JP4728670B2 - Automotive seat backrest frame - Google Patents

Description

  The present invention relates to a backrest frame that forms a skeleton of a seat back of an automobile seat.

  As shown in FIG. 6, a front seat (driver's seat and front passenger seat) 40 of an automobile is attached to a rear end portion of a seat cushion 41 on which an occupant H sits so that a seat back 43 can be reclined via a reclining adjuster mechanism 42. The headrest 44 is attached to the upper end portion of the seat back 43.

  FIG. 5 is a perspective view showing a general structure of a seat frame 45 that is a skeleton of the front seat 40. The seat frame 45 includes a seat cushion frame 46 that forms the skeleton of the seat cushion 41 in FIG. 6 and a seat back frame 47 that forms the skeleton of the seat back 43. The seat cushion frame 46 includes a left side frame 48 and a right side frame 49 arranged in parallel to each other with an interval in the left-right L-Ri direction when viewed from the front side F in an arrangement along the front-rear direction FR of the automobile, A front cross member 50 and a rear cross, which are bridged between the front F-side end and the rear R-side end of both side frames 48 and 49, and are fixed to each side by welding or the like. The member 51 is provided and is configured in a rectangular frame shape in plan view.

  The seat back frame 47 includes an upper pipe 52 formed by bending a metal pipe in a substantially inverted U shape, a pair of left and right side brackets 53 and 54 connected to both ends of the upper pipe 52, An outer peripheral skeleton is constituted by a reinforcing lower cross panel 55 having both ends fixed to each other by means such as welding in an arrangement that spans between the vicinity of the lower ends of the side brackets 53, 54. Further, the wire 56 that is installed over the vicinity of the upper end of each of the side brackets 53 and 54 and the arrangement that is installed between the side brackets 53 and 54 so as to be bridged between the middle portions of the side brackets 53 and 54 absorb and reduce the impact from the front. In this configuration, an occupant support component including four S springs 57 is provided. Two headrest mounting brackets 58 to which the headrest 44 of FIG. 6 is attached are fixed to the upper portion of the upper pipe 52 by welding. Depending on the vehicle model, a contour mat may be used instead of the S spring 57.

  However, the seat back frame 47 has an insufficient function to protect the occupant from being obstructed by absorbing and reducing the load caused by the impact when receiving a rear-end collision from the following vehicle. Will be described with reference to FIG. Immediately after the occurrence of rear-end collision, as shown in FIG. 7A, the torso of the occupant H is moved backward from the normal state of FIG. Situation occurs. At this time, in the seat back frame 47, the occupant support components such as the wire 56 and the S spring 57 are elastically deformed by receiving the input load indicated by the arrow, and therefore the input load by the occupant H moved rearward is the upper pipe 52 in FIG. And the lower cross panel 55 are only received at the upper and lower two places. For this reason, the occupant H can only receive the upper shoulder portion and the lumbar portion in a line-contact state and is not held in the required sitting posture. There is a risk that a fault will occur.

  Further, since the seat back frame 47 has an occupant support component having elasticity, the input load to the upper pipe 52 becomes large, and the headrest 44 is tilted rearward with the lower end portion as a fulcrum. The head of the occupant H at the time of rear-end collision cannot be supported at a very short distance from the head of the vehicle, and the whiplash failure cannot be prevented. Further, when a large impact load starts to be input as time elapses from the time of rear end collision, the seat back frame 47 has a large moment arm for the input load to the upper pipe 52 as shown in FIG. Accordingly, since the vehicle is greatly inclined rearward, the restraining force on the occupant H is almost eliminated. As a result, as shown by the arrow, the occupant H may be thrown upward along the seat back 43 to cause a secondary failure.

Further, even if the S spring 57 and the wire 56 that are occupant support parts are attached with their attachment positions and structures set very accurately, it is difficult to reliably hold the occupant H in a desired seating posture. That is, as shown in FIG. 6, since the human spine H _S has a S-curve shape when viewed from the side, from the ergonomic point of view, when riding, the spine H _{S of the} occupant H is always S-curve when viewed from the side. It is necessary to hold the occupant H in a sitting posture that is maintained in the shape. However, since the S spring 57 and the wire 56 have elasticity that is always deformed by receiving a load caused by vibrations during driving of the automobile, the occupant H can be used as described above even if the mounting position or structure thereof is devised. It is difficult to keep the sitting posture.

