headrest

Abstract

To provide a headrest which enables smooth movement of a movable unit.SOLUTION: A headrest 100 includes: a right stay 40R and a left stay 40L supported by a seat back of a vehicle seat; a support unit 30 supported by the right stay 40R and the left stay 40L; and a movable unit MV configured to be movable in a front-back direction of the vehicle seat with respect to the support unit 30. The support unit 30 includes a lock member 34 which may hold the movable unit MV at a plurality of positions in the front-back direction. The movable unit MV includes a center guide member 20 having an engagement surface part 220 in which a plurality of engagement surfaces 210 configured to engage with the lock member 34 are provided arranged side by side in the front-back direction, and wall portions 213 protruding toward the lock member 34 from both ends in a direction intersecting the front-back direction of the engagement surface part 220.SELECTED DRAWING: Figure 7

Description

Technical Field

[0001] The present invention relates to a headrest.

Background Art

[0002] Patent Document 1 and Patent Document 2 describe a headrest in which at least a part of an outer cover is configured to be movable in the front-rear direction of a seat.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] The technology of the present disclosure aims to smoothly move a movable unit of a headrest.

Means for Solving the Problems

[0005] A headrest according to one aspect of the technology of the present disclosure includes a stay supported by a seat back of a vehicle seat, a support unit supported by the stay, and a movable unit configured to be movable in the front-rear direction of the vehicle seat with respect to the support unit. The support unit has a locking member capable of holding the movable unit at a plurality of positions in the front-rear direction, and the movable unit has an engaging member including an engaging surface portion in which a plurality of engaging surfaces engaging with the locking member are arranged side by side in the front-rear direction, and wall portions protruding toward the locking member side from both ends in a direction intersecting the front-rear direction of the engaging surface portion.

Effects of the Invention

[0006] According to the technique of the present disclosure, it is possible to smoothly move the movable unit of the headrest. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is an external perspective view showing a schematic configuration of a headrest 100 according to an embodiment of the technology of the present disclosure. [Diagram 2] FIG. 2 is an exploded perspective view of the headrest 100 shown in FIG. [Diagram 3] FIG. 3 is an exploded perspective view of the headrest 100 shown in FIG. 1, seen from a different direction. [Figure 4] FIG. 4 is a perspective view showing the front cover 11, the operation buttons 13, and the central guide member 20 of the headrest 100, illustrating a state in which the central guide member 20 has not yet been attached to the front cover 11. As shown in FIG. [Diagram 5] FIG. 5 is a cross-sectional view showing a state in which the front portion of the front cover 11 in FIG. 4 is cut along a plane perpendicular to the front-rear direction. [Figure 6] FIG. 6 is an enlarged view from the rear showing a state in which the flange portion 22 is in the middle of engaging with the front cover 11. As shown in FIG. [Figure 7] FIG. 7 is a perspective view of the central guide member 20. As shown in FIG. [Figure 8] FIG. 8 is an exploded perspective view of the support unit 30. As shown in FIG. [Figure 9] FIG. 9 is a schematic diagram of a cross section passing through the axis of the right stay 40R and the left stay 40L of the support unit 30. As shown in FIG. [Figure 10] FIG. 10 is an exploded perspective view showing a state in which the right stay 40R and the left stay 40L are removed from the lock support member 35. As shown in FIG. [Figure 11] FIG. 11 is a schematic diagram of a cross section perpendicular to the up-down direction of the lock support member 35 shown in FIG. [Figure 12] FIG. 12 is a partial enlarged view of the headrest 100 from the rear side with the rear cover 12 removed. [Figure 13]FIG. 13 is a schematic cross-sectional view when the cutting plane of FIG. 9 is positioned between the rear wall portion 32 and the front wall portion 33. As shown in FIG. [Figure 14] FIG. 14 shows a cross section perpendicular to the up-down direction of the headrest 100, and is a schematic diagram of a cross section passing through the axis of the central guide member 20. As shown in FIG. [Figure 15] FIG. 15 is a diagram showing only the central guide member 20 and the engagement end portion 343, and is a diagram showing the cross section shown in FIG. 14 as viewed from above. [Figure 16] FIG. 16 is a diagram showing a state in which the movable unit MV has moved from the state shown in FIG. 15 to the foremost position. [Figure 17] FIG. 17 is a schematic diagram of a cross section perpendicular to the left-right direction of the headrest 100 and passing through the axis of the central guide member 20, showing a state in which the movable unit MV is in the initial position. [Figure 18] FIG. 18 is a schematic diagram of a cross section perpendicular to the left-right direction of the headrest 100 and passing through the axis of the central guide member 20, showing a state in which the movable unit MV is at the foremost position. [Figure 19] FIG. 19 is a diagram showing a state in which the operation button 13 is pressed in the right direction R in the state shown in FIG. [Figure 20] FIG. 20 is a diagram illustrating the operation button 13, the central guide member 20, and the support unit 30 of the headrest 100, as viewed from above with the movable unit MV in the initial position. [Figure 21] FIG. 21 is a diagram illustrating the operation button 13, the central guide member 20, and the support unit 30 of the headrest 100, as viewed from above with the movable unit MV in the foremost position. [Figure 22] FIG. 22 is a schematic diagram for explaining a preferable arrangement of the operation button 13 and the locking member 34, and is a diagram of the headrest 100 as viewed from the front side. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Fig. 1 is an external perspective view showing a schematic configuration of a headrest 100 according to an embodiment of the technology of the present disclosure. Fig. 2 is an exploded perspective view of the headrest 100 shown in Fig. 1. Fig. 3 is an exploded perspective view of the headrest 100 shown in Fig. 1, seen from another direction. The headrest 100 shown in Fig. 1 shows a state in which a pad serving as a cushioning member and a trim cover serving as a skin covering the pad have been removed.

[0009] In the following description, the front of an occupant sitting in a normal position on a vehicle seat equipped with the headrest 100 is referred to as the forward direction Fr, and the opposite direction of the forward direction Fr is referred to as the rearward direction Rr, and these are collectively referred to as the front-rear direction of the vehicle seat. In addition, the right side of the occupant when viewed from behind is referred to as the right direction R, and the left side of the occupant is referred to as the left direction L, and these are collectively referred to as the left-right direction of the vehicle seat. In addition, a direction perpendicular to the front-rear direction and the left-right direction, which is from the headrest 100 toward the seat cushion side, is referred to as the downward direction D, and the opposite direction of the downward direction D is referred to as the upward direction U, and these are collectively referred to as the up-down direction of the vehicle seat. The front-rear direction, the left-right direction, and the up-down direction are directions that intersect with each other. The left-right direction constitutes a first direction. The up-down direction constitutes a specific direction.

