JP2007029397A - Frp bathtub - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a posh FRP (Fiber-Reinforced Plastic) bathtub capable of efficiently damping a hitting sound. <P>SOLUTION: A damping part 3 is provided in a side wall 2 of a long side of the FRP bathtub 1 formed into an approximately rectangular shape whose plane external shape has long sides and short sides. The side walls 2a in the long sides out of the side walls 2 of the bathtub 1 have span longer than the side walls 2b of the short sides, have low rigidity and are apt to be easily vibrated, so that the damping parts 3 are provided in the side walls 2a in the long sides. Thereby the damping parts 3 with small area highly efficiently damps the vibration of the side walls 2 to surely prevent the reverberant sound of the hitting sound from leaving for a long period of time. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an FRP bathtub.

  As a bathtub, a so-called artificial marble bathtub manufactured by casting using an acrylic resin has been conventionally provided. However, this artificial marble bathtub requires a long manufacturing time and has a problem in productivity. .

  For this reason, bathtubs made of FRP, which can be manufactured in a short time by press molding and have high strength and excellent chemical stability, occupy a large number of bathtubs sold in Japan.

  However, compared to artificial marble, FRP bathtubs have low attenuation characteristics of sound that occurs when a hand hits the bathtub during bathing, and the sound of hitting will sound long. It is a factor.

Therefore, it has been attempted to attenuate the impact sound by providing a vibration damping material in the bathtub and solve such a problem (see, for example, Patent Document 1).
JP 2001-046259 A

  As described above, when the damping material is provided in the FRP bathtub to attenuate the sound, the damping characteristic differs depending on which part of the FRP bathtub is provided with the damping material, and the damping sound is not necessarily efficiently attenuated. There was a problem that I could not.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a high-quality FRP bathtub capable of efficiently attenuating the hitting sound.

  The FRP bathtub according to claim 1 of the present invention is provided with a damping part 3 on the side wall 2 on the long side of the bathtub 1 made of FRP, which is formed in a substantially rectangular shape whose planar outer shape has a long side and a short side. It is characterized by comprising.

  The invention of claim 2 is characterized in that, in claim 1, the damping part 3 is provided at a position that is at least half of the height direction of the side wall 2 on the long side of the bathtub 1.

  The invention of claim 3 is characterized in that, in claim 1 or 2, the damping part 3 is provided in the center part in the width direction of the side wall 2 on the long side of the bathtub 1.

  The invention of claim 4 is characterized in that, in claim 2 or 3, the area of the damping part 3 is 25% or more of the area of the upper half of the side wall 2 on the long side of the bathtub 1. is there.

  According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the viscoelastic layer 4 and the constraining layer 5 that is laminated on the surface of the viscoelastic layer 4 and restrains deformation of the viscoelastic layer 4 are formed. The vibration damping material 6 is attached to the outer surface of the side wall 2 on the long side of the bathtub 1, and the vibration damping portion 3 is provided.

  The invention of claim 6 is characterized in that, in any one of claims 1 to 4, a vibration damping paint is applied to the outer surface of the side wall 2 on the long side of the bathtub 1, and a vibration damping part 3 is provided. To do.

  A seventh aspect of the present invention provides the vibration damping portion according to any one of the first to fourth aspects, wherein the damping layer 7 made of a viscoelastic material is formed in the thickness of the side wall 2 on the long side of the bathtub 1. 3 is provided.

  According to the present invention, by providing the damping part 3 on the long side wall 2 of the bathtub 1 made of FRP, it is possible to attenuate the vibration of the long side wall 2 with low rigidity and easy vibration. In addition, the vibration of the side wall 2 can be efficiently attenuated by the damping unit 3 having a small area, so that it is possible to more reliably prevent the reverberant sound of the hitting sound from remaining for a long time, and a high-quality FRP bathtub can be obtained. Is.

  Hereinafter, the best mode for carrying out the present invention will be described.

  The bathtub 1 is manufactured by FRP. As FRP, arbitrary things, such as thermosetting resins, such as unsaturated polyester resin reinforced with glass fiber and an epoxy resin, can be used. And although the bathtub 1 which an upper surface opens has the side wall 2 in the four circumferences, the bathtub 1 made into object in this invention has a planar shape, as shown in FIG. The other two opposite sides are formed in a substantially rectangular shape with short sides. Here, if the ratio of the long side to the short side is 1, and the length of the short side is 1, the present invention is particularly effective in the bathtub 1 in which the length of the long side is in the range of 1.7 to 2.4. .

