JP4848205B2 - Interior materials for vehicles - Google Patents

Description

  The present invention relates to an interior material for a vehicle formed of a synthetic resin, and more particularly to an interior material for a vehicle that can reduce a sounding level such as a squeaking noise generated with a vehicle structure.

  Synthetic resin products are often used as interior materials in many vehicles such as automobiles. Non-foamed synthetic resin products are also used, but foaming of synthetic resin is necessary for the purpose of improving cushioning and improving ride comfort, absorbing impacts to protect passengers, and ensuring flatness in the vehicle. Car interior materials that are molded products are often used. Various resins such as expandable urethane and expandable polystyrene are used as the expandable synthetic resin, but expandable polystyrene resins are often used because of their excellent moldability and functionality.

  When the synthetic resin foam molded articles rub against each other, or when the vehicle structure and the vehicle interior material, which is a synthetic resin product, rub against each other, a noise such as a squeaking noise or a frictional sound is generated between them. Since such a sound makes an occupant feel uncomfortable, for example, in the case of a vehicle interior material, a felt is attached to the back surface thereof. However, in the case of felt, it has been a problem that the cost is high and it takes a lot of man-hours to attach both of them with an adhesive or a double-sided adhesive tape.

  As another solution, Patent Document 1 proposes to apply a surfactant to the contact surfaces of parts that are synthetic resin foams, and Patent Document 2 discloses a vehicle interior material such as ABS resin. It has been proposed that a convex portion having a predetermined height is provided at a portion facing a mounting surface at a predetermined mounting location in the vehicle, and a coating layer having a low friction coefficient is formed on the surface of the convex portion.

JP-A-10-298341 JP-A-7-246888

  The method of applying a surfactant as described in Patent Document 1 in order to eliminate the noise can produce a certain effect over a long period of time between contact surfaces of parts that are synthetic resin foams. A noise prevention effect cannot be maintained over a long period of time between a vehicle structure that is usually made of metal and a synthetic resin material (vehicle interior material). Also, the operation of applying the surfactant is not easy. In the method of forming a coating layer having a low friction coefficient described in Patent Document 2 on the contact surface, an effective sound can be obtained by selecting an appropriate paint material from the relationship with the material of the vehicle structure which is the counterpart. Although the prevention effect can be expected, since it is a coating film and the coating film layer itself is superficial, it is inevitable that the effect gradually fades by the use of long days.

  The present invention has been made in view of the circumstances as described above, and can effectively reduce the level of sound generated between the vehicle structure and the vehicle over a long period of time while being manufactured at a low cost. An object of the present invention is to provide a vehicle interior material.

  The vehicle interior material according to the present invention is a vehicle interior material formed of a synthetic resin, and has a laminated structure of an upper layer material and a lower layer material laminated on a surface in contact with the vehicle structure material. The synthetic resin constituting the lower layer material has a sounding level generated when the lower layer material is in contact with the vehicle structural material, and the sound generated when the synthetic resin constituting the upper layer material is in contact with the vehicle structural material. It is a synthetic resin having a level lower than the ringing level.

  In the vehicle interior material according to the present invention, the synthetic resin material constituting the upper layer material is arbitrary and is not particularly limited. Conventionally used synthetic resin materials can be used as appropriate. It may be a molded product of non-foamed material or a foamed molded product. The synthetic resin material that constitutes the lower layer material has a noise level that occurs when it comes into contact with the vehicle structural material, and the noise level that occurs when the synthetic resin material that constitutes the upper layer material comes into contact with the vehicle structural material. Any synthetic resin material can be used as appropriate under the condition that the level is lower than the above. It may be a molded product of non-foamed material or a foamed molded product.

  The vehicle interior material according to the present invention is a synthetic resin product as a whole, and the material cost can be reduced as compared with a conventional case where felt is pasted on the entire back surface. In addition, since the surface in contact with the vehicle structural material is made of a synthetic resin and has a thick lower layer material, the number of days is longer than that in which a thin coating film is formed on the surface in contact with the conventional vehicle structural material. The sound level reduction effect is maintained.

