JP2841063B1 - Frontal structure of the composite structure for the leading vehicle - Google Patents

Abstract

To provide a forehead structure of a leading vehicle composite structure capable of reliably shielding a front end opening of the composite material structure with a pressure bulkhead. SOLUTION: The front end of a composite structure 2 made of a plastic molded body 2A is divided in a direction orthogonal to the front-rear direction of the vehicle body, and a front end opening 2B at the division position is shielded by a pressure partition 8. In the forehead structure of 1 above, the tip peripheral edge 2d of the plastic molded body 2A is formed in a solid thin plate shape, and the tip peripheral edge 2d is extended and bent in the radial direction toward the center of the opening 2B to form a composite material structure. A pressure hole 8 made of an aluminum alloy and formed in advance corresponding to the front end opening 2B of the second end 2 is attached to the front end peripheral extension 11e to form a bolt hole 18 and connected by a bolt 17.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for a leading vehicle such as a shinkansen bullet train, and more particularly, to a front end of a composite material structure formed of a plastic molded body divided in a direction orthogonal to the longitudinal direction of a vehicle body. The present invention relates to a forehead structure of a composite structure for a leading vehicle in which a front end opening of the structure is shielded by a pressure partition.

[0002]

2. Description of the Related Art The front vehicle of the above-mentioned Shinkansen has a streamlined front (also called a curved surface) in order to reduce air resistance during high-speed driving. As shown in FIG. 6, the framework 21 of the composite structure for a railway vehicle including the leading vehicle is a circumferential member (transverse member) that is continuous in an arc shape or an inverted U shape.
A slit (not shown) is provided at a position where each of the longitudinal member 22 and the longitudinal member (longitudinal member) 23 intersecting in the longitudinal direction intersects, and the circumferential member 22 and the longitudinal member 23 are arranged at the intersection position. The skeleton of the structure is made by fitting the slits together and joining them by welding. Then, a thin metal outer plate (not shown) is attached to the outer surface of the skeleton 21, and the outer surface of the skeleton 21 is processed into a curved shape corresponding to the outer surface of the skeleton 21 by hitting with a hammer or the like. It is common to make a structure. In addition, a metal material such as an aluminum alloy is used for the circumferential member 22, the longitudinal member 23, and the outer plate constituting the structure.

[0003] As a prior art relating to a method of manufacturing such a structure for a railway vehicle, there is a method described in, for example, JP-A-62-160954 and JP-A-62-160955. In any of the manufacturing methods, slits corresponding to the intersections between the circumferential members and the longitudinal members are provided, and the slits are fitted to each other and joined by welding. As a prior art of a high-speed vehicle using a composite material, Japanese Patent Application Laid-Open No.
Japanese Patent No. 45567 and Japanese Patent Application Laid-Open No. 7-96833.

[0004]

In the above-mentioned conventional vehicle body structure using a metal structure, it is particularly difficult to form a curved surface shape, it takes a long time to manufacture the structure, the manufacturing cost is high, and the vehicle weight is high. There is a problem that it is difficult to reduce the weight.

Therefore, for example, as described in the above-mentioned publication, it is conceivable to manufacture a forehead of a leading vehicle, which mainly requires a curved surface shape, using a composite material structure made of a plastic molded body. . However, in order to manufacture such a composite material structure, the following problems must be solved. That is, this type of composite structure, that is, a plastic molded body is generally molded by using an autoclave molding method. However, even with the largest autoclave equipment currently in Japan, the length is about 12 m, so that the total length is about 12 m. It is small for forming a 16 m Shinkansen vehicle composite structure, and the entire structure cannot be integrally formed.

[0006] Even if a composite body structure for a Shinkansen vehicle can be integrally molded, the length regulated by the Road Traffic Law (12
m) or width (3.5m), transportation is not possible without the permission of each prefectural police.

When a structure is manufactured from a sandwich-shaped plastic molded body in which the outer surface of a fiber-reinforced plastic material layer is integrally coated on the surface of a core material of a hard plastic foam, the structure is vulnerable to pulling in the out-of-plane direction. When the partition wall is directly connected to the outer skin, the outer skin may be separated from the core material due to a pressure fluctuation particularly when the vehicle enters the tunnel.

Since the headlight mounting portion is formed by being cut out, the headlight mounting portion is easily deformed by thermal stress at the time of molding, and the structure is inferior in rigidity.

