JP2009268897A - Headrest support device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent reduction of strength of a stay of a headrest even with a shallow recess for locking to the stay by providing it with sufficient locking force, and achieve molding efficiency by applying roll molding. <P>SOLUTION: The stay to be inserted to a backrest from above for supporting the headrest is composed of a pipe having a circular section. A plurality of recesses are circumferentially formed along the circumference of the stay in vertical stages. A lock member is provided on the backrest side to be resiliently engaged inside the recess by means of a spring in a retractable way to the stay. The headrest is thus supported in various height by varying the vertical position of the recess to which the lock member is inserted into the headrest support device. The circumference of the stay is recessed in an arc shape by roll molding. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a headrest support device that supports a headrest attached to a vehicle seat on a seatback.

  The vehicle seat is provided with a headrest for the safety of the occupant. The height of the headrest can be adjusted in consideration of the physique of the occupant. For this reason, the headrest cannot be fixedly provided on the seat back or the like, and a plurality of upper and lower dents (recesses) are formed on the stay of the headrest formed of a pipe standing up from the seat back as in Patent Document 1 below. The position of the dent is selected and a locking member provided on the seat back is inserted and fixed.

  The stay must not be able to withstand a rear load caused by pressing of the head, and the locking member must not come out of the recess due to vibration or the like. In addition, it must be able to withstand even when a load is applied downward on the headrest, such as when a passenger in the rear seat presses the headrest unexpectedly. Therefore, it is necessary to deepen the dent and ensure a sufficient area of engagement with the locking member.

  By the way, since the conventional dent is dented linearly on the side facing the locking member (the vehicle width direction is common), the interface length (deployment length) with the locking member cannot be increased. Therefore, in order to secure a necessary engagement area with the locking member, the depth of the recess must be increased. However, if the dent is deepened, the strength of the pipe is reduced, so that a thick wall must be used, which increases the weight and the cost.

  The formation of the dent includes a cutting process and a press process. In the former case, since the dent part is all removed, an extra thick pipe is required. For this reason, recently, it is often by press working which forms a dent by plastic flow. However, even in the press work, the substantial depth of the dent is reduced by the sag near the dent entrance, so the dent must be made deeper than necessary. In addition, there is a limit to reducing the thickness of the pipe as a material because there is a reduction in the thickness due to the extension due to the impact of the punch.

  In addition, in order to press the dent, it is necessary to insert a cored bar into the pipe. In consideration of the insertion / extraction, the cored bar must be thinned with a margin with respect to the inner diameter of the pipe. In addition, pipe materials are often manufactured by roll forming and welding, but according to this, a small amount of welding burrs remain inside the pipe material, and the core metal must also be made thin. I must. Such a thing further promotes sagging and elongation. Further, a process for inserting and removing the cored bar is required, and the productivity is inferior.

  Furthermore, in press working, there is a problem of cracking, and it is difficult to use high-strength steel due to restrictions on material selection and the shape of the dent. Under such circumstances, a relatively deep recess having a depth of about 1.5 mm is formed. If the dent is deep, the strength is reduced, so this needs to be compensated. For example, a thick pipe having a tensile strength of 750 MPa, a diameter of 12 mm, and a wall thickness of about 1.5 to 2 mm is required. In any case, if a thick-walled pipe is used, it cannot meet the demand for weight reduction and cost reduction that has been screamed recently.

  The following patent document 2 can be seen as an example of increasing the engagement area. In this preceding example, the dent is formed to an angle close to 180 °. However, since this dent is formed by press molding, the above-described disadvantages of press molding are applied as they are. Rather, the larger the dent angle, the more negative elements mentioned above are weighted. In some cases, the process cannot be performed in a single step, and the machining efficiency is reduced at a stroke by requiring setup change.

Japanese Patent Laid-Open No. 10-1000076 JP 2005-137880 A

  The problem to be solved by the present invention is that a sufficient engagement area with the locking member can be secured without deepening the dent so that it can sufficiently withstand a rear load and a downward load, and vibration This prevents accidental detachment due to, for example. In addition, by forming the dent with a roll, sagging and the like are prevented, and even with roll molding, the dent can be formed at an arbitrary depth and angle in the circumferential direction.

  Under the above-described problems, the present invention provides a plurality of dents in the circumferential direction of the outer periphery of the stay, which is composed of a pipe having a circular cross section that is inserted into the seat back from above and supports the headrest. In addition to the formation, a locking member that is spring-loaded on the seat back side and enters the recess can be retracted from the stay, and the height of the headrest is changed by changing the vertical position of the recess that the locking member enters In the headrest support device for supporting the headrest, the headrest support device is characterized in that the outer periphery of the stay is formed into a recess by arc-shaped by roll forming, and the recess according to claim 2 is provided. Means for forming an angle exceeding 180 °, and means for forming an indentation at 360 ° according to claim 3 are provided.

