JP7272466B2 - VEHICLE OPENING/CLOSING BODY AND METHOD OF MANUFACTURING VEHICLE OPENING/CLOSING BODY - Google Patents

Description

The present disclosure relates to a vehicle opening/closing body and a manufacturing method of the vehicle opening/closing body.

2. Description of the Related Art In recent years, there has been a demand for weight reduction of automobile parts for the purpose of improving the fuel efficiency of automobiles and reducing the environmental load. In order to meet this demand, the number of cases where the material of parts is changed from metal to resin is increasing. For example, the use of resin is also widespread for members constituting an opening/closing mechanism of a vehicle, such as a back door installed in the rear part of an automobile.

Resin members have higher specific rigidity than steel plate products (in other words, they are lighter than steel plate products in terms of bending rigidity). Although it is expensive, it has the advantage of being suitable for small-lot production because the mold cost is low. On the other hand, since resin has lower rigidity than steel plate, techniques for suppressing deformation due to low rigidity are being developed.

For example, a resin back door is generally held to the vehicle body by a hinge installed at the top and a lock set at the center of the bottom, and on both sides are holding and opening and closing functions when the back door is opened. A damper is set to assist the operation of the time. Since the mounting position of the damper and the mounting position of the hinge are set apart from each other, the force of the damper is applied to the back door, which may easily deform the back door.

As a method for suppressing the deformation while making the back door made of resin, for example, in Patent Document 1, a resin outer panel and a resin inner panel are bonded together to form a back door. and a back door for an automobile, in which reinforcing metal plates are arranged inside portions of the inner panel where the dampers are attached, respectively.

Patent Document 1: JP 2015-39996 A

A vehicle opening/closing member containing a thermoplastic resin has advantages such as being lightweight and being able to be easily formed into a complicated shape as compared with a steel plate product. On the other hand, the vehicular opening/closing member containing a thermoplastic resin has a problem that deformation, breakage, and the like are likely to occur due to its low rigidity. In particular, in a vehicle opening/closing member having a lock portion and containing a thermoplastic resin, stress due to deformation or the like tends to concentrate on the lock portion, and it is required to prevent cracks and breakage in the lock portion. However, from the viewpoint of reducing the weight of automobile parts, it is desirable to minimize the use of metal members such as reinforcing metal plates for reinforcement.

In view of the above circumstances, an object of the present disclosure is to provide a vehicle opening/closing body and a manufacturing method of the vehicle opening/closing body that achieve both reduction in the mass of the entire vehicle opening/closing body and improvement in the strength of the lock portion.

Means for solving the above problems include the following embodiments.

<1>
A vehicle opening/closing body having at least a lock portion and containing a thermoplastic resin,
A vehicle opening/closing body having a fiber resin layer containing fiber and resin in a region including the lock portion.
<2>
The vehicle opening/closing body according to <1>, wherein the fibers are inorganic fibers.
<3>
The opening/closing body for a vehicle according to <2>, wherein the fibers are glass fibers.
<4>
The vehicle opening/closing body according to any one of <1> to <3>, wherein the fibers are a woven fabric of continuous fibers.
<5>
The vehicle opening/closing body according to any one of <1> to <4>, wherein the vehicle opening/closing body is a back door.
<6>
comprising an inner panel and an outer panel,
The opening/closing body for a vehicle according to any one of <1> to <5>, which has the fiber resin layer in a region of the inner panel including the lock portion.
<7>
The opening/closing body for a vehicle according to any one of <1> to <6>, wherein the fiber resin layer and the thermoplastic resin are held face to face.
<8>
The fiber resin layer according to any one of <1> to <7>, wherein the fiber resin layer is a layer integrated with the thermoplastic resin by insert molding of a fiber reinforced resin sheet containing the fiber and the resin. Opening and closing body for vehicle.
<9>
The opening and closing body for a vehicle according to any one of <1> to <8>, wherein the fiber resin layer is a preformed body of a fiber reinforced resin sheet containing the fiber and the resin.
<10>
A method for manufacturing a vehicle opening/closing member according to any one of <7> to <9>,
placing a fiber-reinforced resin sheet containing the fibers and the resin in a mold;
molding the thermoplastic resin in the mold in which the fiber-reinforced resin sheet is installed;
A method for manufacturing a vehicle opening and closing body comprising:
<11>
The method for manufacturing a vehicle opening/closing body according to <10>, wherein the fiber-reinforced resin sheet placed in the mold is preheated.

