JP2023030288A - Manufacturing method for fiber resin molding - Google Patents

Abstract

To provide a non-heating method for manufacturing fiber resin molding that can cope with variations in a thickness of each plate.SOLUTION: A method for manufacturing door trim 100 with a base material 1 containing at least fibers and resin and a resin structure 2 provided on the base material 1 includes an injection molding process in which a preboard 1P is sandwiched between a pair of molding dies 51, 61 while resin is injected through recesses 63, 64, 65 provided on a molding surface 61A facing the preboard 1P in the lower die 61 to form the resin structure 2 on the base material 1. The molding surface 61A facing the preboard 1P is provided with a protrusion 66 protruding toward the preboard 1P side at a side portion of the recesses 63, 64, 65.SELECTED DRAWING: Figure 6

Description

The present disclosure relates to a method for manufacturing a fiber resin molding.

Conventionally, the technique described in Patent Literature 1 is known as a method for producing a fiber resin molding. In Patent Document 1, after heating a plate-like body (pre-board) containing vegetable fibers and a thermoplastic resin, the softened plate-like body is pressed (cold pressed) with a mold to form a substrate. Forming a fiber resin molded body (molded structure) in which the resin (resin molded body) is bonded to the base material by injecting molten resin through the molding space while the base material is pressed by the mold. , are disclosed.

JP 2020-157603 A

In the process disclosed in Patent Document 1, for example, in order to reduce the manufacturing cost, the plate-like body is not heated (this is sometimes referred to as a non-heating type), and the plate-like body in an unsoftened state is molded. May be cold pressed in a mold. In such a process, when the thickness of each plate-like object varies, for example, when the plate-like object is relatively thick, the plate-like object is molded by applying excessive pressure from the mold. Destruction or deformation can occur in the substrate. Moreover, when compressing this plate-like body to a desired plate thickness, there is a possibility that the clamping pressure of the mold is insufficient. On the other hand, if the thickness of the plate-like body is relatively thin, the molten resin may leak from between the substrate and the mold when the resin is injected through the molding space.

The present disclosure is a technique perfected based on the above circumstances, and an object thereof is to provide a method for manufacturing a non-heating fiber resin molding that can deal with variations in plate thickness for each plate. .

The present disclosure relates to a method for manufacturing a fiber resin molded body including a plate-like body containing at least fibers and a resin and a resin structure provided on the plate-like body, wherein the plate-like body is formed with a pair of molds. an injection molding step of forming the resin structure on the plate-like body by injecting a resin through a concave portion provided on a molding surface of the mold facing the plate-like body while sandwiching the plate-like body; A method for producing a fiber resin molded article, characterized in that at least one of the molding surface and the plate-like body is provided with a projection projecting toward the other opposite side in a side portion of the recess. is.

According to this method of manufacturing a fiber resin molded article, the thickness of the plate-shaped body is relatively thin at least in the portion where the concave portion is formed (that is, the portion where the resin structure is formed), and the thickness of the plate-shaped body and the molding surface is relatively small. Even in the case where a gap may occur between them, since the protrusions project from at least one of the molding surface and the plate-like body on the side portions of the recess, the protrusions exhibit a damming function, It is possible to prevent the resin from leaking and spreading from the gap between the concave portion and the plate-like body in the injection molding process. In this way, since the projection suppresses the leakage and spread of the resin, there is no problem even if the pressing condition is such that a gap is formed between the plate-like body and the molding surface. It is no longer necessary to adopt a condition that makes the distance of the plate smaller, and it becomes possible to avoid excessive compression of the plate-like body (especially for a relatively thick plate-like body due to a plate thickness error etc. It is possible to avoid a situation in which excessive press pressure is applied.)

In the injection molding step, the protrusions formed on the molding surface and protruding toward the opposing plate-like body in a shape along the groove-shaped recess may be brought into contact with the plate-like body. .

According to the manufacturing method of the fiber resin molded article, the resin passing through the groove-shaped recessed portion in the injection molding process is prevented by the protrusion from flowing laterally from the gap between the recessed portion and the plate-shaped body and leaking and spreading. can be done. Depending on the thickness of the plate-like body, the protrusions can be made to bite into the plate-like body, and in this state, the resin can be injected through the groove-shaped recesses, so that resin leakage from the gap between the recesses and the plate-like body can be further suppressed. can do.