  According to the first aspect of the present invention, since the dent is formed by roll forming, there is no occurrence of thickness reduction, cracking, and complicated operation due to sag or extension in press forming. In addition, since the recess is formed in an arc shape, the interface length with the engagement member is increased, and the depth of the recess corresponding to securing the engagement area can be reduced accordingly. Therefore, a thin-walled pipe can be used, and the weight and cost can be reduced. If the interface length of the means of claim 2 is sufficiently greater than 180 °, the stroke required when the locking member comes out of the recess can be set arbitrarily and arbitrarily, and the accidental disconnection due to vibration etc. Nor. Further, the locking member sandwiches the dent (stay), and the prevention of unintentional detachment and vibration due to vibration or the like can be greatly improved as compared with the conventional linear dent. According to the third aspect of the present invention, in addition to the above-described action, the direction of the dent is not limited during the bending process in order to form the dent on the entire circumference. Therefore, it is possible to easily perform the processing when plating is performed in a straight state and then bending is performed.

It is a partial cross section figure of a headrest support device. It is a partial cross section figure of a headrest support device. It is a longitudinal cross-sectional view of a dent. It is a longitudinal cross-sectional view of the dent of a prior art example. It is a cross-sectional view which shows the relationship between a dent and a locking member. It is a cross-sectional view which shows the relationship between the other example of a dent, and a locking member. It is a front view of a forming roll. It is sectional drawing of a forming roll. It is a front view when forming the dent with a forming roll. It is a perspective view which shows the manufacturing process of a stay. It is explanatory drawing in the case of forming a dent with a forming roll. It is explanatory drawing in the case of forming a dent with a forming roll. It is explanatory drawing in the case of forming a dent with a forming roll.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 and FIG. 2 (the symbols are omitted because they are the same as those in FIG. 1) are partial cross-sectional views of the headrest support device. The headrest 1 is placed on the upper part of the stay 3 inserted into the seat back 2 from above. It can be attached. In this case, the stay 3 is inserted into a support member 4 embedded in the seat back 2 and protrudes from a housing portion 5 attached to the top surface thereof. A lock mechanism 6 is incorporated in the housing part 5 to restrict the vertical movement of the stay 3.

  The lock mechanism 6 of this example is formed with a plurality of upper and lower recesses 7 in the stay 3 and a locking member 8 is inserted into the recesses 7 to be in a locked state (FIG. 1). Specifically, a push button 9 that is slidable in the direction of the stay 3 is provided on the housing portion 5, and a latching portion 8 a, 8 b that projects into the recess 7 is arranged on the opposite side of the push button 9 to the stay 3. The member 8 is fixed. The push button 9 is urged toward the opposite stay 3 by the spring 10, so that when the hand is released from the push button 9, the locking member 8 enters the recess 7 with the force of the spring 10. On the other hand, when the push button 9 is pressed, the locking member 8 moves backward and comes out of the recess 7, and the stay 3 is unlocked so that it can move both upward and downward (FIG. 2).

  FIG. 3 is a vertical sectional view of the recess 7 according to the present invention. The vertical cross-sectional shape of the recess 7 includes a horizontal portion 7a that horizontally cuts inwardly from the outer periphery and a vertical portion 7b that extends vertically downward from the horizontal portion 7a. (Bottom of the dent 7) and an inclined portion 7c that gradually increases downward from the vertical portion 7b toward the outer peripheral side. When the locking member 8 enters the dent 7, the horizontal portion 7a moves the stay 3 downward. Is regulated and locked. In this case, since the inclined portion 7c has a gentle inclination, the locking member 8 can be retracted against the force of the spring 10 and can move upward when the stay 3 is pulled up even in the locked state. It has become. FIG. 4 is a longitudinal sectional view of the recess 7 of the conventional example shown for reference. In the conventional example, the thickness reducing portion P and the extending portion Q accompanying the press working are thus provided.