[0010] [Overall configuration] The headrest 100 is connected to the upper end of a seat back of a vehicle seat and supports the rear of the head of an occupant. The above-mentioned vehicles include automobiles, airplanes, trains, drones, ships, and the like. The headrest 100 includes a right stay 40R and a left stay 40L arranged at an interval in the left-right direction, a support unit 30 supported by the right stay 40R and the left stay 40L, a movable unit MV configured to be movable in the front-rear direction relative to the support unit 30, and a tension coil spring 50 as an elastic member connecting the support unit 30 and the movable unit MV. The right stay 40R and the left stay 40L are formed of, for example, a metal frame, and their lower ends are inserted into the upper end of the seat back of the vehicle seat and supported by the seat back. The right stay 40R constitutes a first stay, and the left stay 40L constitutes a second stay. The support unit 30 has a central guide hole portion 31C, a right guide hole portion 31R, and a left guide hole portion 31L penetrating in the front-rear direction, as will be described in detail later.

[0011] <Movable unit> The movable unit MV has a storage member 10 composed of a front cover 11 and a rear cover 12 arranged side by side in the front-to-rear direction to form a space for accommodating the support unit 30, an operation button 13 attached to the left side part of the front cover 11, and a central guide member 20 configured as a column extending from the front part of the front cover 11 in the rear direction Rr and configured to be detachable from the front cover 11.

[0012] The front cover 11 and the rear cover 12 are provided to sandwich the support unit 30 in the front-rear direction, with the front cover 11 being provided in front of the rear cover 12. The front cover 11 and the rear cover 12 are fixed together by fitting using mating claws. The front cover 11 and the rear cover 12 are made of, for example, a resin molded product. The front cover 11 constitutes a first housing member, the rear cover 12 constitutes a second housing member, the operation button 13 constitutes an operation section, and the central guide member 20 constitutes a first guide member or an engagement member.

[0013] The central guide member 20 is provided to extend in the rear direction Rr from the central portion in the up-down direction and the left-right direction of the front cover 11. A columnar right guide member 11R and a columnar left guide member 11L are further provided on the inner surface of the front cover 11 to extend toward the rear cover 12.

[0014] The right guide member 11R is provided on the right side and below the central guide member 20. The left guide member 11L is provided on the left side and below the central guide member 20. The right guide member 11R and the left guide member 11L are provided side by side in the left-right direction. As shown in FIG. 14, the right guide member 11R has an opening at its rear end face, and the opening fits into a connecting protrusion 12R provided on the inner surface of the rear cover 12. The left guide member 11L has an opening at its rear end face, and the opening fits into a connecting protrusion 12L provided on the inner surface of the rear cover 12. The right guide member 11R and the left guide member 11L constitute a second guide member.

[0015] The central guide member 20, the right guide member 11R, and the left guide member 11L have the function of guiding the movement of the movable unit MV when it moves in the front-rear direction. The central guide member 20 is slidably inserted into the central guide hole portion 31C of the support unit 30. The right guide member 11R is slidably inserted into the right guide hole portion 31R of the support unit 30. The left guide member 11L is slidably inserted into the left guide hole portion 31L of the support unit 30. The movement of the movable unit MV in the front-rear direction is guided by the sliding of the central guide member 20, the right guide member 11R, and the left guide member 11L with the central guide hole portion 31C, the right guide hole portion 31R, and the left guide hole portion 31L.

[0016] The right guide member 11R and the left guide member 11L are integrally molded with the front cover 11. On the other hand, the central guide member 20 is configured as a separate body from the front cover 11. It is preferable that the central guide member 20 is configured to have higher rigidity than the housing member 10. Since the central guide member 20 is configured as a separate body from the front cover 11, the optimal strength and material can be determined for the central guide member 20 and the front cover 11, respectively, and therefore the manufacturing cost of the headrest 100 can be reduced.

[0017] Fig. 4 is a perspective view showing the front cover 11, the operation buttons 13, and the central guide member 20 of the headrest 100, and shows a state in which the central guide member 20 is not yet attached to the front cover 11. Fig. 5 is a cross-sectional view showing a state in which the front portion of the front cover 11 in Fig. 4 is cut along a plane perpendicular to the front-rear direction. Note that the hatched areas in Fig. 5 are shown in a simplified manner, and recesses and ribs for improving strength provided in the front cover 11 are omitted from the illustration.

[0018] As shown in FIG. 4, the central guide member 20 has a rectangular prism-shaped main body portion 21 extending in the rear direction Rr, a flange portion 22 provided at the front end portion of the main body portion 21, and a protrusion portion 23 protruding in the downward direction D from approximately the center in the left-right direction of the lower end portion of the flange portion 22.

[0019] 5, a space SP for receiving the flange portion 22 of the central guide member 20 is provided in the front portion of the front cover 11, approximately in the center in the left-right and up-down directions. The front cover 11 is provided with a front cover wall portion 111 that is L-shaped when viewed in the front-rear direction and spaced apart from the rear of the front surface 11Fr, and the right and bottom edges of the front cover wall portion 111 are connected to the front surface 11Fr. The front cover 11 is also provided with a front cover wall portion 112 that is inverted L-shaped and is formed by mirror-inverting the front cover wall portion 111 from left to right and spaced apart from the rear of the front surface 11Fr, and the left and bottom edges of the front cover wall portion 112 are connected to the front surface 11Fr. Space SP is formed by the portion connecting the front cover wall portion 111 and the front surface 11Fr, the space surrounded by the front cover wall portion 111 and the front surface 11Fr, and the portion connecting the front cover wall portion 112 and the front surface 11Fr, the space surrounded by the front cover wall portion 112 and the front surface 11Fr.

[0020] When the central guide member 20 is attached to the front cover 11, the flange portion 22 is inserted into the space SP from the top to the bottom. As a result, a part of the flange portion 22 engages with the front cover 11, and the right end, left end, and bottom end are sandwiched between the front cover wall portions 111 and 112 and the front surface 11Fr, and movement in the front-rear direction is firmly restricted. As a result, the central guide member 20 can be stably supported by the front cover 11 even when the movable unit MV moves in the front-rear direction or when an impact occurs to the headrest 100 in the front-rear direction.

[0021] The portion of the front cover 11 that forms the space SP (the front cover wall portion 111, the front cover wall portion 112, the front surface 11Fr, and the side portions connecting them) constitute a support portion that supports the central guide member 20 while clamping a portion of the base end portion of the central guide member 20 on the front cover 11 side in the front-to-rear direction.

[0022] In this way, the central guide member 20 can be supported by the front cover 11 by partial engagement between the flange portion 22 and the support portion in the vertical direction, so that the central guide member 20 can be easily assembled to the front cover 11. The front cover 11 has a different thickness between the front portion and the left and right portions. Specifically, the front portion of the front cover 11 is thicker than the left and right portions. Since the front portion supporting the central guide member 20 is thicker than the other portions of the front cover 11, the support of the central guide member 20 can be maintained even when an external impact is applied to the front portion, and durability can be improved. The left and right portions of the front cover 11 constitute a first region, and the front portion of the front cover 11 constitutes a second region.