  On the other hand, as another seat back frame, there is one having a configuration in which both the outer peripheral skeleton and the occupant support components inside the outer skeleton are formed of a pressed metal sheet metal part. The seat back frame hardly deforms even when subjected to an impact load, so that the occupant can be rigidly received and held in a required posture even when a rear-end collision occurs. On the other hand, since the amount of deformation due to impact is extremely small, it is impossible to effectively absorb or mitigate the impact at the time of rear-end collision. Therefore, when a rear-end collision occurs, the occupant is struck against the seat back frame by the impact, and there is a possibility that the occupant may suffer another obstacle such as bruise or spinal cord injury. In addition, since the seat back frame has only a function of catching the occupant moved rearward due to an impact and has a function of restraining the occupant, the occupant follows the seat back 43 in the same manner as the seat back frame 47 described above. Therefore, it is impossible to avoid a situation where a secondary obstacle occurs due to being thrown upward.

  The present invention has been made in view of the above-mentioned conventional problems, and it has an energy absorbing function that can relieve the impact caused by the rear-end collision by deformation, and the deformation that causes a decrease in the restraint of the occupant, thereby ensuring the occupant. An object of the present invention is to provide a backrest frame for an automobile seat having a structure that simultaneously satisfies two contradictory requirements with an occupant restraint function that can be restrained.

  In order to achieve the above object, the backrest frame of the automobile seat of the invention according to claim 1 is a backrest panel formed in a shape that rigidly receives from the shoulder upper part of the occupant to the waist by a metal flat plate material, Left and right side frames fixed to the backrest panel so as to project forward from both left and right sides of the backrest panel, and lower end portions connected to a seat cushion frame via a reclining adjuster mechanism, and the backrest A lower cross member fixed to the lower end portion of the rear surface of the panel and the lower end portions of the left and right side frames, a headrest bracket fixed to the upper end portion of the backrest panel, and a headrest stay supported by the headrest bracket And comprising A cross member is a band-shaped main body fixed to the rear surface of the backrest panel, and extends obliquely outward and outward from both ends of the main body, and the front ends thereof are rear end portions of the left and right side frames. It is characterized by having a pair of left and right mounting pieces fixed together.

  According to a second aspect of the present invention, in the backrest frame of the automobile seat of the first aspect of the invention, each of the left and right ends of the upper portion of the backrest panel is located obliquely forward and outward from the mounting position of the lower cross member. A pair of left and right mounting pieces are integrally formed, and the tip of each mounting piece is fixed to a central portion in the front-rear direction of the left and right side frames.

  In the first aspect of the invention, when a rear end collision occurs, when an initial load is applied to the backrest panel that is displaced rearward from the occupant due to the inertial force due to the impact, the main part of the lower cross member is attached to the left and right mounting pieces. The lower end portion of the backrest panel is moved backward integrally with the main body while being deformed so as to be pushed outward. Thereby, the initial load due to the impact immediately after the rear-end collision occurs is effectively mitigated by energy absorption due to the lower end portion of the backrest panel moving rearward while deforming the pair of attachment pieces of the lower cross member. At the same time, the left and right side frames are deformed into a state in which the rear end is bent inward under a load pushed outward as the mounting piece of the lower cross member is deformed. Restrained to sandwich from the left and right.

  On the other hand, the left and right side frames are connected to the seat cushion frame via the reclining adjuster mechanism, so they are not moved rearward, but are tilted backward with the lower end as a fulcrum. The upper part of the backrest panel moves backward with the side frame, but the lower end part is moved backward, so that it is translated backward while maintaining the vertical arrangement in the normal state. Since this backrest panel is formed of a metal flat plate and has high rigidity, it does not deform in the vertical direction even when it receives a load due to an impact at the time of rear end collision.

