorter than fitting portion 25a by the amount that does not allow reclining operation lever 23 to be attached, and support portion 26 described above.

[0040] Connecting member 22 is formed from a long pipe member (cylindrical member), and both ends are welded to support portion 26 of shaft 24a exposed from gear plate 40 of first reclining unit 21a and support portion 26 of shaft 24b exposed from gear plate 40 of second reclining unit 21b, respectively. By welding connecting member 22 in this manner, shafts 24a and 24b are connected to rotate synchronously, thereby synchronizing the locking and unlocking timings of first reclining unit 21a and second reclining unit 21b.

[0041] With this configuration, in first reclining unit 21a and second reclining unit 21b, cam 70, which serves as a locking member, is pushed and rotated by rotating shafts 24a, 24b, and base plate 30 and gear plate 40, which are now in a relatively rotatable state, rotate relatively around the rotation centers of shafts 24a, 24b in response to the rotation of shafts 24a, 24b. As a result, seat back 12 tilts relative to seat cushion 11.

[0042] Here, the manufacturing process (step) of welding the connecting member 22 by utilizing both support portions 26 will be described with reference to FIGS. 11(A) and 11(B). First, first reclining unit 21a and second reclining unit 21b are assembled to the corresponding portions of lower bracket 11a and upper bracket 12a. At this time, first reclining unit 21a and second reclining unit 21b are arranged so that the rotation centers of respective shafts 24a, 24b are positioned on a predetermined rotation axis L (see FIG. 3) and the respective support portions 26 face each other along the rotation axis L (so that the respective support pieces on both sides are positioned symmetrically) (first step).

[0043] Next, as shown in Figure 11(A), the connecting member 22, which is aligned along the rotation axis L as described above, is supported at one end by the support portion 26 of the shaft 24a in the first reclining unit 21a, and at the other end by the support portion 26 of the shaft 24b in the second reclining unit 21b (second step).

[0044] Then, by pressing connecting member 22 against support portion 26 so as to rotate both shafts 24a, 24b in the locking direction (see the arrows in FIG. 11(B)), shaft 24a of first reclining unit 21a and shaft 24b of second reclining unit 21b rotate to the locking position and stop their rotation. With connecting member 22 pressed against support portion 26 in this manner until the rotation of both shafts 24a, 24b stops, one end and the other end of shaft 24a, 24b are welded and fixed to support portion 26 of each shaft (third step).

[0045] In this way, the connecting member 22 is pressed against both support portions 26 while both ends are welded, so that the welding work can be carried out without the need for jigs or the like for adjusting the rotational positions of the two shafts 24a, 24b for the purpose of synchronizing the first reclining unit 21a and the second reclining unit 21b.

[0046] As described above, in vehicle seat 10 according to this embodiment, first reclining unit 21a and second reclining unit 21b are disposed such that the rotation centers of respective shafts 24a, 24b are located on predetermined rotation axis L and respective support portions 26 face each other along rotation axis L. Support portion 26 is formed so that an end of connecting member 22 is supported at a position offset from the rotation center by a predetermined angle and a predetermined distance. Connecting member 22 is welded and fixed along rotation axis L with one end supported by support portion 26 of shaft 24a of first reclining unit 21a and the other end supported by support portion 26 of shaft 24b of second reclining unit 21b.

[0047] That is, the vehicle seat 10 according to this embodiment is a seat cushion and a seat back; one reclining unit and another reclining unit that control tilting of the seat back relative to the seat cushion; a long connecting member for connecting the one reclining unit and the other reclining unit so as to rotate synchronously; A vehicle seat comprising: The one reclining unit and the other reclining unit are a base plate attached to one of the seat cushion and the seat back; a gear plate attached to the other of the seat cushion and the seat back and assembled to be rotatable relative to the base plate, the gear plate having internal teeth; a lock gear assembled to the base plate so as to be guided slidably in a radial direction, the lock gear having external teeth meshable with the internal teeth; a cam that abuts against the lock gear from the inside in the radial direction when rotated in the unlocking direction, thereby causing the external teeth to mesh with the internal teeth; a shaft having a fitting portion that is fitted to the cam so that the center of rotation of the shaft coincides with the cam and a support portion that is exposed to the outside from the gear plate; a biasing member that biases the cam in a direction that causes the external teeth to mesh with the internal teeth; a release member that can release the meshing between the external teeth and the internal teeth by rotating the cam against the biasing force of the biasing member; wherein the rotation centers of the shafts are positioned on a predetermined rotation axis and the support portions are arranged to face each other along the predetermined rotation axis, the support portion is formed so that an end of the connecting member is supported at a position offset by a predetermined angle and a predetermined distance from the rotation center, The connecting member is characterized in that one end is welded and fixed along the predetermined rotation axis while being supported by the support portion of the shaft in one of the reclining units, and the other end is welded and fixed along the predetermined rotation axis while being supported by the support portion of the shaft in the other reclining unit.

