Headrest

Abstract

To provide a headrest which enables each case to be assembled properly while increasing a movable area of a mass body.SOLUTION: A headrest includes: a case 5 assembled to a headrest stay 3; a mass body 7 disposed in the case 5; and an elastic body 6 supporting the mass body 7. The case 5 has a front case 10 and a rear case 20. The elastic body 6 includes: a front elastic body 30 having front engagement holes 34 engaged with a rear surface of the front case 10, and a front extension part 30a extending from the front engagement holes 34 along the rear surface; and a rear elastic body 40 having rear engagement holes 44 engaged with a front surface of the rear case 20, and a rear extension part 40a extending from the rear engagement holes 44 along the front surface. The mass body 7 is supported sandwiched in a front-back direction between the front extension part 30a and the rear extension part 40a. The front engagement holes 34 and the rear engagement holes 44 are disposed separated at one side and the other side in a height direction, which sandwich the mass body 7.SELECTED DRAWING: Figure 10

Description

Technical Field

[0001] The present invention relates to a headrest. Specifically, it relates to a headrest having a headrest stay provided with legs to be mounted on the upper part of a seat back, a case assembled on the upper part of the headrest stay, and a headrest pad as a cushioning material covering the case.

Background Art

[0002] Patent Document 1 discloses a headrest provided with a dynamic damper for vibration suppression. Specifically, planar slab urethane is set in resin cases divided into front and rear parts, and a mass body forming a weight is sandwiched between the respective slab urethanes by assembling the cases. Each case has an annular rib protruding so as to be abutted against each other front and rear by being assembled with each other. Each slab urethane is fixed to the case by being pressed and sandwiched between the respective ribs along the outer peripheral edge. Further, the mass body is provided so as to be located in an internal region formed by the abutment of the respective ribs.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The slab urethane described above is compressed and sandwiched across its entire periphery by the ribs of each case. This narrows the range of motion of the mass, raising concerns that sufficient vibration suppression may not be achieved. Furthermore, when setting each slab urethane into the case, the slab urethane comes into contact with the ribs, causing it to lift up relative to the case. This raises concerns that when the cases are assembled together, the slab urethanes may interfere with each other, preventing proper assembly. Therefore, the aim is to provide a headrest that allows for a wider range of motion of the mass while enabling proper assembly of the cases. [Means for solving the problem]

[0005] To solve the above problems, the headrest of the present invention employs the following means.

[0006] In other words, the headrest of the present invention comprises a headrest stay having legs attached to the upper part of the seat back, a case assembled to the upper part of the headrest stay, and a headrest pad as a cushioning material covering the case. Furthermore, it comprises a vibration-dampening mass body disposed inside the case, and an elastic body disposed inside the case that elastically supports the mass body relative to the case. The case comprises a front case and a rear case, which are divided so as to be assembled front to back with each other. The elastic body comprises a front elastic body having a front locking portion that locks to the rear surface of the front case and a front extension portion that extends from the front locking portion along the rear surface, and a rear elastic body having a rear locking portion that locks to the front surface of the rear case and a rear extension portion that extends from the rear locking portion along the front surface, and supports the mass body by sandwiching it between the front and rear extension portions. The front locking portion and the rear locking portion are arranged separately in one and the other directions, either in the height direction or the width direction, with the mass body sandwiched between them.

[0007] In this configuration, the front and rear locking parts are positioned separately on one side in the height or width direction that encloses the mass, which suppresses tension and lifting of the elastic body compared to a configuration where the entire circumference of the front elastic body and the entire circumference of the rear elastic body are locked separately. This reduces interference between the front and rear elastic bodies when the front and rear cases are assembled, thereby reducing assembly defects of the cases. Furthermore, the range of motion of the mass body can be increased compared to a configuration where the entire circumference of the front and rear elastic bodies are locked separately. In this way, the cases can be properly assembled while increasing the range of motion of the mass body.

[0008] Furthermore, the headrest of the present invention may be configured as follows: The front case has a front rib that protrudes from the rear surface and linearly contacts the front extension from the front. The rear case has a rear rib that protrudes from the front surface and linearly contacts the rear extension from the rear. As a result, compared to a configuration in which the front case makes surface contact with the front extension or the rear case makes surface contact with the rear extension, the mass body can more easily compress the elastic body. This makes it possible to further widen the range of motion of the mass body.

[0009] Furthermore, the headrest of the present invention may be configured as follows: The front locking portion is positioned in a region above the mass of the front elastic body. The rear locking portion is positioned in a region below the mass of the rear elastic body. This allows the worker to perform the assembly work between the front case and the rear case by placing the front case over the rear case on the installation surface, while looking at the front locking portion from the upper end of the front case. As a result, the worker can efficiently check whether the front elastic body has fallen out of the front case while assembling the case.

