JP2009213541A - Headrest of vehicle seat - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a headrest of a vehicle seat which is capable of suppressing the play of a headrest body at a using position. <P>SOLUTION: The headrest 1 of the vehicle seat includes a base body 2, the headrest body 3 supported by the base body 2 so as to be tilted, an urging spring 6 for urging the headrest body 3 from the using position to a tilted position, and a lock mechanism for locking the headrest body 3 at the using position, and between the base body 2 and the headrest body 3, a shaft member 5 which tiltably connects them is provided. The spring member 6 has a coil part 6a wound around the outer periphery of the shaft member, a fixed end part locked to the base body 2 and a turning end part 6c locked to the headrest body 3. The diameter of the coil part 6a is set to a size to be narrower than the diameter of the shaft member 5 when the headrest body 3 is at the using position and to be larger than the diameter of the shaft member 5 when the headrest body 3 is at the tilted position. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a headrest attached to an upper portion of a seat back of a vehicle seat.

Conventionally, various headrests are known. For example, a headrest having a base body attached to a seat back and a headrest body attached to the base body so as to be tiltable is known (see Patent Document 1). Between the base body and the headrest body, a spring member that urges the headrest body to the tilted position and a lock mechanism that locks the headrest body at the use position are provided. Therefore, the headrest body is locked at the use position by the lock mechanism. And the lock mechanism is tilted by the spring member by unlocking.
JP 2006-87702 A

  However, the lock mechanism has a configuration in which a hook provided on the base body side enters a locking recess provided on the headrest body side. For this reason, there is a problem that the headrest body is loose at the use position due to the gap between the hook and the locking recess. Then, this invention makes it a subject to provide the headrest of the vehicle seat which can suppress the play of the headrest main body in a use position.

  In order to solve the above-mentioned problems, the present invention is a headrest for a vehicle seat having the structure described in each claim. In other words, according to the first aspect of the present invention, the shaft member is provided between the base body and the headrest body so as to be able to tilt them. The spring member has a coil portion that winds around the outer periphery of the shaft member, a fixed end portion that is locked to the base body, and a rotating end portion that is locked to the headrest body. The diameter of the coil portion is sized to become thinner than the diameter of the shaft member when the headrest body is in the use position, and larger than the diameter of the shaft member when the headrest body is in the tilted position. Is set to a size.

  Therefore, when the headrest body is set to the use position, the coil portion is wound in a state where there is almost no gap on the outer peripheral surface of the shaft member. Therefore, backlash does not occur between the coil part and the shaft member, and the headrest body can be prevented from rattling with respect to the base body via the coil part and the shaft member. And the play prevention mechanism of a headrest main part can be comprised by the spring member which urges | biases a headrest main body to a tilting position, and the shaft member which connects a headrest main body and a base body so that tilting is possible, without providing a new component. On the other hand, when the headrest body is in the tilted position, a gap is formed between the coil portion and the shaft member. Therefore, the frictional resistance that can occur between the shaft member and the coil portion is reduced, and the headrest body is easily tilted with respect to the base body.

  According to invention of Claim 2, the shaft member has the adjustment part which has a site | part from which a diameter differs. And the coil part of a spring member is position-adjusted and attached to an adjustment part. Therefore, by adjusting the position of the spring member with respect to the shaft member, the difference in diameter between the coil portion and the shaft member can be adjusted. Therefore, the variation in size in manufacturing the spring member and the shaft member can be adjusted by the position of the coil portion with respect to the adjustment portion. Thus, the coil portion can be securely wound around the shaft member when the headrest body is in the use position.

(Embodiment 1)
The first embodiment will be described with reference to FIGS. As shown in FIG. 1, the vehicle seat 10 includes a seat cushion 11, a seat back 12, and a headrest 1. The seat cushion 11 and the seat back 12 have frames 11a and 12a, and a reclining device 13 is provided between the frames 11a and 12a to connect them so that the angle can be adjusted. A pair of cylindrical holders 12b is attached to the upper part of the frame 12a, and the headrest 1 is movably attached to the holder 12b.

