JP6706102B2 - Molding method for leg structure of composite vehicle seat - Google Patents

Description

The present invention relates to a method for forming a leg structure for a composite vehicle seat, and more particularly, to a method for manufacturing a leg structure for a vehicle seat having front legs extending vertically and rear legs reaching a rear fixing portion in a tilted state. is there. It also seeks to provide a composite vehicle seat manufactured by the method.

Vehicle seats may be able to be slightly displaced back and forth to reposition their seats, but at least during travel they can be secured to the floor. That is, the seat is basically stationary during the movement, and the seat does not move forward together with the passenger even if a slightly large deceleration acts on the passenger wearing the seat belt.

A metal material is applied to the leg structure in order to stabilize the seat, and the leg structure has sufficient strength and high rigidity. In the case of seats for aircraft, light metal is used, and it is often a machined product obtained by performing NC processing on an aluminum forged product. In this case, the front leg, the rear leg, and the members associated therewith are in principle a single product, and the leg structure is a combination thereof. By the way, from the viewpoint of increasing payload, expanding cruising range, and shortening takeoff and landing distance, aircraft and equipment are required to be further reduced in weight.

Japanese Patent Laid-Open No. 2009-532255, which is Patent Document 1, proposes that the seat bottom frame and the seat back frame be made of laminated composite carbon fiber resin to reduce the weight of the seat. Japanese Patent Laid-Open No. 2009-537383, which is Patent Document 2, discloses that some of the components are made of fiber reinforced plastic so that the seat leg portion also has a lightweight structure. To describe the latter in some detail, a honeycomb core plate that enhances the overall structural strength is adopted together with a reinforcing rod material that is a rigid body made of metal, and FRP is used as a backing plate and a reinforcing plate on the front and back of the core plate.

By the way, if most parts of the leg structure are made to be FRP, the front leg and the rear leg cannot endure, and at least a truss structure is required. In that case, either the front leg, the rear leg, and a brace extending from the upper ends of the front leg to the lower end of the rear leg are inserted, or the brace is extended from the lower end of the front leg to the upper end of the rear leg. These have a form in which only one brace is interposed, but when viewed from the left side of the seat, the former is an N type and the latter is an inverted N type (hereinafter referred to as an N type leg and an inverted N type leg). ..

The N-shaped leg is described in FIG. 1 of Japanese Patent Application Laid-Open No. 10-075848, which is Patent Document 3, and the inverted N-shaped leg is described in Japanese Patent Application Laid-Open No. 6-016194, which is Patent Document 4, but these are metal legs. It's not made of FRP. It goes without saying that it is important to utilize the properties of FRP when making FRP legs. That is, it is necessary to take into consideration the strength and weakness of tensile force, compressive force and shearing force, and the magnitude of bending resistance. In addition, it is necessary to take into consideration the avoidance of large molds required for molding (reduction of manufacturing cost).

Regardless of whether the N-type leg or the inverted N-type leg is adopted, it is not preferable to keep the rear leg vertical so that the rear portion of the seat has a space for accommodating the legs and legs of the passenger behind it. .. Therefore, the rear leg is formed in a V shape as in the above-mentioned Patent Document 3. FIG. 17A shows an example of the rear leg 42, which is an example of the rear leg 42 in which the downward inclined portion 41a of the rear half portion of the brace 41 and the upward inclined portion 41b forming the upper portion of the rear leg are combined, and an N-shaped leg is shown. There is. FIG. 2B shows an example of a rear leg 44 in which an upslope portion 43a in the latter half portion of the brace 43 and a downslope portion 43b forming a lower portion of the rear leg are combined, and an inverted N-shaped leg is shown.

By the way, since the seat is fixed, a large deceleration G acts on the occupant when the fuselage lands, and a large force acts on the leg structure together with the inertial force of the seat itself. The leg structure is designed to withstand the G required by law, but it is needless to say that the most rigid body is the front leg. A damper may be used to allow this deformation of the front legs, and measures may be taken to soften the impact.

According to the FEM analysis result in the state where a large negative forward G is applied for each form, the shear force (black arrow) and moment (shaded arc arrow) acting on the N-leg are greater than those on the inverted N-leg. Overall, it is small, but the axial force (hatched arrow) is large. Therefore, when the FRP molded product is used, the N-type leg is preferable in consideration of its advantages and disadvantages. The front leg 2 reaching the front fixing portion 1F is substantially vertical, but the rear leg largely tilts and the rear half portion of the brace toward the rear fixing portion 1R and the upward inclination from the middle portion of the brace to the supporting girder at the rear edge of the seat surface. The structure will consist of parts and parts.

Special table 2009-532255 Special table 2009-537383 Japanese Unexamined Patent Publication No. 10-075848 JP-A-6-016194

By the way, in order to obtain a high-strength FRP molded product, a prepreg laminating process and a heating/pressurizing/curing process by an autoclave are required, which requires a great manufacturing time as compared with shaving from a metal product. At the same time, a molding die is indispensable. If the truss structure leg consisting of the front legs, rear legs, and braces is integrally formed, the production time will be shortened, but the size of the mold will be inevitably increased.