[0048] As a result, connecting member 22 is welded and fixed in a state in which it is supported by support portions 26 of shafts 24a, 24b at a position offset by a predetermined angle and a predetermined distance from rotation axis L. Both support portions 26 are arranged opposite each other along rotation axis L, and therefore connecting member 22, whose both ends are supported by support portions 26 but not welded, can be pressed against support portions 26 in the locking direction to rotate shafts 24a, 24b to the locked rotation position and no longer rotate (a state in which shafts 24a, 24b have rotated to a position for pushing and rotating cam 70, which serves as a locking member). Therefore, simply by welding the pressed ends of connecting member 22 to support portions 26 as described above, the rotation positions of both shafts 24a, 24b can be aligned by welding, thereby improving the synchronization of both reclining units 21a, 21b without making the connection process complicated.

[0049] Furthermore, the manufacturing method for vehicle seat 10 according to this embodiment involves positioning first reclining unit 21a and second reclining unit 21b so that the rotation centers of shafts 24a, 24b are located on a predetermined rotation axis L and the respective support portions 26 face each other along rotation axis L, and connecting member 22, which is aligned with rotation axis L, is supported at one end by support portion 26 of shaft 24a in first reclining unit 21a and at the other end by support portion 26 of shaft 24b in second reclining unit 21b, and with connecting member 22 pressed against both support portions 26, one end and the other end are welded and fixed to support portions 26, respectively.

[0050] That is, the method for manufacturing the vehicle seat 10 according to this embodiment is as follows: a seat cushion and a seat back; one reclining unit and another reclining unit that control tilting of the seat back relative to the seat cushion; a long connecting member for connecting the one reclining unit and the other reclining unit so as to rotate synchronously; A method for manufacturing a vehicle seat comprising: The one reclining unit and the other reclining unit are a base plate attached to one of the seat cushion and the seat back; a gear plate attached to the other of the seat cushion and the seat back and assembled to be rotatable relative to the base plate, the gear plate having internal teeth; a lock gear assembled to the base plate so as to be guided slidably in a radial direction, the lock gear having external teeth meshable with the internal teeth; a cam that abuts against the lock gear from the inside in the radial direction when rotated in the unlocking direction, thereby causing the external teeth to mesh with the internal teeth; a shaft having a fitting portion that is fitted to the cam so that the center of rotation of the shaft coincides with the cam and a support portion that is exposed to the outside from the gear plate; a biasing member that biases the cam in a direction that causes the external teeth to mesh with the internal teeth; a release member that can release the meshing between the external teeth and the internal teeth by rotating the cam against the biasing force of the biasing member; Equipped with the support portion is formed so that an end of the connecting member is supported at a position offset by a predetermined angle and a predetermined distance from the rotation center, a step of disposing the one reclining unit and the other reclining unit such that rotation centers of the respective shafts are positioned on a predetermined rotation axis and the respective support portions face each other along the predetermined rotation axis; a step of supporting the connecting member, which is aligned with the predetermined rotation axis, at one end by the support portion of the shaft of the one reclining unit and at the other end by the support portion of the shaft of the other reclining unit; a step of welding and fixing the one end and the other end to the support portion while pressing the connecting member against the support portion; The present invention is characterized by comprising:

[0051] As a result, simply by welding the end of the connecting member 22 pressed as described above to the support portion 26, the rotational positions of both shafts 24a, 24b can be aligned by welding and fixing, thereby improving the synchronization of both reclining units 21a, 21b without making the connecting work complicated.

[0052] [Second embodiment] Next, a vehicle seat according to a second embodiment of the present invention will be described. The second embodiment differs from the first embodiment mainly in that the structures of both reclining units are modified. Therefore, components that are substantially the same as those in the first embodiment are given the same reference numerals and descriptions thereof will be omitted.