  As shown in FIGS. 1 to 3, the headrest 1 includes a base body 2 and a headrest body 3 that is supported to be tiltable with respect to the base body 2. The base body 2 has a pair of stays 2a (see FIGS. 4 and 5) and a base body 2b (see FIG. 9). The stay 2a is formed of a metal tube as shown in FIGS. 1 and 5, and has a vertical portion 2a1 and a horizontal portion 2a2 extending from the end of the vertical portion 2a1 in a substantially horizontal direction. A lower portion of the vertical portion 2a1 is slidably supported by a holder 12b provided on the seat cushion 11.

  The base main body 2b is made of a metal plate material, and has a main body plate portion 2b1 and standing portions 2b2 that stand on both the left and right sides of the main body plate portion 2b1, as shown in FIGS. The standing portion 2b2 has a recess 2b4 and a mounting hole 2b6. A lateral portion 2a2 of the stay 2a is installed in the recess 2b4. A cylindrical shaft member 5 is inserted into the mounting hole 2b6. Both ends of the shaft member 5 pass through the mounting hole 2b6. Then, both end portions that penetrate are inserted into the bearing portion 3a1 formed in the headrest body 3 as shown in FIG. Therefore, the headrest body 3 is connected to the base body 2 by the shaft member 5 so as to be tiltable.

  The headrest body 3 has a front side portion 3a and a rear side portion 3b as shown in FIGS. As shown in FIG. 5, a bearing portion 3a1 into which the shaft member 5 is inserted is formed in the front side portion 3a. Between the front side part 3a and the rear side part 3b, the base main body 2b and the shaft member 5 are accommodated. A spring member 6 that urges the headrest body 3 in the tilting direction (forward) is attached to the shaft member 5. As shown in FIGS. 5 and 6, the spring member 6 is a torsion spring, and has a coil portion 6 a disposed so as to wind around the outer periphery of the shaft member 5. The number of turns of the coil portion 6a is 3 to 8 times, and the diameter of the coil portion 6a is larger than the diameter of the shaft member 5 in a free state. A fixed end 6b is provided at one end of the spring member 6, and the fixed end 6b is locked to a locking portion 2b5 formed on the base body 2b. The other end portion of the spring member 6 is provided with a rotating end portion 6c, and the rotating end portion 6c is locked to a locking portion 3a2 formed on the front side portion 3a.

  The headrest body 3 tilts between a use position standing with respect to the base body 2 as shown in FIG. 1 and a tilt position tilted with respect to the base body 2 as shown in FIG. When the headrest body 3 is set to the use position, the coil portion 6 a of the spring member 6 is elastically wound as shown in FIG. 11, and the diameter of the coil portion 6 a tends to be smaller than the diameter of the shaft member 5. In other words, when the shaft member 5 is removed in this state, the diameter of the coil portion 6 a becomes thinner than that of the shaft member 5.

  Therefore, as shown in FIG. 11, there is almost no gap 9 between the spring member 6 and the shaft member 5. As a result, the spring member 6 and the shaft member 5 come into contact with each other over a wide area, and a large frictional resistance is generated between the spring member 6 and the shaft member 5. Thus, when the headrest body 3 reaches the use position, it receives a brake against tilting. Furthermore, since the gap 9 between the spring member 6 and the shaft member 5 is almost eliminated, the headrest body 3 can be prevented from rattling with respect to the base body 2 at the use position.

  When the headrest body 3 is in the tilted position shown in FIG. 2, the spring member 6 becomes larger than the diameter of the shaft member 5 as shown in FIG. Therefore, a gap 9 is generated between the spring member 6 and the shaft member 5, and the frictional resistance generated between the spring member 6 and the shaft member 5 is reduced. As a result, the headrest body 3 can easily tilt to the tilt position.