[0010] Furthermore, the headrest of the present invention may be configured as follows: The front case has a front pin protruding from its rear surface, and the front pin passes through a front locking hole that forms the front locking portion of the front elastic body and protrudes rearward from the front elastic body. The rear case has a rear pin protruding from its front surface, and the rear pin passes through a rear locking hole that forms the rear locking portion of the rear elastic body and protrudes forward from the rear elastic body. As a result, the front elastic body can be locked to the front pin in a way that makes it difficult for it to come loose, even without providing a locking portion on the front pin and the rear pin that engages with an elastic body, such as a hook. Also, the rear elastic body can be locked to the rear pin in a way that makes it difficult for it to come loose.

[0011] Furthermore, the headrest of the present invention may be configured as follows: The mass body is cylindrical in shape with its axis oriented in the left-right direction. This reduces the difference in amplitude between the upper and lower ends of the mass body, making it easier to control the vibration of the mass body. As a result, vibration suppression using the mass body can be performed more effectively. [Brief explanation of the drawing]

[0012] [Figure 1] This is a perspective view of the headrest according to the first embodiment. [Figure 2] This is a perspective view showing the internal structure of the headrest. [Figure 3] Figure 2 is an exploded perspective view. [Figure 4] Figure 3 is an exploded perspective view taken from the rear. [Figure 5] This is an exploded perspective view showing the slab urethane assembled into the case. [Figure 6] Figure 5 is an exploded perspective view taken from the rear. [Figure 7] This is a perspective view showing the mass and headrest stay assembled into the rear case. [Figure 8] Figure 2 is a front view. [Figure 9] Figure 8 shows a cross-sectional view along the line IX-IX. [Figure 10] This is a cross-sectional view along line XX in Figure 8. [Figure 11] This is a cross-sectional view taken along the line XI-XI in Figure 8. [Modes for carrying out the invention]

[0013] Hereinafter, embodiments for carrying out the present invention will be described with reference to Figure 1-11. In the following description, when directions such as front, back, up, down, left, and right are indicated, they refer to the respective directions shown in each figure.

[0014] <First Embodiment> First, a headrest 1 according to the first embodiment of the present invention will be described. As shown in Figure 1, the headrest 1 is configured as the headrest portion of a car seat (not shown). The headrest 1 is also equipped with a dynamic damper D for vibration suppression. Specifically, the headrest 1 comprises a headrest pad 2 made of foamed urethane, a headrest cover 4 made of fabric that covers the headrest pad 2, and a headrest stay 3 that extends downward from the headrest pad 2. The headrest stay 3 has two legs 3a. The headrest stay 3 is integrally assembled to the seat back by assembling the lower ends of each leg 3a to the upper end of the seat back (not shown). The headrest 1 also has a headrest case 5 embedded inside the headrest pad 2.

[0015] As shown in FIG. 2, the headrest case 5 is a box-shaped member made of resin. The headrest case 5 is assembled to the upper part of the headrest stay 3. The headrest 1 has a mass body 7 housed in the headrest case 5 and a slab urethane 6 that covers the mass body 7 within the headrest case 5. The mass body 7 has the function of a weight in the dynamic damper D. The slab urethane 6 has the function of an elastic body in the dynamic damper D. Specifically, the mass body 7 is provided so as to be swingable inside the headrest case 5, and when the headrest 1 receives an impact or vibration, the mass body 7 vibrates. Thereby, the kinetic energy due to the vibration of the headrest 1 can be converted into the kinetic energy due to the vibration of the mass body 7. Then, the slab urethane 6 that covers the mass body 7 elastically receives the mass body 7 and absorbs the vibration. In this way, the slab urethane 6 and the mass body 7 can suppress the vibration of the headrest 1. Here, the slab urethane 6 corresponds to the "elastic body" of the present invention.

[0016] <Headrest 1> Hereinafter, each component of the headrest 1 described above will be described in detail. As shown in FIG. 3, the headrest stay 3 has each leg portion 3a and a connecting portion 3b that connects the upper end portions of each leg portion 3a and extends in the left-right direction. The headrest stay 3 forms an inverted U shape when viewed from the front. Each leg portion 3a extends straight downward from the left and right end portions of the connecting portion 3b, and then extends so as to bend obliquely forward downward at a substantially central portion in the vertical direction.

[0017] <Headrest case 5 / Front case 10> As shown in FIGS. 3 and 4, the headrest case 5 has a front case 10 and a rear case 20 that can be divided front and rear. The front case 10 has a generally rectangular general surface portion 11 facing front and rear, and side surface portions 12 extending in a flange shape rearward from the peripheral edge of the general surface portion 11. As shown in FIG. 4, the front case 10 has two stay locking ribs 14 extending vertically on the upper part of the rear surface of the general surface portion 11. Each stay locking rib 14 has a recess 14a with a concave curved surface shape. The connecting portion 3b of the headrest stay 3 is adapted to be applied to each recess 14a from the rear side. Further, the side surface portions 12 have recesses 12a with a concave curved surface shape formed at two positions on the left and right sandwiching the general surface portion 11. Each leg portion 3a of the headrest stay 3 is adapted to be applied to each recess 12a from the rear side. Here, the headrest case 5 corresponds to the "case" of the present invention.