As can be seen from the above description, the leg structure in the seat of an aircraft is not yet made of all FRP or most of FRP at present. Reducing the weight of each seat has a significant effect of reducing the weight in a large passenger aircraft equipped with, for example, 500 seats. Even more so, if a seat made of all-composite material or a form close to it is installed, it will bring extremely important performance improvements in aircraft such as extension of cruising range, reduction of takeoff and landing distance, and increase of payload. The same can be said for vehicles such as automobiles and ships.

The present invention has been made in view of the above problems, and an object thereof is to reduce the weight of a seat as much as possible by completely changing the main members of the front and rear legs to FRP, and the tensile, compression, shear, and bending moments. Considering the size of the load on the FRP, it should be a structure that is FRP molded by giving appropriate strength to each part, but that can exhibit rigidity, and waste of material usage while maintaining appropriate strength and yield strength. It is possible to make FRP products that eliminate as much as possible, to shorten the time for molding FRP products that tend to take a lot of time to manufacture, to reduce the size of molded products and to suppress the number of manufacturing molding gold To provide a leg structure forming method for a composite vehicle seat capable of avoiding diversification and enlargement of molds and reducing manufacturing and equipment costs, and a composite vehicle seat manufactured by the method. Is.

INDUSTRIAL APPLICABILITY The present invention is applied to a method for manufacturing a leg structure for a vehicle seat, which is provided with a front leg reaching a front fixing portion of the floor in a substantially vertical state and having rear legs facing a rear fixing portion in a downward tilted state. Mainly referring to FIG. 1, the feature is that the leg structure 5 is located below the front cross member 6 that supports the own seat 4M (see FIG. 2B) and the adjacent seat 4N just below the front edge of the seat surface. To the front foot 2 of the composite material, and the downward slope 3A of the composite material which slopes downward from the front cross member 6 toward the rear fixing portion 1R, and rises rearward from a substantially middle portion of the downward slope leg 3A. The rear leg 3 is made of a composite material and is formed by an ascending leg portion 3B that is inclined and extends toward the rear cross member 7 that supports the own seat 4M and the adjacent seat 4N just below the rear edge of the seat surface. For each of the front leg 2 and the rear leg 3, the left and right sides of the seat 4 (see FIG. 2A) are in the X direction, the front and rear sides are in the Y direction, and the upper and lower sides are in the Z direction (see FIG. 2B). ) Is an I-shaped structure (see FIG. 4) in which the web portion 16 that bears the shear load is arranged in the YZ plane (vertical plane that extends in the front-back direction of the seat), and bears the axial force of tension/compression and is rigid. Laminated press-molded resin body 18 of continuous carbon fiber reinforcement is arranged on the entire width or a part of the flange portion 17 on the side opposite to the web portion and on a portion of the web portion (see FIG. 4). The remaining area in 17 and the remaining area in the web portion 16 are the compound resin body 19 for injection molding. Then, the compound resin body is molded by pressing the compound molten resin into the residual cavity after the preformed continuous carbon fiber reinforced laminated constitution press-molded resin body 18 is arranged in the molding die as shown in FIG. By injection, the injection compound resin body and the laminate-structured press-molded resin body are integrated by fusion bonding of the respective resins.

The descending oblique leg portion 3A extends directly to the rear fixing portion 1R, and the ascending oblique leg portion 3B is integrally formed with the descending oblique leg portion 3A at a substantially intermediate portion of the descending oblique leg portion 3A.

The composite front leg 2 and the composite rear leg 3 are assembled as an integral structural leg via the front cross member 6 or the rear cross member 7.

As shown in FIG. 11, the descending oblique leg portion 3A is connected to the front transverse member 6 by a front oblique leg element 3F and the rear oblique leg element 3R that is connected to the front oblique leg element by a pin 29 and moves toward the rear fixing portion 1R. On the other hand, the ascending oblique leg portion 3B may be integrally formed at the front end portion of the rear oblique leg element 3R.

As shown in FIG. 5, the continuous carbon fiber reinforced laminate-formed press-molded resin body 18 is a hairpin-shaped molded product that surrounds the front cross member 6 or the rear cross member 7 and is bent, and is arranged in one row or in two rows in parallel. To be done.

The vicinity of the tip of the flange portion 17 of the hairpin-shaped molded product forming the composite rear leg 3 is formed in an arrowhead shape with only one hypotenuse.

As shown in FIG. 9, the front legs 2 made of the composite material are arranged in two rows in parallel, and are closely integrated at the front fixing portion 1F and a portion in the vicinity thereof to enhance lateral rigidity.

As shown in FIG. 1, the flange portion 17 in the vicinity of the front fixing portion of the front leg 2 has an arc shape centering on the rear fixing portion 1R on both the front surface and the rear surface.

As shown in FIG. 9C, the thickness of the flange portion 17 in the vicinity of the front fixing portion of the front leg is gradually reduced toward the fixing portion, and the trigger for delamination failure is easily given.

As shown in FIG. 9B, the flange portion 17 whose thickness is gradually reduced toward the fixing portion 1F is provided with a taper 28 in the shape of an arrowhead in plan view, and the stress is increased toward the tip.

A composite vehicle seat can be manufactured by the leg structure forming method defined in any of the above.