In the injection molding step, the protrusion projecting in a pointed shape toward the plate-like body may be brought into contact with the plate-like body.

According to this method of manufacturing a fiber resin molded article, depending on the thickness of the plate-like body, it becomes easier for the projections to bite into the plate-like body, further suppressing resin leakage from the gap between the concave portion and the plate-like body. can be done.

In the injection molding step, the projections provided on the plate-like body and projecting toward the molding surface may be brought into contact with the vicinity of the groove-shaped recesses and crushed.

According to such a method for manufacturing a fiber resin molding, the protrusions can prevent the resin passing through the groove-shaped recesses from flowing laterally through the gap between the recesses and the plate-like body and leaking and spreading. In addition, even if the thickness of the plate-shaped body varies, the amount of crushing of the protrusion can be changed as appropriate (for example, when the distance between a pair of molds for a plurality of plate-shaped bodies is fixed, any plate-shaped body The greater the thickness of , the greater the amount of crushing of the protrusions). As a result, it is possible to preferably maintain a state in which the protrusion is in contact with the vicinity of the recess and is in close contact with the recess.

The method for manufacturing the fiber resin molding includes a cut forming step of forming a cut portion in the plate-like body, and in the injection molding step, the plate-like body is bent so as to open the cut portion. While sandwiching between the pair of molding dies, the opened cut portion may be filled with the resin injected so as to pass through the concave portion.

According to such a method for manufacturing a fiber resin molding, the shape of the opened cut portion (that is, the shape of the plate-like body bent) can be fixed with the resin. As a result, it is possible to provide a method for producing a fiber resin molded article that can be bent at an arbitrary portion without heating the plate-like article and that can fix its shape.

According to the present disclosure, it is possible to provide a method for manufacturing a non-heating fiber resin molding that can cope with variations in plate thickness for each plate.

FIG. 2 is a perspective view of the door trim according to the first embodiment viewed from the surface side; Perspective view of the door trim viewed from the back side Sectional drawing which shows the aspect which presses a fiber mat with a press type. The perspective view which shows the aspect which formed the cut part in the preboard. Sectional view showing a mode in which a preboard is arranged between the upper mold and the lower mold. Cross-sectional view showing a state in which the upper mold is brought close to the lower mold and the preboard is sandwiched. Enlarged cross-sectional view near the notch Cross-sectional view of the vicinity of the first rib forming recess (section taken along the line IIX-IIX in FIG. 7) Sectional drawing which shows the aspect which injected resin into the recessed part, pinching|interposing a base material. Cross-sectional view of the vicinity of the first rib forming recess (cross section at the same position as the cross section in FIG. 8) Sectional view showing a manner in which the upper mold is separated from the lower mold and the door trim is released from the mold. Cross-sectional view of the vicinity of the first rib forming concave portion according to the second embodiment Cross-sectional view showing a mode in which resin is injected into a concave portion while sandwiching a substrate (a cross section at the same position as the cross section in FIG. 12)

<Embodiment 1>
Embodiment 1 of the present disclosure will be described with reference to FIGS. 1 to 11. FIG. In this embodiment, a door trim (fiber resin molding) 100 as a vehicle interior material attached to a door of an automobile (vehicle) will be described. Arrow direction F is forward, arrow direction B is backward, arrow direction U is upward (front side of door trim 100), arrow direction D is downward (back side of door trim 100), arrow direction L is leftward, and arrow direction R is. are on the right side.

As shown in FIGS. 1 and 2, the door trim 100 includes a plate-like base material (plate-like body) 1 and a plurality of resin structures 2 provided on the base material. The base material 1 contains fibers and a resin, and the entangled fibers are bound by a resin as a binder to form a plate. The fibers contained in the base material 1 are not particularly limited, but one or more fibers selected from the group of vegetable fibers, glass fibers, carbon fibers, and the like can be employed. Among them, vegetable fibers are preferred, and kenaf fibers are preferred. Employing such a fiber for the base material 1 can improve the strength of the base material 1 and contribute to the natural environment. The resin contained in the base material 1 is not particularly limited, but polyolefin-based thermoplastic resins such as polypropylene and polyethylene can be used from the viewpoint of improving workability and reducing production costs.