[0018] As shown in FIG. 4, the front case 10 has a front urethane support portion 13 that supports the front slab urethane 30 of the slab urethane 6 at the central portion of the rear surface of the general surface portion 11. The front urethane support portion 13 has an upper rib 13a forming a U-shape opening downward in a rear view and a lower rib 13b forming a U-shape opening upward in a rear view. The upper rib 13a has two upper side ribs 13a1 protruding from the inner surfaces of the left and right portions thereof. Further, the upper rib 13a has cutouts 13a2 notch-shaped in a concave curved shape at the lower ends of the left and right portions thereof.

[0019] As shown in FIG. 4, the lower rib 13b has two lower side ribs 13b1 protruding from the inner surfaces of the left and right portions thereof. Further, the lower rib 13b has cutouts 13b2 notch-shaped in a concave curved shape at the upper ends of the left and right portions thereof. The cutouts 13a2 of the upper rib 13a and the cutouts 13b2 of the lower rib 13b are formed so as to be substantially adjacent to each other in the vertical direction, and together form a substantially semi-circular cutout.

[0020] As shown in Figure 4, the front urethane support portion 13 has four front ribs 13c extending in the vertical direction. Each front rib 13c is formed from the central part to the lower part in the vertical direction of the front urethane support portion 13. Each front rib 13c is formed at predetermined intervals in the left-right direction. Each front rib 13c has a concave curved front receiving surface 13c1. As shown in Figure 11, each front receiving surface 13c1 is formed to be located approximately in the center in the vertical direction of the front urethane support portion 13. In addition, each front rib 13c has a front overhang 13c2 that extends significantly to the rear below the front receiving surface 13c1.

[0021] As shown in Figure 4, the front urethane support portion 13 has two reinforcing ribs 13d extending in the left-right direction at its upper and lower parts. Specifically, one of the reinforcing ribs 13d is formed to connect the left and right parts of the upper rib 13a. The other of the reinforcing ribs 13d is formed to connect the left and right parts of the lower rib 13b. Each reinforcing rib 13d is formed to extend across each front rib 13c from left to right.

[0022] As shown in Figure 4, the front urethane support portion 13 has two front pins 13e that protrude toward the rear. Each front pin 13e is formed side by side in the left-right direction. Each front pin 13e is positioned above each front rib 13c. As shown in Figure 6, each front pin 13e is inserted into the front locking hole 34 of the front slab urethane 30. This insertion allows the front urethane support portion 13 to hold the front slab urethane 30 in a set position.

[0023] As shown in Figure 4, the front case 10 has protruding portions 15 on the inner surface of the side portion 12 that extend backward from the side portion 12 from four locations on the top, bottom, left, and right sides, sandwiching the front urethane support portion 13. Each of the vertically positioned protruding portions 15 has a fitting claw 15a at its rear end that extends outward in the vertical direction. Similarly, each of the horizontally positioned protruding portions 15 has a fitting claw 15a at its rear end that extends outward in the horizontal direction.

[0024] <Rear case 20> As shown in Figure 3, the rear case 20 has a roughly rectangular general surface portion 21 facing forward and backward, and a side portion 22 that extends forward in a flange-like manner from the periphery of the general surface portion 21. The rear case 20 has two stay locking ribs 24 that extend vertically on the upper front surface of the general surface portion 21. Each stay locking rib 24 has a recess 24a with a concave curved surface shape. The connecting portion 3b of the headrest stay 3 is positioned to rest against each recess 24a from the front. The side portion 22 also has two recesses 22a with a concave curved surface shape formed on the left and right sides of the general surface portion 21. The legs 3a of the headrest stay 3 are positioned to rest against each recess 22a from the front.

[0025] As shown in Figure 3, the rear case 20 has a rear urethane support portion 23 in the center of the front surface of the general surface portion 21 that supports the rear slab urethane 40 of the slab urethane 6. The rear urethane support portion 23 has an upper rib 23a that is U-shaped and opens downward when viewed from the front, and a lower rib 23b that is U-shaped and opens upward when viewed from the front. The upper rib 23a has two upper lateral ribs 23a1 that protrude from the inner surfaces of its left and right sides. The upper rib 23a also has notches 23a2 that are cut out in a concave curve shape at the lower ends of its left and right sides.

[0026] As shown in Figure 3, the lower rib 23b has two lower lateral ribs 23b1 that protrude from the inner surfaces of its left and right sides. The lower rib 23b also has notches 23b2 cut out in a concave curve shape at the upper ends of its left and right sides. The notches 23a2 of the upper rib 23a and the notches 23b2 of the lower rib 23b are formed to be substantially adjacent to each other in the vertical direction, and together they form a substantially semicircular notch.