Since the leg structure is made up of composite front legs and composite rear legs, the weight of the seat is reduced, thus reducing the weight of the aircraft, which results in an increase in payload, an increase in cruising range, It greatly contributes to the reduction of takeoff and landing distance. The front leg extends downward from the front cross member that supports the own seat and the adjacent seat just below the front edge of the seating surface, and the rear leg extends downward from the front cross member to the rear fixing portion, and approximately the middle between the descending oblique legs. Since it is formed by the ascending oblique leg that extends from the part toward the rear cross member, the shearing and moment acting on each part of the leg structure are reduced compared with, for example, the inverted N type, and the truss structure provides a lightweight and rigid leg. Realize the structure.

Each of the front and rear legs has an I-shaped structure in which the web portion that bears the shear load is arranged in the YZ plane, and the entire width or one side of the flange portion that bears the tensile/compression axial force and increases the rigidity is on the side opposite the web portion. Laminated press-molded resin body of continuous carbon fiber reinforcement functioning as reinforcing bars is arranged in the portion and a part of the web portion, and the residual area in the flange portion and the residual area in the web portion are made as a compound resin body by injection molding. From the above, a leg structure having a rigid web portion and a flange portion is formed by fusion-bonding the laminated constitution press-molded resin body and the compound resin body. This further realizes the composite material manufacturing of the leg structure.

Since the front and rear legs are molded as independent parts, the mold specifications conform to the shape of each component, and the size is smaller than the mold that makes a molded product with the front and rear legs integrated reinforcement bars. Therefore, the die for lamination molding and the injection die for post-forming the web portion are downsized. This will help reduce the cost of mold production. Further, even in the autoclave treatment, it is possible to prevent the furnace body from increasing in size and suppress an increase in equipment cost. Further, the time required for molding is also greatly reduced.

The molding of the front and rear legs is performed by pressurizing the compound molten resin into the residual cavity after placing the preformed continuous carbon fiber reinforced laminated constitution press-molded resin body in the molding die. Since the compound resin body and the laminate-structured press-molded resin body are integrated by fusion-bonding the resin, the reinforcement material in the composite material is better than the case where the production by lamination molding alone or the production by injection alone is adopted. The right material is placed in the right place, and the places that cause excessive strength or excessive quality are reduced as much as possible.

The descending oblique leg extends directly to the rear fixing portion, and if the ascending oblique leg is integrally molded with the descending oblique leg at a substantially intermediate portion of the descending oblique leg, the rear leg will be a single component, As a result of the leg structure being composed of two parts, only two injection molds are required. Moreover, since the mold cavity of the front leg is linear and the mold cavity of the rear leg remains in an inverted T shape, the injection mold can be kept small.

Since the composite front leg and the composite rear leg can be assembled as seat legs via the front cross member or the rear cross member, the integrally structured leg can be formed easily and easily. It suffices to perform the bonding or bolt fastening work, and the post-processing as in the case of targeting a metal member is extremely reduced.

The descending oblique leg is formed by a front oblique leg element connected to the front cross member and a rear oblique leg element pin-connected to the front oblique leg element and heading toward the rear fixing portion. In the case where the front legs are integrally formed, the rear legs are two parts, but the molding die can be further miniaturized.

A laminated carbon fiber reinforced press-molded resin body is formed into a hairpin-shaped molded article that is bent by surrounding a front cross member or a rear cross member. Reinforcing bars can be arranged over the entire width. If the two rows are arranged in parallel, the reinforcing bars can be arranged near the left edge and the right edge of the flange portion on the side opposite to the web portion. It becomes possible to provide an appropriate reinforcing form in consideration of the load.

When the vicinity of the tip of the flange part of the hairpin-shaped molded product that forms the composite rear leg is formed in the shape of a single arrowhead, the cross-sectional area of the flange part gradually decreases toward the tip, and other adjacent hairpins are formed. It is possible to prevent a sudden change in rigidity that occurs in the flange portion of the molded product and suppress the occurrence of stress concentration.

The front legs made of the composite material are arranged in parallel in two rows, and if the front legs are closely integrated with each other to form a pine needle, it is convenient because lateral rigidity is enhanced. Further, even if the shock absorber is attached to the leg ends, the reinforcing bars in the proximity state can be integrally targeted for removal, and the shock absorber can be prevented from becoming complicated.

If the front and rear flanges of the front leg have a circular arc shape centering on the rear fixing point on both the front and rear sides, the lower end of the front leg will always keep the same posture when absorbing the shock by retracting the front leg. , The angle of contact of the shock absorber with the destruction action part is constant. That is, it contributes to stabilization of the function of the shock absorber.

If the thickness of the flange portion near the front fixing portion of the front leg is gradually reduced toward the fixing portion, a relatively large stress acts at the start of shock absorption, which easily causes a delamination failure.

If the flange part, whose thickness is gradually reduced toward the fixing part, is tapered in the shape of an arrowhead in plan view, the cross-sectional area becomes smaller toward the tip, and it is possible to increase the stress gently. .. When a large impact is applied, the front leg is likely to be damaged, and it is possible to start from the flange tip.