SUMMARY OF THE INVENTION The present invention relates to the above problems associated with manufacturing a composite body structure for a leading vehicle of a Shinkansen using a composite body structure made of a plastic molded body that can be easily manufactured with a curved surface shape and can be reduced in cost and weight. It is therefore an object of the present invention to provide a forehead structure of a composite structure for a leading vehicle in which the opening at the tip of the composite structure can be reliably shielded by a pressure partition.

[0010]

In order to achieve the above object, the forehead structure of a composite structure for a leading vehicle according to the present invention is characterized in that the front end of a composite material structure formed of a plastic molded body is moved in the longitudinal direction of the vehicle body. It is a forehead structure of a composite structure for a leading vehicle in which a front opening of the structure formed at the dividing position is divided by a pressure bulkhead, and a peripheral edge of a front end of the plastic molded body is a solid thin plate. The distal end peripheral portion is extended and bent in a radial direction toward the center of the distal end opening, and a separate pressure partition formed in advance corresponding to the distal end opening of the composite structure is extended to the distal end peripheral portion. Attached on the part and joined with a fastener.

According to the forehead structure of the composite structure for the leading vehicle of the present invention having the above-described structure, the front end of the composite material structure formed of a plastic molded body is divided by a direction perpendicular to the front-rear direction. In this case, it is possible to perform integral molding by the autoclave molding method, and high accuracy is achieved. In addition, since pressure is applied during heating, bubbles are hardly generated inside the molded body, and the impact resistance (particularly bird resistance) A plastic molded body having excellent impact force can be manufactured. In addition, since the plastic molded article can be transported by ordinary truck service, even if the composite material molding factory and the vehicle assembly factory are far apart, there is no restriction and the cost can be reduced. Further, the connection between the front end (opening) of the composite material structure and the pressure partition is formed at a portion obtained by extending the periphery of the front end, which is integrally hardened into a solid thin plate shape, and bending it inward in the radial direction. Are attached to each other and joined with a stopper, so that the rigidity is high and a sufficient joining strength is obtained. For this reason, even when the composite material structure is provided with a cut-out portion such as a headlight mounting portion and a pressure partition is connected in the vicinity thereof, deformation during molding is small, and the connection can be surely performed. In addition, since the plastic molded body is integrally molded using a mold by an autoclave molding method or the like, the dimensional accuracy is high. Therefore, by accurately manufacturing the pressure bulkhead, the joining operation can be performed efficiently and easily. In addition, the structure that blocks the opening at the tip of the composite material structure by connecting the pressure bulkheads to maintain the airtightness of the room is maintained, so that the composite material structure for the leading vehicle is lightweight, easily formed into a curved shape, and has a beautiful finish. It is excellent in fatigue strength, durable, and enables stable high-speed running for a long period of time.

A connector is arranged in front of the pressure bulkhead, and a peripheral edge of one end of the connector cover is abutted on a peripheral edge of a tip of the plastic molded body.
Can be joined with a stop.

According to the forehead structure of the composite material structure for the leading vehicle according to the second aspect, it is not necessary to seal the inside of the front part from the pressure bulkhead. There is no pressure difference due to the wind pressure between them, so that if the required strength can be ensured, it can be easily connected to the tip of the plastic molded body with a stopper without considering airtightness. The coupler cover is arranged in front of the composite material structure, and is usually a curved part in the leading vehicle of the Shinkansen, so by forming it with a plastic molded plate, the processing accuracy is high, and the appearance is beautifully finished. It is desirable to form with a fiber reinforced plastic plate from the viewpoint of strength.

According to a third aspect of the present invention, the plastic molded body is formed of a sandwich-structured molded body in which a hard foamed plastic material as a core material is integrally covered with a carbon fiber reinforced plastic material layer, and the peripheral edge portion of the tip is formed. Is preferably formed in a solid thin plate shape by laminating carbon fiber reinforced plastic material layers.

According to the forehead structure of the composite structure for a leading vehicle according to the third aspect, since the outer surface and the inner surface are covered with the carbon fiber reinforced plastic material, the breaking strength is high, for example, 275 km / h or more. Fully durable and durable even when birds collide during high-speed operation, and has a hard foam plastic material inside, so it is integrated with the carbon fiber reinforced plastic material of the interior and exterior, and the overall strength In addition to exhibiting the effect of increasing the heat resistance, it also acts as a heat insulating material and a sound insulating material. Furthermore, the plastic molded body of the sandwich structure has a plastic material layer on the surface that is vulnerable to out-of-plane tension and is easy to peel off, but the peripheral edge of the tip is formed into a solid thin plate by laminating a carbon fiber reinforced plastic material layer Since the pressure partition is connected to the extended and bent portion, the rigidity is high, the connection can be surely performed, and the durability is excellent.