  FIG. 5 is a cross-sectional view showing the relationship between the recess 7 and the locking member 8 according to the present invention, in which the up-down direction is the front-rear direction of the vehicle and the left-right direction is the vehicle width direction, 8 is advancing and retracting in the vehicle width direction. Accordingly, the dent 7 of the present invention is gradually shallower toward the vehicle width direction side with the maximum depth S as the center, and the stay 3 does not reach the center line in the front-rear direction. It is strong. Then, the outer periphery of the stay 3 facing the locking member 8 side is recessed into an arcuate curved surface that bulges outward at an angle corresponding to the interface length with respect to the locking member 8 (this is called the interface angle θ). This is a dent 7. That is, assuming that the radius of the stay 3 is r, the recess 7 is expanded at an interface angle θ by an arc of radius R with the maximum depth being a portion where only S is on the horizontal line. Such a recess 7 can be suitably formed by roll forming, which will be described later.

  Accordingly, the locking member 8 also has a shape along the recess 7 and enters the recess 7. At this time, the engagement area is increased so that the tips of the protrusions 8a and 8b of the locking member 8 are in contact with the bottom of the recess 7 (vertical portion 7b). According to this, the interface length with the locking member 8 is longer by a (shaded portion) than the conventional example in which the bottom of the recess 7 is formed by a straight line T in the front and rear direction, and the effect of the engagement area and the pinching is increased. , Stay 3 retention effect is high. Furthermore, increasing the interface length means that the recess 7 may be shallow, which is advantageous in terms of strength, workability, and material selection. However, since an increase in the interface angle θ leads to a decrease in the strength of the stay 3 in the front-rear direction, it is desirable to determine about 150 ° so that the dent 7 does not reach the front-rear center line.

  FIG. 6 is a cross-sectional view showing the relationship between another example of the recess 7 and the locking member 8. In this example, the recess 7 is formed over the entire circumference of the stay 3, and the locking member 8 is formed. The protrusions 8 a and 8 b are inserted at an interface angle of 180 ° which is a half circumference of the stay 3. According to this, the interface length is maximized, and the stroke S ′ required for detachment is also maximized (however, this stroke can be further increased by extending the front ends of the entry portions 8a and 8b forward). As described above, when the interface length between the recess 7 and the locking member 8 is increased, the horizontal portion 7a of the recess 7 does not necessarily have to be horizontal, and is an inclined surface or a gentle surface that increases outward by about 15 ° as shown in FIG. It may be a curved surface, which increases the ease of processing.

  By the way, the detachment stroke increases with an increase in the interface angle θ. On the other hand, the increase in the interface angle θ increases the relationship in which the upward tensile force of the stay 3 is not converted into the retracting force of the locking member 8. In this case as well, if the inclined portion 7c of the recess 7 is loosened, the resistance when the stay 3 moves upward is reduced, but there is a limit to this. From the viewpoint of the backward movement of the locking member 8 due to the upward movement of the stay 3 and the high retainability of the stay 3 due to the increase in the interface length between the recess 7 and the locking member 8, the above-described interface angle of 150 ° is a suitable angle. be able to.

  In this way, if the interface angle is set to 180 °, the detachment stroke of the locking member 8 can be increased, and the maximum squeezing with respect to the dent 7 is possible. Therefore, the dent 7 may be shallow. . Therefore, even if the recess 7 is formed over the entire circumference of the stay 3, the strength is not lowered significantly. According to this example, when the dent 7 is formed over the entire circumference of the stay 3 with a pipe having a thickness of 1.2 mm, it is confirmed that the depth may be about 0.5 to 0.7 mm, which is half of the conventional one. ing. When the interface angle is 180 °, as described above, the locking member 8 does not retract even if the stay 3 is pulled upward while the lock mechanism 6 is in the locked state. Therefore, when the stay 3 is moved upward (of course, downward), it is necessary to push the push button 9 into the unlocked state.

  As described above, the recess 7 is formed in an arc shape with respect to the stay 3. The arc shape in this case means that when the bottom surface of the recess 7 is seen in a sectional view, the recess 7 is formed into an arc (including a full circle) from the outer periphery of the stay 3. In the present invention, the recess 7 is formed by roll forming. 7 is a front view of the forming roll, FIG. 8 is a cross-sectional view, and FIG. 9 is a front view of the forming roll in operation. One or more forming rolls 13 can be rotated on the rotating disk 12 at substantially the same distance. Attach to. The rotating disk 12 has a through hole 12a in the center, and a pipe serving as the stay 3 is inserted into the through hole 12a. In this case, the outer periphery of the forming roll 13 is set so as to enter the through hole 12a.

