Interior material for vehicle

Abstract

To provide an interior material for a vehicle which can improve impact absorption performance at the time of collision of a vehicle.SOLUTION: An interior material for a vehicle includes a first wall part 31 and a second wall part 32 which contain a foamable resin and cross each other, wherein a connection part of the first wall part 31 and the second wall part 32 constitutes a corner part 15 swollen to the cabin inside, a surface on the cabin inside in the corner part 15 is composed of a projecting round surface 16, a surface on the cabin outside in the corner part 15 is composed of a recessed round surface 17, and a radius R7 of the recessed round surface 17 is set at 3.5 mm or more and 9 mm or less.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The technology disclosed in this specification relates to vehicle interior materials. [Background technology]

[0002] Conventionally, a vehicle interior material is known that is described in the following Patent Document 1. The vehicle interior material (door trim) described in Patent Document 1 is made of foamable resin and has an armrest that bulges into the vehicle interior. The armrest is made up of a first wall portion that forms a support surface (upper surface 14) on which an occupant's elbows and the like are placed, and a second wall portion (wall portion that forms the front surface 13) that extends downward from the end of the first wall portion facing the vehicle interior. As a result, the vehicle interior material has a corner portion formed by a connection portion between the first wall portion and the second wall portion. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2008-37191 A Summary of the Invention [Problem to be solved by the invention]

[0004] During a vehicle collision, the vehicle interior material is pressed from the outside of the vehicle. In a vehicle interior material having a corner as in the above configuration, when pressed from the outside of the vehicle, stress is concentrated at the corner, making it prone to breakage. In order to improve the shock absorbing performance during a vehicle collision, it is required to make the corner structure more stretchable and less prone to breakage. In addition, when the vehicle interior material is made of a foamable resin, the ease of stretching changes depending on the foaming state, so it is necessary to design the material while taking into consideration the foaming state.

[0005] The technology disclosed in this specification was developed based on the above circumstances, and aims to provide a vehicle interior material that can improve the impact absorption performance during a vehicle collision. [Means for solving the problem]

[0006] As a means for solving the above-mentioned problems, the vehicle interior material disclosed in this specification comprises two wall portions which contain a foamable resin and which intersect with each other, and the connecting portion between the two wall portions forms a corner portion which bulges into the interior of the vehicle cabin, the surface of the corner portion facing the interior of the vehicle cabin is formed by a convex R surface, and the surface of the corner portion facing the exterior of the vehicle cabin is formed by a concave R surface, and the radius of the concave R surface is set to be equal to or greater than 3.5 mm and equal to or less than 9 mm.

[0007] In the above configuration, the smaller the radius of the concave R surface, the more likely stress concentration occurs at the corner, and the more likely it is to break. In addition, according to the present inventor, it has been confirmed that the larger the radius of the concave R surface at the corner, the more likely it is that large gaps formed by the bubbles formed by the foaming of the foamable resin are formed, and the more likely it is to break. The following is considered as the cause of this. When molding a vehicle interior material containing a foamable resin, after filling the molding space formed by a pair of molding dies with the foamable resin, a process (core back) is performed to expand the molding space by slightly increasing the distance between the pair of molding dies, so as to promote the foaming of the foamable resin. Here, when molding a corner, the molding die is cored back along the plate thickness direction of one of the two wall parts constituting the corner. When a concave R surface is provided, the expansion part of the molding space has a gradually changing part that is smallest at the end and gradually increases as it moves away from the end. In this gradually changing part, the expansion of the molding space (the reduction in pressure) becomes non-uniform. As a result, multiple air bubbles are generated unevenly at the corners, and as a result, the air bubbles are concentrated locally, and it is believed that it is easy for large voids to form when the air bubbles are connected to each other. And, it is believed that the larger the radius of the concave R surface, the wider the gradually changing part becomes, and therefore it is more likely that large voids formed when the air bubbles are connected to each other will form.