  Between the headrest main body 3 and the base body 2, a lock mechanism (7 etc.) for locking the headrest main body 3 at the use position and a lock release mechanism (4 etc.) for unlocking the lock mechanism are provided. As shown in FIGS. 9 and 10, the lock mechanism includes a lock tilting body 7 and a lock portion 2b6 formed on the base body 2b.

  As shown in FIGS. 5 and 10, the lock tilting body 7 has an attachment portion 7 a at the upper end portion and a pair of hook portions 7 c at the lower end portion. The attachment portion 7a is attached to the front side portion 3a via the attachment shaft member 3c so as to be tiltable. An overhang portion 7b is formed at the center of the lock tilting body 7 so as to project toward the front side portion 3a. As shown in FIG. 7, a coil spring 8 is attached to the overhang portion 7b. The coil spring 8 biases the lock tilting body 7 in a direction away from the front side portion 3a. Therefore, the lock tilting body 7 enters the lock portion 2b6 formed in the base body 2b with the hook portion 7c as shown in FIG. Thereby, the headrest main body 3 can be locked to the base body 2 at the use position.

  The lock release mechanism has a release member 4 as shown in FIGS. The release member 4 has an operation part 4a and a shaft part 4b extending from the operation part 4a. The shaft portion 4b is attached to a rotation support portion 3a3 formed on the front side portion 3a so that the shaft can rotate. A cam portion 4c having a non-circular cross section is formed at the center of the shaft portion 4b. The cam portion 4 c comes into contact with the back surface of the bulging portion 7 d formed on the lock tilting body 7. Therefore, the cam part 4c pushes the bulging part 7d by rotating the release member 4 using the operation part 4a. As a result, the lock tilting body 7 tilts around the mounting portion 7 a against the coil spring 8. As a result, as shown in FIG. 8, the hook portion 7c is detached from the lock portion 2b6, and the lock mechanism is unlocked.

  When the locking mechanism is released as shown in FIGS. 7 and 8, the headrest body 3 is biased by the spring member 6 and tilts forward. When the headrest body 3 tilts, the hook portion 7c moves along the arc surface 2b7 of the base body 2b and reaches the first stopper 2b8. The front side portion 3a is also tilted, and the cushioning material 3d attached to the front side portion 3a reaches the second stopper 2b9. Therefore, the tilt of the headrest body 3 is stopped at a predetermined tilt position by the stoppers 2b8 and 2b9.

  As described above, the spring member 6 is locked to the headrest body 3 and the coil portion 6a that winds around the outer periphery of the shaft member 5, the fixed end portion 6b that is locked to the base body 2, as shown in FIGS. The rotating end portion 6c is provided. And the diameter of the coil part 6a is a magnitude | size which is going to become thinner than the diameter of the shaft member 5 when the headrest main body 3 becomes a use position, and when the headrest main body 3 becomes a tilting position, the shaft member 5 The size is set to be larger than the diameter.

  Therefore, when the headrest main body 3 is set to the use position, the coil portion 6a is wound around the outer peripheral surface of the shaft member 5 with almost no gap 9. Therefore, backlash does not occur between the coil portion 6 a and the shaft member 5, and the headrest body 3 can be prevented from rattling with respect to the base body 2 via the coil portion 6 a and the shaft member 5. And the play prevention mechanism of the headrest main body 3 includes a spring member 6 that urges the headrest main body 3 to the tilted position without providing new parts, and a shaft member that connects the headrest main body 3 and the base body 2 so as to be tiltable. 5 can be configured. On the other hand, when the headrest body 3 is set to the tilted position, a gap 9 is formed between the coil portion 6 a and the shaft member 5. Therefore, the frictional resistance that can be generated between the shaft member 5 and the coil portion 6 a is reduced, and the headrest body 3 is easily tilted with respect to the base body 2.

  Thereby, the increase in the mass of the headrest 1 and a cost increase can be suppressed. Furthermore, by avoiding an increase in the number of parts, a space in the headrest body 3 can be secured, and the assembling work can be reduced.