[0023] 6 is an enlarged view of the front cover 11 in the middle of the engagement of the flange portion 22 with the front cover 11, seen from the rear side. Between the front cover wall portion 111 and the front cover wall portion 112, a gap G is provided that constitutes an insertion portion into which the protrusion 23 of the central guide member 20 is inserted. A trapezoidal convex portion 113A that protrudes toward the front cover wall portion 112 is provided at the upper portion of the end of the front cover wall portion 111 that faces the front cover wall portion 112. A trapezoidal convex portion 113B that protrudes toward the front cover wall portion 111 is provided at the upper portion of the end of the front cover wall portion 112 that faces the front cover wall portion 111. The convex portion 113A and the convex portion 113B have an inclined surface 113C that has an inviting shape that assists the protrusion 23 to be inserted into the gap G. The gap G is configured such that its entrance becomes narrower toward the lower side due to the convex portion 113A and the convex portion 113B.

[0024] The protrusion 23 of the central guide member 20 has an engagement protrusion 23A protruding in the right direction R on the right side surface of the end portion on the flange portion 22 side, and an engagement protrusion 23B protruding in the left direction L on the left side surface of the end portion on the flange portion 22 side. When the flange portion 22 engages with the front cover 11, the engagement protrusion 23A and the engagement protrusion 23B come into contact with the inclined surface 113C and move in the downward direction D along the inclined surface 113C. After that, when the engagement protrusion 23A and the engagement protrusion 23B move downward over the inclined surface 113A and the inclined surface 113B, the engagement protrusion 23A engages with the inclined surface 113A and the engagement protrusion 23B engages with the inclined surface 113B, and the movement of the central guide member 20 in the vertical direction is firmly restricted. This engagement can give a clicking feeling, and the central guide member 20 can be efficiently assembled to the front cover 11. The engaging protrusions 23A and 23B form an engaged portion, and the protrusions 113A and 113B form an engaging portion that engages with the engaged portion. The central guide member 20 is positioned in the up-down direction by a rib 24 provided at the left end of the upper end of the flange portion 22 abutting against the front cover wall portion 112.

[0025] As shown in FIG. 5, a plurality of first protrusions 114, each of which has a curved linear surface extending in the vertical direction, are provided on the front surface (the surface facing the flange portion 22) of the front cover wall portion 111 and the front cover wall portion 112 in the illustrated example. The cross-sectional shape of the surface of the first protrusions 114 is, for example, arc-shaped. The flange portion 22 engages with the front cover 11 while sliding against the first protrusions 114. The first protrusions 114 reduce the resistance of the central guide member 20 when it slides, so that the central guide member 20 can be easily attached to the front cover 11. In addition, the first protrusions 114 can reduce the contact area between the front cover wall portion 111 and the front cover wall portion 112 and the flange portion 22, so that manufacturing variations of the front cover 11 and the central guide member 20 can be absorbed.

[0026] The movable unit MV is configured to be capable of being held at multiple positions in the front-rear direction by a locking member 34 (see FIG. 8) included in the support unit 30. The operation button 13 provided on the movable unit is an operation portion for releasing the hold of the movable unit MV by the locking member 34 of the support unit 30, and is configured to be capable of being pressed in the right direction R.

[0027] 4, the operation button 13 includes a columnar operation element 131 with a flange exposed to the outside of the housing member 10, a block-shaped contact portion 132 fixed to the right end portion of the operation element 131, and a spring 133 as a second biasing member that biases the contact portion 132 and the operation element 131 in the left direction L. By pressing the operation element 131 in the right direction R, the contact portion 132 can be moved in the right direction R.

[0028] 7 is a perspective view of the central guide member 20. The main body 21 of the central guide member 20 is provided, on its right side surface, with an engagement surface portion 220 in which a plurality of engagement surfaces 210 for engaging with the locking member 34 included in the support unit 30 are arranged in the front-rear direction, and a pair of wall portions 213 erected from both ends of the engagement surface portion 220 in the up-down direction toward the locking member 34 side (right direction R).

[0029] 7, the engagement surface portion 220 is configured with five engagement surfaces 210 lined up in the front-rear direction. The engagement surface 210 includes a vertical surface 211 that rises in the right direction R from the main body portion 21 and is substantially perpendicular to the front-rear direction, and an inclined surface 212 that rises obliquely in the right direction R and rear direction Rr from a base end edge of the vertical surface 211. The tip edge of the inclined surface 212 and the tip edge of the vertical surface 211 adjacent to the rear of the inclined surface 212 are connected by, for example, a curved surface.

[0030] The wall portion 213 is in the form of a plate that rises from the main body portion 21 in the right direction R and is substantially perpendicular to the up-down direction. The protruding length of the wall portion 213 from the main body portion 21 is equal to or greater than the protruding length of the engagement surface 210 from the main body portion 21. In other words, when viewed in the up-down direction, which is the direction in which the pair of walls 213 are aligned, the engagement surface portion 220 is configured to be entirely covered by the wall portion 213.

[0031] On the upper surface, left surface, and lower surface of the main body portion 21, there are provided a linear convex portion 21A with a curved surface in the front-rear direction and a linear convex portion 21B with a curved surface in the front-rear direction. As shown in FIG. 6, six convex portions 21A are provided at the four corners of the main body portion 21 when viewed in the front-rear direction. Two convex portions 21B are provided between the convex portions 21A on the upper surface, one convex portion 21B is provided between the convex portions 21A on the left surface, and one convex portion 21B is provided between the convex portions 21A on the lower surface. The convex portion 21A and the convex portion 21B each have an arc-shaped cross-sectional shape of the surface, and their curvatures are different from each other. Specifically, the curvature of the convex portion 21B is larger than the curvature of the convex portion 21A.

[0032] By providing the convex portion 21A and the convex portion 21B on the central guide member 20, the contact area between the central guide member 20 and the inner wall surface of the central guide hole portion 31C of the support unit 30 can be reduced, the sliding resistance can be lowered, and the movement of the movable unit MV can be performed smoothly. Also, due to the different curvatures of the convex portion 21A and the convex portion 21B, for example, the convex portion 21A with a smaller curvature can be made to function as a load transmission from the central guide member 20 to the support unit 30, and the convex portion 21B with a larger curvature can be made to function as a sliding portion between the central guide member 20 and the central guide hole portion 31C. In this way, it is possible to achieve both smooth movement of the central guide member 20 and efficient load transmission from the movable unit MV to the support unit 30 with a plurality of types of convex portions (convex portion 21A and convex portion 21B).

[0033] As shown in FIG. 4, on the upper surface, lower surface, right surface, and left surface of the right guide member 11R, there is provided a linear second convex portion 11Ra with a curved surface in the front-rear direction. On the upper surface, lower surface, right surface, and left surface of the left guide member 11L, there is provided a linear second convex portion 11La with a curved surface in the front-rear direction.

[0034] By providing the second convex portion 11Ra and the second convex portion 11La on the right guide member 11R and the left guide member 11L, the contact area between the right guide member 11R and the left guide member 11L and the inner wall surfaces of the right guide hole portion 31R and the left guide hole portion 31L can be reduced, thereby lowering the sliding resistance and allowing the movable unit MV to move smoothly.

[0035] <Support unit> 8 is an exploded perspective view of the support unit 30. The support unit 30 includes a lock member 34 capable of holding the movable unit MV at multiple positions in the front-rear direction, a lock support member 35 that supports the lock member 34 movably in the left-right direction, and a right stay 40R and a left stay 40L that support the lock support member 35.