With any of the above configurations, the composite vehicle seat obtained by the leg structure molding method is light in weight while having the required strength, is easy and quick to manufacture, minimizes the number of parts, and is a manufacturing jig. It brings many advantages such as simplification, cost reduction, and ease of mass production.

The left side external view of the leg structure adopted by the leg structure forming method of the composite material vehicle seat concerning the present invention. It is an example of an aircraft seat, (a) is a left side view, (b) is a perspective view in the case of a continuous seat. The leg structure and the seat bottom frame, (a) is a normal wearing state diagram, (b) is a state diagram in which a large deceleration force acts to absorb the impact at the lower end of the front leg. FIG. 2 is a perspective view showing an I-shaped structure for the front and rear legs, (a) showing a partial width arrangement on a flange portion of a laminated press-formed product, and (b) showing a full width arrangement on a flange portion. .. The layout drawing in the previous stage of the combination for each part of the laminated structure press-formed product. FIG. 3A is a perspective view for a front leg and FIG. 6B is a perspective view for a rear leg, which is a combined arrangement for each part of a laminated structure press-formed product. Left side view of injection-molded product of front leg and injection-molded product of rear leg. (A) is a combination perspective view of a laminate-structured press-molded product incorporated in an injection-molded product, and (b) is a perspective view of a laminate-structured press-molded product in which an end portion of a front leg molded product is subjected to easy damage processing. A combination of press-formed products having a laminated structure in the front legs, (a) is a front view of a basic shape, (b) is a front view of an improved product that has been subjected to a shock absorption facilitation treatment, and (c) is a side view of (b). Figure of transition of shock absorption and stripping bending of flange part. The left side external view of the leg structure provided with different rear legs. FIG. 3A is a perspective view for the front leg, and FIG. 6B is a perspective view for the rear leg, in the arrangement in the previous stage of the combination of the laminated constitution press-formed products for different rear legs. FIG. 5 is a perspective view showing a combination of press-molded products each having a different laminate structure incorporated in the injection-molded product. Left side view of the shock absorber. FIG. 3 is an exploded perspective view of the impact absorber with the lower end of the front leg exposed. It is a shock absorber and a flange part bending mechanism, (a) is sectional drawing which shows the damage mechanism of a web part, (b) is sectional drawing which shows the bending mechanism of a flange part. (A) is a load action diagram in the case of an N-type leg, (b) is a load action diagram in the case of an inverted N-type leg.

A leg structure forming method for a composite vehicle seat according to the present invention and a composite vehicle seat manufactured by the method will be described in detail below with reference to the drawings. FIG. 2(a) is provided with a front leg 2 reaching a front fixing portion 1F (also referred to as a front floor contact portion, which is fixed by an anchor or the like not shown) on the floor in a substantially vertical state, while being tilted downward. 1 is an example of a leg structure 5 of a vehicle seat 4 provided with rear legs 3 heading to a rear fixing portion 1R (a portion fixed by an anchor or the like (not shown) in a rear floor contact portion).

As shown in FIG. 2B, the leg structure 5 supports the front cross member 6 (which supports the own seat 4M and the adjacent seat 4N just below the front edge of each seat surface 4S (see FIG. 2A). (Also referred to as a front beam). The front leg 2 made of a composite material extending downward from the front beam, and the downward bevel leg 3A made of a composite material that inclines downward from the front cross member 6 to the rear fixing portion 1R and the downward bevel leg. Ascending leg portion 3B which is inclined rearward from a substantially middle portion of the portion and extends toward a rear cross member 7 (also referred to as a rear beam) which supports the own seat 4M and the adjacent seat 4N just below the rear edge of the seat surface 4S. It has a rear leg 3 made of a composite material formed by (see also (a) in the figure). The composite material of the front legs and the rear legs are both carbon fiber reinforced thermoplastic resins, for example, a composite material having a PPS resin (polyphenylene sulfide resin) as a matrix. It has high impact resistance, fatigue properties, long-term heat resistance, chemical resistance, and self-extinguishing properties, and its melting point is about 280° C., which is suitable for the hybrid molding described later in the present invention. Is.

As shown in FIG. 2A, the rear leg 3 has a slanted leg shape, so that the rear leg 3 is less likely to be restricted by the front-rear dimension of the seat surface 4S, and the front-rear intervals of the fixing portions 1F and 1R can be easily made longer. . The front beam 6 and the rear beam 7 are pipe-shaped and may be made of light alloy, but if the composite material has a cylindrical structure, the weight reduction is further promoted. By the way, 8 is a backrest, 9 is an armrest, and 10 is a baggage bar.

In this example, the descending oblique leg portion 3A extends directly to the rear fixing portion 1R, and the ascending oblique leg portion 3B is integrally formed with the descending oblique leg portion 3A at a substantially intermediate portion of the descending oblique leg portion 3A. Therefore, the rear leg 3 is made into one component, the leg structure 5 is made up of two components, the front leg and the rear leg, and two types of injection dies to be described later are sufficient. Moreover, the cavity of the front leg mold (not shown) is substantially linear, and the cavity of the rear leg mold (not shown) remains in an inverted T shape, so that the fluidity at the time of injection is good. The injection mold is not large and bulky and has good handleability. As shown in FIG. 3A, the fixing portions 1F and 1R are provided at predetermined seat leg fixing positions such that they are provided on the seat track 11 or the spreader 12 laid on the floor or directly arranged on the floor. Is. Since the leg structure 5 described here is not integrated with the front-rear direction beam that bridges the front cross member 6 and the rear cross member 7 described above, an increase in the size of the mold is eventually avoided. I will touch on this point a little later.

