JPH07257491A - Leg structure for seat absorbing shock energy - Google Patents

Abstract

PURPOSE:To contribute lightening of weight of a seat, particularly in the seat constituted in an aircraft, by forming a sufficient stroke for absorbing shock energy, and obtaining a stable amount of absorbing energy. CONSTITUTION:A front leg 1 is formed of a straight strut vertically extended upward a fixed stud, also to form a rear leg 2 of a lower strut 2a extended on a diagonal of connecting an upper end part of the front leg 1 to a lower end part of the rear leg 2 and an upper strut 2b continued upward the lower strut 2a to bend in bow shape to obliquely tilt upward the rear, and further between the upper end part of the front leg 1 and the lower end part of the rear leg 2, an upper side of a shear deformed part (long groove), formed in the longitudinal direction partly in a diagonal material 12, and a relay member 13 are fixedly penetrated by a connecting shaft. An energy absorbing member 11, constituted so that the connecting shaft absorbs shock energy applied to a seat by shearing or spreading the deformed part, is mounted to be linked.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technology for absorbing impact energy to a seat, and more particularly to a leg of a seat which absorbs an impact load generated at the time of an accident such as an aircraft or a vehicle to ensure passenger safety. It is about structure.

[0002]

2. Description of the Related Art Conventionally, various types of seat cushioning devices have been used. For example, most of the impact energy generated when an aircraft fails to land is absorbed by the cushioning device on the fuselage side. In addition, when the vehicle collides, a shock absorber provided between the bumper and the chassis absorbs the collision energy. However, in a landing failure accident of an aircraft or a collision accident of a car, a shock load exceeding the shock absorbing capacity of the shock absorber may be generated, and an excessive shock load is applied to passengers. Conventionally, in order to absorb such impact energy, a cylindrical body made of a composite material of synthetic resin and carbon fiber is formed, and the energy is absorbed by the crushing load of the member depending on the arrangement and blending ratio of the carbon fiber. The seat which constituted the impact energy absorption member was used.

[0003]

However, according to the impact energy absorbing member constructed in the conventional seat, it is difficult to quantitatively measure the physical properties of the composite material of synthetic resin and carbon fiber. Since it is difficult to control production due to variations in product accuracy, it is not possible to stably secure the amount of energy absorbed, and most of the structural members including the leg structure of the seat are made of materials that do not deform. Therefore, in combination with the structural characteristics of the impact energy absorbing member, there is a problem that the seat movable stroke for absorbing the impact energy cannot be sufficiently taken.

The present invention was devised in view of the above problems, has a simple structure, forms a sufficient stroke for absorbing impact energy, and can obtain a stable energy absorption amount. It is an object of the present invention to provide a seat leg structure that absorbs impact energy and can contribute to weight reduction of the seat.

[0005]

In order to achieve the above object, a leg structure of a seat for absorbing impact energy according to the present invention has a lower end portion of a front leg and a rear leg which are rotated in the front-rear direction via fixed studs. In a leg structure that movably supports and a seat bottom and a seat back are placed on front and rear beams formed on the front legs and rear legs, to form a seat, the front legs extend directly above the fixed studs in a substantially vertical direction. Lower struts extending along a diagonal connecting the upper ends of the front legs and the lower ends of the rear legs, and upper struts that are curved in an arc shape continuously above the lower struts and are inclined upward to the rear. The upper side of the deformed portion formed in a part of the diagonal member in the longitudinal direction and the relay member are penetrated and fixed by a connecting shaft between the upper end of the front leg and the lower end of the rear leg. Shears the deformed part It is an Abstract that it has passed fitted over the energy absorbing member configured to absorb impact energy applied to the seat and widening in.

[0006] Specifically, the energy absorbing member has a relay member having a through hole continuously provided on the upper side of a long groove formed in a part of the diagonal member and having an insertion hole which overlaps with the through hole. Configured by penetrating and fixing by means of a connecting shaft, or constituted by penetrating and fixing by means of a connecting shaft, the relay member having an insertion hole that overlaps at the upper end of the elongated hole formed in a part of the diagonal member. The impact resistance is generated by the loss of mechanical energy when the long groove or the long hole is displaced, and the entire length is extended when the shock is absorbed. Furthermore, the upper end of the diagonal member that constitutes this energy absorbing member is bent, and this bent portion is fixed to the leg of the seat,
The bent portion may also be deformed and extended to absorb the impact energy applied to the seat.