[0036] (locking member) The locking member 34 comprises a first portion 341 having a rectangular prism shape extending in the left-right direction, a second portion 342 extending in the downward direction D from the right end of the first portion 341, an engagement end portion 343 extending in the left direction L from the lower end of the second portion 342, a flat portion 344 extending in the forward direction Fr and downward direction D from the left end of the first portion 341 and whose thickness direction coincides with the left-right direction, and a coil spring 345 as a first biasing member having one end fixed to the right surface of the flat portion 344.

[0037] The engagement end 343 is configured to be able to engage with the engagement surface portion 220 of the central guide member 20, and has a pointed tip whose width in the front-to-rear direction narrows toward the tip. The other end of the coil spring 345 is fixed to the left end surface of the front wall portion 33 described below, and biases the lock member 34 in the left direction L opposite to the pressing direction (right direction R) of the operation button 13.

[0038] The flat plate portion 344 has a contact portion 132 of the operation button 13 disposed on its left side. When the operator 131 of the operation button 13 is pressed in the right direction R, the contact portion 132 comes into contact with the flat plate portion 344 and presses it in the right direction R. As a result, the locking member 34 moves in the right direction R. When the operation button 13 is released from the pressure, the locking member 34 moves in the left direction L due to the biasing force of the coil spring 345, and returns to its original initial position. The flat plate portion 344 constitutes a contact portion configured to be able to come into contact with the contact portion 132 of the operation button 13.

[0039] A plate-shaped locking piece 341A whose thickness direction coincides with the vertical direction is provided to protrude from the front surface of the first portion 341. A plate-shaped locking piece 342A whose thickness direction coincides with the vertical direction is provided to protrude from the front surface of the second portion 342.

[0040] (Lock support member) FIG. 9 is a schematic diagram of a cross section passing through the axis of the right stay 40R and the left stay 40L of the support unit 30. FIG. 10 is an exploded perspective view showing a state in which the right stay 40R and the left stay 40L are removed from the lock support member 35. FIG. 11 is a schematic diagram of a cross section perpendicular to the vertical direction of the lock support member 35 shown in FIG. 10. FIG. 12 is a partially enlarged view of the headrest 100 from the rear side in a state in which the rear cover 12 is removed. FIG. 13 is a schematic cross section when the cutting plane in FIG. 9 is located between the rear wall portion 32 and the front wall portion 33. FIG. 14 is a schematic diagram of a cross section perpendicular to the vertical direction of the headrest 100, passing through the axis of the central guide member 20. The hatched areas in FIG. 9, FIG. 11, FIG. 13, and FIG. 14 are shown in a simplified manner as in FIG. 5.

[0041] As shown in FIG. 8, the lock support member 35 includes a base 31 having a generally rectangular parallelepiped shape extending in the left-right direction, a plate-shaped rear wall portion 32 extending upward in the U direction from the rear end of the base 31 and having a thickness direction that coincides with the front-to-rear direction, and a front wall portion 33 extending upward in the U direction from the front end of the base 31.

[0042] As shown in Fig. 9 and Fig. 13, the base 31 is provided with three holes penetrating in the front-rear direction. Specifically, the base 31 is provided with a central guide hole 31C through which the main body 21 of the central guide member 20 is slidably inserted to guide the movement of the movable unit MV in the front-rear direction, a right guide hole 31R through which the right guide member 11R is slidably inserted to guide the movement of the movable unit MV in the front-rear direction, and a left guide hole 31L through which the left guide member 11L is slidably inserted to guide the movement of the movable unit MV in the front-rear direction. As shown in Fig. 12, the convex portion 21A and the convex portion 21B of the central guide member 20 slide against the inner wall surface of the central guide hole 31C. The central guide hole 31C constitutes a first guide hole, and the right guide hole 31R and the left guide hole 31L constitute a second guide hole.

[0043] As shown in FIG. 9, the base 31 and the rear wall 32 are provided with a first insertion hole 32R through which the right stay 40R is inserted and a second insertion hole 32L through which the left stay 40L is inserted. The first insertion hole 32R is provided with a dividing wall 32Ra at the end opposite to the seat back side, i.e., at the upper end. The second insertion hole 32L is provided with a dividing wall 32La at the upper end, which divides the inside in the radial direction. The dividing wall 32Ra divides the upper end of the first insertion hole 32R into two in the left-right direction. The dividing wall 32La divides the upper end of the second insertion hole 32L into two in the left-right direction.

[0044] As shown in Fig. 10, the right stay 40R is shaped like a pipe and has notches 40Rb on the front and rear surfaces of its upper end. The left stay 40L is shaped like a pipe and has notches 40Lb on the front and rear surfaces of its upper end. The notches 40Rb fit into the divided wall portion 32Ra, and the notches 40Lb fit into the divided wall portion 32La, so that the lock support member 35 is supported by the right stay 40R and the left stay 40L. The lock support member 35 is restricted from rotating around an axis extending in the vertical direction by the divided wall portion 32Ra and the divided wall portion 32La.

[0045] In this way, the right stay 40R and the left stay 40L can be fixed individually to the lock support member 35 by fitting the dividing wall portion 32Ra and the dividing wall portion 32La with the notches 40Rb and 40Lb. Therefore, the position between the two stays can be maintained by utilizing the rigidity of the lock support member 35 without connecting the upper ends of the right stay 40R and the left stay 40L with each other using a separate member. As a result, welding work for connecting the right stay 40R and the left stay 40L is not necessary, and the manufacturing cost of the headrest 100 can be reduced. In addition, even if the intervals between the right stay 40R and the left stay 40L are different, the parts of the stays can be shared, and the manufacturing cost of the headrest 100 can be reduced.

[0046] As shown in Figures 9 and 10, a recess 40Lc extending in the front-rear direction is provided on the right side surface near the upper end of the left stay 40L. A recess 40Rc extending in the front-rear direction is provided on the left side surface near the upper end of the right stay 40R. As shown in Figure 10, an L-shaped pin 32A made of, for example, metal is provided in the rear wall 32 at a position corresponding to the recess 40Lc and the recess 40Rc, and is inserted into the recess 40Lc and the recess 40Rc. One end of the pin 32A is held by a holding portion 32B provided on the rear surface of the rear wall 32, and the other end is inserted into the recess 40Lc and the recess 40Rc.

[0047] By inserting the pin 32A into the recesses 40Lc and 40Rc, the movement of the right stay 40R and the left stay 40L in the downward direction D relative to the lock support member 35 is restricted, thereby preventing the lock support member 35 from coming off the right stay 40R and the left stay 40L. The pin 32A is one form of a restricting member that restricts the movement of the right stay 40R and the left stay 40L in the axial direction.

[0048] As shown in Fig. 10, a plurality of ribs (two ribs, rib 32F and rib 32G in the illustrated example) extending in the left-right direction are provided on the rear surface of the rear wall portion 32 between the right stay 40R and the left stay 40L when viewed in the front-rear direction. As shown in Fig. 11, the rib 32G is provided adjacent in the left-right direction to a portion of the pin 32A inserted into the recess 40Rc and a portion of the pin 32A inserted into the recess 40Lc. The rib 32G is configured to be wider in the up-down direction than the rib 32F.