According to the present disclosure, there are provided a vehicle opening/closing body and a method for manufacturing the vehicle opening/closing body that achieve both reduction in the mass of the entire vehicle opening/closing body and improvement in the strength of the lock portion.

1 is a schematic diagram showing an example of a state in which an upper end of a back door for an automobile is held at the rear portion of the automobile; FIG. FIG. 2 is a schematic diagram showing a surface of the inner panel shown in FIG. 1 on the outer panel side; FIG. 3 is an enlarged schematic diagram of the periphery of the lock portion of the bottom wall of the inner panel shown in FIG. 2 ; FIG. 4 is a cross-sectional view taken along the line AA of FIG. 3;

Hereinafter, embodiments for implementing the present disclosure will be described in detail. However, the present disclosure is not limited to the following embodiments. In the following embodiments, the constituent elements (including element steps and the like) are not essential unless otherwise specified. The same applies to numerical values and their ranges, which do not limit the present disclosure.

As used herein, the term "process" includes a process that is independent of other processes, and even if the purpose of the process is achieved even if it cannot be clearly distinguished from other processes. be
In this specification, the numerical range indicated using "-" includes the numerical values before and after "-" as the minimum and maximum values, respectively.
In the numerical ranges described stepwise in this specification, the upper limit or lower limit described in one numerical range may be replaced with the upper limit or lower limit of the numerical range described in other steps. good. Moreover, in the numerical ranges described in this specification, the upper and lower limits of the numerical ranges may be replaced with the values shown in the examples.
In the present specification, each component may contain multiple types of corresponding substances. When multiple types of substances corresponding to each component are present in the composition, the content of each component means the total content of the multiple types of substances present in the composition unless otherwise specified.
In this specification, the term "layer" refers to the case where the layer is formed in the entire region when the region where the layer exists is observed, and the case where the layer is formed only in a part of the region. is also included.
When embodiments are described herein with reference to the drawings, the configurations of the embodiments are not limited to the configurations shown in the drawings. In addition, the sizes of the members in each drawing are conceptual, and the relative relationship between the sizes of the members is not limited to this.

[Vehicle opening/closing body]
A vehicle opening/closing body according to an embodiment of the present disclosure has at least a lock portion and contains a thermoplastic resin. A fiber resin layer containing fiber and resin is provided in a region including the lock portion.
A vehicular opening/closing body according to an embodiment of the present disclosure includes an inner panel and an outer panel, and the vehicular opening/closing body includes the fiber resin layer in a region including the lock portion of the inner panel. good.
Here, the vehicle opening/closing body is a member that is attached to a vehicle body such as an automobile and that opens and closes among the members that constitute the vehicle. Examples of the vehicle opening/closing member having the lock portion include automobile doors such as back doors and side doors, bonnets, trunk lids, sunroofs, fuel lid covers, and the like.
An automotive back door will be described below as an example of a vehicle opening/closing member having a locking portion, but the present invention is not limited to this.

<Backdoor>
The vehicle back door according to the present embodiment is a door arranged at the rear part of the vehicle body of the vehicle, and is held at the rear part of the vehicle body in an openable and closable state, for example, using a hinge.
FIG. 1 is a schematic diagram showing an example of a state in which the upper end of an automobile back door is held at the rear portion of the automobile. The back door 2 shown in FIG. 1 is configured by bonding and integrating an edge portion of an outer panel 3 containing a thermoplastic resin and an edge portion of an inner panel 4 containing a thermoplastic resin.
Here, the outer panel refers to a member that constitutes the exterior of the automobile in the configuration of the back door, and the inner panel refers to the member that constitutes the interior of the automobile in the configuration of the back door.