According to a fourth aspect of the present invention, in the pressure partition,
It is possible to use a structure in which a reinforcing material made of an aluminum alloy in which ribs are combined in a grid pattern on the outer surface of an aluminum alloy plate is integrally provided.

According to the forehead structure of the composite material structure for the leading vehicle according to the fourth aspect, the structure can be easily manufactured by using the aluminum alloy plate, the cost can be reduced, and the reinforcing member is integrally provided. By doing so, even when the thickness of the aluminum alloy plate is reduced to some extent, deformation during pressure fluctuation can be suppressed, and weight reduction can be achieved.

As described in claim 5, a shearing bolt can be used for the stopper.

According to the forehead structure of the composite material structure for the leading vehicle according to the fifth aspect, since the plastic molded plate has extremely high dimensional accuracy, it does not have as much deformability as an aluminum alloy plate. Generally, holes are usually processed on-site at the site, but it is difficult to provide large-diameter holes, and there is a situation in which a fastener with a small shaft diameter must be used. However, the strength of the aluminum alloy plate can be reduced in thickness, so if a shearing bolt is used,
Since the inconvenience such as bending of the shaft is unlikely to occur, a sufficient bonding strength can be exhibited by properly determining the interval between the bolts.

[0020]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a front vehicle composite structure according to an embodiment of the present invention;

FIG. 1A is a perspective view of a structure for a leading vehicle of a Shinkansen according to an embodiment of the present invention, as viewed from the upper front, and FIG. 1B is a side view showing the vicinity of the forehead in FIG. FIG. 2, FIG. 2 is a perspective view showing a left-side composite material structure obtained by dividing the forehead of the leading vehicle into two parts, FIG. 3 is an enlarged sectional view taken along line AA of FIG. 1, and FIG.
FIG. 5A is an enlarged perspective view showing a part of the headlight mounting portion of FIG. 2 in a cross section, and FIG. 5 is an enlarged cross sectional view taken along the line KK of FIG.

As shown in FIG. 1, the main part of the structure 1 for the leading vehicle of the Shinkansen is composed of a front composite material structure 2 provided with a plastic molded body 2A and a rear aluminum alloy structure provided with an aluminum alloy framework. It is manufactured by combining with the structure 3. As shown in FIGS. 3 and 5, the composite material structure 2 has a core made of a hard foamed plastic (a foam of polymethacrylimide in this example) 2a and a fiber reinforced plastic (FRP, this example) so as to cover the periphery thereof. In this embodiment, a plastic molded body 2A having a sandwich structure integrally provided with a carbon fiber reinforced plastic) material layer (also referred to as an outer skin) 2b is provided as a main component. Further, in this example, the plastic molded body 2A is divided into two right and left parts as shown in FIG.
Each is integrally molded by an autoclave molding method (not shown).

A pair of left and right plastic molded bodies 2A are suspended by a crane, respectively,
It is put on and attached. Plastic molding 2
Almost all equipment (not shown), including electrical components and wiring, is mounted on the chassis 4 on which A is mounted. The front composite structure 2 including the pair of left and right plastic molded bodies 2A is covered so as to wrap the equipment on the chassis 4, and the left and right divided surfaces are integrally bonded with an adhesive. It is connected to the aluminum alloy structure 3.

On the other hand, the tip of the composite material structure 2 is divided (divided) in a direction perpendicular to the front-rear direction (longitudinal direction) of the vehicle body as shown in FIG. The inside of the composite material structure 2 is in communication with the inside of the rear structure 3 on which passengers ride, as well as crew members such as drivers, so it is necessary to shut off from the outside when passing through the tunnel to make it airtight. . Therefore, it is necessary to shield the distal end opening 2B generated by dividing the distal end of the composite material structure 2 by attaching a pressure partition 8 as described later.