[0027] As shown in Figure 3, the rear urethane support section 23 has four rear ribs 23c extending in the vertical direction. Each rear rib 23c is formed from the upper part to the central part in the vertical direction of the rear urethane support section 23. Each rear rib 23c is formed at predetermined intervals in the left-right direction. Each rear rib 23c has a concave curved rear receiving surface 23c1. As shown in Figure 11, each rear receiving surface 23c1 is formed to be located approximately in the center in the vertical direction of the rear urethane support section 23. The front receiving surface 13c1 of the front urethane support section 13 and the rear receiving surface 23c1 of the rear urethane support section 23 are formed to substantially overlap in the vertical direction. In addition, each rear rib 23c has a rear overhang 23c2 that extends significantly forward above the rear receiving surface 23c1.

[0028] As shown in Figure 3, the rear urethane support portion 23 has two reinforcing ribs 23d extending in the left-right direction at its upper and lower portions. Specifically, one of the reinforcing ribs 23d is formed to connect the left and right portions of the upper rib 23a. The other of the reinforcing ribs 23d is formed to connect the left and right portions of the lower rib 23b. Each reinforcing rib 23d is formed to extend across each rear rib 23c from left to right.

[0029] As shown in Figure 3, the rear urethane support portion 23 has two rear pins 23e that protrude forward. Each reinforcing rib 23d is formed side by side in the left-right direction. Each rear pin 23e is positioned below each rear rib 23c. As shown in Figure 5, each rear pin 23e is inserted into the rear locking hole 44 of the rear slab urethane 40. This insertion allows the rear urethane support portion 23 to hold the rear slab urethane 40 in a set position.

[0030] As shown in Figure 3, the rear case 20 has rectangular fitting holes 25 that penetrate through to the inner surface of the side portion 22 at four locations on the top, bottom, left, and right sides, sandwiching the rear urethane support portion 23. Each fitting hole 25 is formed so as to overlap with the arrangement of each protruding portion 15 of the front case 10 in the vertical and horizontal directions. As shown in Figure 9, each fitting claw 15a of each protruding portion 15 snaps into each fitting hole 25. This fitting allows the front case 10 and the rear case 20 to be assembled as a single unit.

[0031] <Slab Urethane 6> As shown in Figures 3 and 4, the slab urethane 6 has a front slab urethane 30 and a rear slab urethane 40. The front slab urethane 30 is a cross-shaped planar member that protrudes convexly in the upper, lower, left, and right directions from the central part. The front slab urethane 30 has two front locking holes 34 formed in the shape of circular holes arranged on the left and right. The front slab urethane 30 also has a front extension portion 30a that extends downward from each front locking hole 34. Here, the front slab urethane 30 corresponds to the "front elastic body" of the present invention. The front locking holes 34 also correspond to the "front locking portion" of the present invention.

[0032] As shown in Figure 4, the front slab urethane 30 has a horizontally elongated portion 31 that extends longer than the left-right width of the mass body 7, and an upper overhang portion 32 and a lower overhang portion 33 that protrude vertically from the horizontally elongated portion 31, respectively. Each of the front locking holes 34 described above is formed to penetrate the upper overhang portion 32 in the front-rear direction.

[0033] As shown in Figure 6, the front slab urethane 30 is set on the front urethane support part 13 such that each front pin 13e of the front urethane support part 13 is inserted from the front into each front locking hole 34. In this way, the front slab urethane 30 is cantilevered to the rear surface of the front case 10. As shown in Figure 10, when the front slab urethane 30 is properly set to the rear surface of the front case 10, the tips of each front pin 13e pass through each front locking hole 34 and protrude from the rear surface of the front slab urethane 30.

[0034] As shown in Figure 6, when the front slab urethane 30 is set onto the front urethane support portion 13, the upper overhang portion 32 is sandwiched from both sides by the upper lateral ribs 13a1. The lower overhang portion 33 is sandwiched from both sides by the lower lateral ribs 13b1. The ends of the horizontally elongated portion 31 that protrude to the left and right are sandwiched from above and below by the upper lateral ribs 13a1 and the lower lateral ribs 13b1.

[0035] As shown in Figure 3, the rear slab urethane 40 is a cross-shaped planar member that protrudes convexly in the upper, lower, left, and right directions from the central part. The rear slab urethane 40 has two rear locking holes 44 formed in the shape of circular holes arranged side by side. The rear slab urethane 40 also has rear extensions 40a that extend upward from each rear locking hole 44. Here, the rear slab urethane 40 corresponds to the "rear elastic body" of the present invention. The rear locking holes 44 also correspond to the "rear locking part" of the present invention.

[0036] As shown in Figure 3, the rear slab urethane 40 has a horizontally elongated portion 41 that extends longer than the left-right width of the mass body 7, and an upper overhang portion 42 and a lower overhang portion 43 that protrude vertically from the horizontally elongated portion 41, respectively. Each of the rear locking holes 44 described above is formed to penetrate the lower overhang portion 43 in the front-rear direction.