[0008] From the above, it is considered that the radius of the concave R surface is too small and the radius of the concave R surface is too large, and that the material is easily broken. In other words, it is considered that the corner is least likely to break when the radius of the concave R surface is within a certain range. Therefore, the inventor of the present application conducted a test using a test piece simulating a corner of a vehicle interior material in order to investigate the correlation between the radius of the concave R surface and the amount of displacement (fracture displacement) of the pressing part until the material breaks when a load is applied to the corner using the pressing part. According to the test results, it was confirmed that when the radius of the concave R surface is set in the range of 3.5 mm or more and 9 mm or less, the fracture displacement can be increased by 1.1 times compared to the conventional configuration (configuration in which the radius of the concave R surface is set to 2 mm).

[0009] In this manner, in a configuration in which a vehicle interior material containing a foamable resin has corners, by setting the radius of the concave R surface in the range of 3.5 mm or more and 9 mm or less, the breaking displacement can be made sufficiently large, thereby further improving the impact absorption performance during a vehicle collision.

[0010] In the above configuration, the concave R surface is the surface on the outer side of the vehicle cabin at the corner, and is the surface opposite the design surface. In contrast, since the convex R surface is a design surface, design considerations are required in setting the radius of the convex R surface. For example, if the radius of the convex R surface is too large, the corner will lose its sharpness, and there is a concern that the design will be reduced. In the above configuration, the impact absorption performance can be improved by setting the radius of the concave R surface on the surface opposite the design surface, which is preferable as it allows for greater freedom in design.

[0011] Furthermore, each of the two wall portions includes a foamed layer containing a plurality of bubbles formed by foaming the foamable resin, and an unfoamed layer arranged to cover both the front and back sides of the foamed layer and in which the foamable resin is in an unfoamed state, and in the unfoamed layer, a portion of the foamed layer arranged on the interior side of the vehicle cabin is designated as a first unfoamed layer, and a portion of the foamed layer arranged on the exterior side of the vehicle cabin is designated as a second unfoamed layer, the total thickness of the first unfoamed layer and the second unfoamed layer can be set to be 0.6 mm or more and 1.0 mm or less.

[0012] The smaller the thickness of each of the first unfoamed layer and the second unfoamed layer, the lower the rigidity. Also, the larger the thickness of each of the first unfoamed layer and the second unfoamed layer, the smaller the thickness of the foamed layer, making it difficult to ensure the thickness of each wall (each of the two wall parts), and therefore difficult to manufacture. By setting the total thickness of both unfoamed layers to 0.6 mm or more and 1.0 mm or less, it is possible to ensure the thickness of each wall part and prevent the rigidity from decreasing.

[0013] In the foamed layer, the number density of the bubbles having a circularity of 0.5 or more among the plurality of bubbles is 1.55 bubbles / mm 2 The above can be set. For example, air bubbles that are elongated in the thickness direction of each wall portion have little room to expand in the thickness direction, so when force is applied to each wall portion, the wall portion around the air bubble is likely to break. However, with the above-mentioned configuration, air bubbles that are close to perfect circles are densely contained in the foam layer, making it possible to achieve a configuration that is easy to expand while also achieving sufficient weight reduction. Effect of the Invention