  Therefore, since the backrest panel receives the load from the occupant vertically and holds the occupant in the vertical direction as a whole, the backrest panel can be guided rearward while maintaining a required posture with respect to the occupant. In addition to this, the initial load can be effectively mitigated, and the lower end portions of the left and right side frames are deformed inward to restrain the occupant's waist from being sandwiched from both the left and right sides. Therefore, the input of bending load and shear load to the entire spine is remarkably reduced, and there is no risk of being damaged. In addition, since the backrest panel receives the load from the occupant vertically, the headrest supports the head at a close distance without leaving the occupant's head, thereby preventing the occurrence of whiplash damage.

  In the invention of claim 2, when a large impact load is input due to the occurrence of a rear-end collision, the backrest frame stops at a predetermined rearward tilt angle preset by design, and the upper portion of the lower cross member on the backrest panel is separated from the occupant. Since the left and right side frames are connected to the seat cushion frame via the reclining adjuster mechanism, they can only be tilted backwards, and the rearward displacement is restricted. Therefore, the backrest panel mounting piece displaced rearward receives an inward pulling force and is deformed to be bent inward. The left and right side frames that are deformed inwardly restrain the occupant while being sandwiched from the left and right. For this reason, the occupant is reliably restrained by the backrest panel and the left and right side frames while maintaining the required seating posture even when the seat back is tilted back to a predetermined backward tilt angle. There is no risk of being thrown out toward the vehicle, and it is possible to avoid the occurrence of a secondary obstacle in the passenger.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the best embodiment of the present invention will be described in detail with reference to the drawings. 1A and 1B are perspective views showing a backrest frame BF according to an embodiment of the present invention as seen from the front side and the rear side, respectively. The backrest frame BF of the present invention has a name in accordance with a function described later, and is used in the same form as the existing seat back frame 47 shown in FIG. 5 for an automobile seat. is there.

  The backrest frame BF is roughly divided into a back plate 1 and a left and right side of the back rest panel 1 with respect to the back rest panel 1. Left and right side frames 2 and 3 fixed in a projecting manner from the front to the front, and lower cross members fixed to the vicinity of the lower end of the backrest panel 1 and the lower ends of the left and right side frames 2 and 3 respectively. 4, a headrest bracket 7 fixed to the front surface of the upper end of the backrest panel 1, and a headrest stay 8 held by the headrest bracket 7.

The said backrest panel 1 has the external shape which forms the outer periphery frame | skeleton as a backrest frame BF, and also has a function as a passenger | crew support member, and is an AA cut | disconnected end view of Fig.1 (a). As clearly shown in FIG. 2 (b), it is formed in a side view shape corresponding to the S-shaped curve of the spine H _s (FIG. 6) from the upper shoulder of the human body through the thoracic vertebra to the lumbar vertebra, and has a rectangular shape on the back surface. The reinforcing concave portion 9 is formed so as to extend in the vertical direction in the upper half portion. The reinforcing recess 9 increases the vertical rigidity of the backrest panel 1 to prevent the backrest panel 1 from being deformed in the vertical direction even when receiving a load due to an impact at the time of rear end collision. It functions to ensure the strength of the bracket 7.

  Moreover, as shown to Fig.3 (a) which is sectional drawing which cut | disconnected the BB line | wire equivalent part of FIG.1 (b) in the seat back 14 comprised using the said backrest panel 1, the backrest panel 1 is shown. A pair of lower mounting pieces that are formed in a curved shape that is slightly recessed toward the rear to improve rigidity, and that extend in the vicinity of the lower end from both the left and right sides toward the front diagonally outward. 10 is integrally formed by bending means. Therefore, when viewed as a whole, the backrest panel 1 has a substantially U-shaped cross-sectional shape that expands outward. On the other hand, at the upper end of the backrest panel 1, as shown in FIG. 1 (a), upper mounting pieces 11 are integrally projected from both left and right sides by bending means.

  The lower left and right side frames 2 and 3 are connected to the seat cushion frame 46 via the reclining adjuster mechanism 42 so that the reclining adjuster mechanism 42 can recline, as in the existing seat frame 45 of FIG. Further, as shown in FIG. 3A, the left and right side frames 2 and 3 have the front end portions of the lower mounting pieces 10 on the left and right sides of the backrest panel 1 at the inner surface portions near the front side in the vicinity of the lower ends. It is fixed by a joining portion 12A by laser welding. Since both the side frames 2 and 3 are disposed substantially along the front-rear direction of the vehicle body, a triangle in plan view surrounded by the side frames 2 and 3 and the lower mounting piece 10 is provided at the rear portion from the joint 12A. A shaped space 13 is formed. Further, as shown in FIG. 1A, the upper ends of the side frames 2 and 3 are fixed to the upper mounting pieces 11 on the left and right sides of the backrest panel 1 by joint portions 12B by laser welding.