[0037] As shown in Figure 5, the rear slab urethane 40 is set on the rear urethane support part 23 such that each rear pin 23e of the rear urethane support part 23 is inserted from the rear into each rear locking hole 44. In this way, the rear slab urethane 40 is cantilevered to the front surface of the rear case 20. As shown in Figure 10, when the rear slab urethane 40 is properly set up to the front surface of the rear case 20, the tips of each rear pin 23e pass through each rear locking hole 44 and protrude from the front surface of the rear slab urethane 40.

[0038] As shown in Figure 5, when the rear slab urethane 40 is set onto the rear urethane support portion 23, the upper overhang portion 42 is sandwiched from both sides by the upper lateral ribs 23a1. The lower overhang portion 43 is sandwiched from both sides by the lower lateral ribs 23b1. The ends of the elongated portion 41 that protrude to the left and right are sandwiched from above and below by the upper lateral ribs 23a1 and the lower lateral ribs 23b1.

[0039] <Mass body 7> As shown in Figures 3 and 8, the mass body 7 is a cylindrical member made of a metal material such as stainless steel. The left and right ends of the mass body 7 are rounded off. The mass body 7 is positioned so that its axis is oriented in the left-right direction. By positioning the mass body 7 laterally in this way, the difference in amplitude between the upper and lower ends when the mass body 7 oscillates can be reduced. This makes it easier to control the vibration of the mass body 7 and allows for proper vibration suppression.

[0040] <Assembly of Dynamic Damper D> The assembly of each component that makes up the dynamic damper D described above will be explained in detail below. First, as shown in Figure 3-4, the front case 10 and the rear case 20 of the headrest case 5 are separated into front and rear sections. First, as shown in Figure 6, the front slab urethane 30 is assembled to the front urethane support section 13 from the rear. Specifically, each front pin 13e is inserted through each front locking hole 34 from the front. Then, the front extension 30a is pressed against the front receiving surface 13c1 (see Figure 4) of each front rib 13c from the rear.

[0041] Next, as shown in Figure 5, the rear slab urethane 40 is assembled to the rear urethane support portion 23 from the front. Specifically, each rear pin 23e is inserted through each rear locking hole 44 from the rear. Then, the rear extension portion 40a is pressed against the rear receiving surface 23c1 (see Figure 3) of each rear rib 23c from the front.

[0042] Next, as shown in Figure 7, the headrest stay 3 is assembled to the rear case 20. Specifically, the connecting portion 3b of the headrest stay 3 is fitted from the front into the recess 24a (see Figure 3) of each stay locking rib 24. Also, each leg portion 3a of the headrest stay 3 is fitted from the front into the recess 22a (see Figure 3) of the side portion 22. Next, the mass body 7 is assembled to the rear case 20. Specifically, with the axis of the mass body 7 facing left and right, it is pressed from the front against the horizontally elongated portion 41 (rear extension portion 40a) of the rear slab urethane 40. As a result, the mass body 7 compresses the rear slab urethane 40 and is fitted into the rear receiving surface 23c1 of each rear rib 23c. When assembling the headrest stay 3 and the mass body 7 as described above, it is preferable to place the rear case 20 on the installation surface with its front surface facing upward. This prevents the headrest stay 3 and the mass body 7 from falling downward due to gravity.

[0043] Next, as shown in Figures 2 and 8, the front case 10 and the rear case 20 are assembled together. Specifically, as shown in Figure 9, the side portion 12 of the front case 10 and the side portion 22 of the rear case 20 are overlapped so that they abut each other. This causes the fitting claws 15a of each protruding portion 15 of the front case 10 to snap-fit ​​into each fitting hole 25 of the rear case 20. As a result, the front case 10 and the rear case 20 are assembled together as a single unit.

[0044] As shown in Figure 11, when the front case 10 and the rear case 20 are assembled together, the recesses 14a of each stay locking rib 14 are brought into contact with the connecting portion 3b of the headrest stay 3 from the front. This sets the connecting portion 3b to be sandwiched from the front and rear between the stay locking rib 14 of the front case 10 and the stay locking rib 24 of the rear case 20. In addition, each recess 12a of the front case 10 is brought into contact with each leg portion 3a of the headrest stay 3 from the front. This sets each leg portion 3a to be sandwiched from the front and rear between the recesses 12a of the front case 10 and the recesses 22a of the rear case 20. In this way, the headrest stay 3 and the headrest case 5 are assembled together.

[0045] Furthermore, as shown in Figure 11, the elongated portion 31 (front extension portion 30a) of the front slab urethane 30 is pressed against the mass body 7 from the front. As a result, the mass body 7 crushes the front slab urethane 30 and fits into the front receiving surfaces 13c1 of each front rib 13c. In this way, when the front case 10 and the rear case 20 are assembled, the front extension portion 30a of the front slab urethane 30 is crushed so as to curve along the shape of each front receiving surface 13c1. As a result, the front extension portion 30a supports the mass body 7 from the front over a wide area spanning above and below the mass body 7. Similarly, the rear extension portion 40a of the rear slab urethane 40 is also crushed so as to curve along the shape of each rear receiving surface 23c1. As a result, the rear extension portion 40a supports the mass body 7 from the rear over a wide area spanning above and below the mass body 7. Therefore, the mass body 7 is supported by being sandwiched between the front extension 30a and the rear extension 40a.