A connector 5 is provided at a lower front portion of the composite structure 2, and a connector cover 6 which is curved in an arc shape as shown in FIG. A hemispherical cap 7 is detachably attached to the front, that is, to the forefront end of the composite structure 1 for the leading vehicle. It is not necessary to make the interior of the chamber in front of the pressure partition 8 airtight, and the interior of the interior may be in a so-called open-to-open state. For this reason, there is no need to consider the strength in the out-of-plane direction, so that the peripheral parts of the connector covers 6 are joined by a large number of blind fasteners 9 penetrating in the thickness direction as described later. In addition, since the coupler cover 6 has a curved shape,
Although it is formed of a fiber reinforced plastic plate (FRP plate) for ease of processing, beautiful finish and light weight, the thickness is relatively large from the viewpoint of preventing damage when a bird collides.

In the present embodiment, the pressure partition 8 is formed of an aluminum alloy plate 8a, and takes into account deformation when pressure fluctuations are applied (particularly, when passing through a tunnel, it bulges outward). A reinforcing material 8b in which ribs of an aluminum alloy plate cut to a predetermined width are combined in a lattice shape is integrally fixed to the front surface of the aluminum alloy plate 8a by welding or the like. The shape of the aluminum alloy plate 8a has a substantially semicircular shape corresponding to the distal end opening 2B of the composite material structure 2 obtained by bonding a pair of left and right plastic molded bodies 2A in FIG. The plastic molded body 2A has a core material of a hard foamed plastic 2a as shown in FIG. 3, except for the headlight mounting portion 2C in FIG. As shown in FIGS. 4 and 5, the headlight mounting portion 2C is formed by laminating the FRP material layer 2b and integrally curing and molding the solid thin plate-shaped portion into a concave shape as shown in FIGS. 1
1 is formed. An opening 11a in front of the irradiation chamber 11
Is surrounded by the FRP material layer 2b to increase the thickness by one step, and the FRP material layer 2b, which has been lowered by one step,
An annular frame 12 made of a material layer is mounted on a plurality of blind rivets 1.
3 and a glass plate 15 is removably mounted on the annular frame 12 via a fitting 14. Glass plate 15
Is relatively thick (8 mm
Degree) Polycarbonate glass is used. Headlight 1
Numeral 0 is exchangeably attached to the vertical wall 11b at the back of the irradiation chamber 11.

[0027] Tip peripheral edge 2d of plastic molded body 2A
Is formed by laminating and integrally curing the FRP material layers 2b to form a solid thin plate, and extending the tip peripheral edge 2d and bending it radially toward the center of the opening 2B to form the mounting flange 2.
e. The mounting flange 2e is formed continuously with the inner peripheral portion of the distal end opening 2B of the plastic molded body 2A.

The peripheral edge of the pressure bulkhead 8 abuts on the mounting flange 2e, and a bolt hole 8f penetrating through the two in the thickness direction of both.
・ Drill 2f. The bolt holes are formed at equal intervals in the circumferential direction. Also, the angle member 16 is placed on the lower chassis 4.
Are fixed in the vehicle width direction by welding, and bolt holes 16f.
Drill 2f.

Then, from the pressure partition 8 side, each bolt hole 8f
, And screw it into the nut 17a on the inside to tighten it. Normally, there is an opening below the pressure bulkhead 8 , from which an operator puts a hand and screws the nut 17a into the bolt 17 to tighten it. If there is no such opening, use a blind fastener. Thereby, the pressure bulkhead 8 can be mounted on the mounting flange 2e only by an external operation.

The peripheral edge of one end of the connector cover 6 molded in advance is attached to the peripheral edge 2d of the front end of the plastic molded body 2A, and a mounting hole 18 penetrating in the thickness direction of the both is formed by blinding as shown in FIG. They are connected by fasteners 9. As shown in FIGS. 3 and 5, a putty (sealant) 19 is provided in a gap between the connector cover 6 and the plastic molded body 2A.
Is filled.

As described above, the distal end opening 2B of the composite material structure 2 is shielded by the pressure partition 8 made of aluminum alloy. With this configuration, the pressure bulkhead 8 of the leading vehicle structure 1 is formed.
Although the room at the rear is kept airtight, the above embodiment has the following advantages.

(A) The attachment between the plastic molded body 2A having the sandwich structure and the pressure partition wall 8 is formed by laminating the FRP material layers 2b and integrally hardening them into a solid thin plate, and furthermore, bending them at substantially right angles. Pressure bulkhead 8 against flange 2e
Is carried out by bolting, so that the rigidity is high, and unlike the connection to the outer cover 2b, it is difficult to peel off in the out-of-plane direction. Therefore, even in the vicinity of a notched portion such as the headlight mounting portion 2C, deformation during molding is small, and the connection can be reliably performed.