[0053] The first reclining unit (one reclining unit) 121a and the second reclining unit (the other reclining unit) 121b according to this embodiment operate using the driving force of a motor. As in the first embodiment, the rotation centers of the respective shafts are located on a predetermined rotation axis, and the respective support portions supporting the connecting members of the shafts are arranged to face each other along the predetermined rotation axis. The support portions are formed so that the ends of the connecting members are supported at positions offset from the rotation center by a predetermined angle and a predetermined distance. The connecting member is welded and fixed along the predetermined rotation axis, with one end supported by the support portion of the shaft of one reclining unit and the other end supported by the support portion of the shaft of the other reclining unit.

[0054] Specifically, the first reclining unit 121a is configured to include an external gear 130 attached to the lower bracket 11a, an internal gear 140 attached to the upper bracket 12a, a shaft 150, a U-shaped bushing 161 that functions as a locking member, a pair of wedge-shaped cams 162, a spring 163, a plate cover 170, a shaft cover (not shown), etc.

[0055] The external gear 130 has external teeth 131 formed on its outer circumferential surface, and a substantially cylindrical boss portion 132 formed in its center. The external gear 130 can be an example of a “first plate” attached to the seat cushion 11.

[0056] The internal gear 140 is configured to include a cylindrical portion having internal teeth 141 formed on its inner circumferential surface, and a side plate portion having a substantially cylindrical boss portion 142 formed in the center. The internal teeth 141 mesh eccentrically with the external teeth 131, and are therefore formed to have a greater number of teeth than the external teeth 131. A resin bearing 143 is fitted inside the boss portion 142 of the internal gear 140, and a U-shaped bushing 161 and a pair of wedge-shaped cams 162 are arranged between the inner circumferential surface of the boss portion 142 formed by this resin bearing 143 and the outer circumferential surface of the boss portion 132 of the external gear 130. The internal gear 140 can be an example of a "second plate" attached to the seat back 12.

[0057] The shaft 150 is configured to include the support portion 26 exposed to the outside in the positional relationship described above, a main body portion 151 having serrations formed on its inner surface and coaxially fitted to the inner circumferential surface of the boss portion 132 of the external gear 130, and a U-shaped portion 152 covering part of the outer circumferential surface of the boss portion 132 fitted with the main body portion 151. The U-shaped portion 152 is configured so that its both end faces in the rotation direction abut against both end faces in the rotation direction of a U-shaped bushing 161 incorporated into the inner circumferential side of the boss portion 142 of the internal gear 140, and pushes and rotates one wedge-shaped cam 162 when rotating in a rotation direction that tilts the seat back 12 forward (forward tilt rotation direction), and pushes and rotates the other wedge-shaped cam 162 when rotating in a rotation direction that tilts the seat back 12 backward (rearward tilt rotation direction).

[0058] The wedge-shaped cam 162 is formed in a wedge shape so that its radial thickness decreases toward the tip. The wedge-shaped cam 162 is interposed between the outer circumferential surface of the boss portion 132 of the external gear 130 and the U-shaped bushing 161, with its tip end face facing the end face of the U-shaped portion 152 in the rotation direction, and is arranged so that it is pressed against both the outer circumferential surface of the boss portion 132 and the U-shaped bushing 161 by being biased from the base end side by a spring 163.

[0059] When the pair of wedge-shaped cams 162 are pressed as described above, the internal gear 140 becomes eccentric with respect to the external gear 130, and some of the external teeth 131 mesh with the internal teeth 141. In this eccentric state, the external gear 130 rotates relative to the internal gear 140 as described below, causing the external gear 130 to revolve around the gear axis of the internal gear 140, changing the meshing position between the external teeth 131 and the internal teeth 141. Furthermore, when the pair of wedge-shaped cams 162 are pressed against both the outer circumferential surface of the boss portion 132 and the U-shaped bushing 161 by the spring 163 so as to move them away from each other, the pair of wedge-shaped cams 162 are interposed at predetermined interpositions, restricting the relative rotation between the external gear 130 and the internal gear 140.

[0060] The plate cover 170 is assembled to the internal gear 140 so as to suppress axial misalignment of the external gear 130 relative to the internal gear 140. The shaft cover is assembled to the internal gear 140 so as to suppress axial misalignment of the shaft 150 relative to the internal gear 140.

[0061] The first reclining unit 121a configured in this manner is welded and fixed to the lower bracket 11a using multiple protrusions formed on the side of the external gear 130, and is welded and fixed to the upper bracket 12a using multiple protrusions formed on the side of the internal gear 140.