  As is clear from comparison between FIG. 2A and FIG. 6, the left and right side frames 2 and 3 have a front protrusion length D1 that is the front protrusion of the side brackets 53 and 54 of the existing seat back frame 47. The required value is set larger than the length D2. The required value referred to here is a value that can sufficiently suppress the displacement and shake of the upper body of the occupant H by the side frames 2 and 3 on both the left and right sides.

  As shown in FIG. 1 (b), the lower cross member 4 includes a belt-like main body portion 4a that is superposed and fixed in an arrangement along the left-right direction on the rear surface near the lower end of the backrest panel 1, and the main body 4a. Both ends of the portion 4a are bent and have a shape integrally including a pair of left and right attachment pieces 4b extending obliquely outward and rearward. In the main body 4a, a reinforcing portion 4c is formed by a bending means. The reinforcing portion 4c is formed by bulging the central portion in the width direction of the belt-like shape into a U-shaped cross-section. The lower cross member 4 is provided with lasers on the plurality of (six in this embodiment) mounting portions 1a of the backrest panel 1 shown in FIG. It is fixed to the backrest panel 1 by welding. Moreover, as shown in FIG. 3C, which is a cross-sectional view of the seatback 14 taken along the line CC in FIG. The side frames 2 and 3 are fixed to the rear ends of the side frames 2 and 3 by a joining portion 12C by laser welding.

  Therefore, the backrest frame BF of this embodiment has enhanced lateral rigidity (left-right direction) due to the presence of the lower cross member 4, and as clearly shown in FIG. The lower mounting piece 10 and the mounting piece 4b of the lower cross member 4 are fixed to the upper part and the lower end of the left and right side frames 2 and 3, respectively. The overall rigidity is remarkably increased by the left and right side frames 2 and 3 that connect the backrest panel 1 and the lower cross member 4 to each other.

  The headrest bracket 7 is fixed to the upper end of the front surface of the backrest panel 1 by laser welding, and the headrest stay 8 held by the headrest bracket 7 is attached so as to cover a pad (not shown). Thus, the headrest 17 shown in FIG. 4 is configured. In the case of a headrest integrated seat, the headrest stay 8 is fixed to the headrest bracket 7 by welding. On the other hand, in the case of a headrest split seat, the headrest stay 8 is held by the headrest bracket 7 with a fitting structure including holding resin parts. It has come to be.

Seat back 14 with the backrest frame BF of this embodiment, the backrest panel 1 made of a metallic flat material, along the S-shaped curve of the spine H _S of toward lumbar from the body of the shoulder top, as described above It has a shape that can secure a basic skeleton, and can support so that the posture from the lumbar vertebra to the pelvis is the most important posture for low back pain countermeasures due to long-term riding so that the ideal posture can be maintained. Unlike the existing S-spring 57, wire 56 or contour mat, which is elastically deformed, as shown in Fig. 5, it is made of metal and does not have elasticity. Can be held. With this structure that can hold the occupant in a rigid manner, the occupant is always in good condition while forcibly restraining the occupant from losing posture due to fatigue due to driving for a long time. It will function to maintain a sitting posture. Further, the left and right sides of the side frames 2 and 3, as these forward projection length D1 is set to a required value greater than the existing, to minimize the stress to enter the passenger spine H _S and muscle around the It can be stopped and high-dimensional seating performance can be obtained.

  Next, the operation when receiving a rear-end collision from the following vehicle will be described with reference to FIGS. 3 and 4. FIG. 4 (a) shows a normal running state. The backrest panel 1, the left and right side frames 2, 3 and the lower cross member 4 at this time have the shapes shown in FIGS. 3 (a) and 3 (c). Keep. When a rear-end collision occurs, an inertial force due to the impact causes an initial load to be displaced rearward from the occupant H to the backrest panel 1 of the backrest frame BF as indicated by an arrow in FIG. At this time, as shown in FIG. 3 (c), the lower cross member 4 has a pair of left and right mounting pieces in which the main body portion 4a fixed to the backrest panel 1 extends obliquely outward from the left and right ends. Since it is located closer to the front than the joint 12C with the side frames 2 and 3 via 4b, the main body 4a can be retracted when subjected to a large rearward impact load.