[0007]

According to the above construction, when an impact load is applied to the seat, the rear legs rotate forward around the fixed stud as a rotation center, and at the same time, the load applied to the energy absorbing member reaches a predetermined value,
For example, when it exceeds 12 G, the connecting shaft of the relay member shears or expands the deformed portion such as the long groove or the long hole, and operates so as to extend the entire length of the energy absorbing member. The energy absorbing member rotates while extending along the substantially axial direction that is a diagonal direction to the impact direction to be absorbed and the rotation direction of the front leg, that is, absorbs the impact load in the pulling direction. That is, the impact load applied to the leg structure is absorbed by the loss of mechanical energy due to the plastic deformation associated with the extension of the rear leg and the plastic deformation associated with the extension of the energy absorbing member. Further, the bent portion at the upper end of the diagonal member can be deformed and extended to absorb the impact energy applied to the seat. Also, at the time of impact, the seat moves in the impact direction so as to crush the leg structure,
Since the seat surface is rotated while being held in a substantially original horizontal posture, the passenger can maintain the posture of sitting on the seat.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a seat leg structure for absorbing impact energy according to the present invention will be described below with reference to the drawings. In the seat according to the present invention, the front and rear beams 3 and 4 are stretched over the front leg 1 and the rear leg 2, and the front and rear beams 3 and 4 are arranged.
A base frame 5 is laid between the front and rear beams 3, 4
The seat bottom 6 and the seat back 7 are placed on the base frame 5 and the seat back 7.
Is supported so as to be tiltable rearward of the seat through a reclining device (not shown).

The lower ends of the front leg 1 and the rear leg 2 of the seat having the above structure are fixed to the floor surface X via fixed studs 8 and 9, respectively.
It is fixed to a fixed structure (not shown) such as a rail configured as described above, and is rotatably supported in the front-rear direction with respect to a bracket 10 formed on the fixed stud 9 of the rear leg 2. is there. Thus, the front leg 1 is formed by a straight post extending substantially vertically above the fixed stud 8, and the rear leg 2 is on a diagonal line connecting the upper end of the front leg 1 and the lower end of the rear leg 2. Lower strut 2a extending to the bottom and the lower strut 2
a, which is continuous with the upper part of a, and which is formed by an upper strut 2b which is curved in an arcuate shape so as to project to the front of the rear leg 1 and is inclined rearward and upward, and which has an upper end portion of the front leg 1 and a lower end portion of the rear leg 2. And the energy absorbing member 11 according to the present invention as a diagonal member
At least the front fixing portion is pivotally attached to the upper end portion of the front leg 1 so as to be freely rotatable.

Further, in the leg structure of the seat according to the present invention, at least the rear leg 2 is, as shown in FIGS. 1 and 3,
When an impact more than a predetermined load is applied from behind (arrow G
Direction, leg structure is deformed and moved to the position indicated by the chain double-dashed line), and is made of a material that can be bent and deformed forward, that is, in the impact direction. The inside of the metal material is appropriately hollowed out, or the cross-sectional shape is approximately H The leg structure is configured to have a light weight, and as described later, the leg structure portion has a structure that facilitates plastic deformation to enhance impact energy absorption performance in the leg structure portion. The upper end of the upper strut 2b of the rear leg 2 extends upward from the lower end of the rear leg 2 in the normal use posture of the seat.
In order to be positioned above or in front of it, the rear leg 2 is curved and inclined in an arcuate shape so that the rear leg 2 can be easily bent and deformed forward without buckling downward. Further, the front leg 1 is also made lighter like the rear leg 2 while the inner side of the metal material is hollowed out in order to increase the strength, or the cross section is formed into a substantially H shape. There is.

In the present invention, the seats such as the seat bottom 6 and the seat back 7 formed on the upper part of the leg structure are supported so as to maintain a substantially normal use posture even when the leg structure is deformed. The upper end portions of the front leg 1 and the rear leg 2 are indicated by arrows C with respect to the front and rear beams 3 and 4 (see FIG. 2).
And the D arrow portion (see FIG. 2) are attached so as to freely rotate in the front-rear direction, and especially when the absorption amount of impact energy is small, the front and rear legs 1 and the rear leg 2 are configured. It is also possible to fix the beams 3 and 4 by a mounting method that does not rotate.

Further, as a mechanism for maintaining the supporting posture of the seat in normal use, a stop device (not shown) is formed at the lower end of the rear leg 2 to prevent the rear leg 2 from rotating forward. It is also possible to adopt a structure in which the pivotal support portions at the lower end portions of the front leg 1 and the rear leg 2 are fixed by a tightening force that does not rotate under a load of a predetermined value or less.