The base material 1 includes a body portion 10 forming a major part, and bent portions 11 arranged on both left and right sides of the body portion 10 and bent downward from the body portion 10 in a crank shape. The bent portion 11 includes a cut portion 18 connected to the main body portion 10, an inclined portion 14 inclined downward toward the outside in the left-right direction from the cut portion 18, and an outside in the left-right direction from the inclined portion 14. and a flange portion 16 extending toward. The cut portion 18 has a shape in which a V-shaped groove cut in a V shape from the surface 1A side of the base material 1 extends in the front-rear direction in a cross-sectional view viewed from the front side (or the rear side). ing. On the upper side (surface side) of the cut portion 18, a linear filling portion 28 is provided, which is formed by filling the V-shaped groove of the cut portion 18 with a thermoplastic resin such as polypropylene and extends in the front-rear direction. there is

As shown in FIG. 2, on the side of the back surface 1B of the base material 1, a mounting boss 20 extending downward from the back surface of the main body portion 10 and first ribs 23 extending in both left and right directions from the mounting boss 20 and having a linear shape in a bottom view are provided. a second rib 25 extending in the front-rear direction perpendicular to the first rib 23 and extending in the front-rear direction on the back side of the cut portion 18; Retaining ribs 26 are provided. The filling portion 28 , the mounting boss 20 , the first ribs 23 , the second ribs 25 and the holding ribs 26 are examples of the resin structure 2 . Such a resin structure 2 is made of polypropylene, which is a thermoplastic resin, for example.

The mounting boss 20 includes a cylindrical portion 21 whose height is in the vertical direction, and reinforcing ribs 22 extending in both the front and rear directions from the upper end of the cylindrical portion 21 . The mounting boss 20 is a portion for mounting other members such as a door pocket, an ornament, an armrest, and the like. The holding rib 26 has a plate-like shape extending in the left, right, up and down planes, and stands so as to bridge the main body portion 10 and the bent portion 11 of the base material 1 . The holding ribs 26 suppress elastic deformation of the bent portion 11 in the vertical direction with respect to the main body portion 10 .

The first ribs 23 are formed by cooling molten resin that has passed through the first rib molding recesses 63 in an injection molding process, which will be described later. Similarly, the second ribs 25 are formed by cooling the molten resin that has passed through the second rib molding recesses 64 in the injection molding process, which will be described later. The mounting boss 20 and the plurality of holding ribs 26 are connected via the first ribs 23 and the second ribs 25 .

The mounting bosses 20, the holding ribs 26, the first ribs 23, and the second ribs 25 on the side of the base material 1 (upper side) each spread laterally (in the front-rear direction and the left-right direction on the back surface 1B of the base material 1). A thin film portion 29 is provided. The thickness (distance in the vertical direction) of the thin film portion 29 is thinner than the thicknesses of the mounting boss 20 , the holding ribs 26 , the first ribs 23 and the second ribs 25 . The thin film portion 29 is provided on the front, rear, left, and right sides of the mounting boss 20 , both front and rear sides of the first rib 23 , the inner side (one side) of the holding rib 26 in the left and right direction, and the inner side (one side) of the second rib 25 in the left and right direction. . Thin film portion 29 is also one of the plurality of resin structures 2 .

Next, a manufacturing apparatus for manufacturing the door trim 100 will be described. The apparatus for manufacturing the door trim 100 is roughly divided into press dies 30 and 31 for manufacturing a preboard (plate-like body) 1P by heating and pressing a mat-like fiber mat 1M in which vegetable fibers and resin fibers are intertwined. and a molding device 50 that molds the door trim 100 by injecting resin with the preboard 1P interposed therebetween.

As shown in FIG. 3, press dies 30 and 31 (sometimes referred to as press plates or hot plates) include a lower die 31 and an upper die 30 provided at a position facing the lower die 31. . The upper die 30 is provided with a driving device (eg, an electric motor, an air cylinder, a hydraulic cylinder, etc.) (not shown), and is a movable die capable of moving vertically with respect to the lower die 31 . The press dies 30 and 31 incorporate heat generating devices such as heaters, and can heat and press the fiber mat 1M at an arbitrary temperature. Such a heater may be provided on only one of the press dies 30 and 31 . The heating by the press molds 30 and 31 is a step for melting the resin fibers of the fiber mat 1M and binding them to the vegetable fibers to form the preboard 1P. It is not a process for molding such as softening and bending 1P (the injection molding process of this technique is performed by a non-heating method).

