Vehicle interior materials and seat back panels

Abstract

To provide an interior material for a vehicle which is easily sewn while securing rigidity.SOLUTION: When Shore hardness of an interior material for a vehicle is represented by H [Hs], thickness thereof is represented by d [mm], and flexural rigidity thereof is represented by K[Mpa mm4], an index X=H×K×d2 is set to be smaller than an upper limit value that is set according to sewing easiness required for the interior material for the vehicle. Otherwise, the index X is set to be larger than 3,500 and smaller than 54,000.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] This application relates to a vehicle interior material and a seat back panel using the same.

Background Art

[0002] For example, Patent Document 1 discloses a vehicle seat. The seat back of this vehicle seat includes a seat back board, and a cover member is sewn to the back cover portion of the seat back board. Patent Document 1 describes that the back cover portion of the seat back board is made of a resin material and has a shore hardness greater than 50 and is sewable.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Parts having a structure in which a skin material is sewn to a vehicle interior material made of resin or the like are used in various places inside the vehicle cabin. A vehicle seat in which a cover is sewn to a resin seat back board, as in Patent Document 1, is also an example. Thus, in the case of a part having a structure in which a skin material is sewn to a vehicle interior material, the vehicle interior material to be used usually requires high rigidity.

[0005] Also, in the case of a vehicle interior material to which a skin material is sewn and used, ease of sewing is also important. For example, if one attempts to sew a skin material to a base material that is difficult to sew, such as a resin material, a sewing machine having a very high penetration force is required, and at the time of sewing, it is necessary to slow down the sewing speed, so the work efficiency decreases. Also, the life of the needle used in the sewing machine is shortened. Therefore, from the viewpoint of reducing manufacturing costs, in the case of a vehicle interior material to which a skin material is sewn, it is desirable that it be easy to sew.

[0006] However, rigidity and ease of sewing in vehicle interior materials are inversely related; increasing the rigidity of vehicle interior materials makes it difficult to sew the surface material, making it difficult to achieve both. In this regard, while Patent Document 1 uses a sewable material with a Shore hardness of 50 or higher for the back cover portion of the seat backboard, it does not solve the problem of difficulty in sewing the back cover portion, which is made of resin material.

[0007] In view of the above issues, this application aims to provide vehicle interior materials and seat back panels that take both rigidity and ease of sewing into consideration. [Means for solving the problem]

[0008] In one embodiment of the present application, when the Shore hardness is H [Hs], the thickness is d [mm], and the bending stiffness is K [Mpa·mm4], the index X shown in the following equation (1) is configured to be smaller than the upper limit set according to the ease of sewing required for the vehicle interior material.

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[0009] Here, the vehicle interior material may be configured such that index X is greater than a lower limit value set according to the rigidity required for the vehicle interior material.

[0010] In other embodiments of this application, the interior material for vehicles is configured such that the index X shown in equation (1) above is less than 54000. Here, the interior material for vehicles may also be configured such that the index X is greater than 3500.

[0011] Vehicle interior materials relating to these forms may have a Shore hardness H[Hs] value of 50 or higher. Furthermore, vehicle interior materials may be composed of one or more of the following: fibers, felt, foamed resin, and hollow resin structures.

[0012] A seat back panel according to one embodiment of this application is formed using a vehicle interior material according to any embodiment of this application. [Effects of the Invention]

[0013] The index X for vehicle interior materials is expressed by Shore hardness H, thickness d, and bending stiffness K, and can also be used as a value indicating ease of sewing. That is, by keeping the values ​​of Shore hardness H and bending stiffness K within an acceptable range, and further keeping this index X within a set range, vehicle interior materials and seat back panels can be made to possess both the necessary rigidity and ease of sewing. [Brief explanation of the drawing]