  FIG. 2 shows an example of the damping material 6, in which the constraining layer 5 is laminated on one side of the viscoelastic layer 4. The viscoelastic layer 4 is a rubber-based, plastic-based, asphalt-based, etc. material having viscoelasticity, for example, having a thickness of about 1.4 mm. The constraining layer 5 is a non-stretchable sheet material such as an aluminum sheet. For example, it is formed to a thickness of about 0.1 mm, and the damping material 6 can be formed in a sheet shape by bonding and consolidating the constraining layer 5 to one side of the viscoelastic layer 4. is there. As such a sheet-like damping material 6, for example, a commercially available “Regitorex” manufactured by Nitto Denko Corporation can be used.

  The damping member 3 is provided on the side wall 2 of the bathtub 1 by adhering the surface of the viscoelastic layer 4 opposite to the constraining layer 5 to the outer surface (back surface) of the side wall 2 of the bathtub 1. It is something that can be done. When a hitting sound is generated by applying a hit or the like to the bathtub 1, the side wall 2 vibrates and a reverberation sound of the hitting sound is generated. It is absorbed by the sluggishness of the viscoelastic layer 4 of the vibration damping material 6 that occurs, attenuates the vibration of the side wall 2, and can prevent the reverberant sound of the hitting sound from remaining for a long time. In particular, since the viscoelastic layer 4 of the damping material 6 is fixed with both sides being constrained by the side wall 2 of the bathtub 1 and the constraining layer 5, use of the displacement (shear strain) between layers resulting from deformation due to the excitation stress. Thus, the excitation energy is efficiently absorbed, and the vibration of the side wall 2 is attenuated with high efficiency, so that it is possible to more reliably prevent the reverberant sound of the hitting sound from remaining for a long time.

  Here, the present invention has been made by clarifying the causal relationship between the place where the damping unit 3 is provided and the area of the damping unit 3 and the damping effect, as shown in FIG. It is necessary to provide the damping part 3 on the side wall 2a on the long side of 1. Of the side walls 2 of the bathtub 1, the long side wall 2 a has a longer span and is less rigid than the short side wall 2 b, so that it vibrates easily. By providing, it is possible to obtain a high effect of damping the vibration, and the vibration of the side wall 2 is efficiently attenuated by the damping unit 3 having a small area, and it is more certain that the reverberation sound of the hitting sound remains for a long time. It can be prevented. In the bathtub 1, the long side wall 2 a is opposed to two sides, but the damping unit 3 may be provided only on one side wall 2 a or the damping unit 3 may be provided on both side walls 2 a. Any of them may be used.

  Further, when providing the damping part 3 on the side wall 2a on the long side, it is preferable to provide the damping part 3 in a region of a height position of more than half in the height direction, that is, a region of the upper half position of the side wall 2a. . Since the upper end of the side wall 2a is open, the upper half of the side wall 2a is particularly easy to vibrate. Thus, by providing the damping part 3 at the upper half position of the side wall 2a, a small area is controlled. The vibration of the side wall 2a can be attenuated with high efficiency by the vibration part 3, and the reverberation sound of the hitting sound can be prevented more reliably.

  Furthermore, when providing the damping part 3 in the upper half position of the side wall 2a on the long side in this way, it is preferable to provide the damping part 3 at the central position in the horizontal direction of the side wall 2a. The side wall 2a is particularly easy to vibrate in the central portion rather than the end portion. By thus providing the vibration damping portion 3 at the central portion of the side wall 2a, the vibration of the side wall 2a can be reduced by the vibration damping portion 3 having a small area. Is effectively attenuated, and it is possible to more reliably prevent the reverberant sound of the hitting sound from remaining for a long time.

  And when providing the damping part 3 in the center part of the upper half position of the long side wall 2a as described above, the damping part 3 is provided with an area of 25% or more of the area of the upper half of the side wall 2a. It is preferable to do so. If the area of the damping unit 3 is less than 25% of the area of the upper half of the side wall 2a, the vibration damping effect by the damping unit 3 may be insufficient. Although the upper limit of the area of the damping part 3 is not specifically limited, it is 100% of the area of the upper half of the side wall 2a.

  In the above embodiment, the damping part 3 is formed by attaching the damping material 6 including the viscoelastic layer 4 and the constraining layer 5 to the side wall 2 (long side wall 2a) of the bathtub 1. However, you may make it form the damping part 3 with a damping paint by apply | coating a liquid damping paint to the outer surface of the side wall 2 of the bathtub 1, and drying and hardening. The vibration-damping paint is prepared by blending acrylic emulsion, styrene butadiene rubber, and the like. By coating the vibration-damping paint on the outer surface of the side wall 2, it can be easily applied to a portion having a complicated uneven shape on the side wall 2. The vibration control part 3 can be provided.