[0049] In this way, by making the width of the rib 32G wider, when a rotational force about the axis extending in the vertical direction acts on the lock support member 35, the load can be transmitted in the order of the rib 32G, the pin 32A, the right stay 40R, and the left stay 40L. By making the width of the rib 32G wider, durability can be ensured.

[0050] As shown in Fig. 12, a part of the inner wall surface of the central guide hole portion 31C of the base 31 is configured to be elastically deformable. In the example of Fig. 12, the inner wall surface of the central guide hole portion 31C includes an upper surface 32SU and a lower surface 32SD arranged opposite to each other in the vertical direction, and a right surface 32SR and a left surface 32SL arranged opposite to each other in the horizontal direction. In this embodiment, only the lower surface 32SD of the upper surface 32SU and the lower surface 32SD is configured to be elastically deformable, and only the left surface 32SL of the right surface 32SR and the left surface 32SL is configured to be elastically deformable. The upper surface 32SU and the lower surface 32SD constitute a first surface, and the right surface 32SR and the left surface 32SL constitute a second surface.

[0051] The base 31 is provided with a through hole 322 penetrating in the front-rear direction next to the lower side of the lower surface 32SD. Due to the presence of this through hole 322, the lower surface 32SD is structured to bend toward the through hole 322. The base 31 is provided with a through hole 321 penetrating in the front-rear direction next to the left side of the left surface 32SL. Due to the presence of this through hole 321, the left surface 32SL is structured to bend toward the through hole 321.

[0052] In this way, the left surface 32SL and the bottom surface 32SD are configured to be elastically deformable, so that the operation load when moving the central guide member 20 relative to the support unit 30 can be reduced, allowing for smooth movement. Also, rattling of the central guide member 20 during movement can be suppressed. Moreover, the right surface 32SR opposite the left surface 32SL is configured to be non-elastically deformable, so that movement of the central guide member 20 in the left-right direction can be suppressed. Also, the right surface 32SR can efficiently release the load applied to the movable unit MV to the base 31.

[0053] Moreover, since the upper surface 32SU opposite the lower surface 32SD is configured to be non-deformable, it is possible to suppress vertical movement of the central guide member 20. In addition, the load applied to the movable unit MV can be efficiently released to the base 31 by the upper surface 32SU.

[0054] 13, an opening 32H for receiving an engagement end 343 of the locking member 34 is provided between the rear wall 32 and the front wall 33 in the left-right direction in a side wall surface on the right side of the central guide hole 31C (the side wall surface facing the engagement surface 220 of the central guide member 20). The opening 32H is provided at a position facing the engagement surface 220 of the central guide member 20 inserted into the central guide hole 31C. A recess 320 connecting the opening 32H and the right guide hole 31R is provided in the base 31 to the right of the central guide hole 31C in the region between the rear wall 32 and the front wall 33 when viewed in the up-down direction.

[0055] At least one (two in the example of FIG. 13) linear convex portion 32D with a curved surface is provided on the upper portion 32U of the central guide hole portion 31C of the base 31, extending in the left-right direction. The cross-sectional shape of the surface of the convex portion 32D is, for example, an arc shape. The first portion 341 of the locking member 34 is disposed on this upper portion 32U and is in sliding contact with the convex portion 32D.

[0056] The second portion 342 and the engagement end 343 of the locking member 34 are disposed in the recess 320. When the operation button 13 is not pressed, the engagement end 343 is held in a state in which it has entered the central guide hole 31C from the opening 32H by the biasing force of the coil spring 345. The engagement surface portion 220 is disposed to face the opening 32H. Therefore, as shown in FIG. 14, the engagement end 343 having entered the central guide hole 31C from the opening 32H is configured to be able to engage with any of the engagement surfaces 210 of the engagement surface portion 220.

[0057] 14, a tip portion of the engagement end 343 of the locking member 34 is shaped to mesh with each engagement surface 210 of the engagement surface portion 220. The engagement surface portion 220 and the engagement end 343 form a so-called ratchet mechanism. Although details will be described later, this ratchet mechanism allows the movable unit MV to be manually moved in the forward direction Fr without operating the operation button 13. On the other hand, when moving the movable unit MV in the rearward direction Rr, it is necessary to operate the operation button 13.

[0058] 13, first elastic portions 33A that are elastically displaceable in the front-rear direction are provided on the front wall 33 at a distance from each other in the left-right direction on a surface facing the locking member 34. The first elastic portions 33A are housed in through holes that penetrate the front wall 33 in the front-rear direction and are plate-shaped extending downward from the upper side of the through hole. The first elastic portions 33A have elasticity such that the surface facing the locking member 34 protrudes slightly rearward from the rear end surface of the front wall 33 in a steady state, and are configured to be able to abut against a first portion 341 of the locking member 34.

[0059] When the first elastic portion 33A and the first portion 341 come into contact with each other, the first portion 341 is sandwiched between the rear wall portion 32 and the front wall portion 33 in the front-rear direction, and is therefore firmly supported by the lock support member 35. Even if there is manufacturing variation between the lock support member 35 and the lock member 34, this can be absorbed by the deformation of the first elastic portion 33A. When the operation button 13 is pressed and the lock member 34 moves in the left-right direction, the deformation of the first elastic portion 33A can prevent this movement from being hindered. When the lock member 34 moves in the left-right direction, the protrusion 32D can reduce the sliding resistance between the lock member 34 and the lock support member 35. This allows the lock member 34 to move smoothly. Furthermore, by providing a plurality of protrusions 32D, dust can be guided between the protrusions 32D, and an increase in sliding resistance due to dust can be suppressed.

[0060] Second elastic parts 33B that are elastically displaceable in the vertical direction are further provided at a distance in the vertical direction on the front wall part 33. The second elastic parts 33B are accommodated in through holes that penetrate the front wall part 33 in the front-rear direction, and are configured as claws that are L-shaped when viewed in the front-rear direction and extend in the downward direction D and leftward direction L from the upper side of the through hole.

[0061] The locking piece 341A and the locking piece 342A of the locking member 34 are inserted into the gap between the second elastic part 33B and the base 31. The second elastic part 33B has an elasticity that urges the locking piece 341A and the locking piece 342A downward in a steady state. The locking member 34 is in a state in which the locking piece 341A and the locking piece 342A are sandwiched between the second elastic part 33B and the base 31 in the vertical direction. Therefore, the locking member 34 is stably supported by the lock support member 35 in the vertical direction as well. In addition, even if there is manufacturing variation between the lock support member 35 and the locking member 34, this can be absorbed by the deformation of the second elastic part 33B. In addition, when the locking member 34 moves in the left-right direction, the deformation of the second elastic part 33B can prevent this movement from being hindered.

[0062] As shown in Fig. 8, at least one (four in the example of Fig. 8) linear protrusion 32E with a curved surface is provided on the front surface of rear wall 32 at a position facing first portion 341 of locking member 34, extending in the vertical direction. Protrusion 32E has a cross-sectional surface shape that is, for example, arc-shaped. First portion 341 of locking member 34 comes into sliding contact with protrusion 32E.