FIG. 5 shows a cross section of the molding device 50 and the preboard 1P at a position corresponding to the cross section taken along line XI-XI of FIG. The molding device 50 has a pair of molding dies 51 and 61 . The pair of molds 51 , 61 includes a lower mold 61 and an upper mold 51 arranged at a position facing the lower mold 61 . The upper die 51 is provided with a driving device (eg, an electric motor, an air cylinder, a hydraulic cylinder, etc.) (not shown), and is a movable die that can move vertically with respect to the lower die 61 . FIGS. 6 to 10 show a state in which the upper mold 51 is brought close to the lower mold 61 to close the pair of molds 51 and 61 . The upper mold 51 has a molding surface 51A facing the lower mold 61 and recessed upward from the lower mold 61 side. The lower mold 61 has a molding surface 61A that faces the molding surface 51A of the upper mold 51 and bulges toward the upper mold 51 side. In the pair of molds 51 and 61 in the closed state, the space between the molding surface 51A of the upper mold 51 and the molding surface 61A of the lower mold 61 is defined as a first molding space S1.

In the pair of molds 51 and 61, the preboard 1P is arranged between the molding surfaces 51A and 61A in a state before mold closing (mold open state), and the upper mold 51 is brought closer to the lower mold 61 to open the mold. By closing, the preboard 1P can be sandwiched between the first molding spaces S1. When placing the preboard 1P between the pair of molds 51 and 61, the molding surface 51A faces the surface 1PA of the preboard 1P (the surface that becomes the surface 1A of the substrate 1), and the molding surface 61A faces the preboard 1P. is positioned so as to face the back surface 1PB of the substrate 1 (the surface that becomes the back surface 1B of the base material 1).

A screw-type injection device 41 , for example, is attached to the lower mold 61 . The injection device 41 can inject the melted resin (for example, a thermoplastic resin such as polypropylene) forming the resin structure 2 toward the sprue 62 . As shown in FIGS. 5 and 7, the lower die 61 extends from the injection device 41 toward the molding surface 61A. It includes a gate 69 provided, and a plurality of recesses 63, 64, 65 which are recessed portions provided on the molding surface 61A and recessed toward the injection device 41 side (downward). A plurality of recesses 63, 64, and 65 are composed of a first rib forming recess 63 that extends inward in the left-right direction from the gate 69 in a groove shape, and an outer side in the front-rear direction from the gate 69 (in FIG. 5, toward the back of the paper surface). A second rib forming recess 64 extending in a groove shape and orthogonal to the first rib forming recess 63, and the middle of the first rib forming recess 63 (between two first rib forming recesses 63 provided in the left-right direction) and a plurality of retaining rib molding recesses (not shown) located intermediate the second rib molding recesses.

The sprue 62 serves as a flow path through which the resin injected from the injection device 41 flows toward the molding surface 61A. The gate 69 is provided at a portion where the first rib-molding recess 63 and the second rib-molding recess 64 intersect perpendicularly, and allows the resin flowing from the sprue 62 to pass through the first rib-molding recess 63 and the second rib-molding recess 64. This is the part that divides the current. The first rib-molding recess 63 and the second rib-molding recess 64 are flow paths through which the resin flowing from the gate 69 passes along the molding surface 61A. A shallow portion recessed downward from 61A is sometimes called a runner. The first rib-molded recess 63 serves as a flow path through which the resin flowing from the gate 69 passes inward in the left-right direction (toward the attachment boss-molded recess 65). The second rib-molding recess 64 serves as a channel through which the resin flowing from the gate 69 flows outward in the front-rear direction (toward the holding rib-molding recess).

As shown in FIGS. 5, 7, and 8, the molding surface 61A has side portions (front and rear portions) of the first rib molding recess 63 on the side of the upper mold 51 (preboard 1P in the first molding space S1). is sandwiched, two projections 66 projecting toward the rear surface 1PB side of the preboard 1P facing the molding surface 61A) are provided. The protrusion 66 extends in the left-right direction along the groove-shaped first rib-forming recess 63 . The protruding portion 66 protrudes in a pointed shape from the molding surface 61A toward the back surface 1PB side of the preboard 1P. Note that the projection 66 includes side portions of the recess other than the first rib-molded recess 63 (the inner portion in the left-right direction of the second rib-molded recess 64, the portion around the mounting boss-molded recess 65, and the holding rib-molded recess). inner portion in the left-right direction) are also provided, respectively.