A side wall 13 of the inner panel 4 has a hinge 8 attached to its upper portion and a damper 10 attached to its central portion. The upper end of the back door 2 is held at the rear upper end of the vehicle body 1 by the hinge 8 and the damper 10 so that the lower end of the back door 2 can be opened and closed with the upper end of the back door 2 as an axis.
A lock portion 5 is provided on the bottom wall 14 of the inner panel 4 . When the back door 2 is closed, the bottom wall 14 of the back door 2 is held at the rear lower end of the vehicle body 1 by a lock mechanism (not shown) provided in the lock portion 5 .
Each of the inner panel 4 and the outer panel 3 will be described below.

-Inner panel-
FIG. 2 is a schematic diagram showing the surface of the inner panel 4 on the outer panel 3 side. An opening 12 for installing a window is provided on the upper side of the central portion of the inner panel 4 . The edge 6 of the inner panel 4 and the edge 9 of the opening 12 are the bonding surfaces for the edge (not shown) of the outer panel 3 and the edge (not shown) of the opening in the outer panel 3, respectively. It's becoming
A central portion of the inner panel 4 excluding the edge portions 6 and 9 is convex toward the side opposite to the outer panel 3 and concave toward the outer panel 3 side. As a result, the inner panel 4 has side walls 13 and a bottom wall 14 , and a space (not shown) is formed between the inner panel 4 and the outer panel 3 .
A hinge mounting portion 17 for mounting the hinge 8 is provided on the upper portion of the side wall 13 , and a damper mounting portion 16 for mounting the damper 10 is provided on the central portion of the side wall 13 . A lock portion 5 for attaching a lock mechanism is provided in the central portion of the bottom wall 14 .

3 is an enlarged schematic view of the lock portion 5 of the bottom wall 14 of the inner panel 4, and FIG. 4 is a sectional view taken along the line AA of FIG. As shown in FIGS. 3 and 4, the lock portion 5 in the central portion of the bottom wall 14 is provided with a lock hole 5A. The bottom wall 14 has a fiber resin layer 18 on the inner surface side of the inner panel 4 (that is, on the outer panel 3 side) around the lock hole 5A.
In addition, in the lock portion 5, the fiber resin layer 18 is provided so as to be in contact with the lock hole 5A and surround the lock hole 5A. It may be provided so as to surround the lock hole 5A in this state. Hereinafter, the region having the fiber resin layer 18 is also referred to as "fiber resin region". In addition, as shown in FIG. 4, the outer surface side of the inner panel 4 in the fiber resin region of the bottom wall 14 (that is, the side opposite to the outer panel 3) and the region other than the fiber resin region of the bottom wall 14 are made of thermoplastic resin. The thermoplastic resin layer 20 is composed of

Since the back door 2 has the fiber resin layer 18 in the lock portion 5 of the inner panel 4, the strength of the lock portion 5 is improved compared to the case where the fiber resin layer 18 is not provided. In addition, the back door 2 having the fiber resin layer 18 in the lock portion 5 of the inner panel 4 reduces the mass of the entire back door and increases the strength of the lock portion 5 compared to a back door in which the lock portion 5 is reinforced with a metal member. Is high.
When the lock portion 5 is reinforced with a metal member, the metal member is usually held in the lock portion 5 using a bolt or the like. On the other hand, in the inner panel 4 having the fiber resin layer 18 in the lock portion 5, the fiber resin layer 18 and the thermoplastic resin layer 20 are integrated with each other. That is, the fiber resin layer 18 and the thermoplastic resin layer 20 are held not by points or lines but by planes. Therefore, strength transmission is better than in the case of being reinforced with a metal member, and further strength improvement is realized. In particular, since the lock portion 5 is likely to be subjected to tensile stress in addition to stress due to deformation, by integrating the fiber resin layer 18 and the thermoplastic resin layer 20 on the surface, durability against these stresses can be obtained. and the strength of the lock portion 5 is further improved.