[0014] According to the present invention, it is possible to provide an interior material for a vehicle that can further improve the shock absorbing performance during a vehicle collision. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1 is a perspective view showing a door trim according to an embodiment of the present invention; [Diagram 2]Cross-sectional view of the door trim armrest seen from the rear of the vehicle [Diagram 3] A diagram showing the cross-sectional configuration of the trim body part [Figure 4] A diagram showing the molding process of the trim body. [Diagram 5] FIG. 13 is a diagram showing a state where the molding die 52 is cored back in the molding process. [Figure 6] A diagram showing the molding process for a trim body with a relatively small concave R radius. [Figure 7] Graph showing the correlation between the radius of the concave R surface and the amount of displacement until fracture [Figure 8] Table showing the results of tensile tests performed on resin components DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] An embodiment of the present invention will be described with reference to Figs. 1 to 8. In this embodiment, a door trim for a vehicle is exemplified as an interior material for a vehicle. As shown in Fig. 1, the door trim 10 includes a trim main body 11 (interior material main body) having a plate shape. The trim main body 11 contains a foamable resin. The material of the foamable resin is not particularly limited, but for example, a mixture of a thermoplastic resin such as polypropylene resin and a foaming agent can be used. As the foaming agent, for example, inorganic foaming agents such as sodium bicarbonate, ammonium bicarbonate, and ammonium carbonate, nitroso compounds such as N,N'-dinitrosopentamethylenetetramine, azo compounds such as azodicarbonamide and azobisisobutyronitrile, sulfonyl hydrazides such as benzenesulfonyl hydrazide, toluenesulfonyl hydrazide, and diphenylsulfone-3,3'-disulfonyl hydrazide, and organic foaming agents such as p-toluenesulfonyl semicarbazide can be used.

[0017] The trim body 11 is provided with a speaker grill 12 and a storage section 13 for storing an inside handle. As shown in FIG. 2, the trim body 11 is provided with a main wall section 30 that covers a metal door panel 29 that constitutes a vehicle door from the inside of the vehicle compartment. The trim body 11 is provided with an armrest 14 that bulges toward the inside of the vehicle. As shown in FIG. 1 and FIG. 2, the armrest 14 has a shape that extends in the vehicle front-rear direction and is composed of a first wall section 31 that constitutes a support surface 31A on which an occupant places his / her elbows, and a second wall section 32 that is disposed on the inside of the vehicle compartment relative to the main wall section 30 and extends downward from an end of the first wall section 31 on the inside of the vehicle compartment. The first wall section 31 and the second wall section 32 (two wall sections) extend in a manner that crosses each other, and a corner section 15 that bulges toward the inside of the vehicle compartment (the inside of the vehicle compartment, the left side of the figure) is formed by a connection section between the first wall section 31 and the second wall section 32.

[0018] The surface of the corner 15 facing the interior of the vehicle cabin (inside the vehicle cabin) is formed by a convex R surface 16, and the surface of the corner 15 facing the exterior of the vehicle cabin (outside the vehicle cabin) is formed by a concave R surface 17. The radius R7 of the concave R surface 17 is set to, for example, 3.5 mm or more and 9 mm or less. In this embodiment, the convex R surface 16 is illustrated as being arranged parallel to the concave R surface 17. That is, the radius R6 of the convex R surface 16 is a value obtained by adding the plate thickness of the corner 15 to the radius R7. The radius R6 of the convex R surface 16 may be set to a value different from the radius R7. For example, the radius R6 may be made smaller than the radius R7 to give the corner 15 a sharper shape and improve the design.

[0019] As shown in Fig. 3, the trim main body 11 includes a foamed layer 19 containing a plurality of bubbles 18 formed by foaming a foamable resin, and an unfoamed layer 20 in which the foamable resin is not yet foamed and is disposed so as to cover both the front and back sides of the foamed layer 19. In the following description, of the unfoamed layer 20, a portion disposed on the interior side of the foamed layer 19 (upper side in Fig. 3) is referred to as a first unfoamed layer 21, and a portion disposed on the exterior side of the interior is referred to as a second unfoamed layer 22. The unfoamed layer 20 is sometimes referred to as a skin layer.

[0020] The total thickness of the first unfoamed layer 21 and the second unfoamed layer 22 is set to, for example, 0.6 mm or more and 1.0 mm or less. In the foamed layer, the number density of the bubbles 18 having a circularity of 0.5 or more is, for example, 1.55 bubbles / mm. 2 It is set as above.