Next, a method for manufacturing the door trim 100 will be described. The method of manufacturing the door trim 100 can be broadly divided into a pre-board forming step of forming a fiber mat 1M as a pre-board (plate-like body) 1P, a cut-forming step of forming cut portions 18 in the pre-board 1P, and a pair of pre-boards 1P. an injection molding step of forming a plurality of resin structures 2 on a substrate (plate-like body) 1 by injecting resin so as to pass through a plurality of recesses 63, 64, 65 while sandwiching between molding dies 51, 61; and each step shall be executed in this order.

As shown in FIG. 3, in the preboard molding step, a mat-like fiber mat 1M containing fibers and a thermoplastic resin is pressed by press dies 30 and 31 while being heated. As a result, the fiber mat 1M is compressed and the thermoplastic resin contained in the fiber mat 1M is melted. Thereafter, the fiber mat 1M is cooled and solidified to bind the thermoplastic resin to the fibers. Next, the cooled and solidified fiber mat 1M is cut into a predetermined size and shape using a cutting machine (not shown) to form a preboard 1P. As the fibers and thermoplastic resins constituting the fiber mat 1M, those described as the fibers and resins contained in the substrate 1 are employed.

As shown in FIG. 4, in the cut forming step, a plurality of cuts 18 linearly extending in the front-rear direction are formed on both left and right sides of the preboard 1P. The cut portion 18 is formed by cutting from the surface 1PA side of the preboard 1P with a cutter or the like. The cut portion 18 has a depth that does not penetrate to the back surface 1PB side of the preboard 1P.

As shown in FIG. 5, the preboard 1P is arranged between the upper mold 51 and the lower mold 61 in the injection molding process. At this time, the preboard 1P is arranged so that the front surface 1PA provided with the notch 18 faces the molding surface 51A of the upper mold 51 and the rear surface 1PB faces the molding surface 61A of the lower mold 61. Also, the preboard 1P is positioned so that the two cuts 18 are positioned directly above the two second rib forming recesses 64 .

Next, as shown in FIG. 6, the upper mold 51 is brought close to the lower mold 61 to close the mold, and the preboard 1P is sandwiched between the molding surface 51A of the upper mold 51 and the molding surface 61A of the lower mold 61. . As a result, the left and right portions 1PC of the preboard 1P are bent toward the lower mold 61 with the cutouts 18 as starting points to form the bent portions 11, and the preboard 1P is formed as the base material (plate-like body) 1. In the non-heated injection molding process according to the present embodiment, the preboard 1P is not softened by heating, so that the plurality of cuts 18 are torn in the front-rear direction (backward-frontward direction of the paper surface in FIG. 6) to form a continuous piece. It has a linear shape. In addition, the cut portion 18 opens so as to be stretched in the left-right direction, and the cross-sectionally V-shaped shape spreads in the left-right direction.

In the injection molding process, the distance between the molding surface 51A of the upper mold 51 and the molding surface 61A of the lower mold 61 (sometimes referred to as the distance between molds) is a representative value ( (mean value, median value, etc.). The inter-mold distance is preferably, for example, a representative value or more calculated from the thickness of a plurality of preboards 1P, more preferably a maximum error (variation) of the representative value or more, and a maximum error of the representative value. preferable. For example, when the average value of the thickness of a certain number of preboards 1P is 2.5 mm and the error is ±0.3 mm (that is, the thickness of a certain number of preboards 1P is in the range of 2.2 mm or more and 2.8 mm or less) If there is variation), the inter-mold distance is preferably 2.5 mm or more, more preferably 2.8 mm or more, and even more preferably 2.8 mm. The method of manufacturing the door trim 100 may include a step of measuring a representative value of the thickness of the plurality of preboards before the injection molding step. In addition, there may be a slight gap wholly or partially between the molding surface 61A of the lower mold 61 and the back surface 1PB of the preboard 1P (that is, the back surface 1PB of the preboard 1P is formed by the molding surface 61A. may be in an unpressed state).