FIGS. 4 to 7 show a first embodiment of a leg structure of a seat that absorbs impact energy. The energy absorbing member 11 according to the present invention is composed of two members connected to each other so that they can be extended and displaced, and absorbs impact at the time of extensional displacement by the loss of mechanical energy of the energy absorbing member 11. The structure has a structure in which the entire length of the member is extended when the above is absorbed. That is, the energy absorbing member 11 is composed of two members, a diagonal member 12 and a relay member 13, and the diagonal member 12 is
As shown in FIG. 4, an elongated plate material made of a metal, such as an aluminum material, which is relatively soft and easy to break, and has a lower portion 12a.
A long groove 14 having a thickness smaller than that of the other portion of the diagonal member 12 is formed along the longitudinal direction, and a through hole 15 is formed on the upper side of the long groove 14. Further, the relay member 13 is composed of two plate members 1 made of a material harder than the diagonal member 12.
3a, 13b, each plate material 13a, 13b
A long hole 16 functioning as a guide hole is opened in the longitudinal direction of the, and insertion holes 17, 17 are transparently provided at both ends of the long hole 16. Since the relay member 13 is formed of a material having a higher material strength than the diagonal member 12 as described above, the through hole 15 of the diagonal member 12 and the insertion holes 17 of both plate members 13a and 13b of the relay member 13 are formed. , 17 when the connecting shaft 18 such as a bolt that simultaneously fixes the same through is pulled in the direction of the arrow by the diagonal member 12 (see FIGS. 7A and 7B), the hard relay member 13 is made of the same material. Since the strength is higher than that of the soft diagonal member 12, the long groove 1 of the diagonal member 12 is fixed by the connecting shaft 18 fixed in the insertion hole 17 of the relay member 13.
The four parts are sheared (see FIG. 7 (c)).

At this time, the insertion hole 17 of the relay member 13 penetrating the connecting shaft 18 for fixing has the long groove 14 of the diagonal member 12.
When the rear leg 2 is subjected to an impact load, the connecting shaft (fixing bolt) 18 that penetrates the through hole 15 formed on the upper side of the long groove 14 and fixes both of them is used. The hole 15 is broken, and the long groove 14 is moved to the lower end portion while shearing the long groove 14. In addition, the connecting shaft 18
As shown in FIG. 7A, the plastic deformation resistance of the long groove 14 by the can be adjusted by the thickness dimension W of the long groove 14 that absorbs the energy of the relay member 13 in contact with the inner surface of the long groove 14, and is required for each seat as appropriate. The design can be changed according to the impact energy absorption working load.

The energy absorbing member 11 according to the present invention is
Usually, two members, that is, the diagonal member 12 and the relay member 13, are pierced and fixed by a connecting shaft 18 capable of resisting a tensile load of a predetermined value or less, and a load is applied to an operating portion of the energy absorbing member 11 under a normal use load. It has a unique structure and functions as a diagonal member of the seat leg structure without degrading performance. Reference numeral 19 is a brace stretched between the front leg 1 and the rear leg 2.

An upper end portion of the diagonal member 12 of the energy absorbing member 11 according to the present invention is bent, and the bent portion 12b is screwed and fixed to the upper part of the front leg 1 of the seat. In this way, the bent portion 12b of the diagonal member 12 can also be deformed and extended to absorb the impact energy applied to the seat (see the chain double-dashed line in FIG. 3), and along with the above-described plastic deformation of the long groove 14 and shearing of the long groove. , It is possible to completely absorb the impact energy applied to the seat.

FIG. 8 shows a second embodiment of the energy absorbing member. In the first embodiment, the diagonal member 1
Although the long groove 14 of No. 2 has a thin shape, the mechanical energy generated by the impact load can be absorbed and lost by the shearing action of the long groove 14 of the diagonal member 12 by the connecting shaft 18 caused by the displacement of the front leg 1. As long as a leg structure of a typical shock absorbing sheet can be constructed, a long hole 20 narrower than the outer diameter of the connecting shaft 18 is opened in the longitudinal direction of the diagonal member 12 instead of the long groove 14. It may be. With this structure, the mechanical energy generated by the impact load can be absorbed and lost by the expanding action of the elongated hole 20 of the diagonal member 12 by the connecting shaft 18 caused by the displacement of the front leg 1.

FIG. 9 shows a third embodiment of the energy absorbing member. In the second embodiment, the diagonal member 1
The second elongated hole 20 is formed as an elliptical elongated hole such that the opening width thereof is narrower than the outer diameter of the connecting shaft 18, and the elongated hole 21 is gradually formed in the shearing direction. It can also be opened to taper. Thus long hole 2
By gradually narrowing the opening width of No. 1, the mechanical energy generated by the impact load is absorbed and lost by the expanding action of the elongated hole 21 of the diagonal member 12 by the connecting shaft 18 caused by the displacement of the front leg 1. You can

In the above-mentioned embodiment, the embodiment in which the two members of the energy absorbing member 11 are configured to be extended and displaced is shown. On the contrary, this energy absorbing member is provided between the lower part of the front leg 1 and the upper part of the rear leg 2. It is also possible to mount it on and to be deformed and displaced in the contracting direction.