[0046] As shown in Figure 8, the left and right ends of the mass body 7 have a gap in the left-right direction between them and the inner surfaces of the left and right sides of the front urethane support portion 13. As shown in Figures 6 and 8, the left and right ends of the elongated portion 31 of the front slab urethane 30 are configured to make surface contact with the inner surfaces of the left and right sides of the front urethane support portion 13. As a result, when the front slab urethane 30 is pressed against the mass body 7, the left and right ends of the elongated portion 31 can fit into the gap between the inner surfaces of the left and right sides of the front urethane support portion 13 and the mass body 7, covering the mass body 7 from the outside in the left-right direction. The same applies to the rear slab urethane 40, where the left and right ends of the mass body 7 have a gap in the left-right direction between them and the inner surfaces of the left and right sides of the rear urethane support portion 23. As shown in Figures 5 and 8, the left and right ends of the elongated portion 41 of the rear slab urethane 40 are configured to make surface contact with the inner surfaces of the left and right sides of the rear urethane support portion 23. As a result, when the mass body 7 is pressed against the rear slab urethane 40, the left and right ends of the horizontally elongated portion 41 can fit into the gap between the inner surfaces of the left and right portions of the rear urethane support portion 23 and the mass body 7, thereby covering the mass body 7 from the outside in the left-right direction.

[0047] As shown in Figures 8 and 10, the front locking hole 34 of the front slab urethane 30 is formed in a region above the mass body 7. The rear locking hole 44 of the rear slab urethane 40 is formed in a region below the mass body 7. In other words, the front locking hole 34 and the rear locking hole 44 are positioned above and below the mass body 7 in the height direction. This allows for a wider range of motion of the mass body 7 compared to a configuration where the entire circumference of the front slab urethane 30 and the entire circumference of the rear slab urethane 40 are locked. It also suppresses tensioning and lifting of the front slab urethane 30 and the rear slab urethane 40. As a result, when the front case 10 and the rear case 20 are assembled together, it is less likely that the front slab urethane 30 and the rear slab urethane 40 will interfere with each other.

[0048] Furthermore, since the front locking hole 34 is formed in a region above the mass body 7, for example, when assembling the front case 10 and the rear case 20 by placing the rear case 20 on the installation surface and then placing the front case 10 over it, the worker can perform the assembly work while looking into the front locking hole 34 from the upper end of the front case 10. This allows for efficient confirmation of whether the front slab urethane 30 has fallen off the front case 10 while assembling the front case 10 and the rear case 20.

[0049] <Movement of Mass Body 7> As described above, the mass body 7 is elastically supported by being covered by the front slab urethane 30 and the rear slab urethane 40. With this configuration, the mass body 7 oscillates while compressing the front slab urethane 30 and the rear slab urethane 40. When the mass body 7 oscillates greatly back and forth, it comes into contact with the front support surfaces 13c1 and the rear support surfaces 23c1, restricting further movement (see Figure 11). Therefore, the front support surfaces 13c1 and the rear support surfaces 23c1 prevent the mass body 7 from falling off the front slab urethane 30 and the rear slab urethane 40. Furthermore, when the mass body 7 oscillates greatly from side to side, it comes into contact with the left and right sides of the front urethane support portion 13 and the rear urethane support portion 23.

[0050] As shown in Figures 8 and 11, the front receiving surface 13c1 of each front rib 13c makes line contact with the front slab urethane 30. Similarly, the rear receiving surface 23c1 of the rear rib 23c makes line contact with the rear slab urethane 40. This makes it easier for the mass body 7 to crush the front slab urethane 30 and the rear slab urethane 40 compared to a configuration where the front case 10 makes surface contact with the front slab urethane 30 or the rear case 20 makes surface contact with the rear slab urethane 40. Therefore, the range of motion of the mass body 7 can be increased.

[0051] As shown in Figure 10, each front pin 13e has a protruding pin shape. Therefore, when the mass body 7 moves in the forward upward direction, which is not covered by each front receiving surface 13c1, it can be restricted from moving any further by contacting each front pin 13e. Similarly, each rear pin 23e also has a protruding pin shape. Therefore, when the mass body 7 moves in the rear downward direction, which is not covered by each rear receiving surface 23c1, it can be restricted from moving any further by contacting each rear pin 23e.

[0052] In summary, the headrest according to the first embodiment has the following configuration. In the following, the reference numerals in parentheses correspond to the respective components shown in the above embodiment.