As shown in FIGS. 6 to 8, the pair of molding dies 51 and 61 are closed to sandwich the preboard 1P, and the protrusions 66 are brought into contact with the preboard 1P from the back surface 1PB side. The protrusion height of the protrusion 66 protruding from the molding surface 61A toward the preboard 1P may be a value obtained by subtracting the thickness of the preboard 1P corresponding to the minimum error of the representative value from the distance between the molds. A value obtained by subtracting the minimum value from the maximum error value may be used. For example, when the average value of the thickness of a certain number of preboards 1P is 2.5 mm, the error is ±0.3 mm, and the distance between the molds is 2.8 mm, the protrusion height of the protrusion 66 is set to 0.6 mm. set. When the projection height of the protrusion 66 is such a value, as shown in FIGS. When the thickness of the preboard 1P to be molded is 2.8 mm), the tip portion 66A of the protrusion 66 located on the upper mold 51 side can be pierced and bit into the back surface 1PB of the preboard 1P. On the other hand, when the thickness of the preboard 1P is relatively thin (for example, when the thickness of the preboard 1P to be molded is 2.2 mm when the average value is 2.5 mm), the tip portion 66A of the protrusion 66 is preboarded. It can be brought into contact with the rear surface 1PB of 1P. A space surrounded by the first rib molding recess 63, the projection 66, and the back surface 1PB of the preboard 1P is defined as a second molding space S2.

Next, as shown in FIG. 9, the preboard 1P (base material 1) is sandwiched between a pair of molding dies 51 and 61 without changing the distance between the dies. 41 to the sprue 62 . The resin injected into the sprue 62 flows from the gate 69 into the first rib forming recesses 63 and the second rib forming recesses 64 . The resin passing through the first rib molding recess 63 reaches the mounting boss molding recess 65 while filling the second molding space S2 (see FIG. 10). Then, the resin fills the space surrounded by the mounting boss molding recess 65, the protrusion 66, and the back surface 1B of the base material 1. As shown in FIG. The resin passing through the second rib forming recesses 64 reaches the holding rib forming recesses and fills the space surrounded by the second rib forming recesses 64, the holding rib forming recesses, the projections 66, and the back surface 1B of the base material 1. .

The resin passing through the second rib molding recesses 64 is impregnated from the back surface 1B side to the front surface 1A side in the open cut portion 18 positioned directly above, and the cut portion 18 and the molding surface 51A of the upper mold 51 are impregnated. The space between is filled with resin (the opened cut portion 18 is filled with resin).

The injection of the resin is stopped, the state of sandwiching the base material 1 between the pair of molds 51 and 61 is maintained for a predetermined time, and the injected resin is cooled and solidified, thereby forming a plurality of resins on the front and back sides of the base material 1. of the resin structure 2 is formed. Specifically, as shown in FIGS. 9 and 10, by solidifying the injected resin, the resin filling the second molding space S2 forms the first rib 23 and the thin film portion 29, and protrudes from the mounting boss molding recess 65. The space surrounded by the portion 66 and the back surface 1B of the base material 1 is filled with resin as the mounting boss 20 and the thin film portion 29 (see FIG. 2). 1B is used as the second rib 25 and the thin film portion 29, and the resin filled in the space surrounded by the holding rib molding concave portion, the protrusion 66, and the back surface 1B of the base material 1 is used as the holding rib. 26 and the thin film portion 29 are formed by filling the space between the notch portion 18 and the molding surface 51A of the upper die 51 with the resin filled as the filling portion 28, respectively.

Subsequently, as shown in FIG. 11, the upper mold 51 is separated from the lower mold 61 to open the pair of molds 51 and 61 . Then, the door trim 100 formed by forming the resin structure 2 on the base material 1 is released from the pair of molds 51 and 61 . The cross section of the door trim 100 shown in FIG. 11 corresponds to the XI-XI line cross section of FIG.

Next, the effects of this embodiment will be described. In this embodiment, a method for manufacturing a door trim 100 including a base material 1 containing at least fibers and resin and a resin structure 2 provided on the base material 1 includes forming a preboard 1P with a pair of molds 51 and 61. It includes an injection molding step of forming the resin structure 2 on the base material 1 by injecting the resin so as to pass through the concave portions 63, 64, and 65 provided on the molding surface 61A facing the preboard 1P in the lower mold 61 while sandwiching. 3 shows the manufacturing method of the door trim 100 in which the molding surface 61A facing the preboard 1P is provided with the protrusions 66 protruding toward the preboard 1P side at the side portions of the recesses 63, 64, 65. FIG.