[0063] When the locking member 34 moves in the left-right direction, the protrusions 32E can reduce the sliding resistance between the locking member 34 and the lock support member 35. This allows the locking member 34 to move smoothly. Furthermore, by providing a plurality of protrusions 32E, dust can be guided between the protrusions 32E, and an increase in sliding resistance due to dust can be suppressed. Furthermore, even if there is manufacturing variation between the lock support member 35 and the locking member 34, this can be absorbed.

[0064] 10, a protrusion 31A extending in the rear direction Rr is provided at the center in the left-right direction at the lower end of the rear surface of the base 31. One end of a tension coil spring 50, which is one type of elastic member, is fixed to the protrusion 31A. The other end of the tension coil spring 50 is fixed to the protrusion 23 of the central guide member 20. The tension coil spring 50 has a function of biasing the protrusion 23 in a direction approaching the support unit 30.

[0065] Fig. 15 is a diagram showing only the central guide member 20 and the engagement end 343, and is a diagram showing the cross section shown in Fig. 14 as viewed from above. In the headrest 100, as shown in Figs. 14 and 15, a state in which the engagement end 343 is engaged with the engagement surface 210 located closest to the front cover 11 is set as the initial position of the movable unit MV.

[0066] When the movable unit MV is moved in the forward direction Fr from the state shown in FIG. 15, the central guide member 20 moves in the forward direction Fr, and the engagement end 343 engages with the engagement surface 210 located second closest to the front cover 11, and the position of the movable unit MV is held in a state where it has moved one step in the forward direction Fr. When the movable unit MV is further moved in the forward direction Fr from this state, the engagement surface 210 engaging with the engagement end 343 moves forward in sequence. Then, as shown in FIG. 16, when the engagement end 343 engages with the engagement surface 210 located closest to the rear cover 12, the movable unit MV is configured to be unable to move further in the forward direction Fr. As shown in FIG. 16, the state where the engagement end 343 engages with the engagement surface 210 located closest to the rear cover 12 is the foremost position of the movable unit MV. In this way, the headrest 100 is capable of holding the movable unit MV in five positions in the front-rear direction.

[0067] A pair of walls 213 are provided on the central guide member 20 so as to sandwich the engagement end 343 in the vertical direction. By providing these walls 213, it is possible to guide the relative movement of the engagement end 343 in the front-rear direction with respect to the engagement surface portion 220. Furthermore, regardless of the position of the movable unit MV in the movable range, the engagement end 343 is sandwiched vertically by the pair of walls 213, so that it is possible to prevent the movable unit MV from moving in the vertical direction. Therefore, it is possible to stably hold the movable unit MV in a desired position.

[0068] In the central guide member 20, a right edge 21R of the main body 21 is parallel to the front-rear direction, whereas a left edge 21L of the main body 21 is inclined relative to the front-rear direction. In other words, the left-right width of the main body 21 of the central guide member 20 decreases the farther it is from the flange 22. As a result, the left-right width D1 (see FIG. 15) of the area of ​​the central guide member 20 where the engagement surface 210 closest to the front cover 11 is provided differs from the left-right width D2 (see FIG. 15) of the area of ​​the central guide member 20 where the engagement surface 210 closest to the rear cover 12 is provided, and the width D2 is smaller than the width D1.

[0069] With this configuration, when the movable unit MV is moved in the forward direction Fr from the state shown in FIG. 15, the gap in the left-right direction between the central guide hole portion 31C and the main body portion 21 becomes smaller. Therefore, the sliding resistance against the base 31 when the movable unit MV is moved in the forward direction Fr increases, and a larger force is required to move the movable unit MV. On the other hand, when the movable unit MV moves in the forward direction Fr from the state shown in FIG. 15, the sliding resistance gradually decreases. Therefore, the force required to move the movable unit MV decreases. On the other hand, as described below, when the movable unit MV moves in the forward direction Fr, the tensile load of the tension coil spring 50 increases. Therefore, no matter where the movable unit MV is moved to, it is possible to move it with a similar force.

[0070] Next, the state of the tension coil spring 50 when the movable unit MV moves will be described with reference to Fig. 17 and Fig. 18. Fig. 17 and Fig. 18 are schematic diagrams of a cross section perpendicular to the left-right direction of the headrest 100 and passing through the axis of the central guide member 20, with Fig. 17 showing the movable unit MV in its initial position and Fig. 18 showing the movable unit MV in its frontmost position.

[0071] The tension coil spring 50 has an initial length in the front-rear direction (minimum value) when the movable unit MV is in the initial position as shown in Fig. 17. As the movable unit MV moves in the forward direction Fr from the state shown in Fig. 17, the length in the front-rear direction of the tension coil spring 50 increases, and the tensile load of the tension coil spring 50 increases. Then, the length in the front-rear direction of the tension coil spring 50 reaches a maximum value when the movable unit MV is in the frontmost position as shown in Fig. 18.

[0072] When the tension coil spring 50 extends from a state in which the movable unit MV is in the initial position, a force acts on the movable unit MV to rotate counterclockwise around the rear end edge and upper end edge of the central guide member 20 as shown by the black arrow in FIG. 18. That is, a force acts on the movable unit MV to tilt in the forward direction Fr. In this embodiment, a restricting rib 120 (see FIGS. 2, 17, and 18) that restricts the inclination of the movable unit MV in the forward direction Fr due to this force is provided on the inner surface of the rear cover 12. The restricting rib 120 constitutes a restricting portion. As shown in FIG. 2, the restricting rib 120 is a plate-like shape extending in the front-rear direction with a thickness direction coinciding with the left-right direction, and in the example of FIG. 2, three restricting ribs 120 are provided side by side in the left-right direction at the upper end and the center in the left-right direction of the rear cover 12.

[0073] As shown in Fig. 17, when the movable unit MV is in the initial position, the restricting rib 120 is not located above the support unit 30, and the support unit 30 cannot come into contact with the restricting rib 120. When the movable unit MV moves in the forward direction Fr from the state shown in Fig. 17, the support unit 30 and the restricting rib 120 overlap when viewed in the up-down direction, and the gap between the support unit 30 and the restricting rib 120 becomes very small.

[0074] In this embodiment, for example, in the movement range of the movable unit MV from a state in which the engagement end 343 engages with the engagement surface 210 located second closest to the front cover 11 to a state in which the movable unit MV is at the frontmost position, the support unit 30 and the restricting rib 120 overlap in the vertical direction. In this movement range, the extension amount of the tension coil spring 50 is large, so the movable unit MV is likely to rotate. However, in this movement range, as shown in FIG. 18, the upper end edge of the support unit 30 abuts against the restricting rib 120, thereby restricting the inclination of the movable unit MV in the forward direction Fr.

[0075] In this way, even if the length of the tension coil spring 50 in the front-rear direction becomes equal to or greater than the threshold value THL (the length when the engagement end 343 is engaged with the engagement surface 210 that is second closest to the front cover 11) and the attitude of the movable unit MV relative to the support unit 30 becomes unstable, the inclination of the movable unit MV in the forward direction Fr relative to the support unit 30 is restricted by the contact between the restricting rib 120 and the support unit 30. Therefore, the attitude of the movable unit MV can be stabilized regardless of the position of the movable unit MV within its movable range.