[0053] Specifically, it comprises a headrest stay (3) having legs (3a) attached to the top of the seat back, a case (5) assembled to the top of the headrest stay (3), and a headrest pad (2) as a cushioning material covering the case (5). Furthermore, it comprises a vibration-dampening mass body (7) disposed inside the case (5), and an elastic body (6) disposed inside the case (5) that elastically supports the mass body (7) relative to the case (5). The case (5) has a front case (10) and a rear case (20) which are divided so that they can be assembled front to back with each other. The elastic body (6) has a front elastic body (30) having a front locking portion (34) that locks onto the rear surface of the front case (10) and a front extension portion (30a) that extends from the front locking portion (34) along the rear surface, and a rear elastic body (40) having a rear locking portion (44) that locks onto the front surface of the rear case (20) and a rear extension portion (40a) that extends from the rear locking portion (44) along the front surface, and the mass body (7) is supported by being sandwiched between the front extension portion (30a) and the rear extension portion (40a). The front locking portion (34) and the rear locking portion (44) are arranged separately in one direction in the height direction or width direction and the other direction, sandwiching the mass body (7) between them.

[0054] In this way, the front locking portion (34) and the rear locking portion (44) are arranged separately on one side in the height direction or width direction that sandwiches the mass body (7), which suppresses tension and lifting of the elastic body (6) compared to a configuration in which the entire circumference of the front elastic body (30) and the entire circumference of the rear elastic body (40) are locked, respectively. As a result, when the front case (10) and the rear case (20) are assembled, the front elastic body (30) and the rear elastic body (40) are less likely to interfere with each other, thereby reducing assembly defects of the case (5). In addition, the range of motion of the mass body (7) can be increased compared to a configuration in which the entire circumference of the front elastic body (30) and the entire circumference of the rear elastic body (40) are locked, respectively. In this way, the case (5) can be properly assembled while increasing the range of motion of the mass body (7).

[0055] Furthermore, the headrest of the present invention may be configured as follows: The front case (10) has a front rib (13c) that protrudes from the rear surface and linearly contacts the front extension (30a) from the front. The rear case (20) has a rear rib (23c) that protrudes from the front surface and linearly contacts the rear extension (40a) from the rear. Therefore, compared to a configuration in which the front case (10) makes surface contact with the front extension (30a) and the rear case (20) makes surface contact with the rear extension (40a), the mass body (7) can more easily crush the elastic body (6). This makes it possible to further widen the range of motion of the mass body (7).

[0056] Furthermore, the headrest of the present invention may be configured as follows: The front locking portion (34) is positioned in a region above the mass body (7) of the front elastic body (30). The rear locking portion (44) is positioned in a region below the mass body (7) of the rear elastic body (40). This allows the worker to perform the assembly of the front case (10) and the rear case (20) by placing the rear case (20) on the installation surface and then placing the front case (10) over it, while looking at the front locking portion (34) from the upper end of the front case (10). Therefore, the worker can efficiently check whether the front elastic body (30) has fallen off the front case (10) while performing the assembly of the case (5).

[0057] Furthermore, the headrest of the present invention may be configured as follows: The front case (10) has a front pin (13e) protruding from the rear surface, and the front pin (13e) passes through a front locking hole (34) that forms the front locking portion (34) of the front elastic body (30) and protrudes rearward from the front elastic body (30). The rear case (20) has a rear pin (23e) protruding from the front surface, and the rear pin (23e) passes through a rear locking hole (44) that forms the rear locking portion (44) of the rear elastic body (40) and protrudes forward from the rear elastic body (40). As a result, the front elastic body (30) can be locked to the front pin (13e) in a way that prevents it from coming loose, even without providing the front pin (13e) and the rear pin (23e) with locking portions that engage with an elastic body (6), such as a hook. Furthermore, the rear elastic body (40) can be locked to the rear pin (23e) in a way that prevents it from easily coming loose.

[0058] Furthermore, the headrest of the present invention may be configured as follows: The mass body (7) is cylindrical in shape with its axis oriented in the left-right direction. This makes it possible to reduce the difference in amplitude between the upper and lower ends of the mass body (7), making it easier to control the vibration of the mass body (7). As a result, vibration suppression using the mass body (7) can be performed more effectively.

[0059] <Other Embodiments> Although the present invention has been described above using one embodiment, the present invention can be implemented in various forms other than those described above.

[0060] 1. Headrests can be widely applied not only to automobile seats, but also to seats used in various vehicles other than automobiles, such as trains, aircraft, and ships, as well as seats other than those used in vehicles, such as in public facilities like movie theaters and in homes. Headrests can be widely applied in forms other than those described above, as long as they elastically support the head of the person sitting. For example, a configuration in which a headrest pad is provided only on the front part of the headrest case.

[0061] 2. The front case and the rear case may be assembled integrally with each other by any method other than snap-fit ​​fitting of mating claws, such as fastening with screws or other fasteners, adhesive bonding, or welding. The front case may not have a front rib, and the rear case may not have a rear rib.