According to this method of manufacturing the door trim 100, the thickness of the preboard 1P is relatively thin at least in the portions where the recesses 63, 64, 65 are formed (that is, the portions where the resin structure 2 is formed). 61A, since the protrusions 66 project from the molding surface 61A at the side portions of the recesses 63, 64, 65, the protrusions 66 have a damming function. can be expressed, and the resin can be prevented from leaking and spreading from the gaps between the side portions of the recesses 63, 64, 65 and the preboard 1P in the injection molding process. Since the protrusion 66 suppresses the resin from leaking and spreading, there is no problem even if the press condition is such that a gap is formed between the preboard 1P and the molding surface 61A. It is no longer necessary to adopt a condition that makes the distance between 51 and 61 smaller, and it becomes possible to avoid excessive compression of the preboard 1P (especially for a relatively thick preboard 1P caused by a plate thickness error etc. can avoid situations where excessive press pressure is applied).

In the injection molding process, the projections 66 that follow the groove-shaped recesses 63 and 64 provided on the molding surface 61A and protrude toward the opposing preboard 1P are brought into contact with the preboard 1P.

According to this method of manufacturing the door trim 100, in the injection molding process, the resin passing through the groove-shaped recesses 63, 64 flows laterally from the gap between the recesses 63, 64 and the preboard 1P and leaks and spreads. can be blocked by Depending on the thickness of the preboard 1P, the protrusions 66 can be made to bite into the preboard 1P, and in this state, the resin can be injected through the groove-shaped recesses 63, 64. Therefore, the resin from the gaps between the recesses 63, 64 and the preboard 1P Leakage can be further suppressed.

In the injection molding process, the preboard 1P is brought into contact with the protruding portion 66 projecting in a pointed shape toward the preboard 1P side.

According to this method of manufacturing the door trim 100, depending on the thickness of the preboard 1P, it becomes easier for the protrusions 66 to bite into the preboard 1P, and resin leakage from the gaps between the recesses 63, 64 and the preboard 1P can be further suppressed. can.

The method for manufacturing the door trim 100 includes a cut forming step for forming the cut portion 18 in the preboard 1P. While being sandwiched by 61 , the opened cut portion 18 is filled with the resin injected so as to pass through the concave portion 64 .

According to such a method for manufacturing the door trim 100, the shape of the open cut portion 18 (that is, the shape of the preboard 1P bent) can be fixed with resin. Accordingly, it is possible to provide a method for manufacturing the door trim 100 that can be bent at an arbitrary portion without heating the preboard 1P and that can be fixed in shape.

<Embodiment 2>
Next, Embodiment 2 of the present disclosure will be described with reference to FIGS. 12 and 13. FIG. In addition, in this embodiment, the same reference numerals are used for the same portions as those in the above-described embodiment, and duplicate descriptions of structures, actions, and effects are omitted.

As shown in FIG. 12, the pre-board 201P has projections 219 projecting from its rear surface 201PB toward the molding surface 261A of the lower mold 261. As shown in FIG. The projecting portion 219 has a ridge shape extending in the left-right direction (backward direction of the paper) on the side (front and rear direction) of the facing portion 217 facing the first rib forming recess 63 . A lower end portion 219B of the projecting portion 219 is semicylindrical in cross section. In addition, the protrusions 219 are also provided on the sides of the portions of the preboard 201P facing the recesses other than the first rib-molded recesses 63 (the second rib-molded recesses 64, the mounting boss-molded recesses 65, and the holding rib-molded recesses). is provided.

The projections 219 are formed when the fiber mat 1M is hot-pressed by the press dies 30 and 31 in the preboard molding process shown in FIG. Specifically, a groove extending in one direction such as the left-right direction is formed in the lower die 31, and the shape of the groove is transferred to the back surface of the fiber mat 1M by pressing, thereby allowing the groove to extend in one direction. A protrusion 219 extending from the protrusion is formed.

As shown in FIG. 13, in the injection molding process, the preboard 201P is sandwiched between a pair of molding dies 51 and 261, and the protrusion 219 is pressed (brought into contact) against the molding surface 261A of the lower die 261, thereby forming the protrusion. 219 is crushed at the lower end 219B. Then, without changing the inter-mold distance in this state, the mold is injected into the space between the concave portions 63, 64, 65 and the partially collapsed projection 219 and the back surface 201PB of the preboard 201P (the back surface 201B of the base material 201). Molten resin is injected from device 41 through sprue 62 and gate 69 . The space between the first rib molding recess 63, the partially collapsed protrusion 219, and the rear surface 201PB of the preboard 201P is defined as a second molding space S2.