As described above, the composite front leg 2 and the composite rear leg 3 are assembled as an integral structural leg via the front cross member 6 or the rear cross member 7 as shown in FIG. 3A. .. This is also shown in FIG. 1, and the leg structure 5 can be assembled easily and easily. It is sufficient to adhere each horizontal member to each other by the bolt fastening work of the seat track fitting 13 at the fixing portion, and there is an advantage that the post-processing step required for a welding structure for a leg made of a metal member is extremely reduced. is there. By the way, the composite material molded article integrated with the front-rear beam (member corresponding to the reference numeral 14 described below) bridging the front cross member 6 and the rear cross member 7 is not used, but the large size of the molding die. Care has been taken to avoid this. That is, the front cross member 6 and the rear cross member 7 are bridged to each other and integrated in the front-rear direction by another material such as the seat bottom frame 14 (see FIG. 3A).

When the left and right sides of the seat 4 are in the X direction, the front and rear sides are in the Y direction, and the upper and lower sides are in the Z direction (see FIG. 2B), the front leg 2 and the rear leg 3 respectively bear the shear load on the web portion 16. Is arranged in the YZ plane to form an I-shaped structure as shown in FIG. Laminated press molding with continuous carbon fiber reinforcement in the full width or part of the anti-web side of the flange 17 (located in the vertical plane extending in the left-right direction of the seat) that bears tensile/compression axial force and enhances rigidity The resin body 18 is arranged. The cross section of the molded resin body is shown in a darkened color, and FIG. 4A is a partial one in which the molded resin bodies are arranged in parallel on the left and right, and in FIG. The remaining area of the flange portion 17 and the web portion 16 (all of which are shown thin in cross section) are molded by injecting and solidifying the compound resin. That is, as shown in FIG. 5, press-formed preform products 2P ₁ , 2P ₂ , 3P ₁ , 3P ₂ , 3P ₃ reinforced by laminating continuous fibers are manufactured in advance. In the case of the front leg 2, the preform products 2P ₁ and 2P ₂ are combined as shown in FIG. 6(a) and placed in a mold (not shown), and in the case of the rear leg 3, the preform products 3P ₁ and 3P ₂ , 3P ₃ is combined as shown in FIG. 6B and placed in a mold (not shown). The compound resin is injected so as to form the web portion while filling the back portion of the preform product, and by solidifying and molding the laminated constitution press-molding resin body 18 and compound resin body 19 as shown in FIG. As shown, the front leg 2 and the rear leg 3 are shaped with the ribs 20.

Therefore, each leg is a molded article that has undergone a hybrid molding method including a laminated molding method of a reinforced plastic molding material in which continuous fibers as a reinforcing member are impregnated with a thermoplastic resin and an injection molding method of a compound resin. According to this hybrid molding method, large-scale auto-grading and long-time curing are not necessary, and therefore mass production can be speeded up. In more detail, the main component of the strength of the flange portion 17 is the carbon fiber reinforced PPS resin, which has already been touched, and the fibers are unidirectional reinforcing material (UD material) or woven material (cloth). The proof stress of the flange is high. When the compound molten resin is injected under pressure, the compound resin body 19 and the laminated constitution press-molded resin body 18 are highly entangled with each other due to mutual fusion of the respective resins, and are integrated without boundaries.

As shown in FIG. 5, the partial parts obtained by separating the laminated structure press molding into the left and right sides are the front leg 2 and the rear fixing portion side of the descending oblique leg portion 3A of the rear leg 3 and the upward oblique leg portion 3B. Is the front cross member side of the descending oblique leg portion 3A of the rear leg 3. That is, the press-formed preform product 3P ₁ is for full width structure, and the press-formed preform products 2P ₁ , 2P ₂ , 3P ₂ , 3P ₃ are for partial width structure. By the way, the preform products 2P ₁ and 2P ₂ exhibit a bilaterally symmetrical bend as will be seen from FIG. 9 described later, and _two of the preform products 3P ₂ have a tapered portion at the tip (the arrow-shaped portion 23 described later). 2) of the same shape except for) and the preform product 3P ₃ have the same shape.

The preform product press-molded by the laminate-structured press-molded resin body 18 is a hairpin-shaped molded product which is bent by surrounding the front transverse member 6 or the rear transverse member 7 and the rear fixing metal fitting fastening pin hole portion 22. There is. In addition, even in a one-row arrangement, or in a two-row arrangement in which the flange portion 17 is dispersed near the left edge and the right edge on the side opposite to the web portion, the number of layers is changed in consideration of the load load. It can be a reinforced reinforcement. Immediately before the injection molding for molding the front leg 2 and the rear leg 3 of the leg structure 5 by these, the arrangement is as shown in FIG. 6 already shown, and the front and rear legs after the injection molding have the appearances as shown in FIG. Become. In addition, as shown in FIG. 8A, in the front leg 2, the upper half part is arranged in two rows separated from the preform products 2P ₁ and 2P ₂ , and the lower half part is arranged in two rows combined. .. This figure shows a full view of the reinforcement when assembled as a leg structure.