(B) Pressure bulkhead 8 of plastic molded body 2A
Since the joint surface with the slab is integrally formed by the autoclave molding method, the dimensional accuracy is high. Therefore, the joining operation can be easily performed by accurately manufacturing the pressure bulkhead 8.

(C) Since the composite material structure 2 can be manufactured by joining the plastic molded body 2A obtained by dividing the composite material structure 2 into a plurality of parts, the composite material molding factory equipped with an autoclave facility is separated from the vehicle assembly factory. Also, it can be easily transported by regular truck service.

(D) Since the pressure partition 8 is connected to block the distal end opening 2B to maintain the airtightness of the room, the composite material is lightweight, easily formed into a curved shape, and has excellent fatigue strength. The structure 2 can be applied to the leading vehicle of the Shinkansen.

(E) The main body of the pressure bulkhead 8 is formed of an aluminum alloy plate 8a, and the reinforcing member 8b is integrally provided on the surface, so that the plate thickness can be reduced. By using, even if the shaft diameter is not too large, the interval between the bolts 17 is widened to some extent, the number of bolts 17 used is reduced, the joining operation is facilitated, the work efficiency is improved, and a sufficient joining strength can be obtained. The pressure fluctuation during the passage through the tunnel acts on the pressure bulkhead 8, causing the pressure bulkhead 8 to swell or dent. However, the amount of deformation is suppressed by the reinforcing member 8b.

Although one embodiment of the forehead structure of the composite structure for a leading vehicle according to the present invention has been described above, the present invention can be implemented as follows.

(A) Plastic molded body 2A of front structure 2
From the viewpoint of handling such as transportation, it is desirable to form them separately and then join them together, but it is also possible to integrally form the whole without dividing them.

(B) As the pressure bulkhead 8, a carbon fiber reinforced plastic plate or a glass fiber reinforced plastic plate can be used other than the aluminum alloy plate.

(C) The outer cover (coating layer) 2b of the plastic molded body 2A may be a carbon fiber reinforced plastic material or a plastic material reinforced with a highly elastic woven cloth such as Kevlar (trademark, aramid fiber).

(D) It goes without saying that the present invention can be applied not only to the structure 1 for a leading vehicle of a Shinkansen but also to a structure for a leading vehicle of a conventional line having a curved surface.

[0042]

As is apparent from the above description,
The frontal structure of the composite structure for a leading vehicle according to the present invention has the following effects.

(1) According to the first aspect of the present invention, since the length of the composite material structure made of a plastic molded body can be shortened, integral molding by the autoclave molding method becomes possible, high accuracy and high heating Due to the application of pressure, bubbles are hardly generated inside the molded product, and plastic molded products with excellent impact resistance (especially bird impact resistance) can be manufactured, and the plastic molded products can be transported by ordinary truck service. Therefore, even if the composite material molding plant and the vehicle assembly plant are far from each other, there is no restriction and the cost can be reduced.

A separate pressure bulkhead is attached to a part of the composite material structure and the pressure bulkhead, which is integrally solidified into a solid thin plate and is hardened integrally, and which is extended inwardly and bent inward in the radial direction. Since the connection is performed by a tool, the rigidity is high and a sufficient connection strength can be obtained. Therefore, even when the pressure bulkhead is connected to the vicinity of the cutout portion such as the headlight mounting portion, the connection can be surely performed.

Further, since the composite material structure is integrally molded using a mold by an autoclave molding method or the like, if the dimensional accuracy is high and the pressure bulkhead is manufactured accurately, the joining operation can be performed efficiently and easily. Furthermore, the pressure partition is combined to block the opening of the tip of the composite material structure so that the airtightness of the room can be maintained, so the composite material structure for the leading vehicle is lightweight, the curved shape is easy to mold, and the finish is beautiful, Excellent fatigue strength, high durability, and stable high-speed operation for a long period of time.

(2) According to the second aspect of the present invention, since there is no need to seal the inside in front of the pressure bulkhead, there is no pressure difference between the outside and the inside due to wind pressure even when entering a tunnel. As long as the required strength is secured, it can be easily connected to the front end of the plastic molded body with a stopper without considering airtightness.