[0062] The second reclining unit 121b is formed in a shape that is basically the symmetrical shape to the first reclining unit 121a.

[0063] Both ends of connecting member 22 are welded to support portion 26 of exposed shaft 150 of first reclining unit 121a and support portion 26 of exposed shaft 150 of second reclining unit 21b, respectively. By welding connecting member 22 in this manner, both shafts 150 are connected to rotate synchronously.

[0064] With this configuration, in the first reclining unit 121a and the second reclining unit 121b, when both shafts 150 do not rotate, the pair of wedge-shaped cams 162 restrict the relative rotation between the external gear 130 and the internal gear 140, thereby maintaining the tilt angle of the seat back 12 relative to the seat cushion 11.

[0065] When the motor is driven in response to a forward tilting operation and both shafts 150 rotate in the forward tilting rotation direction, one of the two wedge-shaped cams 162, which is opposite to the rotation direction, is pushed and rotated by the U-shaped portion 152 against the biasing force of the spring 163, thereby releasing the pressing state of the one wedge-shaped cam 162. As a result, the external gear 130, which rotates relative to the internal gear 140, rotates together with the shaft 150 in the forward tilting rotation direction, and the seat back 12 tilts forward relative to the seat cushion 11.

[0066] On the other hand, when the motor is driven in response to a rearward tilting operation and both shafts 150 rotate in the rearward tilting rotation direction, the other of the two wedge-shaped cams 162, which is opposite to the rotation direction, is pushed and rotated by the U-shaped portion 152 against the biasing force of the spring 163, thereby releasing the pressing state of the other wedge-shaped cam 162. As a result, the external gear 130, which rotates relative to the internal gear 140, rotates together with the shaft 150 in the rearward tilting rotation direction, and the seat back 12 tilts backward relative to the seat cushion 11.

[0067] In this embodiment, in the manufacturing process of welding connecting member 22 using both support portions 26, similarly to the first embodiment, by pressing connecting member 22, whose both ends are supported by support portions 26 but not welded, against support portions 26, shaft 150 rotates to a rotation position where U-shaped portion 152 presses wedge-shaped cam 162 and does not rotate further (a state in which shaft 150 has rotated to a position for pressing and rotating wedge-shaped cam 162, which serves as a locking member). Therefore, simply by welding the end portions of connecting member 22 pressed as described above to support portions 26, both shafts 150 can be welded and fixed so that their rotational positions are aligned, thereby improving the synchronization of both reclining units 121a, 121b without making the connection process complicated.

[0068] [Third embodiment] Next, a vehicle seat according to a third embodiment of the present invention will be described. The third embodiment differs from the first embodiment mainly in that the shaft of one reclining unit and the connecting member are integrally molded. Therefore, the same reference numerals are used to designate components that are essentially the same as those in the first embodiment, and descriptions thereof will be omitted.

[0069] In this embodiment, a connecting member 200 is employed instead of the shaft 24a and connecting member 22 of first reclining unit 21a in the first embodiment. As shown in Fig. 13, connecting member 200 includes a main body portion 201 corresponding to connecting member 22 and a shaft end portion 202 corresponding to shaft 24a, and is configured such that one end portion 201a of main body portion 201 and the end portion of shaft end portion 202 are integrally connected in the positional relationship between connecting member 22 and shaft 24a described above.

[0070] That is, the shaft end 202, which becomes the shaft in the first reclining unit 21a, is integrally molded with one end 201a of the main body 201 so that the rotation center of the shaft end 202 is located on a predetermined rotation axis L, and the main body 201 along the predetermined rotation axis L is offset from the rotation center of the shaft end 202 at a predetermined angle and a predetermined distance.

[0071] On the other hand, the second reclining unit 21b has the same configuration as the first embodiment, and the shaft 24b in the second reclining unit 21b is configured to have a support portion 26 that supports the other end 201b of the main body portion 201 in a state where the rotation center of the shaft 24b is located on a predetermined rotation axis L and is offset at a predetermined angle and a predetermined distance from the rotation center of the shaft 24b.

[0072] In this embodiment, in the manufacturing process (step) of welding the connecting member 200, the first reclining unit 21a and the second reclining unit 21b are positioned so that the rotation centers of the shaft end 202 assembled to the first reclining unit 21a and the shaft 24b of the second reclining unit 21b are located on a predetermined rotation axis L, and the main body 201, which is aligned with the predetermined rotation axis L, is supported at the other end 201b by the support portion 26 of the shaft 24b in the second reclining unit 21b (first step).