The size of the fiber resin region is not particularly limited as long as it includes at least the lock portion 5 . The larger the fiber resin region, the higher the strength of the lock portion 5, but the higher the cost of the material used to form the fiber resin layer 18. Therefore, from the viewpoint of low cost, the smaller the fiber resin region, the better. The size of the fiber resin region in the lock portion 5 is preferably 200 cm ² to 3000 cm ² , more preferably 500 cm ² to 2800 cm ² , and 800 cm ² to 2500 cm ² from the viewpoint of improving the strength of the lock portion 5 and reducing the cost. is more preferred. Here, "the size of the fiber resin region" means the area of the main surface of the fiber resin layer.
The fiber resin region in the lock portion 5 may be a region having a plurality of fiber resin layers 18 . When the fiber resin region has a plurality of fiber resin layers 18 , the size of the fiber resin region means the sum of the areas of the main surfaces of the plurality of fiber resin layers 18 .

The thickness of the fiber resin layer 18 is not particularly limited, and may be, for example, a range of 0.1 mm to 6 mm. A range is more preferred.
From the viewpoint of moldability, the thickness of the fiber resin layer 18 is preferably 5% to 40%, more preferably 10% to 30%, of the entire thickness of the bottom wall 14 in the lock portion 5. More preferably 15% to 25%. The thickness of the entire bottom wall 14 in the lock portion 5 means the total thickness of the thickness of the fiber resin layer 18 and the thickness of the thermoplastic resin layer 20 .

The fiber resin layer 18 is a layer containing fibers and resin.
Examples of the material of the fibers contained in the fiber resin layer 18 include inorganic fibers such as glass fibers, carbon fibers, metal fibers and ceramic fibers; organic fibers such as aramid fibers and cellulose fibers. From the viewpoint of strength improvement, the material of the fiber is preferably an inorganic fiber among these, more preferably a glass fiber, a carbon fiber, or a metal fiber among the inorganic fibers, and still more preferably a glass fiber.

Types of fibers include single fibers, long fibers, continuous fibers, etc. Among these, continuous fibers are preferred from the viewpoint of strength improvement. Here, continuous fibers are fibers that are continuous from one end of the fiber resin layer 18 to the other end. For example, when the fiber resin layer 18 is formed using a fiber reinforced resin sheet as described later, the fiber resin layer containing continuous fibers is formed by using a fiber reinforced resin sheet containing continuous fibers. That is, by using a fiber-reinforced resin sheet containing fibers continuous from one end to the other end, a fiber resin layer containing fibers continuous from one end to the other end is formed. Moreover, when a plurality of fiber resin layers 18 are included in the fiber resin region, it is preferable that all the fiber resin layers 18 each include continuous fibers.

Examples of the form of the fiber include nonwoven fabric, unidirectionally arranged UD material (Uni Delection material), and woven fabric. Among these, woven fabric is preferable from the viewpoint of strength improvement. By using a woven fabric as the fibers contained in the fiber resin layer 18, the strength of the lock portion 5 can be improved even if the fiber resin region is made small. In particular, since stress from all directions, such as stress due to deformation and tensile stress, is likely to be applied to the lock portion 5, the fiber is preferably a woven fabric of continuous fibers from the viewpoint of obtaining durability against such stress. preferable.

The types of resin contained in the fiber resin layer 18 include polyolefins such as polyethylene and polypropylene; thermoplastic resins such as polycarbonate, polyester, polyamide, polyvinyl chloride, polyurethane, and acrylic resins; epoxy resins, oxazine resins, bismaleimide resins; Thermosetting resins such as phenol resins, unsaturated polyester resins, and silicone resins; From the viewpoint of adhesiveness with the thermoplastic resin layer 20, thermoplastic resins are preferred among these, and among these, polyolefins are more preferred, and polypropylene is even more preferred.
The resin contained in the fiber resin layer 18 is preferably the same kind of resin as the thermoplastic resin contained in the thermoplastic resin layer 20 from the viewpoint of adhesiveness with the thermoplastic resin layer 20 . Here, the same type means that the main skeleton of the resin is the same, and specific examples of the resin of the same type include polypropylenes.