[0076] Furthermore, when the length of the tension coil spring 50 in the front-rear direction is less than the threshold value THL, the restricting rib 120 and the support unit 30 are not in contact with each other, and the movable unit MV can move smoothly. On the other hand, when the length of the tension coil spring 50 in the front-rear direction is equal to or greater than the threshold value THL, the support unit 30 may come into contact with the restricting rib 120 and provide resistance to the movement of the movable unit MV. However, in this case, the tension of the tension coil spring 50 is large, so that the user does not feel that resistance. As a result, the movable unit MV can be moved smoothly throughout its entire movable range.

[0077] Fig. 18 shows the shortest distance L1 in the front-rear direction between the support unit 30 and the rear cover 12 when the movable unit MV is in the front-most position. Fig. 16 also shows the distance L2 between the engagement end 343 and the closest part 214 of the main body 21 that is the shortest distance in the rear direction Rr to the engagement end 343. It is preferable that the distance L2 is greater than the shortest distance L1.

[0078] By doing so, when an external load is applied to the rear cover 12, the rear cover 12 collides with the support unit 30 before the closest portion 214 of the main body 21 collides with the engagement end 343, so that the load can be concentrated on the support unit 30. This prevents the load from being transmitted to the locking member 34, and the position of the movable unit MV can be stably maintained even when an impact is received. In addition, the durability of the locking member 34 can be increased.

[0079] In the headrest 100, when moving the movable unit MV forward in the forward direction Fr, the operation of the operation button 13 is unnecessary. On the other hand, when moving the movable unit MV backward in the backward direction Rr, the operation of the operation button 13 is necessary. FIG. 19 is a diagram showing a state where the operation button 13 is pressed in the right direction R in the state shown in FIG. 16.

[0080] When the operation button 13 is pressed, the engagement end portion 343 moves a maximum distance L5 in the right direction R. In this state, since the holding of the position of the movable unit MV by the locking member 34 is released, the movable unit MV can be moved backward in the backward direction Rr.

[0081] The maximum distance L5 is larger than the left - right protruding height L3 of the vertical plane 211 of each engagement surface 210 except for the engagement surface 210 at the position closest to the front cover 11. The maximum distance L5 is preferably less than the protruding height L4 of the wall portion 213 in the right direction R.

[0082] By making the maximum distance L5 less than the protruding height L4, even when the operation button 13 is being operated, the engagement end portion 343 can be clamped vertically by the pair of wall portions 213. Therefore, the relative movement of the engagement end portion 343 with respect to the movable unit MV can be stably performed. Thus, even when moving the movable unit MV backward in the backward direction Rr, the movable unit MV can be stably moved.

[0083] Note that the protruding height of the vertical plane 211 of the engagement surface 210 at the position closest to the front cover 11 in the right direction R is preferably a value sufficiently larger than the maximum distance L5. By doing so, even when the operation button 13 is pressed in the state shown in FIG. 15, the movement of the central guide member 20 backward in the backward direction Rr can be prevented.

[0084] Fig. 20 is a diagram showing the operation button 13, central guide member 20, and support unit 30 of the headrest 100, viewed from above with the movable unit MV in its initial position. Fig. 21 is a diagram showing the operation button 13, central guide member 20, and support unit 30 of the headrest 100, viewed from above with the movable unit MV in its foremost position. In Fig. 21, the position of the support unit 30 when the movable unit MV is in its initial position is shown by an imaginary line.

[0085] 21, the center guide member 20 can move in the front-rear direction by a maximum distance L6. The contact portion 132 of the operation button 13 has a width in the front-rear direction of a distance L7. The distance L7 is equal to or greater than the distance L6.

[0086] 20 and 21, this configuration makes it possible for the abutment portion 132 and the flat plate portion 344 to overlap in the left-right direction regardless of the position of the movable unit MV within its movable range. Therefore, regardless of the position of the movable unit MV, the lock member 34 can be pressed to release the retention of the position of the movable unit MV. This allows the structure of the operation button 13 to be simplified, thereby reducing the manufacturing cost of the headrest 100.

[0087] FIG. 22 is a schematic diagram for explaining a preferred arrangement of the operation button 13 and the locking member 34, and is a view of the headrest 100 seen from the front side. FIG. 22 shows the vertical center line C1 of the coil spring 345 that biases the locking member 34 in the left direction L, and the vertical center line C2 of the abutting portion 132. In the example of FIG. 22, the center line C1 and the center line C2 coincide with each other. FIG. 22 shows the vertical center line C3 of the spring 133 that biases the abutting portion 132 and the operating element 131 in the left direction L. FIG. 22 shows the vertical center line C4 of the engagement end 343. FIG. 22 shows the maximum width AR of the operation button 13 in the vertical direction. As shown in FIG. 22, the center line C1, the center line C2, the center line C3, and the center line C4 are all located between both ends of the maximum width AR. With such an arrangement, the space in the storage member 10 can be effectively utilized.

[0088] In the above description, one embodiment of the headrest 100 has been shown, but the embodiment is not limited to the illustrated embodiment and may be modified as appropriate within the scope of the technical concept of the present disclosure. For example, the central guide member 20 is configured to be detachable from the front cover 11, but may be configured integrally with the front cover 11. The central guide member 20 may be configured to be detachable from the rear cover 12 or integrally with the rear cover 12, instead of the front cover 11. In this case, the right guide member 11R and the left guide member 11L are preferably also provided on the rear cover 12.

[0089] Moreover, although the tension coil spring 50 is fixed to the protruding portion 23 of the central guide member 20, it may be configured to be fixed to the front cover 11. Moreover, the tension coil spring 50 may be provided so as to connect the rear cover 12 and the protrusion 31A.

[0090] As described above, the present specification discloses the following:

[0091] (1) A stay supported by a seat back of a vehicle seat; A support unit supported by the stay; a movable unit configured to be movable in a front-rear direction of the vehicle seat relative to the support unit, the support unit has a locking member capable of holding the movable unit at a plurality of positions in the front-rear direction, The movable unit is a headrest having an engagement member including an engagement surface portion having a plurality of engagement surfaces arranged in the front-to-rear direction for engaging with the locking member, and wall portions protruding toward the locking member from both ends of the engagement surface portion in a direction intersecting the front-to-rear direction.

[0092] According to (1), for example, in a configuration in which the wall portions are aligned in the vertical direction of the vehicle seat, when the locking member is engaged with the engagement surface, the movable unit can be prevented from moving in the vertical direction, so that the movable unit can be stably held in a desired position. Also, when the movable unit moves in the front-rear direction from a state in which the movable unit is held in a predetermined position, the wall portions act as a guide for the movement of the locking member, so that the movable unit can be stably moved in the front-rear direction.

[0093] (2) A headrest according to (1), The headrest is such that, when viewed in the direction in which the two wall portions are arranged, the engagement surface portion is covered by the wall portion.