[0073] Next, in the same manner as in the first embodiment, the other end 201b of the main body 201 is welded and fixed to the support portion 26 of the shaft 24b while the main body 201 of the connecting member 200 is pressed against the support portion 26 (second step).

[0074] Even in this way, the other end 201b of the main body 201 pressed as described above can be welded and fixed to the support portion 26 of the shaft 24b in the second reclining unit 21b so that the rotational positions of both shafts are aligned, thereby improving the synchronization of both reclining units without making the connection work complicated.

[0075] Note that connecting member 200 is not limited to being configured to include main body 201 corresponding to connecting member 22 and shaft end 202 corresponding to shaft 24a of first reclining unit 21a and be fixed by welding to shaft 24b of second reclining unit 21b, but may also be configured to include main body 201 and a shaft end corresponding to shaft 24b of second reclining unit 21b and be fixed by welding to shaft 24a of first reclining unit 21a. Furthermore, the characteristic configuration of this embodiment in which the shaft of one reclining unit and the connecting member are integrally molded can be applied to other embodiments, etc.

[0076] [Other embodiments] The present invention is not limited to the above-described embodiments, and may be embodied as follows, for example. (1) The support portions 26 of both shafts 24a, 24b are not limited to being formed so as to position and support the ends of the connecting member 22 by using some of the four cross-shaped support pieces, but may also be formed so as to be capable of supporting the ends of the connecting member 22 and to support the ends of the connecting member 22 at positions offset at a predetermined angle and a predetermined distance from the center of rotation (rotation axis L).

[0077] (2) The long connecting member 22 is not limited to being formed of a pipe member having a circular cross section, but may be formed of, for example, a pipe member having a rectangular cross section, or may be formed of a solid member such as a connecting rod.

[0078] (3) The present invention is not limited to being applied to a vehicle seat 10 having a reclining device 20 in which a base plate 30 is attached to a lower bracket 11a and a gear plate 40 is attached to an upper bracket 12a, but may also be applied to a vehicle seat having a reclining device in which a base plate is attached to an upper bracket 12a and a gear plate is attached to a lower bracket 11a.

[0079] (4) In the first embodiment and the like, instead of reclining units 21a and 21b excluding shafts 24a and 24b, a reclining unit may be used that controls the engagement between the external teeth of a lock gear that is guided radially slidably relative to a base plate and the internal teeth of a gear plate by rotating a cam, such as the reclining unit disclosed in JP 2018-114095 A or the reclining unit disclosed in JP 2013-163474 A, which have the same basic configuration.

[0080] (5) In the above second embodiment, etc., instead of reclining units 121a, 121b excluding the shaft, a reclining unit may be adopted, such as the reclining unit disclosed in Patent Publication No. 2021-146833 or the reclining unit disclosed in Patent Publication No. 2021-83659, which have the same basic configuration, in which some of the external and internal teeth are meshed by eccentrically positioning two plates, restricting the relative rotation of the two plates when the shaft does not rotate, and controlling the two plates to a state in which they can rotate relative to each other by pushing and turning a cam by rotating the shaft. [Explanation of symbols]

[0081] 10...Vehicle seat 11...Seat cushion 12...Seat back 20...Reclining device 21a, 121a...First reclining unit (one of the reclining units) 21b, 121b...Second reclining unit (the other reclining unit) 22,200...Connecting member 24a, 24b, 150...shaft 25a, 25b…Mating part 26...Support part 30...Base plate (first plate) 40...Gear plate (second plate) 41...Inner teeth 61...1st lock gear 61a…external teeth 62...Second lock gear 62a...external teeth 70...Cam (locking component) 80... Urging member 90...Cam lever 130...External gear (first plate) 140...Internal gear (second plate) 162...Wedge-shaped cam (locking member) L…Rotation axis

Claims

1. a seat cushion and a seat back; one reclining unit and another reclining unit that control tilting of the seat back relative to the seat cushion; a long connecting member for connecting the one reclining unit and the other reclining unit so as to rotate synchronously; A vehicle seat comprising: The one reclining unit and the other reclining unit are a shaft and a locking member; a first plate attached to the seat cushion; a second plate attached to the seat back; Each equipped with The locking member is pushed and rotated by the rotating shaft, and the first plate and the second plate, which are in a relatively rotatable state, rotate relatively around the rotation center of the shaft in response to the rotation of the shaft, thereby tilting the seat back relative to the seat cushion, a rotation center of the shaft is located on a predetermined rotation axis, and support portions of the shaft that support the connecting member are arranged to face each other along the predetermined rotation axis; the support portion is formed so that an end of the connecting member is supported at a position offset by a predetermined angle and a predetermined distance from the rotation center, The vehicle seat is characterized in that one end of the connecting member is welded and fixed along the predetermined rotation axis while being supported by the support portion of the shaft in one of the reclining units, and the other end is welded and fixed along the predetermined rotation axis while being supported by the support portion of the shaft in the other reclining unit.