The fiber resin layer 18 may be formed using, for example, a fiber reinforced resin sheet containing the above fibers and the above resin. As will be described later, the inner panel 4 may be, for example, an insert-molded body manufactured by insert molding using a fiber-reinforced resin sheet as an insert member. That is, the fiber resin layer 18 may be a layer integrated with the thermoplastic resin 20 by insert molding of a fiber reinforced resin sheet containing the fiber and the resin.
As shown in FIG. 3, when the lock portion 5 has a step and has a fiber resin layer 18 across the step, the fiber resin layer 18 is formed using a preformed fiber reinforced resin sheet. good too. In other words, the fiber resin layer 18 may be a preformed body of a fiber reinforced resin sheet containing the fibers and the resin.

Examples of the thermoplastic resin contained in the thermoplastic resin layer 20 include those exemplified as the thermoplastic resin contained in the fiber resin layer 18. Among them, polyolefin is preferable from the viewpoint of weight reduction and appearance. Polypropylene is more preferred.
The thermoplastic resin layer 20 may contain components other than the thermoplastic resin. Components other than the thermoplastic resin include inorganic fillers, release agents, flame retardants, colorants, and the like. The thermoplastic resin layer 20 preferably contains a thermoplastic resin as a main component, and is more preferably made of a thermoplastic resin. In addition, that the thermoplastic resin is the main component means that the content of the thermoplastic resin with respect to the entire thermoplastic resin layer 20 is 50% by mass or more. The thermoplastic resin content of the entire thermoplastic resin layer 20 is preferably 70% by mass or more, more preferably 80% by mass or more, further preferably 90% by mass or more, and 95% by mass. It is particularly preferable that it is above.

Although the inner panel 4 shown in FIG. 2 has the fiber resin layer 18 only in the lock portion 5 and its periphery, it is not limited to this, and may further have fiber resin layers in other positions. Other locations include the hinge mounting portion 17 on the side wall 13, the damper mounting portion 16 on the side wall 13, and the like. In addition to the lock portion 5, the hinge mounting portion 17 and the damper mounting portion 16 also have a fiber resin layer, thereby reducing the mass of the inner panel 4 as a whole and improving the strength of the lock portion 5, thereby increasing the strength of the back door. 2 deformation is also suppressed.
From the viewpoint of low cost, the fiber resin region is preferably 80% or less of the entire surface of the inner panel 4 on the outer panel 3 side, and from the viewpoint of improving strength and reducing cost, it is 5% or more and 50%. It is more preferably 10% or more and 40% or less.

- Outer panel -
The outer panel 3 contains at least thermoplastic resin.
Examples of the thermoplastic resin contained in the outer panel 3 include those exemplified as the thermoplastic resin contained in the fiber resin layer 18. Among them, polyolefin is preferable from the viewpoint of weight reduction and appearance, and polypropylene is preferable. more preferred. The thermoplastic resin contained in the outer panel 3 is preferably the same type of resin as the thermoplastic resin contained in the thermoplastic resin layer 20 of the inner panel 4 from the viewpoint of adhesion to the inner panel 4. , may contain components other than the thermoplastic resin. Components other than the thermoplastic resin include release agents, flame retardants, colorants, and the like. The main component of the outer panel 3 is preferably thermoplastic resin, and more preferably made of thermoplastic resin. In addition, that the thermoplastic resin is the main component means that the content of the thermoplastic resin with respect to the entire outer panel 3 is 50% by mass or more. The thermoplastic resin content of the entire outer panel 3 is preferably 70% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, and 95% by mass or more. It is particularly preferred to have

-Other parts-
The back door 2 may have other members in addition to the inner panel 4 and the outer panel 3 . Metal members for reinforcing the hinge mounting portion 17, the damper mounting portion 16, the lock portion 5, and the like of the inner panel 4 may be used as long as the weight of the back door 2 as a whole can be reduced. In addition, the back door 2 may have hinges, dampers, lock mechanisms, windows, etc. as other members.