As shown in FIG. 5, the vicinity of the tip of each press-formed preform product in the flange portion 17 of the hairpin-shaped molded product forming the composite rear leg 3 is formed in the shape of an arrowhead having only one hypotenuse. This arrowhead portion 23 gradually reduces the cross-sectional area of the flange portion 17 toward the tip, suppresses a sudden change in rigidity that occurs with another adjacent hairpin-shaped molded product, and avoids the occurrence of stress concentration. Is intended.

As shown in FIG. 6, the front legs 2 made of the composite material are arranged in parallel in two rows, and are closely integrated at the front fixing portion 1F and a portion in the vicinity of the front fixing portion 1F. That is, as shown in FIGS. 8A and 9A, the rigidity in the left-right direction is improved by forming the V shape or the pine needle shape. Further, as will be described later, even if the shock absorber 25 (see FIG. 1) is attached to the leg ends, the reinforcing bar formed by the laminate-structured press-molded resin body 18 in the close state is integrally removed. It is also possible to reduce the complexity of the structure of the shock absorber 25.

Returning to FIG. 1, the flange portion 17a in the vicinity of the front fixing portion 1F of the front leg 2 has an arc shape with radii r ₁ and r ₂ centered on the rear fixing portion 1R on both the front surface and the rear surface. If the seat tries to fall forward during sudden deceleration, the shock is absorbed by shortening the length of the front leg 2. At this time, the arcuate portion 26 keeps the lower end of the front leg 2 in a constant posture such as a right angle with respect to the destruction acting portion of the shock absorber 25, so that the reliability of the shock absorbing action can be improved. .. The compound resin is relatively brittle when cured, and the web portion 16 is instantaneously scattered by the impact force, but the absorption of the impact is achieved by the bending deformation of the CFRP flange which starts due to fiber breakage and delamination. In this way, if the impact absorbing action is also taken into consideration, it can be seen that making the leg structure a composite material is extremely convenient.

By the way, as shown in FIG. 8B, it is preferable that the thickness of the lower end portion of the flange portion 17 of the front leg 2 is gradually reduced toward the fixing portion 1F so as to easily give a chance for fiber breakage and delamination. The thickness gradually decreasing portion 27 is convenient because a large stress can be applied at the start of shock absorption. Further, the flange portion 17 whose thickness is gradually reduced toward the fixing portion 1F is also provided with a taper 28 in the shape of an arrowhead in a plan view, so that the stress acting toward the tip can be further increased. Since the cross-sectional area becomes smaller toward the tip, the gentle increase in stress promotes the fail-safe effect and behavior of the front leg 2 and is extremely convenient for starting from the flange tip.

In this way, by sharpening the tip in both the plane direction and the plate thickness direction, the breakage from the flange tip can be made even smoother. FIG. 3A shows a state of the seat in normal times, and FIG. 3B shows a state in which the front leg 2 is contracted. Even if the seat surface does not seem to have a large inclination, the shock absorbing effect is great. As can be seen from FIGS. 10(a) to 10(c), whether the flange portion 17 is peeled off from the front leg and the front flange portion 17F and the rear flange portion 17R are projected as flange bent strips 17b although they will be touched later. Behaves like. Since the appearance is in the Y direction of the seat, it is possible to minimize heading toward one's feet or legs.

By the way, as shown in FIG. 11, the descending oblique leg portion 3A is connected to the front transverse member 6 by the front oblique leg element 3F and the rear oblique leg which is connected to the front oblique leg element by the pin 29 and goes to the rear fixing portion 1R. It is also possible to form the rear leg 3 with the element 3R, and the ascending oblique leg portion 3B is integrally formed at the front end portion of the rear oblique leg element 3R. In this case, the rear leg 3 is made into two parts, that is, the straight link of the front oblique leg element 3F and the "L"-shaped link 3M composed of the rear oblique leg element 3R and the upward oblique leg portion 3B. On the other hand, the size of the molding die can be further reduced. Needless to say, no moment is generated at the pin connection portion, and the beam rigidity required for the front oblique leg element 3F can be kept low.

FIG. 12 shows the arrangement of the press-molded preform products 3Q ₁ , 3Q ₂ , 3Q ₃ , 3Q ₄ , and 3Q ₅ by continuous fiber lamination in the case of the configuration of FIG. 11 and the same as in the case of FIG. 6A. The integrated product of the front leg preform products 2P ₁ and 2P ₂ is shown. A perspective view of the laminate-structured press-molded product built in the injection-molded product is as shown in FIG. 13 similar to FIG. With any of the configurations described above, the composite vehicle seat manufactured by the leg structure molding method according to the present invention has a required strength, yet is lightweight, easy and quick to manufacture, and the number of parts is high. There are many advantages such as the minimization of manufacturing cost, simplification and cost reduction of manufacturing jigs, and facilitation of mass production.