When the resin injected through the recesses 63, 64, 65 and filling the respective spaces is cooled and solidified, the resin structure including the thin film portion 229, the first ribs 23, the second ribs 25, the mounting bosses 20, the holding ribs 26, etc. Door trim 200 is manufactured with body 202 formed on base material 201 .

According to this method of manufacturing the door trim 200, the protrusion 219 prevents the resin passing through the groove-shaped recesses 63, 64 from flowing laterally from the gap between the recesses 63, 64 and the preboard 1P and leaking and spreading. can be done. In addition, even if the thickness of the preboard 201P varies, the amount of crushing of the protrusion 219 is appropriately changed (for example, when the distance between the pair of molds 51 and 261 for the plurality of preboards 201P is fixed, any preboard As the thickness of 201P increases, the amount of crushing of the protrusion 219 increases). As a result, the protruding portion 219 can be kept in contact with the vicinity of the recessed portions 63 and 64 and in close contact with them.

<Other embodiments>
The present disclosure is not limited to the embodiments described in the above description and drawings, and for example, the following embodiments are also included in the technical scope of the present disclosure. can be implemented by

(1) In the above embodiment, the protrusions are provided on either the molding surface or the preboard, but the present invention is not limited to this. For example, protrusions may be provided on both the molding surface and the preboard.

(2) The shape of the notch can be changed as appropriate in addition to the above embodiments. For example, the cutout may extend in a straight line from one end of the preboard to the other. Moreover, the cut portion may penetrate to the back side of the preboard.

(3) In the injection molding process, the preboard may be pressed with a pair of molds. That is, the molding surface of the upper mold may contact and press the surface of the preboard, and the molding surface of the lower mold may contact and press the back surface of the preboard.

(4) The method of manufacturing the fiber resin molded body exemplified in the above embodiment is not only applied when manufacturing a door trim as a fiber resin molded body, but also can be used for pillar garnish, instrument panel, roof lining, etc. It can also be applied when manufacturing an interior material for a vehicle. In addition, the method of manufacturing a fiber resin molded body illustrated in the above embodiment may be applied to manufacturing a fiber resin molded body to be mounted on various vehicles without being limited to vehicles. For example, the above-mentioned fiber resin molding is also applied to the fiber resin moldings mounted on vehicles such as trains and amusement vehicles as ground vehicles, airplanes and helicopters as flying vehicles, and ships and submarines as sea and undersea vehicles. Body manufacturing methods can be applied.

DESCRIPTION OF SYMBOLS 1,201... Base material (plate-shaped body) 1P, 201... Preboard (plate-shaped body) 2,202... Resin structure 11... Bending part 18... Cut part 20... Mounting boss 41... Injection device 51, 61, 261 Mold 61, 261 Lower mold 61A, 261A Molding surface of lower mold 63, 64, 65 Concave portion 66, 219 Projection 100, 200 Door trim ( fiber resin molding)

Claims (5)

A method for producing a fiber resin molding comprising a plate-like body containing at least fibers and a resin and a resin structure provided on the plate-like body, comprising:
While sandwiching the plate-like body between a pair of molds, the resin structure is formed on the plate-like body by injecting resin so as to pass through recesses provided on molding surfaces facing the plate-like body in the molds. Including injection molding process to form,
A fiber resin molding characterized in that at least one of the opposing molding surfaces or the plate-shaped body is provided with a projection projecting toward the other opposing side in a side portion of the recess. Production method. In the injection molding step, the projection that is formed along the groove-shaped recess provided on the molding surface and protrudes toward the opposing plate-like body is brought into contact with the plate-like body. The method for producing a fiber resin molding according to claim 1. 3. The method of manufacturing a fiber resin molding according to claim 2, wherein in the injection molding step, the projecting portion projecting in a pointed shape toward the plate-like body is brought into contact with the plate-like body. In the injection molding step, the protrusions provided on the plate-like body and having a ridge shape and protruding toward the molding surface side are brought into contact with the vicinity of the groove-shaped recesses and crushed. The method for producing a fiber resin molding according to claim 1. Including a cut forming step of forming a cut in the plate-shaped body,
In the injection molding step, the plate-like body is bent so as to open the cut portion and sandwiched between the pair of molds, and the resin injected so as to pass through the recess is injected into the opened cut portion. 5. The method for producing a fiber resin molding according to any one of claims 1 to 4, characterized in that filling is performed.

Images