JP6030376B2 - Anti-vibration structure for heavy machinery - Google Patents

Description

  The present invention relates to an anti-vibration structure for mounting on a heavy machine that can control ground vibration when the heavy machine travels or works at a construction site or the like.

  In construction work sites, etc., if there is a vibration maintenance target such as a house in the vicinity of the heavy machinery moving route or work location, a laying iron plate is laid on the heavy machinery moving route, under the laying iron plate Is equipped with a vibration isolation mat to absorb vibrations during heavy machine travel. As this anti-vibration mat, as described in the following patent documents, there are many that employ a plate-like foam molded from an olefin resin.

JP 7-279443 A Utility Model Registration No. 3152250

  As described in the above-mentioned patent document, according to the structure in which the laying iron plate is placed on the foam molded from the olefin resin, it becomes possible to suitably absorb the vibration during the heavy equipment traveling. . However, in the foam molded from the olefin resin, the cells are independent, and therefore, when used for a long period of time, the cells are damaged, the thickness is reduced, and the vibration-proof performance tends to be lowered. In addition, a foam molded from an olefin-based resin requires a thickness of about 150 to 300 mm in order to exhibit appropriate vibration-proof performance, but because heavy machinery rides on such a thick foam. Must have a certain long ramp. Furthermore, in order to store such a thick foam, a certain large volume is required.

  As described above, the anti-vibration mats that are required to have high anti-vibration properties leave a lot of room for improvement. By applying various improvements, the anti-vibration mats on the heavy machinery equipped with the anti-vibration mats are provided. It is thought that the practicality of the structure is improved. This invention is made | formed in view of such a situation, and makes it a subject to provide the anti-vibration structure for heavy machine mounting with high practicality.

In order to solve the above-described problems, the vibration isolating structure for mounting on heavy machinery according to the present invention includes a plate-like open-cell polyurethane foam which is a thermosetting resin, and a rigid floor plate placed on the open-cell polyurethane foam. A vibration isolating structure for mounting on heavy machinery that can absorb vibrations when the heavy machinery travels or works on the rigid floor plate by the open cell polyurethane foam, and the apparent density of the open cell polyurethane foam (JIS K 7222: 2005) is 100 to 600 kg / m ³ , and the non-overlaid thickness, which is the thickness of the open cell polyurethane foam when the rigid floor plate and heavy machinery are not overlaid, is 20 to 120 mm, and the continuous The maximum surface pressure of the cellular polyurethane foam is 0.4 kgf / cm ² or more, and the rigid floor plate and heavy machinery are mounted on top. Wherein when mounting on a compression ratio of open cell polyurethane foam compression ratio when being is said more than 5% non upper Notoki thickness and less than 40% der is, is one of the rigid floor plate, a plurality The area of the plurality of open-cell polyurethane foams that receives the load of the one rigid base plate is smaller than the area of the lower surface of the single rigid base plate. It is characterized by.

  In the vibration isolating structure for mounting on heavy machinery according to the present invention, a plate-like open-cell polyurethane foam, which is a thermosetting resin, is used as a vibration-isolating mat that is laid under a rigid base plate including a base iron plate and an FRP floor slab. Yes. In the open-cell polyurethane foam, the cells are not independent and are continuous, so even if they are used for a long time, there is little reduction in the overall thickness caused by cell breakage. For this reason, even if it is at the time of long-term use, vibration-proof performance hardly falls. In the vibration isolating structure for mounting on heavy machinery according to the present invention, the thickness of the vibration isolating mat is 20 to 120 mm, which is relatively thin. For this reason, it is possible to considerably shorten the ramp for riding heavy machinery on the structure.

Furthermore, the compression ratio at the time of mounting is 5% or more and less than 40% of the thickness at the time of non-mounting. In other words, the compression ratio, which is the ratio of the amount compressed at the time of mounting to the thickness at the time of non-mounting, is 5% or more and less than 40%. The compression rate is very deeply related to the natural frequency of the vibration isolation mat, and the natural frequency is very deeply related to the vibration isolation effect. More specifically, it is known that the anti-vibration effect of the anti-vibration mat is high for vibrations more than √2 times the natural frequency of the anti-vibration mat. The lower limit value of the high vibration region is lowered, and vibration can be effectively absorbed. The natural frequency when the compression rate is 5% or more and less than 40% is lower than the natural frequency when the compression rate is less than 5%. The reason for this is not clear, but since the cell shape of urethane foam is usually an oval shape that is vertically long in the foaming direction, the compression rate changes due to compression of a predetermined amount in the same direction and the cell approaches a spherical shape. The number is estimated to change significantly. In addition, when the compression ratio is 40% or more, the cell shape is crushed and flattened, and at the same time, it is presumed that the vibration in the cell is reduced by reducing the space in the cell. To do. For this reason, it becomes possible to absorb a vibration effectively because the compression rate of an anti-vibration mat shall be 5% or more and less than 40%. Further, the polyurethane foam can be made compact by making the area of the polyurethane foam rigid sheet that receives the load smaller than the area of the lower surface of the rigid sheet. Furthermore, one polyurethane foam can be made considerably small by supporting one rigid base plate with a plurality of polyurethane foams. This makes it possible to make the polyurethane foam more compact.