[0021] In this embodiment, the unfoamed layers 21, 22 are portions located outside the outermost bubble 18 (designated by reference symbol 18A) of the foamed layer 19 in the thickness direction of the trim main body 11 (the up-down direction in FIG. 3). Specifically, as shown in FIG. 3, if the lines tangent to the outer surface of the bubble 18A and parallel to the plate surface direction of the trim main body 11 are defined as boundary lines L1, L2, the unfoamed layers 21, 22 are portions located outside the boundary lines L1, L2 in the thickness direction. In other words, the foamed layer 19 is a portion located inside the boundary lines L1, L2 in the thickness direction.

[0022] The maximum inner diameter of the bubble 18 is set to, for example, 0.33 mm or less. If the maximum inner diameter of the bubble 18 exceeds 0.33 mm, the wall (cell) around the bubble 18 becomes thin and the wall has a structure with few branches, which makes it easy for force to concentrate on the wall. However, if the maximum inner diameter of the bubble 18 is 0.33 mm or less, the wall around the bubble 18 becomes thick and the wall has a structure with many branches, which makes it easy for force to be dispersed. As a result, when force is applied to the trim main body 11, the wall around the bubble 18 has a structure that allows it to stretch (has room to stretch), so that the trim main body 11 can be easily stretched and difficult to break. The maximum inner diameter of the bubble is the value at which the diameter (inner diameter) of the bubble is the largest.

[0023] Next, the effect of this embodiment will be described. In the above configuration, the smaller the radius R7 of the concave R surface 17, the more likely stress concentration occurs at the corner 15, making it easier to break. In addition, the inventors of the present application have confirmed that the larger the radius R7 of the concave R surface 17 at the corner 15, the more likely it is that large gaps connecting the bubbles 18 will occur in the multiple bubbles 18 formed by foaming the foamable resin, making it easier to break. The following is thought to be the cause of this.

[0024] When molding the door trim 10 (more specifically, the trim body 11) containing a foamable resin, as shown in FIG. 4, the molding space formed by a pair of molding dies 51, 52 is filled with molten foamable resin, and then, as shown in FIG. 5, the distance between the pair of molding dies 51, 52 is slightly increased to expand the molding space (core-back), so as to promote foaming of the foamable resin. Here, when molding the corner 15, as shown in FIG. 5, the molding die 52 is core-backed along the plate thickness direction of one of the two walls (the first wall 31 and the second wall 32) constituting the corner 15 (for example, the first wall 31). In the case of having a concave R surface 17, as shown in FIG. 5, the expanded portion of the molding space during core-back (the space between the trim body 11 and the molding die 52) has a gradually changing portion 53 that is smallest at the end and gradually becomes larger as it moves away from the end. In this gradually changing portion 53, the expansion of the molding space (reduction in pressure) during core back becomes uneven.

[0025] As a result, in the corner portion 15, a plurality of bubbles are generated unevenly, and as a result, the bubbles are concentrated locally, and it is considered that a large gap formed by bubbles connecting with each other is easily generated. As shown in the gradually changing portion 53 in FIG. 5 and the gradually changing portion 54 in FIG. 6, the larger the radius of the concave R surface 17, the wider the gradually changing portion becomes, and it is considered that a large gap formed by bubbles connecting with each other is easily generated. Note that FIG. 5 shows a configuration in which the radius R7 of the concave R surface 17 is larger than that in FIG. 6, and the gradually changing portion 53 is formed in a wider range than the gradually changing portion 54. Note that, in FIG. 5 and FIG. 6, a configuration in which the molding die 52 is moved in a direction away from the first wall portion 31 (toward the bottom of the figure) during core back is illustrated, but the displacement direction of the molding die 52 can be set appropriately, and for example, the molding die 52 may be moved in a direction away from the second wall portion 32 (to the right of the figure). Also, the core back may be performed by operating the molding die 51. However, since the molding die 51 has a molding surface for molding the design surface, it is preferable not to move the molding die 51 in order to mold the design surface more accurately. Therefore, it is more preferable to operate the molding die 52 to perform the core back.