[0094] According to (2), when the locking member is engaged with the engagement surface, it is possible to enhance the effect of preventing the movable unit from moving in the direction in which the wall portions are arranged and the effect of guiding the movement of the movable unit in the front-rear direction.

[0095] (3) A headrest according to (1) or (2), the movable unit has a first housing member and a second housing member arranged side by side in the front-rear direction to form a space for housing a part of the support unit, The engaging member is configured in a columnar shape extending in the front-rear direction from the first accommodating member or the second accommodating member in the space, the support unit includes a lock support member that movably supports the lock member and has a first guide hole portion through which the engaging member is slidably inserted and that guides the movement of the engaging member in the front-rear direction, The headrest has an inner wall surface of the first guide hole portion facing the engagement surface portion, and an opening is provided in the inner wall surface of the first guide hole portion to receive an engagement end portion of the locking member that is engageable with the engagement surface.

[0096] According to (3), since the portion that forms the first guide hole of the lock support member exists between the engaging member and the portion of the locking member other than the engaging end, it is possible to easily prevent the locking member from interfering with the engaging member when the locking member is not engaged with the engaging member, and therefore the engaging member can be moved smoothly.

[0097] (4) A headrest according to (3), A headrest in which, when the locking member is engaged with the engagement surface located closest to the second accommodating member, the distance between the locking member and a closest portion of the engagement member located at the shortest distance in the front-to-rear direction on the second accommodating member side to the locking member is greater than the shortest distance between the support unit and the second accommodating member.

[0098] According to (4), when an external load is applied to the second housing member, the load can be concentrated on the support unit. This prevents the load from being transmitted from the engaging member to the locking member, and the position of the movable unit can be stably maintained even when an impact is received. In addition, the durability of the locking member can be increased.

[0099] (5) A headrest according to (3), a convex portion having a curved surface extending in the front-rear direction is provided on a surface of the engaging member that faces an inner wall surface of the first guide hole portion, the protrusion and an inner wall surface of the first guide hole are in sliding contact with each other, The headrest includes a plurality of convex portions each having a different curvature.

[0100] According to (5), the contact area between the engaging member and the first guide hole can be reduced to lower the sliding resistance, and the movable unit can move smoothly. In addition, the presence of convex portions with different curvatures allows, for example, the convex portion with a lower curvature to function as a load transmitting portion from the engaging member to the support unit, and the convex portion with a higher curvature to function as a sliding portion between the engaging member and the first guide hole. In this way, it is possible to achieve both smooth movement of the engaging member and efficient load transmission from the movable unit to the stay.

[0101] (6) A headrest according to (3), A headrest in which the width in the protruding direction of the wall portion of the region in which the engagement surface is located closest to the first accommodating member is different from the width in the protruding direction of the wall portion of the region in which the engagement surface is located closest to the second accommodating member.

[0102] According to (6), the sliding force between the engaging member and the first guide hole can be changed in the process of changing the state in which the locking member engages with the engaging surface located closest to the first housing member to the engaging surface located closest to the second housing member. For example, in a case in which the base end of the engaging member and the support unit are connected by a coil spring or the like and the movement of the engaging member in one direction is assisted by the force of the coil spring, the sliding resistance can be reduced as the tensile load of the coil spring increases, making it possible to improve operability during movement of the engaging member. [Explanation of symbols]

[0103] 100 Headrest 10. Storage material 11 Front cover 11L Left guide member 11R Right guide member 11Ra, 11La 2nd convex part 11Fr front 111,112 Front cover wall 113A, 113B Convex part 113C Slope 114 First protrusion 12 Rear cover 12L, 12R connecting protrusion 120 Regulating Rib 13 Operation buttons 131 Controls 132 Contact part 133 Spring 20 Central guide member 21 Main body 21A, 21B Convex part 21L,21R edge 22 Flange 23 Protrusion 23A, 23B Engagement protrusion 24 Ribs 211 Vertical plane 212 Slope 210 Engagement surface 213 Wall 214 Nearest part 220 Engagement surface part 30 Support Unit 31 Foundation 31A protrusion 31C Center guide hole 31L Left guide hole 31R Right guide hole 32 Rear wall 32A pin 32B Holding part 32SD bottom side 32H opening 32L Second insertion hole 32SL left side 32R First insertion hole 32SR right side 32U upper part 32SU top 32Ra,32La dividing wall part 32D, 32E convex part 32F, 32G Rib 33 Front wall 33A First elastic part 33B Second elastic part 34 Locking member 341 Part 1 341A,342A Locking piece 342 Part 2 343 Engagement end 344 Flat plate part 345 Coil Spring 35 Lock support member 40L Left stay 40R Right stay 40Lc, 40Rc, 320 recess 50 Tension coil spring 321,322 Through hole L1 shortest distance C1,C2,C3,C4 center line L3 Height L4 protruding height L5 maximum distance L2,L6,L7 distance D1,D2 width

Claims

1. A stay supported by a seat back of a vehicle seat; A support unit supported by the stay; a movable unit configured to be movable in a front-rear direction of the vehicle seat relative to the support unit, the support unit has a locking member capable of holding the movable unit at a plurality of positions in the front-rear direction, The movable unit is a headrest having an engagement member including an engagement surface portion having a plurality of engagement surfaces arranged in the front-to-rear direction for engaging with the locking member, and wall portions protruding toward the locking member from both ends of the engagement surface portion in a direction intersecting the front-to-rear direction.

2. 2. The headrest according to claim 1, The headrest is such that, when viewed in the direction in which the two wall portions are arranged, the engagement surface portion is covered by the wall portions.

3. 3. The headrest according to claim 1 or 2, the movable unit has a first housing member and a second housing member arranged side by side in the front-rear direction to form a space for housing a part of the support unit, The engaging member is configured in a columnar shape extending in the front-rear direction from the first accommodating member or the second accommodating member in the space, the support unit includes a lock support member that movably supports the lock member and has a first guide hole portion through which the engaging member is slidably inserted and that guides the movement of the engaging member in the front-rear direction, A headrest, wherein an opening is provided on an inner wall surface of the first guide hole portion that faces the engagement surface portion, the opening receiving an engagement end portion of the locking member that is engageable with the engagement surface.

4. 4. The headrest according to claim 3, A headrest in which, when the locking member is engaged with the engagement surface located closest to the second accommodating member, the distance between the locking member and a closest portion of the engagement member that is located at the shortest distance in the front-to-rear direction on the second accommodating member side to the locking member is greater than the shortest distance between the support unit and the second accommodating member.

5. 4. The headrest according to claim 3, a curved convex portion extending in the front-rear direction is provided on a surface of the engaging member that faces an inner wall surface of the first guide hole portion, The protrusion and the inner wall surface of the first guide hole are in sliding contact with each other, The headrest includes a plurality of types of protrusions having different curvatures.

6. 4. The headrest according to claim 3, A headrest, wherein the width in the protruding direction of the wall portion of the region in which the engagement surface is located closest to the first accommodating member is different from the width in the protruding direction of the wall portion of the region in which the engagement surface is located closest to the second accommodating member.

Images