  Therefore, as shown in FIG. 3 (d), the main portion 4a of the lower cross member 4 pushes the attachment pieces 4b on both sides to the left and right outwards by the initial impact load applied to the backrest panel 1 from the occupant. The backrest panel 1 is moved backward while being deformed, and the lower end portion of the backrest panel 1 corresponding to the waist of the occupant H is moved backward integrally with the main body portion 4a. Thereby, the initial load due to the impact immediately after the rear-end collision occurs is effectively mitigated by the energy absorption by the lower end portion of the backrest panel 1 moving backward while the pair of mounting pieces 4b of the lower cross member 4 is deformed. Is done. At the same time, the left and right side frames 2 and 3 are connected to the lower mounting piece 10 of the backrest panel 1 at a position closer to the front of the center portion, and the lower end portion is removed as the mounting piece 4b of the lower cross member 4 is deformed. Since it receives the load pushed out toward the direction, as shown by the arrow in FIG. 3 (d), it is deformed into a state where it is bent inward, and the waist portion of the occupant H is restrained so as to be sandwiched from the left and right.

  When the state of the backrest frame BF as a whole when an initial load is applied due to the impact immediately after the occurrence of the above-described rear-end collision, as shown in FIG. Since it is connected to the frame (not shown) of the seat cushion 41 via the reclining adjuster mechanism 42, it is tilted backward with the lower end portion as a fulcrum without moving backward. In contrast, the upper portion of the backrest panel 1 is tilted back together with the side frames 2 and 3, but the lower end member 4 is lower as described above as shown in FIGS. 3 (c) and 3 (d). Is moved backward by a distance P corresponding to the deformation of the mounting piece 4b. As a result, the backrest panel 1 translates backward while substantially maintaining the vertical arrangement in the normal state of FIG. 4A despite the fact that the left and right side frames 2 and 3 are tilted backward. In addition, since the backrest panel 1 has high rigidity as described above, the backrest panel 1 is not deformed in the vertical direction even when it receives a load due to an impact at the time of rear end collision.

  Therefore, unlike the existing seat back frame, the backrest panel 1 receives the occupant vertically at the two upper and lower lines, and receives the load from the occupant H vertically to make the occupant rigid in the entire vertical direction. Since it hold | maintains, it can guide to the back, hold | maintaining a required attitude | position with respect to the passenger | crew H. FIG. In addition, the initial load can be effectively reduced as described above, and the lower end portions of the left and right side frames 2 and 3 are deformed inward to restrain the occupant H from being sandwiched from the left and right sides. . Thereby, since the occupant H is ensured in the relaxation of the impact and the posture maintenance, the input of the bending load and the shear load to the entire spine is remarkably reduced, and there is no possibility of being damaged. Since the backrest panel 1 receives the load from the occupant H vertically, the headrest 17 supports the head at a close distance without leaving the occupant H's head, as shown in FIG. It is possible to prevent the occurrence of hitting failures.

  In this way, after the initial load due to the impact of the rear-end collision is alleviated by the deformation of the lower cross member 4, when a large impact load is subsequently input, as shown in FIG. Then, after being further tilted, it stops at a predetermined tilt angle that is preset by design. At this time, as shown in FIG. 3 (b), the upper part of the lower cross member 4 in the backrest panel 1 is displaced rearward under the load from the occupant H, and the left and right side frames 2, 3 are reclining. Since it is connected to the seat cushion frame via the adjuster mechanism 42, the lower mounting piece 10 of the backrest panel 1 that has been displaced rearward is restricted because the rearward displacement is restricted only by falling backward. In response to the inward pulling force, it is deformed into a state of being bent inward.