  In the vehicle interior material according to the present invention, the upper layer material is preferably a foam molded product made of a foamable synthetic resin, particularly a foamable polystyrene resin. The reason for this is that, compared with other expandable synthetic resins, expandable polystyrene resins have good moldability and also have excellent functions as vehicle interior materials such as shock absorption. When the upper layer material is a foamed molded product of an expandable polystyrene resin, the lower layer material is preferably an expandable polyolefin resin, particularly an expandable polyethylene resin or an expandable polypropylene resin. The level of squeaking like a squeaking noise generated between these foam molded products and a metal plate is lower than that of foamed polystyrene resin foam molded products, and the squeaking is greatly reduced.

  In the vehicle interior material of the present invention, the upper layer material and the lower layer material may be separately molded and bonded together with an adhesive to form the vehicle interior material. When manufacturing automotive interior materials as molded products of foamed resin, place the foamed upper layer material in the mold for molding automotive interior materials in that state, and in that state, expandable synthesis for the lower layer material A vehicle interior material having a two-layer structure can be obtained by filling a resin in a mold and performing foam molding in the mold. First, the foamable synthetic resin for the upper layer material is filled in the mold and the upper layer material is foamed.Next, the foamable synthetic resin for the lower layer material is placed in the mold with the mold slightly opened. The interior material for a vehicle having a two-layer structure can also be molded by filling and heating again to perform foam molding of the lower layer material. In that case, after filling the foaming synthetic resin for the lower layer material into the mold, so-called cracking may be performed and heated.

  When the above foam molding method is used, the resin material of the upper layer material and the lower layer material is different, so that the compatibility is lacking, and separation is likely to occur at the laminated interface between the upper layer material and the lower layer material. This has the merit that when the vehicle interior material is disposed of, the upper layer material and the lower layer material of different materials can be easily separated and recovered. However, it is not preferable from the viewpoint of work efficiency that the two are easily separated during normal handling such as when mounted on a vehicle. It is desirable that the two stick to each other with a force that does not easily separate under normal handling, and the two are separated when a force exceeding a predetermined level is applied consciously.

  As one means for that purpose, small holes that function as anchor holes are formed in advance on the surface of the upper layer material that comes into contact with the lower layer material during molding. When in-mold foam molding is performed as an interior material for a vehicle, a resin material that forms a lower layer material enters into the small holes and foams, where an anchor effect occurs, making it difficult to separate the two easily. And both can also be isolate | separated by applying required external force.

  As another means, or in addition to the above means, the synthetic resin material constituting the lower layer material includes a resin component common to the resin component of the synthetic resin constituting the upper layer material in a part of the resin material. Use things. In this case, when the resin component common to the resin material of the synthetic resin constituting the upper layer material contained in the synthetic resin material for the lower layer material is subjected to in-mold foam molding as a vehicle interior material, the upper layer A compatible state is partially formed with the material side, and a required sticking force is formed between the upper layer material and the lower layer material. Since the sticking force can be adjusted by adjusting the content of the common resin component, it is not difficult to separate them.

  In the case of employing the above production method, when the upper layer material is a foam molded product of an expandable polystyrene resin, the expandable styrene modified polyolefin resin particles are used as the expandable synthetic resin constituting the lower layer material. It is desirable to use it. The styrene-modified polyolefin resin is obtained by impregnating and polymerizing a polyolefin resin particle with a styrene monomer. Among the styrene-modified polyolefin resins, a styrene-modified polyethylene resin is preferable, for example, The proportion of the styrene component is 40 to 90% by weight, preferably 50 to 85%, more preferably 55 to 75% by weight, and the pre-expansion ratio of the foam of the styrene-modified polyethylene resin is preferably 3 to 60 times.

  In the vehicle interior material according to the present invention, the back surface side (the side in contact with the vehicle structure) of the lower layer material may be a flat surface, but it is more preferable to form a concavo-convex pattern. As shown, the ringing level is further reduced.

  The vehicle interior material according to the present invention can be used as a vehicle interior material for any vehicle including an automobile. In the case of an automobile, it is particularly effectively used as an interior material for vehicles such as a floor spacer, a door pad, and a tool box.

  While the vehicle interior material according to the present invention can be manufactured at low cost, it is possible to reduce the occurrence of an irregular sound such as an irritating sneaky sound for the occupant. Furthermore, in a preferred embodiment, it is possible to easily collect and collect different materials at the time of disposal.