[0026] From the above, it is considered that if the radius R7 of the concave R surface 17 is too small, the material will break easily, and if it is too large, the material will break easily. In other words, it is considered that at the corner 15, the material will be least likely to break when the radius R7 of the concave R surface 17 is within a predetermined range. The inventors of the present application conducted a test using a test piece simulating the corner 15 to investigate the correlation between the radius R7 of the concave R surface 17 and the fracture displacement when a load is applied to the corner 15. Next, an evaluation test using a test piece simulating the corner 15 and the test results will be described.

[0027] In the evaluation test, a test piece simulating the corner 15 and its surroundings was fixed at the locations corresponding to the main wall 30 and the first wall 31, and at a location of the second wall 32 located below the pressing location 33 (see FIG. 2), and the second wall 32 was pressed into the interior of the vehicle by the pressing part 40 with a load F1 simulating a side collision, and the displacement X1 of the pressing part 40 toward the interior of the vehicle until the test piece broke was measured. The above measurement was performed on multiple types (three types) of test pieces with different radii R7 of the concave R surface 17. The measurement results are shown at points P1 to P3 in FIG. 7.

[0028] 7, the horizontal axis indicates the radius R7 of the concave R surface 17, and the vertical axis indicates the amount of displacement X1 of the pressing part 40 toward the inside of the vehicle cabin until the test piece breaks. Note that the larger the amount of displacement X1, the less likely the member is to break (the easier it is to stretch), and the higher the impact absorbing effect. Note that the radius R6 of the convex R surface 16 is the value obtained by adding the thickness T3 of the corner 15 (and thus the test piece) to the radius R7, and in the test piece, the thickness T3 is set to 0.7 mm.

[0029] According to the measurement results (points P1 to P3) in FIG. 7, the relationship between the radius R7 of the concave R surface 17 and the amount of displacement X1 is approximately a quadratic function (curve L3 in FIG. 7, approximate formula X1=-0.0737*R7 2 It was confirmed that when the radius R7 of the concave R surface 17 is set in the range of 3.5 mm or more and 9 mm or less, the displacement amount X1 until fracture can be increased by 1.1 times compared to the conventional configuration (where the radius of the concave R surface is set to 2 mm).

[0030] In this manner, in a configuration in which the door trim 10 containing a foamable resin has a corner portion 15, by setting the radius R7 of the concave R surface 17 in the range of 3.5 mm or more and 9 mm or less, the displacement amount X1 until breakage can be made sufficiently large, and the impact absorption performance during a vehicle collision can be further improved.

[0031] In addition, the concave R surface 17 is the surface on the outer side of the vehicle cabin at the corner 15, and is the surface opposite to the design surface. In contrast, since the convex R surface 16 is the design surface, design consideration is required in setting the radius R6. For example, if the radius R6 of the convex R surface 16 is too large, the corner 15 will lose its sharpness, and there is a concern that the design will be reduced. In the above configuration, the impact absorption performance can be improved by setting the radius R7 of the concave R surface 17, which is the surface opposite to the design surface, and therefore the degree of freedom in design can be increased, which is preferable.

[0032] In addition, each of the first wall portion 31 and the second wall portion 32 comprises a foamed layer 19 containing a plurality of bubbles 18 formed by foaming of a foamable resin, and an unfoamed layer 20 arranged to cover both the front and back sides of the foamed layer 19 and in which the foamable resin is in an unfoamed state. In the unfoamed layer 20, when the portion of the foamed layer 19 arranged on the interior side of the vehicle cabin is designated as a first unfoamed layer 21 and the portion of the foamed layer 19 arranged on the exterior side of the vehicle cabin is designated as a second unfoamed layer 22, the total thickness obtained by adding the thickness T1 of the first unfoamed layer 21 and the thickness T2 of the second unfoamed layer 22 is set to be 0.6 mm or more and 1.0 mm or less.