[0014] [Figure 1] This figure shows the results of puncture tests on multiple substrate samples. [Figure 2] This figure shows the values ​​representing the characteristics of multiple substrate samples. [Figure 3] This figure shows the relationship between the index X of the vehicle interior material according to the embodiment of this application and the ease of sewing. [Figure 4] This is a schematic perspective view showing the overall configuration of a vehicle seat according to an embodiment of this application. [Figure 5] This is a schematic front view showing a portion of the rear side of the seat back panel according to an embodiment of this application. [Modes for carrying out the invention]

[0015] Hereinafter, embodiments of the vehicle interior material according to this application will be described with reference to the drawings. In each drawing, the same or corresponding parts are denoted by the same reference numerals, and their descriptions are simplified or omitted.

[0016] Embodiment. As materials for the base material of the vehicle interior material according to this embodiment, for example, felt such as fiber, compressed felt or knitted felt, foamed resin such as foamed urethane, and hollow structures of resin (for example, honeycomb structures) can be used. Further, the base material may have a structure in which any two or more of these materials are laminated. Further, the base material may be one in which these materials are covered with a skin material. As the skin material, for example, synthetic leather containing PVC (polyvinyl chloride), or non-woven fabric, etc. are used. Here, the synthetic leather containing PVC includes synthetic leather made only of PVC and synthetic leather having PVC as a main component. The synthetic leather having PVC as a main component includes, for example, those in which a resin such as nylon or polyurethane is applied to the surface of PVC. Further, the skin material may be made of, for example, synthetic leather containing other materials such as PP (polypropylene), fibers such as non-woven fabric and woven fabric, and natural leather.

[0017] The base material is required to have necessary rigidity. Specifically, it is desirable that the base material has a Shore hardness of 50 or more, and in some cases, it is desirable to have an even higher hardness. The above-mentioned materials for the base material are subjected to a treatment for curing as necessary so as to have the necessary rigidity. Various methods for increasing the rigidity of these materials are well-known and will not be described here.

[0018] On the other hand, if the rigidity of the base material is increased, the ease of sewing on the base material decreases. Therefore, in the case of the base material used by sewing the skin material, simply making it have a higher rigidity is not sufficient. The base material as the vehicle interior material according to this embodiment is made to have the necessary rigidity while ensuring the ease of sewing.

[0019] Here, the ease of sewing the base material can be confirmed by a piercing test. FIG. 1 is a diagram showing the results of the piercing test for two samples of base material A and base material B. In FIG. 1, the vertical axis represents the piercing load [N], and the horizontal axis represents the piercing stroke [mm]. This piercing test is a piercing test using a universal material testing machine (manufactured by Instron, model 3344) and a piercing jig (manufactured by Imada, TKS250N). The test speed in the test is 50 [mm / min], the stroke is 0 to 10 "mm", and the size of each sample of the base material is 60 [mm] × 60 [mm].

[0020] The base material B indicated by the broken line is a resin base material having high rigidity. In the case of this base material B, particularly, until the piercing stroke exceeds 4 [mm], that is, until the piercing jig penetrates the base material B, the piercing load is very high, and the frictional resistance after penetration is also somewhat large. That is, it is considered to be a material that is relatively difficult to sew.

[0021] On the other hand, the base material A indicated by the solid line has a smaller piercing load as a whole compared to the base material B, and even near the stroke of 4 [mm] where the piercing load is maximum, it is less than half of that in the case of the base material B. Also, the piercing load after the piercing load reaches the maximum is relatively low.

[0022] It can be considered that the easier the base material is to penetrate and the smaller the frictional resistance after penetration, the easier it is to sew the base material. That is, the integral value of the curve showing the change in the piercing load [N] from stroke 0 to 10 [mm] in FIG. 1, that is, the area value of the portion surrounded by the vertical axis, the horizontal axis, and the curve showing the piercing load [N] (hereinafter simply referred to as the "area value") is easier to sew when it is small, and more difficult to sew when it is large. Thus, the area value in FIG. 1 can be used as a value indicating the ease of sewing the base material. That is, it can be said that the base material is easier to sew as the area value is smaller, and more difficult to sew as the area value is larger.