  FIG. 1 shows one form of a floor spacer as an example of a vehicle interior material according to the present invention, and FIG. 2 shows another form of the floor spacer. 3 to 5 show one example of the case where the floor spacer 1 shown in FIG.

  In the example shown in FIG. 1, the floor spacer 1 includes an upper layer material 2 that is a foam molded product made of an expandable polystyrene resin, and a surface side that comes into contact with a vehicle structural material (not shown) when the upper layer material 2 is attached to the vehicle. And a lower layer material 3 which is a foam-molded product of an expandable styrene-modified polyethylene resin. The lower layer material 3 may be a foam-molded product of other expandable styrene-modified polyolefin resin such as expandable styrene-modified polypropylene resin. Moreover, the foaming molded article of a normal foamable polyolefin resin may be sufficient.

  In manufacturing, as shown in FIG. 1, the upper layer material 2 and the lower layer material 3 may be separately foam-molded using a molding die, and both may be laminated and integrated using an adhesive or the like to form a floor spacer 1. You may manufacture by the in-mold foam molding method mentioned later based on FIGS.

  The floor spacer 1 is composed of only the upper layer material 2 that does not have the lower layer material 3 due to the difference in the synthetic resin material constituting the upper layer material 2 and the lower layer material 3. Compared with the case where the rear surface of the vehicle is in direct contact with the vehicle structure, it is possible to greatly reduce the irregular noise such as the squeaking noise that is annoying to the occupant, and even if it occurs, the level is extremely small.

  In the floor spacer 1a shown in FIG. 2, a plurality of small holes 2a are formed on the back surface of the upper layer material 2, and the surface facing the upper layer material 2 of the lower layer material 3 is located at a position facing the small holes 2a. A protrusion 3a having a size to be press-fitted into the small hole 2a is formed. Furthermore, many uneven | corrugated patterns 3b are formed in the surface (back surface) which contact | connects the vehicle structure material of the lower layer material 3. As shown in FIG. In this form, the upper layer material 2 and the lower layer material 3 are laminated and integrated with the protrusions 3a entering the small holes 2a by pressing them in opposition to form the floor spacer 1a. For this reason, the two are not separated by normal handling. On the other hand, when the floor spacer 1a is discarded, there is an advantage that the upper layer material 2 and the lower layer material 3 which are different materials can be easily separated by pulling and peeling the both with a certain amount of force. Furthermore, the unevenness pattern 3b is formed on the surface of the lower layer material 3 that is in contact with the vehicle structural material, so that it is possible to further reduce the level of squealing noise.

  One example in the case of in-mold foam molding of the floor spacer 1 shown in FIG. 1 will be described with reference to FIGS. As shown in FIG. 3, the mold 30 is conventionally known as a mold for foam molding in a bead mold, and includes a movable mold 31 and a fixed mold 32, and a cavity 33 serving as a molding space therebetween. Is formed. In this example, a filling port 34 for filling the foamable resin particles into the cavity 33 is formed on the fixed mold 32 side. Heated steam is introduced into the movable mold 31 and the fixed mold 32 to heat the expandable resin particles filled in the cavity 33.

  As shown in FIG. 4, with the mold closed, a material (for example, pre-expanded particles of polystyrene resin) for foaming the upper layer material 2 is filled into the cavity 33 from the filling port 34, and the movable mold 31 is filled. The upper layer material 2 is foam-molded in the mold by supplying heated steam to both the stationary mold 32 and the stationary mold 32. Next, as shown in FIG. 5, a material (for example, a material for foam molding the lower layer material 3 into the cavity 33 from the filling port 34 (or from another filling port not shown) with the mold slightly opened. The pre-expanded particles of styrene-modified polyethylene resin) are filled, and heated steam is supplied to the fixed mold 32, and the lower layer material 3 is subjected to in-mold foam molding.

  The floor spacer 1 having the two-layer structure shown in FIG. 1 is obtained by opening the mold after cooling. Since the resin material of the lower layer material 3 contains a resin component (styrene-based resin) common to the resin component of the resin material of the upper layer material 2, in the floor spacer 1 formed by in-mold foam molding, the upper layer material 2 and the lower layer material 3 The material 3 is stuck with an appropriate force that does not separate in normal handling. However, the fusion rate between them is low, and when they are actively separated with a certain amount of force, they are reliably separated from the laminated interface.