(3) According to the third aspect of the present invention, since the outer surface and the inner surface are covered with a carbon fiber reinforced plastic material, the breaking strength is high, and it can sufficiently withstand a bird or the like during high-speed running. It is durable and has a hard foam plastic material inside, so it not only functions as an integral part of the interior and exterior carbon fiber reinforced plastic material to increase the overall strength, but also acts as a heat insulating material and a sound insulating material. Also acts as. Furthermore, the plastic molded body of the sandwich structure has a plastic material layer on the surface that is vulnerable to out-of-plane tension and is easy to peel off, but the peripheral edge of the tip is formed into a solid thin plate by laminating a carbon fiber reinforced plastic material layer Since the pressure partition is connected to the extended and bent portion, the rigidity is high and the durability is excellent.

(4) According to the fourth aspect of the present invention, the use of an aluminum alloy plate for the pressure bulkhead facilitates manufacture, reduces cost, and achieves a structure in which a reinforcing material is integrally provided. Even when the thickness of the alloy plate is reduced to some extent, deformation during pressure fluctuation is suppressed, and the weight can be reduced.

(5) According to the fifth aspect of the present invention, since the thickness of the aluminum alloy plate can be reduced in strength, use of a shear-type bolt hardly causes inconvenience such as bending of the shaft body. Sufficient bonding strength is exhibited by properly determining the interval.

[Brief description of the drawings]

FIG. 1A is a perspective view of a structure for a leading vehicle of a Shinkansen according to an embodiment of the present invention, as viewed from the upper front, and FIG.
(a) is a side view showing the vicinity of the forehead.

FIG. 2 is a perspective view showing a left-side composite material structure obtained by dividing a frontal part of a leading vehicle into two parts.

FIG. 3 is an enlarged sectional view taken along line AA of FIG. 1;

FIG. 4 is an enlarged perspective view showing a cross section of a part of the headlight mounting portion in FIGS. 1 (a) and 2;

FIG. 5 is an enlarged sectional view taken along line KK of FIG. 4;

FIG. 6 is a perspective view showing a frame structure (left half) of a conventional general metal structure of a Shinkansen leading vehicle.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Top vehicle structure 2 Composite material structure 2A Plastic molded body 2B Tip opening 2a Hard foamed plastic 2b Fiber reinforced plastic film layer 2d Peripheral edge 2e Mounting flange (extended part) 3 Aluminum alloy structure 4 Chassis 5 Linkage 6 Linkage cover 7 Cap 8 Pressure bulkhead 8a Aluminum alloy plate 8b Reinforcement (rib) 10 Headlight 11 Irradiation chamber 17 Bolt 17a Nut 18 Bolt hole

Continuation of front page (72) Inventor Masaaki Konishi 1 Kawasaki-cho, Kakamigahara-shi, Gifu Kawasaki Heavy Industries, Ltd. Gifu factory (58) Fields investigated (Int. Cl. ⁶ , DB name) B61D 17/02 B61D 17 / 04

Claims (5)

(57) [Claims] 1. A front end of a composite material structure formed of a plastic molded body is divided in a direction orthogonal to a front-rear direction of a vehicle body,
A forehead structure of a leading vehicle composite structure in which a leading end opening of the structure at the dividing position is blocked by a pressure partition, wherein a peripheral edge of a leading end of the plastic molded body is formed in a solid thin plate shape. Extending the distal end peripheral portion and radially bending it toward the center of the distal end opening, attaching a separate pressure partition formed in advance corresponding to the distal end opening of the composite material structure on the distal end peripheral extension portion, and stopping The forehead structure of the composite body structure for the leading vehicle, wherein the forehead structure is joined by fasteners. 2. A connector is disposed in front of the pressure bulkhead, and a peripheral edge of one end of the cover for the connector is abutted on a peripheral edge of a front end of the plastic molded body and is joined by a stopper. The forehead structure of the leading vehicle composite structure as described. 3. The plastic molded product is a molded product having a sandwich structure in which a hard foamed plastic material as a core material is integrally coated with a carbon fiber reinforced plastic material layer, and the peripheral edge of the tip is formed of a carbon fiber reinforced plastic material. 3. The forehead structure of a composite structure for a leading vehicle according to claim 1, wherein the layers are laminated to form a solid thin plate. 4. The composite for a leading vehicle according to claim 1, wherein said pressure bulkhead is integrally provided with a reinforcing material made of an aluminum alloy in which ribs are combined in a grid pattern on the outer surface of an aluminum alloy plate. The forehead structure of the timber structure. 5. The forehead structure of a composite structure for a leading vehicle according to claim 1, wherein the stopper is a shearing bolt.