-Method of manufacturing a back door-
The method of manufacturing the back door 2 includes a step of preparing an inner panel 4 having a fiber resin layer 18 in a region including the lock portion 5, a step of preparing an outer panel 3, and the obtained inner panel 4 and outer panel 3. and a step of bonding.

The inner panel 4 containing thermoplastic resin is formed, for example, by insert molding using a fiber-reinforced resin sheet and thermoplastic resin.
For example, the inner panel 4 is formed by a process of installing a fiber reinforced resin sheet in a mold, molding a thermoplastic resin in the mold in which the fiber reinforced resin sheet is installed, and integrating the fiber reinforced resin sheet and the thermoplastic resin. It is manufactured through a process of converting. As a result, the inner panel 4 having the fiber resin layer 18 and the thermoplastic resin layer 20 in the thickness direction in the fiber resin region is obtained. That is, the method for manufacturing the inner panel 4 includes placing a fiber-reinforced resin sheet containing the fiber and the resin in a mold, and setting the thermoplastic resin sheet in the mold in which the fiber-reinforced resin sheet is installed. and molding the resin.

A fiber reinforced resin sheet is generally planar, and if the shape of the mold at the position where the fiber reinforced resin sheet is installed has unevenness, it is difficult for the fiber reinforced resin sheet to follow the unevenness in a normal molding process. Therefore, before setting the fiber reinforced resin sheet in the mold, the fiber reinforced resin sheet is preheated to reduce the hardness, and the fiber reinforced resin sheet is preliminarily shaped into an uneven warped shape. It is desirable to perform preliminary operations such as operations. The fiber-reinforced resin sheet placed in the mold may be preheated or preformed. In other words, when manufacturing the inner panel 4, a step of heating the fiber reinforced resin sheet before being placed in the mold, a step of pre-shaping the fiber reinforced resin sheet before being placed in the mold, and the like are further carried out. You can go through.

The heating temperature in the step of preheating the fiber reinforced resin sheet before placing it in the mold is not particularly limited, and may be, for example, a range of 180°C to 240°C. from the viewpoint of 190° C. to 210° C. is preferable.
The step of pre-shaping the fiber-reinforced resin sheet before placing it in the mold is not particularly limited, and a known shaping method such as a method of pressing a mold against the fiber-reinforced resin sheet to shape an uneven shape may be used. can be done. The temperature at the time of preforming is not particularly limited, and is appropriately set according to the types of fibers and resins constituting the fiber-reinforced resin sheet. C. to 200.degree. C. is preferred. The pressure during pre-shaping is not particularly limited, and is, for example, in the range of 0.1 MPa to 10 MPa, preferably in the range of 2 MPa to 8 MPa from the viewpoint of appearance. Also, the pre-shaping time is not particularly limited, and is, for example, in the range of 30 seconds to 2 minutes, preferably in the range of 30 seconds to 1 minute from the viewpoint of improving the production cycle.

The molding method for molding the thermoplastic resin with the mold provided with the fiber-reinforced resin sheet is not particularly limited, and examples thereof include press molding and injection molding.
The molding conditions for molding the thermoplastic resin with the mold provided with the fiber-reinforced resin sheet are not particularly limited. The temperature at which the thermoplastic resin is molded in the mold provided with the fiber-reinforced resin sheet is appropriately set according to the type of the thermoplastic resin, and is, for example, in the range of 210°C to 250°C. From the point of view, the range of 230°C to 250°C is preferable.

The outer panel 3 containing thermoplastic resin is formed, for example, by a general thermoplastic resin molding method using a mold.
A molding method for molding the thermoplastic resin with a mold is not particularly limited, and includes press molding, injection molding, and the like.
Molding conditions for molding the thermoplastic resin with a mold are not particularly limited. The temperature at which the thermoplastic resin is molded in the mold provided with the fiber-reinforced resin sheet is appropriately set according to the type of the thermoplastic resin, and is, for example, in the range of 210°C to 250°C. From the point of view, the range of 230 ° C. to 250 ° C. is preferable.