  The upper layer material 2 foam-molded using another molding die is fitted into the cavity of the movable die 31, and the mold is clamped to the extent that the molding space remains for the lower layer material 3, and in that state, from the filling port 34 (or illustrated) The material for foam molding of the lower layer material 3 (for example, pre-expanded particles of styrene-modified polyethylene resin) is filled in the cavity 33 and heated steam is supplied to the fixed mold 32. The floor spacer 1 having a two-layer structure as shown in FIG. 1 can also be foam-molded in the mold by molding the lower layer material 3 in-mold. Also in this case, the upper layer material 2 and the lower layer material 3 are adhered with an appropriate force that is not separated by normal handling. To separate.

  When this manufacturing method is adopted, the upper layer material 2 having a plurality of small holes 2 a formed on the back surface is foam-molded in advance using another molding die, and the foam material is placed in the cavity of the movable die 31. The floor spacer 1a having the shape shown in FIG. 2 (however, the concavo-convex pattern 3b is not provided) can be obtained by fitting and subsequently performing the foam molding of the lower layer material 3 in the same manner. The depth of the small hole 2a is preferably about 10 mm, and the protrusion 3a is formed in the small hole 2a by foaming with the resin material of the lower layer material 3 entering the small hole 2a. An anchor effect occurs and a greater sticking force is obtained.

[Test Example 1]
Itching sound was measured using the apparatus shown in FIG. The apparatus 10 can move left and right on the base 11, ten metal rolls (diameter 40 mm × length 150 mm) 12 arranged on the base 11 so as to be rotatable at equal intervals, and the metal roll 12. And a moving plate 13 disposed on the surface. The moving plate 13 includes a surface-plated metal plate (thickness 10 mm) 14 that moves in contact with the surface of the test body 20, and a buffering felt (thickness 15 mm) 15 attached to the back surface thereof. This surface-plated metal plate 14 is assumed to be a standard structure of an automobile.

  The apparatus 10 further supports a support frame 16 composed of four support columns that stand up with the moving plate 13 sandwiched from both sides, and is supported on the support frame 16 so as to be freely movable in the vertical direction via a sliding tool 17. The load supporting plate 18 is provided, and a fixing tool 19 for fixing the test body 20 is attached to the back surface of the load supporting plate 18.

  In the test, four types of synthetic resin foam molded articles shown in Table 1 were prepared, and a plate material having a length of 50 mm, a width of 50 mm, and a thickness of 50 mm was cut out therefrom and used as the test body 20. The expansion ratio of the four types of foamed molded products was 30 times. The test body 20 was fixed to the fixture 19 on the back surface of the load support plate 18, the load support body 18 was lowered, and the lower surface of the test body 20 was brought into contact with the surface plated metal plate 14. Thereafter, a load was placed on the load support plate 18 to adjust the load on the surface-plated metal plate 14 of the test body 20 to 20 kg.

  In this state, the average sound pressure (sounding level) (dB) generated when the moving plate 13 was moved 200 mm to the left and right 20 times each was measured with a noise measuring device 21 installed at a location 300 mm away.

  The column of polystyrene resin in Table 1 corresponds to the upper layer material 2 of the floor spacer 1 shown in FIG. 1, and the column of polypropylene resin and the three columns of styrene-modified polyethylene resin are lower layer materials. It corresponds to 3. As shown in Table 1, the polystyrene resin foam molded product showed a high squealing sound (sounding level) of 107 dB, but the polypropylene resin and styrene modified polyethylene resin foam molded products were 96-74. It shows decibels and low squealing (sounding level). The styrene-modified polyethylene resin (with surface irregularity pattern) has a sound level lower than 64 dB, indicating the effectiveness of applying the surface irregularity pattern.

  From this, it is molded from a material (for example, polypropylene resin or styrene-modified polyethylene resin) different from the upper layer material (for example, polystyrene-based resin) 2 like the vehicle interior material (floor spacer 1) according to the present invention. It is shown that an interior material for a vehicle with less noise can be obtained by forming the lower layer material 3 in a portion in contact with the vehicle structure.