  In the embodiment of FIG. 3, the damping layer 7 is embedded in the wall thickness of the side wall 2 (long side wall 2 a) of the FRP bathtub 1, thereby controlling the side wall 2 of the bathtub 1. The vibration part 3 is formed. The vibration damping layer 7 is made of a viscoelastic material such as rubber, plastic, or asphalt. In this structure, the vibration damping portion 3 can be incorporated in the wall thickness of the side wall 2 of the bathtub 1. .

  The invention will now be illustrated by means of examples.

  Using the bathtub 1 formed in the shape and dimensions (unit: mm) of FIG. 1, the sound attenuation characteristics of the bathtub 1 were measured. The measurement was performed as follows. First, the bathtub 1 is installed in an environment that realizes anechoic so that the reverberant sound can be ignored, and the sound is collected at a height of 500 mm from the upper surface of the bathtub 1 at the center of the bathtub 1 as shown in FIG. A microphone 11 is arranged. And the hard ball 13 suspended from the string 12 as shown in FIG. 5 (b) is pulled and separated at a distance of 80 mm, so that it is at the center in the width direction of the side wall 2a on the long side of the bathtub 1 and 150 mm below the upper end. A hard ball 13 was struck (indicated by x in FIG. 5A), and the sound generated by this struck was collected by the sound collecting microphone 11.

  First, with respect to the bathtub 1 made of FRP and the bathtub 1 made of artificial marble, the sound attenuation characteristics were measured without using the damping material 6, and the results are shown in Table 1. Here, FIG. 6 (a) shows the change over time of the sound pressure of the bathtub 1 made of FRP, and FIG. 6 (b) shows the change over time of the sound pressure of the bathtub 1 made of artificial marble. The time shown in the figure is the reverberation time calculated by the RT60 (Reverberation Time 60) method. The time required to decrease by -30 dB from the maximum sound pressure generation is read from the figure, and its double value (time required to decrease by -60 dB from the maximum sound pressure generation) is the reverberation time. The sound attenuation characteristics can be evaluated based on the reverberation time. The FRP bathtub 1 has a reverberation time of 1.32 seconds, but the artificial marble bathtub 1 has a short reverberation time of 0.20 seconds, and the artificial marble bathtub 1 has a high vibration damping characteristic and produces a sharp sound. This can be confirmed.

  Next, as the damping material 6, “Regetorex D-300N” manufactured by Nitto Denko Corporation is used, and the damping material 6 is attached to various portions of the side wall 2 of the FRP bathtub 1 as shown in FIG. The sound attenuation characteristics were measured.

  FIG. 4A shows the damping material 6 attached to the central part of the upper half of the side wall 2a on the long side of the bathtub 1 with an area in the range of 25% of the upper half of the side wall 2a.

  FIG. 4B shows an area of 25% of the upper half at the center of the upper half of the side wall 2a on the long side of the bathtub 1, and a range of 25% of the lower half at the center of the lower half. The damping material 6 is pasted in each area.

  FIG. 4C shows a case where the damping material 6 is attached to the center of the lower half of the side wall 2a on the long side of the bathtub 1 with an area in the range of 25% of the upper half of the side wall 2a.

  FIG. 4D shows the vibration damping material 6 attached to the center portion of the upper half of the side wall 2b on the short side of the bathtub 1 with an area of 50% of the lower half of the side wall 2b.

  FIG. 4E shows the damping material 6 attached to the center of the upper half of the side wall 2a on the long side of the bathtub 1 in an area of 50% of the upper half of the side wall 2a.

  FIG. 4 (f) shows that the damping material 6 having an area in the range of 25% of the upper half of the side wall 2 a is attached to both sides of the upper half of the side wall 2 a on the long side of the bathtub 1.

  FIG. 4G shows a case where the damping material 6 is attached to the upper half of the side wall 2a on the long side of the bathtub 1 in an area of 100% of the upper half of the side wall 2a.

  FIG. 4 (h) shows that the damping material 6 is attached to the lower half of the side wall 2 a on the long side of the bathtub 1 with an area in the range of 100% of the lower half of the side wall 2 a.

  These measurement results are shown in Table 1. 4A shows the time-dependent change in the sound pressure of the bathtub 1 in FIG. 4A, FIG. 7B shows the time-dependent change in the sound pressure of the bathtub 1 in FIG. FIG. 8A shows the change over time in the sound pressure of the bathtub 1 in FIG. 8A, FIG. 8B shows the change over time in the sound pressure of the bathtub 1 in FIG. 4D, and FIG. 9A shows the change over time in the sound pressure of the bathtub 1 in FIG. 9A, FIG. 9B shows the change over time in the sound pressure of the bathtub 1 in FIG. 4F, and FIG. FIG. 10A shows the change with time of the pressure, and FIG. 10B shows the change with time of the sound pressure of the bathtub 1 in FIG. 4H.