As can be seen from the above description of each embodiment, in a vehicle seat made of a composite material to which the front leg mounting shock absorber of the present invention is applied, the leg structure is made of a composite material (carbon fiber reinforced thermoplastic composite material) front leg. Since the rear legs are made of composite material, the weight of the seat can be reduced. Therefore, the weight reduction of the aircraft can increase the payload, the cruising range, and the takeoff and landing distance. The front leg extends downward from the front cross member that supports the own seat and the adjacent seat just below the front edge of the seating surface, and the rear leg extends downward from the front cross member to the rear fixing portion, and approximately at the middle of this down oblique leg portion. Since it is formed by the ascending leg portion extending from the portion toward the rear cross member, shear and moment acting on each portion of the leg structure are reduced as compared with, for example, the inverted N type. By the way, since the flange portion contains a press-molded resin body having a continuous carbon fiber reinforced laminate structure, a force against axial forces such as tension and compression is sufficiently secured. In addition, since the rear leg is in an oblique form, it is less restricted by the front-back dimension of the seat surface, and it becomes easier to increase the distance between the fixing portions.

Each of the front and rear legs has an I-shaped structure in which the web portion that bears the shear load is arranged in the YZ plane, and the entire width or one side of the flange portion that bears the tensile/compression axial force and increases the rigidity is on the side opposite the web portion. Laminated press-molded resin body reinforced with continuous carbon fiber that functions as a reinforcing bar is arranged in the section, and the residual area and the web portion in the flange section are made into a compound resin body for injection molding. The leg structure has a rigid web portion and a flange portion formed by fusion bonding with the body. As a result, the composite material of the leg structure is further manufactured, a structure with good strength balance and less mechanical waste is achieved, and the consumption of the molding material is suppressed.

Since the front and rear legs are molded as independent parts, the mold specification conforms to the shape of each component, and the size is smaller than the mold that makes the molded product with the front leg and rear leg integrated reinforcement braces. Therefore, the mold for forming the reinforcing bar is indispensable, but the injection mold for forming the web portion is downsized, and the cost for manufacturing the mold is reduced. Further, even in the autoclave treatment, it is possible to prevent the autoclave from becoming large in size and suppress an increase in equipment cost. The time required for molding is also greatly reduced (eg 15 minutes). The number of parts is significantly smaller than that of the metal leg structure, and the number of manufacturing steps including assembly can be significantly reduced.

The molding of the front and rear legs with compound resin is based on the pressure injection of the compound molten resin into the residual cavity after placing the preformed continuous carbon fiber reinforced laminated structure press-molded resin body in the mold. At that time, since the compound resin body and the continuous carbon fiber reinforced laminated structure press-molded resin body are made to be integrated by resin fusion, it is possible to use only the laminated molding or the injection molding. In comparison, the reinforcing material is properly arranged in the composite material, and the number of places that cause excessive strength or excessive quality is reduced as much as possible.

Since the front leg is made of a resin molded product, it is easy to introduce a shock absorbing method and a device therefor that utilize the damage or destruction phenomenon according to the fail-safe idea when a large shock is applied. That is, since the composite material product has an I-shaped structure, it is easy to raise the level of safety by developing two different shock absorbing forms, such as breaking in a non-rigid place and deforming in a rigid place. be able to. It is also possible to mix a laminate-structured press-molded resin plate in a part of the web portion. A part of the meaning means that there is a web part including the laminate-structured press-molded resin plate and a web part that does not include the laminate-structured press-molded resin plate, and the laminate-structured press-molded resin plate is a core material in a cross section having the web part. And is in either or both states in the case of being covered with a compound resin. Although not shown, the laminate-structured press-molded resin plate serving as the core material may be formed in a strip shape, for example. Only the compound resin may be left in the portion where the web portion is broken and the impact is absorbed, and the number of laminated layers is reduced when interposing the laminated constitution press-molded resin plate as the core material, and the web portion and the flange portion are formed. It is possible to intentionally generate strength.

By the way, an example of the shock absorber 25 mentioned above will be briefly described. FIG. 14 is an enlarged photograph of the corresponding part on the left side surface of the seat, which is made of metal. This is composed of the left half body 31 and the right half body 32 shown in FIG. 15 that hold the lower end portion of the composite front leg 2 having the I-shaped cross section by arranging the web portion 16 in the YZ plane. Both the left half body and the right half body are provided with holding guides 33A and 33B into which the respective lower end portions of the two flange portions 17 located in the ZX plane are fitted, and the lower end of the web portion 16 is mounted. The crushed surface 34 of the web portion is formed. The left half body and the right half body are provided with holding tongues 35 and 36, which are fitted between the flange portions so as to contact the left surface or the right surface of the web portion 16, corresponding to the web portion 16, and the web portion crushing surface. A waste port 37 for discharging the web waste 16a from 34 in the X direction is formed. In the lower part of the holding guides 33A and 33B, a deflection surface 38 for bending the flange portion 17 after losing the integrity with the web portion 16 and a deflected flange bending strip 17b are separated into two hands in the Y direction. A discharge port 39 for discharging is provided. FIGS. 16A and 16B show these configurations in different cross sections, and the respective functional parts can be understood.