[Test Example 2]
About one form of the interior material for vehicles by this invention, the peeling test between the laminated | stacked upper layer material and lower layer material was done. The test specimen was molded by foam molding in a bead mold.
(1) With the mold clamped, foamable polystyrene resin particles pre-foamed 50 times as a resin material for the upper layer material are filled in the cavity and heated (heating steam pressure 0.8 kg / cm ^2). , Heating time 10 seconds), foaming was performed in the mold, and an upper layer material having an expansion ratio of 50 times was molded.
(2) In a state where the movable mold is evacuated, the mold is opened slightly, and the foamed styrene-modified polyethylene resin particles pre-foamed 30 times as a resin material for the lower layer material are filled in the cavity, Only the surface filled with expandable styrene-modified polyethylene resin particles is heated (heating steam pressure 0.8 kg / cm ² , heating time 10 seconds), and foamed in the mold to form a lower layer material having an expansion ratio of 30 times. Molded.
(3) After cooling, the mold was opened, and a foamed molded article as a test body having a two-layer structure was taken out. In the test body, the thickness of the upper layer material is approximately 30 mm, and the thickness of the lower layer material is approximately 5 mm.
(4) A large number of test pieces having a width of 25 mm and a length of 150 mm were cut out from the test body and subjected to a peeling test. Using Tensilon universal testing machine UCT-10T (Orientec Co., Ltd.), the test equipment is attached to the tip of the lower layer material with the upper layer side fixed in a horizontal posture, and the cotton yarn is oriented approximately 90 degrees. It pulled upwards at a speed of 200 mm / min. When the integrated average load was measured at a separation distance of 120 mm, it was approximately 0.75 N / 25 mm. Further, when the peeled surface was visually observed, it was a beautiful peeled surface, and no trace of fusion was observed.
(5) From this, in an actual interior material for indoors having a two-layer structure, the upper layer material and the lower layer material are not separated by normal handling, and when necessary, the upper layer material can be separated with the required force. It can be seen that the two different materials can be easily separated by separating the lower layer material. This is because the synthetic resin constituting the lower layer material includes a resin component common to the resin material of the synthetic resin constituting the upper layer material in a part of the resin material (in the above example, a polystyrene resin component). Because it is.

The figure which shows an example of the interior material for vehicles by this invention. The figure which shows the other example of the vehicle interior material by this invention. The figure explaining the shaping | molding die used when carrying out the in-mold foam molding of the vehicle interior material by this invention. FIG. 4 is an intermediate view when a vehicle interior material is molded using the mold shown in FIG. 3. FIG. 5 is an intermediate view following FIG. 4 when a vehicle interior material is molded using the molding die shown in FIG. 3. The figure explaining the apparatus for measuring a squeaking sound used in the test example.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1, 1a ... Interior material (floor spacer) for vehicles by this invention, 2 ... Upper layer material, 2a ... Small hole, 3 ... Lower layer material, 3b ... Uneven pattern, 10 ... Device for measuring squeaking noise, 20 ... Test body, 30 ... Molding die, 31 ... Movable die, 32 ... Fixed die, 33 ... Cavity, 34 ... Filling port

Claims (3)

A vehicle interior material formed of synthetic resin,
The upper layer material and the upper layer material have a laminated structure with the lower layer material laminated on the surface in contact with the vehicle structural material, the synthetic resin constituting the upper layer material is an expandable polystyrene resin, and the synthetic resin constituting the lower layer material is The synthetic resin in which the noise level generated when the lower layer material contacts the vehicle structural material is lower than the noise level generated when the synthetic resin constituting the upper layer material contacts the vehicle structural material. A foamable styrene-modified polyolefin resin,
The synthetic resin constituting the lower layer material includes a resin component common to the resin component of the synthetic resin constituting the upper layer material in a part of the resin material,
The vehicle is characterized in that a pre-formed upper layer material is put in a mold and filled with a synthetic resin that forms the lower layer material, and the lower layer material is fused and laminated to the upper layer material. Interior material.   The vehicle interior material according to claim 1, wherein an anchor hole for inserting a part of the lower layer material is formed on a surface of the upper layer material in contact with the lower layer material. The vehicle interior member according to claim 1 or 2 lower member, characterized in that the uneven pattern is formed on the surface in contact with the vehicle structural member.

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