In the process of bonding and integrating the inner panel 4 and the outer panel 3, for example, the bonding surface of the inner panel 4 (that is, the edge 6 and the edge 9) and the bonding surface of the outer panel 3 are bonded with an adhesive or the like. It is adhered by a method of bonding by heating, a method of fusing by heating, or the like. Examples of adhesives include urethane-based adhesives and the like.

As described above, an example of a vehicle back door has been described as an example of a vehicle opening/closing body having a lock portion. Other vehicle opening/closing members such as a bonnet, a trunk lid, a sunroof, and a fuel lid cover may also be used.

EXAMPLES Hereinafter, the above-described embodiment will be specifically described with reference to Examples, but the above-described embodiment is not limited to these Examples.

<Example 1>
A fiber-reinforced resin sheet (LANXESS, TEPEX, glass/polypropylene impregnated sheet) was prepared. The prepared fiber-reinforced resin sheet was a sheet obtained by impregnating a continuous glass fiber woven fabric with polypropylene, and had a sheet thickness of 0.5 mm and a sheet area of 2400 cm ² .

The prepared fiber-reinforced resin sheet was preliminarily shaped as follows.
Specifically, a press mold for only the lock portion of the inner panel was prepared, and the heated fiber-reinforced resin sheet was preliminarily shaped by cooling press. The sheet temperature during pre-shaping was 200° C., the press pressure was 7 MPa, and the pre-shaping time was 30 seconds.

A preformed fiber reinforced resin sheet was placed at a position corresponding to the locking portion of the inner panel mold.
Using a glass-fiber-filled polypropylene resin as the thermoplastic resin for the inner panel, and using a mold for the inner panel on which a fiber-reinforced resin sheet is installed, injection molding is performed under the conditions of a resin temperature of 240 ° C and an injection pressure of 100 MPa. An inner panel integrated with a fiber-reinforced resin sheet was obtained.
The thickness of the fiber resin layer in the resulting inner panel was 0.5 mm, and the thickness of the entire bottom wall was 3 mm. The size of the fiber resin region was 2400 cm ² , which was 20% of the total area of the inner panel on the outer panel side. Moreover, the content of the thermoplastic resin with respect to the entire thermoplastic resin layer of the bottom wall was 100%.

A polypropylene resin was used as the thermoplastic resin for the outer panel, and an outer panel was obtained by performing injection molding using a mold for the outer panel under conditions of a resin temperature of 240° C. and an injection pressure of 100 MPa.
The adhesion surface of the inner panel and the adhesion surface of the outer panel thus obtained were bonded together at 25° C. with a urethane-based adhesive to form a back door.

<Example 2>
The same fiber-reinforced resin sheet as in Example 1 was prepared.
A fiber-reinforced resin sheet heated to 200° C. was placed at a position corresponding to the lock portion of the inner panel mold. Using the same thermoplastic resin for an inner panel as in Example 1, an inner panel integrated with a fiber-reinforced resin sheet was obtained in the same manner as in Example 1.
The thickness of the fiber resin layer in the obtained inner panel, the thickness of the entire bottom wall, the size of the fiber resin region, the ratio to the total area of the outer panel side in the inner panel, and the heat to the entire thermoplastic resin layer of the bottom wall. The plastic resin content was the same as in Example 1.
An outer panel was obtained in the same manner as in Example 1. An inner panel and an outer panel obtained in the same manner as in Example 1 were integrated to obtain a back door.

<Comparative Example 1>
An inner panel was obtained in the same manner as in Example 1, except that the fiber-reinforced resin sheet was not used.
An outer panel was obtained in the same manner as in Example 1. An inner panel and an outer panel obtained in the same manner as in Example 1 were integrated to obtain a back door.

<Comparative Example 2>
A metal plate made of a steel plate having a thickness of 1.5 mm and an area of 1500 cm ² was prepared as a metal member.
An inner panel was obtained in the same manner as in Example 1, except that the fiber-reinforced resin sheet was not used.
A metal plate was fixed to the lock portion of the inner panel by bolting.
An outer panel was obtained in the same manner as in Example 1. An inner panel and an outer panel obtained in the same manner as in Example 1 were integrated to obtain a back door.