  As seen in Table 1, from the comparison between the bathtub 1 in FIG. 4A and the bathtub 1 in FIG. 4D, among the side walls 2 of the bathtub 1, the damping material is applied to the side wall 2 a on the long side with low rigidity. It is confirmed that the sound generated at the time of impact can be effectively attenuated by pasting 6.

  Moreover, from the comparison of the bathtub 1 of FIG. 4A and the bathtub 1 of FIG. 4C, and the comparison of the bathtub 1 of FIG. 4G and the bathtub 1 of FIG. It is confirmed that the sound generated at the time of striking can be attenuated more effectively by attaching the damping material 6 to the upper half in 2a.

  Further, from the comparison between the bathtub 1 of FIG. 4 (e) and the bathtub 1 of FIG. 4 (f), the damping material 6 is applied to the central portion of the upper half of the side wall 2a on the long side of the bathtub 1, so It is confirmed that the sound generated at the time can be attenuated more effectively.

  Furthermore, from the comparison of the bathtub 1 in FIG. 4A, the bathtub 1 in FIG. 4E, and the bathtub 1 in FIG. 4G, the damping material 6 is applied to the entire upper half of the side wall 2a on the long side of the bathtub 1. It is confirmed that the damping performance equivalent to that of the artificial marble bathtub can be sufficiently obtained by pasting the damping material 6 having an area amount corresponding to 25% of the upper half of the side wall 2a. .

An example of embodiment of this invention is shown, (a) is a top view, (b) is a front view, (c) is a side view. It is sectional drawing which shows a damping material same as the above. It is sectional drawing which shows an example of other embodiment of this invention. The affixing position and area of a damping material are shown, and (a) to (h) are perspective views. The method of measuring the sound attenuation characteristic of a bathtub is shown, (a) is a perspective view and (b) is a partial perspective view. (A) is a figure which shows the time-dependent change of the sound pressure of the FRP bathtub which has not attached the damping material, (b) is a figure which shows the time-dependent change of the sound pressure of the artificial marble bathtub which has not attached the vibration-damping material. . (A) is a figure which shows the time-dependent change of the sound pressure of the bathtub of Fig.4 (a), (b) is a figure which shows the time-dependent change of the sound pressure of the bathtub of Fig.4 (a). (A) is a figure which shows the time-dependent change of the sound pressure of the bathtub of FIG.4 (c), (b) is a figure which shows the time-dependent change of the sound pressure of the bathtub of FIG.4 (d). (A) is a figure which shows the time-dependent change of the sound pressure of the bathtub of FIG.4 (e), (b) is a figure which shows the time-dependent change of the sound pressure of the bathtub of FIG.4 (f). (A) is a figure which shows the time-dependent change of the sound pressure of the bathtub of FIG.4 (g), (b) is a figure which shows the time-dependent change of the sound pressure of the bathtub of FIG.4 (h).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Bathtub 2 Side wall 3 Damping part 4 Viscoelastic layer 5 Constrained layer 6 Damping material 7 Damping layer

Claims (7)

  An FRP bathtub comprising a damping section provided on a side wall on a long side of a bathtub made of FRP formed in a substantially rectangular shape having a planar outer shape having a long side and a short side.   2. The FRP bathtub according to claim 1, wherein the damping part is provided at a position that is at least half of the height direction of the side wall on the long side of the bathtub.   3. The FRP bathtub according to claim 1, wherein the damping part is provided at a center part in the width direction of the side wall on the long side of the bathtub.   The area of a vibration control part is 25% or more of the area of the upper half of the side wall of the long side of a bathtub, The FRP bathtub of Claim 2 or 3 characterized by the above-mentioned.   A damping material formed with a viscoelastic layer and a constraining layer that is laminated on the surface of the viscoelastic layer and restrains deformation of the viscoelastic layer is attached to the outer surface of the side wall on the long side of the bathtub, and The FRP bathtub according to any one of claims 1 to 4, wherein a vibration part is provided.   The FRP bathtub according to any one of claims 1 to 4, wherein a damping part is provided by coating damping paint on the outer surface of the side wall on the long side of the bathtub. The FRP according to any one of claims 1 to 4, wherein a damping layer made of a viscoelastic material is formed in a wall thickness of a side wall on the long side of the bathtub, and a damping part is provided. Bathtub.

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