2. a seat cushion and a seat back; one reclining unit and another reclining unit that control tilting of the seat back relative to the seat cushion; a long connecting member for connecting the one reclining unit and the other reclining unit so as to rotate synchronously; A vehicle seat comprising: The one reclining unit and the other reclining unit are a shaft and a locking member; a first plate attached to the seat cushion; a second plate attached to the seat back; Each equipped with The locking member is pushed and rotated by the rotating shaft, and the first plate and the second plate, which are in a relatively rotatable state, rotate relatively around the rotation center of the shaft in response to the rotation of the shaft, thereby tilting the seat back relative to the seat cushion, the shaft of the one reclining unit is integrally molded with one end of the connecting member such that a rotation center of the shaft is located on a predetermined rotation axis, and the connecting member along the predetermined rotation axis is offset from the rotation center of the shaft by a predetermined angle and a predetermined distance; the shaft of the other reclining unit includes a support portion that supports the other end of the connecting member in a state where a rotation center of the shaft is positioned on the predetermined rotation axis and is offset from the rotation center of the shaft by the predetermined angle and the predetermined distance, The vehicle seat is characterized in that the connecting member is welded and fixed with the other end supported by the support portion of the shaft in the other reclining unit along the specified rotation axis.

3. a seat cushion and a seat back; one reclining unit and another reclining unit that control tilting of the seat back relative to the seat cushion; a long connecting member for connecting the one reclining unit and the other reclining unit so as to rotate synchronously; A method for manufacturing a vehicle seat comprising: The one reclining unit and the other reclining unit are a shaft and a locking member; a first plate attached to the seat cushion; a second plate attached to the seat back; Each equipped with The locking member is pushed and rotated by the rotating shaft, and the first plate and the second plate, which are in a relatively rotatable state, rotate relatively around the rotation center of the shaft in response to the rotation of the shaft, thereby tilting the seat back relative to the seat cushion, a support portion of the shaft that supports the connecting member is formed so that an end of the connecting member is supported at a position offset by a predetermined angle and a predetermined distance from the rotation center, a step of disposing the one reclining unit and the other reclining unit such that rotation centers of the respective shafts are positioned on a predetermined rotation axis and the respective support portions face each other along the predetermined rotation axis; a step of supporting the connecting member, which is aligned with the predetermined rotation axis, at one end by the support portion of the shaft of the one reclining unit and at the other end by the support portion of the shaft of the other reclining unit; a step of welding and fixing the one end and the other end to the support portion while pressing the connecting member against the support portion; A method for manufacturing a vehicle seat, comprising:

4. a seat cushion and a seat back; one reclining unit and another reclining unit that control tilting of the seat back relative to the seat cushion; a long connecting member for connecting the one reclining unit and the other reclining unit so as to rotate synchronously; A method for manufacturing a vehicle seat comprising: The one reclining unit and the other reclining unit are a shaft and a locking member; a first plate attached to the seat cushion; a second plate attached to the seat back; Each equipped with The locking member is pushed and rotated by the rotating shaft, and the first plate and the second plate, which are in a relatively rotatable state, rotate relatively around the rotation center of the shaft in response to the rotation of the shaft, thereby tilting the seat back relative to the seat cushion, the shaft of the one reclining unit is integrally molded with one end of the connecting member such that a rotation center of the shaft is located on a predetermined rotation axis, and the connecting member along the predetermined rotation axis is offset from the rotation center of the shaft by a predetermined angle and a predetermined distance; a step of positioning the one reclining unit and the other reclining unit so that the rotation centers of the shafts are positioned on the predetermined rotation axis line and the other end of the connecting member, which is aligned with the predetermined rotation axis line, is supported by a support portion of the shaft of the other reclining unit; welding and fixing the other end portion to the support portion while pressing the connecting member against the support portion; A method for manufacturing a vehicle seat, comprising:

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