[0033] The smaller the thickness of each of the first unfoamed layer 21 and the second unfoamed layer 22, the lower the rigidity. Also, the larger the thickness of each of the first unfoamed layer 21 and the second unfoamed layer 22, the smaller the thickness of the foamed layer 19, making it difficult to ensure the thickness of the trim body 11, and therefore difficult to manufacture. By setting the total thickness of both unfoamed layers 21, 22 to 0.6 mm or more and 1.0 mm or less, it is possible to ensure the thickness of the trim body 11 while preventing the rigidity from decreasing. The thicknesses of the first unfoamed layer 21 and the second unfoamed layer 22 can be adjusted, for example, by adjusting the time of contact with the molding die or the temperature of the mold surface during molding.

[0034] In the foamed layer 19, the number density of the cells 18 having a circularity of 0.5 or more is 1.55 cells / mm 2The above is set. For example, air bubbles having a long shape in the thickness direction of the first wall portion 31 (or the second wall portion 32) have little room to expand in the thickness direction, so when force is applied to the first wall portion 31 (or the second wall portion 32), the wall portion around the air bubble is likely to break. However, according to the above-mentioned configuration, the foam layer 19 contains air bubbles 18 that are close to perfect circles densely, so that the foam layer 19 can be configured to be easily expanded while being sufficiently lightweight. The number of air bubbles 18 can be adjusted, for example, by adjusting the viscosity of the molten resin during molding. Also, the number of air bubbles can be increased by promoting the kneading of the thermoplastic resin and the foaming agent that constitute the molten resin in the screw portion of the injection molding machine.

[0035] The inventors of the present application performed an evaluation by a tensile test on a plate-shaped resin member simulating a wall portion constituting the trim main body portion 11. The resin member for testing was molded as follows. First, a foamable resin was injected into the space (molding space) between a pair of molding dies (upper and lower dies) to fill it. As the foamable resin, a mixture of polypropylene resin as a thermoplastic resin and sodium bicarbonate as a foaming agent was used. After the molding space was filled with the foamable resin, the upper die was slightly separated from the lower die to expand the molding space (this process is called core back) to promote foaming of the foamable resin. This state was maintained for a certain period of time to harden the foamable resin, and the hardened molded body was removed from the pair of molding dies to obtain a resin member. In the above process, the degree of core backing, the temperature of the molding dies after the foamable resin was filled in the molding space, and the holding time were appropriately changed to obtain seven types of resin members A to G with different cross-sectional states.

[0036] Next, the resin members A to G were cut, and the cross sections were photographed and the obtained images were analyzed by a computer. From this analysis, the thickness of the resin member, the thickness of the first unfoamed layer disposed on the front side (inner side of the vehicle cabin) of the foamed layer, the thickness of the second unfoamed layer disposed on the back side (outer side of the vehicle cabin) of the foamed layer, the maximum inner diameter of the bubbles, and the photographed range (area 45 mm 2 ) (unit: bubbles / 45mm 2" was measured. The thickness of the unfoamed layer was measured from the outer part in the thickness direction than the boundary lines L1 and L2 shown in FIG. 3. The measurement of the maximum inner diameter of the bubbles and the counting of the number of bubbles were limited to bubbles with a circularity of 0.5 or more. The total thickness of the unfoamed layers was calculated by summing the thickness of the first unfoamed layer and the thickness of the second unfoamed layer. The ratio of the thickness of the second unfoamed layer to the first unfoamed layer was calculated by dividing the thickness of the second unfoamed layer by the thickness of the first unfoamed layer and expressing the value as a percentage. The ratio of the thickness of the unfoamed layer to the resin member was calculated by dividing the total thickness of the unfoamed layers by the thickness of the entire resin member and expressing the value as a percentage. The analysis results are shown in FIG. 8.