[0020]

Since the leg structure of the seat for absorbing impact energy according to the present invention is constructed as described above, the energy absorbing member can function as a diagonal member of the leg structure when the seat is normally used. Since it is not necessary to separately configure the energy absorbing member of the present invention, an increase in seat weight can be avoided, and since the leg structure is almost the same as the conventional structure, it can be easily modified and adjusted. When a shock load equal to or more than a predetermined value is applied to, the impact energy can be absorbed with a large stroke due to the mechanical energy absorbing action due to the plastic deformation of the leg structure and the energy absorbing member. In particular, the mechanical energy generated by the impact load can be absorbed and lost by the shearing or expanding action of the deformed portion such as the long groove or the long hole of the diagonal member by the connecting shaft of the relay member due to the displacement of the rear leg.

Further, since the front leg can rotate forward around the fixed stud portion as a center of rotation without being plastically deformed, bending accident of the passenger due to bending of the front leg when an impact occurs may occur. It also has an extremely excellent effect such that it can prevent

[Brief description of drawings]

FIG. 1 is a side view of essential parts showing an embodiment of a leg structure of a seat for absorbing impact energy according to the present invention.

FIG. 2 is an enlarged side view showing the leg structure.

FIG. 3 is an enlarged side view showing the leg structure.

FIG. 4 is a plan view (a) showing a first embodiment of a diagonal member of an energy absorbing member according to the present invention and a side view (b) showing a partial cross section.

FIG. 5 is a plan view showing a plate member which also constitutes the relay member.

FIG. 6 is a plan view (a) and a side view (b) showing another plate member which also constitutes the relay member.

FIG. 7 is an enlarged side sectional view (a) showing the energy absorbing member, an enlarged side view (b) of the long groove before shearing, and an enlarged side sectional view (c) of the long groove during shearing.

FIG. 8 is an enlarged plan view (a) and an enlarged side sectional view (b) showing a second embodiment of the energy absorbing member.

FIG. 9 is an enlarged plan view (a) and an enlarged side sectional view (b) showing a third embodiment of the energy absorbing member.

[Explanation of symbols]

 1 front leg 2 rear leg 3 front beam 4 rear beam 5 base frame 8 front fixed stud 9 rear fixed stud 11 energy absorbing member 12 diagonal member 13 relay member 14 long groove 15 through hole 18 connecting shaft (bolt) 20 long hole 21 long hole

Claims (5)

[Claims] 1. The lower ends of the front and rear legs are supported rotatably in the front-rear direction via fixed studs, respectively.
In a leg structure in which a seat bottom and a seat back are placed on front and rear beams formed on the front legs and upper rear legs to form a seat, the front legs are formed by straight columns extending substantially vertically above the fixed studs, and The rear leg is formed by a lower strut extending on a diagonal line connecting the upper end of the front leg and the lower end of the rear leg, and an upper strut that is continuous above the lower strut and is curved in an arc shape and is inclined obliquely upward to the rear. An upper portion of a deforming portion formed in a longitudinal direction on a part of a diagonal member interposed between the upper end portion of the front leg and the lower end portion of the rear leg and a relay member are fixed by a connecting shaft so that the connecting shaft penetrates the deforming portion. A leg structure of a seat for absorbing impact energy, characterized in that an energy absorbing member configured to absorb or impact energy applied to the seat by being sheared or expanded is attached. 2. The energy absorbing member comprises: a relay member having a through hole continuously provided on the upper side of a long groove formed in a part of the diagonal member and having an insertion hole overlapping with the through hole. 2. The leg structure of a seat for absorbing impact energy according to claim 1, wherein the leg structure of the seat is fixed through the connecting shaft. 3. The energy absorbing member comprises an elongated hole formed in a part of the diagonal member, and an intermediate member having an insertion hole which overlaps with the upper end and fixed to the upper end of the elongated member by a connecting shaft. The leg structure of a seat for absorbing impact energy according to claim 1, wherein. 4. A structure in which an upper end of the diagonal member is bent, the bent portion is fixed to a leg of a seat, and the bent portion is deformed and extended to absorb impact energy applied to the seat. A leg structure for a seat that absorbs impact energy according to claim 1, 2, or 3. 5. The leg structure of a seat for absorbing impact energy according to claim 1, 2, 3 or 4, wherein the rear leg is formed by arranging two plate members in parallel.