(Embodiment 2)
A second embodiment will be described with reference to FIG. The second embodiment is formed in substantially the same manner as the first embodiment, but is different from the first embodiment in that the shaft member 5 is provided with an adjusting portion 5a. Hereinafter, the second embodiment will be described focusing on the differences.

  As shown in FIG. 13, the shaft member 5 has an adjustment portion 5a, and the adjustment portion 5a has a first portion 5a1 and a second portion 5a2 having different diameters. The second part 5a2 is adjacent to the first part 5a1 in the axial direction. The diameter of the second part 5a2 is smaller than that of the first part 5a1, and has an inclination angle that gradually decreases as the distance from the first part 5a1 increases. The coil portion 6a of the spring member 6 is attached to the adjustment portion 5a with its position adjusted in the axial direction (arrow direction).

  Therefore, by adjusting the position of the spring member 6 relative to the shaft member 5, the difference in diameter between the coil portion 6a and the shaft member 5 can be adjusted. Therefore, the variation in size in manufacturing the spring member 6 and the shaft member 5 can be adjusted by adjusting the position of the coil portion 6a with respect to the adjusting portion 5a. Thus, the coil portion 6a can be securely wound around the shaft member 5 when the headrest body is in the use position. When the headrest body is set to the tilted position, the diameter of the coil portion 6a is surely larger than the diameter of the shaft member 5.

(Other embodiments)
The present invention is not limited to the above-described first and second embodiments, and may be the following forms.
(1) The headrest 1 of the first and second embodiments is a form in which the headrest main body 3 tilts forward with respect to the base body 2. However, the headrest body may be tilted backward with respect to the base body.
(2) The adjusting portion 5a of the second embodiment has the second portion 5a2 having an inclination angle that gradually decreases in diameter. However, the second part may not have an inclination, may be in a form adjacent to the first part and having a smaller diameter than the first part.

It is a perspective view of a vehicle seat. It is a perspective view of the vehicle seat in a state where the seat back is tilted forward and the headrest body is in the tilted position. It is a perspective view from the left front of the frame of a headrest. It is a perspective view from the left rear of the framework of a headrest. It is a perspective view from the left rear of the framework of a headrest in the state which removed the rear side part and the base main body. It is a rear view of the frame of a headrest in the state where a part of front side part was excised. FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. 6. FIG. 8 is a cross-sectional view taken along line VIII-VIII in FIG. 6. It is a perspective view from the left rear of a base body. It is a perspective view from the left front of a lock tilting body. It is a schematic side view of a spring member and a shaft member when the headrest body is in a use position. It is a schematic side view of a spring member and a shaft member when the headrest is in the tilted position. 6 is a partial schematic front view of a spring member and a shaft member in Embodiment 2. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Headrest 2a ... Stay 2 ... Base body 2b ... Base main body 3 ... Headrest main body 3a ... Front side part 3b ... Rear side part 4 ... Release member 5 ... Shaft member 5a ... Adjustment part 6 ... Spring member 6a ... Coil part 6b ... Fixed End 6c ... Rotating end 7 ... Lock tilting body 10 ... Vehicle seat 11 ... Seat cushion 12 ... Seat back

Claims (2)

A base body, a headrest body supported by the base body so as to be tiltable, a biasing spring that biases the headrest body from a use position to a tilt position, and a lock mechanism that locks the headrest body at the use position. A vehicle seat headrest comprising:
Between the base body and the headrest body, there is provided a shaft member that connects these in a tiltable manner,
The spring member has a coil portion that winds around the outer periphery of the shaft member, a fixed end portion that is locked to the base body, and a rotating end portion that is locked to the headrest body,
The diameter of the coil portion is sized to become thinner than the diameter of the shaft member when the headrest body is in the use position, and when the headrest body is in the tilted position, A headrest for a vehicle seat, wherein the headrest is set to be larger than the diameter. The vehicle seat headrest according to claim 1,
The shaft member has an adjustment portion having portions with different diameters,
A headrest for a vehicle seat, wherein a coil portion of a spring member is attached to the adjustment portion with its position adjusted.

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