[0037] Next, a tensile test was conducted on the resin members A to G in accordance with JIS K 7161. The yield stress and distortion of the resin members were measured. The results are shown in Figure 8. Resin members A to E, which have a maximum bubble inner diameter of 0.33 mm or less, have a larger distortion than resin members F and G, which have a maximum bubble inner diameter of 0.34 mm, and all of them have a distortion of 20 mm or more. 2 (1.55 pieces / mm 2 ) and above for resin materials A to E, the number of air bubbles is 70 / 45 mm 2 The amount of distortion is larger than that of resin members F and G where the ratio of the thickness of the second unfoamed layer to the first unfoamed layer is less than 70%, and all of the amounts of distortion are 20 mm or more. The amount of distortion is larger than that of resin members F and G where the ratio exceeds 70%, and all of the amounts of distortion are 20 mm or more. As shown in FIG. 8, it was confirmed that the smaller the maximum inner diameter of the bubbles, the greater the number of bubbles per unit area, or the smaller the ratio of the thickness of the second unfoamed layer to the first unfoamed layer, the greater the amount of distortion of the resin member.

[0038] 8, the resin members B, C, and E have a higher yield stress than the resin members F and G. The resin member C, in which the ratio of the thickness of the unfoamed layer to the thickness of the resin member is 25% or more, has a higher yield stress than the resin members A, B, D, E, F, and G, in which the ratio is less than 25%.

[0039] <Other embodiments> The technology disclosed in this specification is not limited to the embodiments described above and illustrated in the drawings, and for example, the following embodiments are also included within the technical scope. (1) In the above embodiment, a door trim for a vehicle is exemplified as an example of a vehicle interior material, but the vehicle interior material can also be applied to other interior materials such as side trim, quarter trim, pillar garnish, etc. In addition, the vehicle interior material is not limited to vehicles. For example, the vehicle interior material can also be applied to vehicles such as trains and recreational vehicles as ground vehicles, airplanes and helicopters as flying vehicles, and ships and submarines as marine and underwater vehicles. (2) In the above embodiment, the corner portion may be formed by two intersecting walls, and the location where the corner portion is formed is not limited to the armrest. The corner portion may be formed in another component constituting the vehicle interior material, for example, the corner portion may be formed in a door pocket. [Explanation of symbols]

[0040] 10...door trim (vehicle interior material), 15...corner, 16...convex R surface, 17...concave R surface, 18...air bubble, 19...foamed layer, 20...unfoamed layer, 21...first unfoamed layer, 22...second unfoamed layer, 31...first wall portion (one of two wall portions), 32...second wall portion (the other of two wall portions), R7...radius of concave R surface, T1...thickness of first unfoamed layer, T2...thickness of second unfoamed layer

Claims

1. The housing has two walls including a foamable resin and intersecting each other, A connection portion between the two wall portions constitutes a corner portion that bulges into the interior of the vehicle, The surface of the corner portion facing the interior of the vehicle is configured as a convex R surface, The surface of the corner portion facing the outside of the vehicle cabin is formed by a concave R surface, The radius of the concave R surface is set to be equal to or greater than 3.5 mm and equal to or less than 9 mm.

2. Each of the two walls is a foamed layer containing a plurality of bubbles formed by foaming the foamable resin; an unfoamed layer disposed in a manner covering both the front and back surfaces of the foamed layer, the foamed resin being in an unfoamed state; In the unfoamed layer, a portion of the foamed layer disposed on the vehicle cabin interior side is a first unfoamed layer, and a portion of the foamed layer disposed on the vehicle cabin exterior side is a second unfoamed layer, 2. The vehicle interior material according to claim 1, wherein a total thickness of the first unfoamed layer and the second unfoamed layer is set to be 0.6 mm or more and 1.0 mm or less.

3. In the foamed layer, the number density of the bubbles having a circularity of 0.5 or more among the plurality of bubbles is 1.55 bubbles / mm ２ The vehicle interior material according to claim 2, wherein the above is set.

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