  Now, when the stay 3 inserted through the through hole 12a is moved to the forming roll 13 side by rotating the rotary disk 12, the forming roll 13 interferes with the stay 3, and the outer periphery thereof is recessed by a depth corresponding to the interference. Set to 7. In this case, if a plurality of forming rolls 13 having the same shape are slightly shifted from each other (in this example, a first forming roll 13a for roughing and a second forming roll 13b for finishing are provided. ), The working depth of the one that acts later is gradually increased, thereby facilitating the molding process. The shape of the recess 7 in this case is such that the outer side of the radius A gradually decreases from the center O of the rotating disk 12, which is the envelope of the outer periphery of the final finishing forming roll 13, toward the end of the interface angle θ. It becomes a bulging arc.

  Furthermore, when the stay (work) 3 is rotated or can be moved toward and away from the forming roll 13, the shape and interface angle of the recess 7 can be freely set. FIGS. 11 to 13 are explanatory views, but the rotating disk 12 is fixed (even in this case, the forming roll 13 is allowed to rotate), the stay 3 is pushed into the through-hole 12a and rotated while being rotated. 13 is made to approach and bite. The amount of biting at this time becomes the depth of the recess 7 of the stay 3, and when the stay 3 is rotated through 360 ° in this state (in this case, the rotating disk 12 may also be rotated), the recess 7 having the same depth. Can be formed (FIG. 11). In addition, when the amount of biting is too large for one bite and molding is difficult, molding can be performed in several times.

  Moreover, if the approaching amount to the forming roll 13, that is, the amount of biting, is controlled according to the rotation angle of the stay 3, the depth and angle of the recess 7 can be freely adjusted (FIG. 12). Furthermore, the part which does not form the dent 7 in the outer periphery of the stay 3 can also be formed over arbitrary angles (FIG. 13). In short, the depth and angle of the recess 7 can be freely formed in the circumferential direction by controlling the rotation angle of the stay 3 and the approaching amount of the stay 3 to the forming roll 13 side. Further, at this time, the rotating disk 12 can be rotated within a range that does not affect the depth and angle, so that the molding efficiency can be improved. In addition, the recess 7 can be continuously formed in a spiral shape (however, it is necessary to match the protrusions 8a and 8b of the locking member 8), and the strength reduction of the stay 3 can also be suppressed.

  In this way, the dent 7 is gradually plastically flow-formed by roll forming, so that there is no fear of material cracking that frequently occurs due to impact during pressing, and the dent 7 is reduced in thickness due to sagging and extending. Does not happen. In this respect, high-strength steel can be used, and a thinner pipe can be used for the increase in strength. In fact, it has been confirmed that high-tensile steel having a tensile strength of 1,200 MPa can be used. Further, as a matter of course, a mandrel or the like is unnecessary, and the step of inserting and removing it can be omitted, so that productivity is improved.

  FIG. 10 is an explanatory view showing the manufacturing process of the stay 3, and the stay 3 has a gate shape formed by the vertical leg portion 14 and the horizontal portion 15 as a final shape. In the manufacture, first, the pipe is cut into the length of the stay 3 (1), and then the recess 7 (in this example, formed over the entire circumference) is formed (2) after the plating treatment (3). According to this, since the stay 3 is linear at the time of the plating process, when it is suspended in the plating tank, many things are suspended as compared with those formed in a gate shape, and the productivity is improved. In this case, chrome plating is suitable for the plating. Finally, the gate is bent (4). However, if the recess 7 is formed over the entire circumference of the stay 3, there is an advantage that an order cannot be placed in the bending direction of the horizontal portion 15.

DESCRIPTION OF SYMBOLS 1 Headrest 2 Seat back 3 Stay 4 Support member 5 Housing part 6 Lock mechanism 7 Indentation 7a Indentation horizontal part 7b Indentation vertical part 7c Indentation inclined part 8 Engagement member 8a Engagement part of engagement member 8b Engagement of engagement member Part 9 Push button 10 Spring 11 Stopper 12 Rotating disk 12a 貫通 through-hole 13 Forming roll 13a First forming roll 13b Second forming roll 14 Stay vertical leg part 15 Stay horizontal part

Claims (3)

  A plurality of dents are formed in the circumferential direction of the outer periphery of the stay, which is composed of a pipe having a circular cross section that is inserted into the seat back from above to support the headrest, and is spring-loaded on the seat back side to enter the dent. In the headrest support device that supports the headrest by changing the height of the recess by providing the locking member so as to be retractable with respect to the stay and changing the vertical position of the recess into which the locking member enters, the outer periphery of the stay is arc-formed by roll forming A headrest support device characterized by being recessed to form a dent.   The headrest device according to claim 1, wherein an angle at which the recess is formed exceeds 180 °.   The headrest device according to claim 1 whose angle which makes a dent concave is 360 degrees.