  The left and right side frames 2 and 3 that are deformed inward in this way restrain the occupant H in a state of sandwiching the occupant H from the left and right, and FIGS. 4 (b) and 4 (c) and FIGS. 7 (a) and 7 (b). As can be seen from the comparison with), the backrest panel 1 receives the load from the occupant H vertically by the deformation of the lower cross member 4 in spite of the side frames 2 and 3 being tilted backward. Is held in the required sitting position. Therefore, the occupant H is reliably restrained by the backrest panel 1 and the left and right side frames 2 and 3 while maintaining the required seating posture even when the seat back 14 is tilted back to the predetermined rearward tilt angle. Therefore, there is no possibility of being thrown upward along the seat back 14, and the occurrence of a situation where a secondary obstacle occurs in the occupant H can be avoided.

  In the vehicle seat constructed using the backrest frame of the present invention, the lower end portion of the backrest panel moves rearward while deforming the pair of mounting pieces of the lower cross member with the initial load due to the impact immediately after the rear end collision occurs. The left and right side frames are deformed into a state where they are bent inward by receiving a load that pushes the rear end portion outward as the mounting piece of the lower cross member is deformed. The backrest panel with high rigidity that restrains the occupant's waist from both the left and right sides and does not deform in the vertical direction translates backward while maintaining the normal vertical arrangement. Because the load from the occupant is received vertically and the occupant is held rigidly in the whole vertical direction, the bending load on the entire occupant's spine And the input of the shear load is greatly reduced, the occupant is that there is no danger of being fault. In addition, since the backrest panel receives the load from the occupant vertically, the headrest supports the head at a close distance without leaving the occupant's head, thereby preventing the occurrence of whiplash damage. In addition, the left and right side frames receive a tensile force inward by the mounting pieces of the backrest panel displaced rearward, and are deformed into a state of being bent inward to restrain the passenger from being sandwiched from the left and right. There is no possibility that the occupant will be thrown upward along the seat back, and the occurrence of a situation in which the occupant has a secondary obstacle can be avoided.

(A), (b) is the perspective view seen from the front side and the back side which respectively show the backrest frame which concerns on one embodiment of this invention. (A) is a right view which shows a backrest frame same as the above, (b) is an AA cut end view of FIG. 1 (a). (A), (b) is a normal cross-sectional view of the seat back constructed by using the backrest panel in the same backrest frame as shown in FIG. Sectional drawing at the time, (c), (d) is a sectional view at the normal time when the portion corresponding to the CC line in FIG. (A)-(c) is a vertical right side view schematically showing the situation of the front seat configured using the seat back of the above, in the normal state, immediately after the occurrence of rear-end collision, and when the time has elapsed since the occurrence. The perspective view which shows the seat frame containing the conventional seat back frame. The right view which shows the conventional front seat for motor vehicles. (A), (b) is a vertical right side view schematically showing the situation immediately after the rear-end collision of the front seat and the time after the occurrence.

Explanation of symbols

BF Backrest frame 1 Backrest panel 2 Left side frame 3 Right side frame 4 Lower cross member 4a Main body 4b Lower cross member mounting piece 7 Headrest bracket 8 Headrest stay 10 Lower part of backrest panel 42 Reclining adjuster mechanism

Claims (2)

A backrest panel formed in a shape that rigidly receives from the upper shoulder of the occupant to the waist by a metal flat plate,
Left and right side frames that are fixed to the backrest panel in such a manner as to project forward from the left and right sides of the backrest panel, and whose lower ends are connected to the seat cushion frame via a reclining adjuster mechanism;
A lower cross member fixed to a lower end vicinity portion on the rear surface of the backrest panel and a lower end portion of the left and right side frames;
A headrest bracket fixed to the upper end of the backrest panel and a headrest stay supported by the headrest bracket;
The lower cross member has a band-shaped main body fixed to the rear surface of the backrest panel, and extends obliquely outward and rearward from both ends of the main body, and its front ends are rear ends of the left and right side frames. A backrest frame for a vehicle seat characterized by integrally including a pair of left and right mounting pieces fixed to the respective parts.   A pair of left and right mounting pieces that extend obliquely outward and forward are integrally formed at the left and right ends of the upper portion of the backrest panel above the lower cross member mounting position. The backrest frame of the automobile seat according to claim 1, wherein the backrest frame is fixed to a central portion of the side frame in the front-rear direction.

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