It is a figure which shows the anti-vibration structure for heavy equipment mounting of an Example. It is a table | surface which shows the relationship between the compression rate of the polyurethane foam which comprises the vibration proof structure for heavy machinery mounting, and a natural frequency. It is a table | surface which shows the physical-property value of the polyurethane foam of an Example, and the physical-property value of the olefin type foam of a comparative example. It is a table | surface which shows the vibration level at the time of heavy machinery driving | running | working in the vibration isolating structure for heavy machinery mounting by which the rigid base plate was mounted on the polyurethane foam of an Example. It is a table | surface which shows the physical-property value before and behind the water absorption test with respect to the polyurethane foam of an Example. It is a table | surface which shows the relationship between the thickness of the polyurethane foam of an Example, and a natural frequency (at the time of 25% compression).

  As shown in FIG. 1, a vibration isolating structure 10 for mounting on heavy machinery according to the present invention is placed on a plate-like open-cell polyurethane foam 20 that is a thermosetting resin, and the open-cell polyurethane foam 20. It is constituted by a rigid laying board (laying iron board) 22. And the heavy machine 24 is comprised so that it may drive | work or work on the rigid floorboard 22, and the vibration at the time of heavy machine 24 driving | running | working or operation | work is absorbed by the open cell polyurethane foam 20 which functions as an anti-vibration mat.

  The open-cell polyurethane foam 20 is prepared by mixing at least a urethane foam raw material containing polyol, polyisocyanate, and a foaming agent, foaming the raw material by a foaming reaction, and curing the foamed raw material by a resinification reaction. Is formed into a three-dimensional mesh shape. Many of the bubbles foamed by the foaming reaction become continuous bubbles, resulting in a polyurethane foam in which the cells communicate with each other. In the polyurethane foam 20 having such continuous cells, physical properties such as hardness caused by the damage of the cell membrane are difficult to change, and even when the cells are crushed, air flows between the cells. Easy to restore, easy to restore to the original shape. For this reason, according to the “vibration-proof structure for mounting on heavy equipment” described in the present invention, it is possible to appropriately absorb vibration during traveling of heavy equipment even when used repeatedly for a long time.

The ease of restoring the polyurethane foam to the original shape is evaluated by the compressive residual strain (%) obtained by the measurement method based on JIS K 6400-4: 2004. Specifically, a polyurethane foam test piece (thickness 25 mm × width 50 mm × length 50 mm) of a predetermined size is compressed under a load of 2.7 N / cm ² and left to stand at 25 ° C. for 48 hours. And the ratio of the difference of the thickness of the test piece before and after the test to the thickness of the test piece before the test is calculated. Thereby, compression residual strain (%) is obtained. The compression residual strain (%) indicates that the smaller the numerical value is, the easier it is to restore. In the open-cell polyurethane foam of the present invention, the compression residual strain is preferably 2% or less. 1% or less is preferable.

The ease of restoring the polyurethane foam to its original shape can also be evaluated by repeated compression residual strain (%). Specifically, a test piece of polyurethane foam of a predetermined size (thickness 25 mm × width 50 mm × length 50 mm) is subjected to a load of 2.7 N / cm ² under a condition of 25 ° C., with an amplitude of 1 mm and a frequency. Compression is performed 100,000 times at 5 Hz with a load of 2.7 N / cm ² . And the ratio of the difference of the thickness of the test piece before and after the test to the thickness of the test piece before the test is calculated. Thereby, repeated compression residual strain (%) is obtained. The repeated compressive residual strain (%) also indicates that the smaller the value is, the easier it is to restore. In the open-cell polyurethane foam of the present invention, the repeated compressive residual strain is preferably 2% or less, In other words, it is preferably 1% or less.