[0062] 3. The elastic body may be molded urethane in addition to slab urethane, or any other rubber-like material with cushioning properties. The elastic body may be of any shape. The front elastic body may be divided into multiple parts to support the mass from the front. The rear elastic body may be divided into multiple parts to support the mass from the rear. The front extension may extend in any direction from the front locking part, as long as it is oriented along the rear surface of the front case. For example, it may extend not only in one direction such as upward or downward, but also in multiple directions such as up and down or left and right. Similarly, the rear extension may extend in any direction from the rear locking part.

[0063] 4. The front locking portion and the rear locking portion may be locked to the case by pins or hooks protruding from the elastic body in addition to the locking holes, or they may be adhesive portions that are bonded to the case with adhesive, such as hook-and-loop fasteners. The front locking portion and the rear locking portion may be arranged separately on one side and the other side in the width direction that sandwiches the mass body, or they may be arranged diagonally across the mass body. The front locking portion may lock the area of ​​the front elastic body below the mass body, and the rear locking portion may lock the area of ​​the rear elastic body above the mass body. The front locking hole does not have to penetrate the front elastic body, and the rear locking hole does not have to penetrate the rear elastic body.

[0064] 5. The front pin and rear pin may be provided one at a time, or three or more of each may be provided. The front pin and rear pin do not have to be configured to protrude through the elastic body. The front pin and rear pin may have locking parts such as hooks or flanges at their protruding tips to prevent them from coming loose from the elastic body.

[0065] 6. The mass body may be cylindrical, prismatic, cubic, spherical, or any other shape. A cylindrical mass body may be positioned vertically with its axis oriented in the vertical direction. [Explanation of Symbols]

[0066] 1 Headrest 2 headrest pads 3 Headrest stays 3a Legs 3b Connecting part 4 Headrest Covers 5. Headrest Case (Case) 6. Slab urethane (elastic material) 7 mass body 10 Front case 11 General area 12 Side part 12a depression 13 Front urethane support section 13a Upper rib 13a1 Upper lateral rib 13a2 Notch 13b Lower rib 13b1 Lower lateral rib 13b2 Notch 13c Front Rib 13c1 Front receiving surface 13c2 Front protrusion 13d Reinforcement Rib 13e Front pin 14 Stay locking rib 14a depression 15 Overhang 15a Engaging claw 20 Rear case 21 General area 22 Side part 22a depression 23 Rear urethane support section 23a Upper rib 23a1 Upper lateral rib 23a2 Notch 23b Lower rib 23b1 Lower lateral rib 23b2 Notch 23c Rear rib 23c1 Rear receiving surface 23c2 Rear overhang 23d Reinforcement Rib 23e Rear pin 24 Stay locking rib 24a depression 25 Fitting holes 30 Front slab urethane (front elastic body) 30a Front extension 31 Horizontal section 32 Upper overhang 33 Lower overhang 34 Front locking hole (front locking part) 40. Rear slab urethane (rear elastic body) 40a Rear extension 41 Horizontal section 42 Upper overhang 43 Lower overhang 44 Rear locking hole (rear locking part) D Dynamic Damper

Claims

1. A headrest comprising a headrest stay having legs attached to the top of the seat back, a case assembled to the top of the headrest stay, and a headrest pad as a cushioning material covering the case, A mass body for vibration suppression is placed inside the case, The case has an elastic body disposed inside the case and elastically supporting the mass relative to the case, The aforementioned case has a front case and a rear case that are divided so as to be assembled front to back with each other, The elastic body comprises a front elastic body having a front locking portion that engages with the rear surface of the front case and a front extension portion that extends from the front locking portion along the rear surface, and a rear elastic body having a rear locking portion that engages with the front surface of the rear case and a rear extension portion that extends from the rear locking portion along the front surface, and the mass body is supported by being sandwiched between the front extension portion and the rear extension portion. A headrest in which the front locking portion and the rear locking portion are arranged separately in one direction in the height direction or the width direction and the other direction, with the mass body sandwiched between them.

2. A headrest according to claim 1, The front case has a front rib that protrudes from the rear surface and strikes the front extension linearly from the front, The rear case has a rear rib that protrudes from the front and strikes the rear extension linearly from the rear.

3. A headrest according to claim 1 or claim 2, The front locking portion is positioned in a region above the mass body of the front elastic body, The rear locking portion is positioned in a region below the mass body of the rear elastic body of the headrest.

4. A headrest according to claim 1 or claim 2, The front case has a front pin protruding from the rear surface, and the front pin passes through a front locking hole that forms the front locking portion of the front elastic body and protrudes rearward from the front elastic body. The rear case has a rear pin that protrudes from the front surface, and the rear pin passes through a rear locking hole that forms the rear locking portion of the rear elastic body and protrudes forward from the rear elastic body.

5. A headrest according to claim 1 or claim 2, The aforementioned mass is a headrest with a cylindrical shape whose axis is oriented in the left-right direction.

Images