<Evaluation>
-mass-
The mass of the backdoor was weighed with a digital scale.
Table 1 shows the difference from the mass of the back door of Comparative Example 1. Specifically, Table 1 shows a positive number when the mass is larger than that of Comparative Example 1, and a negative number when the mass is smaller.

- Destruction mode confirmation -
The destruction mode of the lock part of the back door was confirmed as follows.
Specifically, a constant load was applied to the periphery of the lock of the back door fixed to the jig in the direction in which the lock portion was pulled out, and the fracture mode of the periphery of the lock was visually confirmed. Table 1 shows the results.

- Torsion test -
The torsional stiffness (torsion displacement amount) of the lock portion of the back door was measured as follows.
Specifically, a test was conducted in which a couple of forces were applied to both sides of the back door with the back door attached to the vehicle body left half open. At that time, the displacement of the back door before and after the test was measured. Table 1 shows the magnitude of the displacements of Examples 1, 2, and Comparative Example 2 relative to the displacement of Comparative Example 1 as an index.

As can be seen from the results shown in Table 1, in the example, compared to the comparative example, both reduction in the mass of the entire back door and improvement in the strength of the lock portion are achieved.

The disclosure of Japanese Patent Application No. 2019-227067 filed on December 17, 2019 is incorporated herein by reference in its entirety.
All publications, patent applications and technical standards mentioned herein are to the same extent as if each individual publication, patent application and technical standard were specifically and individually noted to be incorporated by reference. incorporated herein.

1 vehicle body, 2 back door, 3 outer panel, 4 inner panel, 5 lock part, 5A lock hole, 6 edge part, 8 hinge, 9 edge part, 10 damper, 12 opening part, 13 side wall, 14 bottom wall, 16 damper attachment part 17 hinge attachment part 18 fiber resin layer 20 thermoplastic resin layer

Claims (13)

A vehicle opening/closing body having at least a lock portion and containing a thermoplastic resin,
Having a fiber resin layer containing fibers and resin in a region including the lock portion,
An opening/closing member for a vehicle , wherein the area having the fiber resin layer has a size of 200 cm ² to 3000 cm ² . 2. The vehicle opening/closing member according to claim 1, wherein the fiber resin layer has a thickness of 0.1 mm to 6 mm. 3. The vehicle opening/closing body according to claim 1 , wherein the fibers are inorganic fibers. 4. The vehicle opening/closing body according to claim 3 , wherein the fibers are glass fibers. The vehicle opening/closing member according to any one of claims 1 to 4 , wherein the fibers are woven fabrics of continuous fibers. The vehicle opening/closing member according to any one of claims 1 to 5 , wherein the vehicle opening/closing member is a back door. comprising an inner panel and an outer panel,
The opening/closing body for a vehicle according to any one of claims 1 to 6 , wherein the fiber resin layer is provided in a region of the inner panel including the lock portion. 8. The vehicle opening/closing body according to claim 7, wherein the thickness of the fiber resin layer is 5% to 40% of the thickness of the entire region of the inner panel including the lock portion. The opening/closing member for a vehicle according to any one of claims 1 to 8 , wherein the fiber resin layer and the thermoplastic resin are held face to face. 10. The fiber resin layer according to any one of claims 1 to 9 , wherein the fiber resin layer is a layer integrated with the thermoplastic resin by insert molding of a fiber reinforced resin sheet containing the fiber and the resin. Opening and closing body for vehicle. The vehicle opening/closing member according to any one of claims 1 to 10 , wherein the fiber resin layer is a preformed body of a fiber reinforced resin sheet containing the fiber and the resin. The method for manufacturing a vehicle opening/closing member according to any one of claims 9 to 11 ,
placing a fiber-reinforced resin sheet containing the fibers and the resin in a mold;
molding the thermoplastic resin in the mold in which the fiber-reinforced resin sheet is installed;
A method for manufacturing a vehicle opening and closing body comprising: 13. The method of manufacturing a vehicle opening/closing member according to claim 12 , wherein the fiber-reinforced resin sheet placed in the mold is preheated.

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