[0023] Figure 2 is a table showing the characteristic values ​​of several base material samples. The table in Figure 2 shows values ​​indicating ease of sewing (i.e., the area values ​​mentioned above) obtained from puncture tests performed on each base material sample. In Figure 2, base materials 2 and 12 are the same as base materials A and B in Figure 1, respectively. Base materials 1 to 11 are base materials for vehicle interior materials according to this application, and base materials 12 to 14 are conventional base materials used for vehicle interior materials.

[0024] In Figure 2, conventional base materials 12-14 have high rigidity, but their area values ​​indicating ease of sewing are large, indicating poor sewability. Base material 11 has slightly lower rigidity, but it is a material that is sufficiently easy to sew. This base material 11 can be used by adding reinforcement or other modifications as needed, depending on the rigidity required for the part in which it is used. Base materials 1-10 all have a Shore hardness of 50 or higher, possessing sufficient rigidity as interior materials for vehicles, and their area values ​​indicating ease of sewing are also sufficiently low, making them easy to sew. In other words, they are considered to be more suitable materials for interior materials for vehicles.

[0025] The inventors of this application repeatedly performed puncture tests on each of these substrates and, after diligent research, found that the index X shown in the following formula (1), which uses Shore hardness, correlates with the sutureability of the substrate.

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[0026] Figure 3 shows the relationship between index X and ease of sewing. In Figure 3, the horizontal axis represents index X, and the vertical axis represents ease of sewing, i.e., the area value. From Figure 3, it can be seen that the value of ease of sewing approximates the value of a linear function of index X.

[0027] In this embodiment, a lower limit α and an upper limit β are set for index X, which are within the range that ensures the required rigidity and the required ease of stitching. The base material for the vehicle interior according to this embodiment ensures the necessary rigidity and ease of stitching by having index X satisfy the following equation (2).

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[0028] By the way, index X is an index that indicates the difficulty of suturing; the smaller the value, the easier it is to sew, and the larger the value, the more difficult it is to sew. On the other hand, index X is a value obtained by multiplying Shore hardness H, thickness d, and bending stiffness K by values ​​that are all correlated with stiffness; the smaller this value, the lower the stiffness, and the larger this value, the higher the stiffness tends to be. Therefore, the range shown for index X can be set so that the lower limit α is a value corresponding to the required stiffness, and the upper limit β is a value corresponding to the required ease of sewing. Also, index X includes the thickness d of the base material as a parameter. Therefore, for example, if there is some requirement for the thickness d of the base material, the lower limit α and upper limit β can be set within the range that satisfies the required thickness d.

[0029] Furthermore, the inventors of the present invention derived from the results of puncture tests, including the substrate shown in Figure 2, that a more preferable range for the index X of the substrate is a lower limit α of 3500 and an upper limit β of 54000. That is, the substrate for the interior material of a vehicle according to this embodiment is more preferably such that the index X satisfies the following equation (3).

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[0030] As explained above, by using vehicle interior materials that satisfy equation (2) or (3), it is possible to obtain vehicle interior materials that are easy to sew while ensuring the necessary rigidity. By using these vehicle interior materials, it is possible to eliminate the need for sewing machines with high penetration power, improve the work efficiency of sewing vehicle interior materials, and extend the lifespan of sewing machine needles. Therefore, it is possible to contribute to reducing the cost of parts used in the vehicle interior.

[0031] In the embodiments described above, the case where the index X of the vehicle interior material is within the range indicated by the lower limit α and the upper limit β, or within the range greater than 3500 and less than 54000, was explained. However, the vehicle interior material only needs to have an index X that is less than the upper limit β or 54000, and is also acceptable if it is less than or equal to the lower limit α or 3500.