A detailed description of the shock absorbing behavior is omitted, but the shock absorbing behavior can be modified as shown in FIGS. In this behavior, crushing or crushing of the web portion precedes. This is because the web portion made of the compound resin is a little brittle, and is easily broken when an impact of a predetermined value or more is applied. Since there is a laminated carbon-fiber-reinforced press-molded resin body in the flange portion, it is tough, and even if the compound resin forming a part of the flange portion collapses, the fiber-reinforced resin laminate is not severely destroyed. Therefore, as shown in FIG. 10, some deformation may occur in the laminated body. However, because it is a laminate, delamination occurs and deformation continues to proceed, and the impact on the occupant is moderated to some extent.

The leg structure and the leg structure molding method according to the present invention described above have been described by taking an aircraft seat as an example. Nowadays, there is a demand for weight reduction in any vehicle, and it is needless to say that the present invention can be applied to the seats of various vehicles and the like by making use of the configuration and can be applied.

1F... Front fixing part, 1R... Rear fixing part, 2... Front leg, 3... Rear leg, 3A... Down oblique leg, 3B... Upward oblique leg element, 3R... Rear oblique leg element, 4 ...Seat, 4M...self seat, 4N...adjacent seat, 5...leg structure, 6... front cross member (front beam), 7...rear cross member (rear beam), 16...web part, 17...flange part, 18...continuous Carbon fiber reinforced laminated structure Press-molded resin body, 19...Compound resin body, 23...Arrow portion, 27...Reduced portion, 28...Taper, 29...Pin, r ₁ , r ₂ ... The radius of the arc.

Claims (11)

In a leg structure manufacturing method for a vehicle seat, in which a front leg reaching a front fixing portion of the floor is provided in a substantially vertical state, and a rear leg facing a rear fixing portion in a downward tilted state is provided,
The leg structure includes a front foot made of a composite material that extends downward from a front cross member that supports the own seat and an adjacent seat just below a front edge of a seat surface, and a down bevel leg made of a composite material that tilts backward from the front cross member toward a rear fixing portion. Portion, and an ascending oblique leg portion that slopes upward from a substantially middle portion of the descending oblique leg portion and extends toward a rear cross member that supports the own seat and the adjacent seat immediately below the rear edge of the seat surface. Has rear legs made of wood,
When the left and right sides of the seat are in the X direction, the front and rear sides are in the Y direction, and the upper and lower sides are in the Z direction, the composite front legs and rear legs each have an I-shaped structure in which a web portion that bears a shear load is arranged in the YZ plane. A continuous carbon fiber reinforced laminated structure press-molded resin body is provided on the entire width or a part of the flange portion that bears a tensile/compression axial force to enhance rigidity, and on a part of the web portion. The remaining area in the flange portion and the remaining area in the web portion is a compound resin body for injection molding,
The molding of the compound resin body is carried out by pressure injection of the compound molten resin into the residual cavity after the pre-formed laminated constitution press-molding resin body is placed in a molding die. And a laminated structure press-molded resin body are integrated by resin fusion, and a leg structure molding method for a composite vehicle seat is characterized. The descending oblique leg portion extends directly to the rear fixing portion, and the ascending oblique leg portion is integrally formed with the descending oblique leg portion at a substantially intermediate portion of the descending oblique leg portion. Method for forming leg structure of composite vehicle seats. The composite material vehicle seat according to claim 2, wherein the composite material front leg and the composite material rear leg are assembled as an integral structural leg through the front cross member or the rear cross member. Leg structure molding method. The descending oblique leg portion is formed by a front oblique leg element connected to the front cross member and a rear oblique leg element pin-connected to the front oblique leg element and heading toward a rear fixing portion, and the upward oblique leg portion is The method for forming a leg structure for a composite vehicle seat according to claim 1, wherein the rear oblique leg element is integrated at a front end portion thereof. 2. The laminate-structured press-molded resin body is a hairpin-shaped molded product that surrounds the front cross member or the rear cross member and is bent, and is arranged in one row or in two rows in parallel. Method for forming leg structure of composite vehicle seats. 6. The composite material vehicle according to claim 5, wherein the hairpin-shaped molded article forming the composite rear leg is molded in the shape of an arrowhead with only one hypotenuse in the vicinity of the tip of the flange portion. Seat leg structure molding method. 6. The front legs made of the composite material are arranged in the two rows in parallel, and are closely integrated at the front fixing portion and a portion close to the front fixing portion to enhance lateral rigidity. Composite leg forming method for vehicle seats. The leg of the composite vehicle seat according to claim 5, wherein a flange portion of the front leg near the front fixing portion has an arc shape centering on the rear fixing portion on both front and rear surfaces. Structural molding method. 6. The composite material vehicle according to claim 5, wherein the flange portion of the front leg in the vicinity of the front fixing portion is gradually reduced in thickness toward the fixing portion to facilitate the delamination failure. Seat leg structure molding method. 10. The flange portion, the thickness of which is gradually reduced toward the fixing portion, is tapered in an arrowhead shape in a plan view so that stress is easily increased along with the tip end. Structure forming method for composite vehicle seats made by A composite vehicle seat manufactured by the leg structure molding method according to claim 1.