[0032] Figure 4 is a schematic side view showing an example of a vehicle seat arranged inside a vehicle. The base material for the vehicle interior according to this embodiment is used, for example, as the material for the seat back panel 10 of the vehicle seat 1, as shown in Figure 4.

[0033] The vehicle seat 1 shown in Figure 4 comprises a seat back 2, a seat cushion 3, and a headrest 4. The seat back 2 is supported at the rear end of the seat cushion 3. The seat back 2 is for supporting the occupant's back. The headrest 4 is located at the upper end of the seat back 2. The headrest 4 is for supporting the occupant's head. The seat back 2 includes a seat back body (not shown). The seat back body may include cushioning material such as a pad and a support frame. A seat back panel 10 is installed on the rear side of the seat back body.

[0034] Figure 5 is a schematic front view showing a portion of the rear side of the seat back panel 10. As shown in Figure 5, the seat fabric 20 is sewn to the sewing position 11 on the outer periphery of the seat back panel 10. The portion of the front side of the seat back body that is not covered by the seat back panel 10 is covered by the seat fabric 20 sewn to the seat back panel 10.

[0035] In this embodiment, there are no particular limitations on the material used to form the seat fabric 20. However, since the seat fabric 20 covers the part that comes into contact with passengers, it is desirable to select the constituent material of the seat fabric 20 with consideration for tactile feel and a sense of luxury in appearance. Specifically, as the seat fabric 20, for example, synthetic leather containing PVC (polyvinyl chloride) or nonwoven fabric can be used. Here, synthetic leather containing PVC includes synthetic leather made only of PVC and synthetic leather with PVC as the main component. Synthetic leather with PVC as the main component includes, for example, a material in which a resin such as nylon or polyurethane is coated on the surface of PVC. Furthermore, the seat fabric 20 may also be made of synthetic leather containing other materials such as PP (polypropylene), fibers such as nonwoven fabric and woven fabric, and natural leather.

[0036] By using the vehicle interior material of this embodiment as the seat back panel 10, the necessary rigidity of the seat back panel 10 can be ensured while facilitating the sewing of the seat fabric 20. This improves the efficiency of the sewing work in the manufacturing of the seat back panel 10, thereby reducing the manufacturing cost of the seat back panel 10.

[0037] The vehicle interior material according to this embodiment is not limited to being applied to the seat back panel 10, but can be suitably used in other parts installed in the vehicle, which are constructed by sewing a surface material onto a base material that is the vehicle interior material. Specifically, in addition to the seat back panel, the vehicle interior material can be used as a material that constitutes all or part of the dashboard, instrument panel, door trim, pillar trim, and rear parcel shelf, for example.

[0038] In the embodiments described above, when numbers such as the number of elements, quantities, amounts, or ranges are mentioned, unless specifically stated or clearly defined in principle, the examples of seat back panels and vehicle seats of this application are not limited to the mentioned numbers. Furthermore, the structures described in these embodiments are not necessarily essential to the configuration of seat back panels and vehicle seats of this application, unless specifically stated or clearly defined in principle. [Explanation of symbols]

[0039] 1. Vehicle seat 2 seatbacks 3 Seat cushions 4 headrests 10 Seat back panel 11 Sewing position 20 sheets of fabric

Claims

1. Shore hardness is H [Hs], thickness is d [mm], and bending stiffness is K [MPa・mm]. ４ When this is the case, the index X shown in equation (1) below is configured to be less than 54000, This is a base material used by suturing the surface material. A vehicle interior material characterized by the following features. [Math 1]

2. The vehicle interior material according to claim 1, characterized in that the index X is configured to be greater than 3500.

3. The vehicle interior material according to claim 1 or 2, characterized in that the Shore hardness H [Hs] value is 50 or higher.

4. The vehicle interior material according to any one of claims 1 to 3, characterized in that it is composed of one or more of the following: fibers, felt, foamed resin, and hollow resin structures.

5. A seat back panel formed using the vehicle interior material described in any one of claims 1 to 4.

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