  Moreover, the compression amount (see FIG. 1: t1-t2) at the time of loading, which is the compression amount of the open-cell polyurethane foam when the rigid floor plate and heavy machinery are loaded, is 5% or more of the non-mounted thickness t1 and 40 Less than%. That is, the compression ratio, which is the ratio of the on-loading compression amount t1-t2 to the non-mounting thickness t1, is 5% or more and less than 40%. In general, it is known that the anti-vibration effect is high for vibrations more than √2 times the natural frequency of anti-vibration mats, etc., and the frequency when a 20-ton heavy machine travels is about 20 Hz. ing. For this reason, in order to absorb the vibration during running of a heavy machine of 20 tons, it is desirable that the natural frequency of the vibration isolating mat or the like is about 14 Hz or less. On the other hand, the natural frequency and compression rate of the open-cell polyurethane foam functioning as a vibration-proof mat are very deeply related. As shown in FIG. 2, when the compression rate becomes 10% or more, the natural frequency Becomes about 14 Hz or less. However, taking into consideration that dynamic load is applied due to heavy machinery vibration when traveling heavy machinery, even if the calculated compression rate is 5%, the actual compression rate is about 10%, and the natural frequency is up to about 14 Hz. It is thought to go down. In particular, as can be seen from FIG. 2, the natural frequency when the compression rate is 5% rapidly decreases from the natural frequency when the compression rate is 3%. In addition, when the compression ratio is 40% or more, the cell shape is crushed and flattened, and at the same time, it is presumed that the vibration in the cell is reduced by reducing the space in the cell. To do. For this reason, by setting the compression ratio to 5% or more and less than 40%, it becomes possible to lower the natural frequency of the open-cell polyurethane foam to an appropriate frequency, and appropriately absorb vibrations during heavy machine travel. Is possible. The compression rate is preferably 7% or more and less than 35%, and more preferably 10% or more and less than 30%.

In the “open-cell polyurethane foam” of the present invention, the apparent density measured according to the method based on JIS K 7222: 2005 is 100 to 600 kg / m ^3, and it is a high-density urethane foam. . This makes it possible to support heavy machinery with a large load. The apparent density is preferably 150 to 500 kg / m ³ . As shown in FIG. 6, this range is preferable because the natural frequency can be 10.6 Hz or less at 25% compression.

  In addition, in the “vibration-proof structure for mounting heavy machinery” described in the present invention, the thickness t1 (see FIG. 1) when not mounted (refer to FIG. 1), which is the thickness of the open-cell polyurethane foam when the rigid floor plate and the heavy machinery are not mounted, It is set to 20 to 120 mm. Preferably it is 40-110 mm. As a result, it is possible to reduce the heavy equipment-like vibration isolation structure, and it is possible to reduce the size of the ramp for guiding the heavy equipment on the vibration isolation structure. As shown in FIG. 6, the greater the thickness, the better the natural frequency decreases. However, when the thickness is greater than 120 mm, it is difficult to guide heavy machinery. On the other hand, if the thickness is less than 20 mm, the natural vibration is larger than 10 Hz, and the open-cell polyurethane foam is locally compressed by the unevenness of the ground at the construction site, and the thickness cannot be secured, so that the vibration is easily transmitted to the ground. Become. The anti-vibration mat may be formed by overlapping a plurality of open-cell urethane foams. In this case, the thickness of the anti-vibration mat is the total thickness of the plurality of open-cell urethane foams.

In addition, the compression ratio is adjusted by changing at least one of the hardness of the polyurethane foam and the ratio of the area of the polyurethane foam rigid sheet to the area of the lower surface of the rigid sheet, and appropriately setting the relationship between the two. Is done. Hardness (N / cm ² ) is measured in accordance with a method based on JIS K6400-2: 2012 (D method without pre-compression), and indicates the difficulty of deformation of an object, that is, stiffness. . For this reason, hardness has shown that it is hard to deform | transform, so that the value is large. Therefore, when it is desired to increase the compression rate, a polyurethane foam having a low hardness is employed. When a compression rate is desired to be decreased, a polyurethane foam having a high hardness is employed. Further, as the ratio of the area receiving the load of the polyurethane foam laying iron plate to the area of the lower surface of the laying iron plate increases, the load on the laying iron plate or the like can be dispersed. For this reason, when an area ratio becomes high, a polyurethane foam becomes difficult to deform | transform and a compression rate becomes low. That is, when it is desired to increase the compression ratio, the area ratio is decreased, and when the compression ratio is desired to be decreased, the area ratio is increased. Thereby, it becomes possible to adjust a compression rate appropriately and to absorb the vibration at the time of heavy machinery driving | running | working appropriately.

  In addition, when the said area ratio is set to less than 100%, the area which receives the load of the rigid baseplate of a polyurethane foam is smaller than the area of the lower surface of a rigid baseplate. That is, it becomes possible to make the polyurethane foam smaller than the rigid floor plate, and it is possible to make the polyurethane foam compact. Furthermore, one polyurethane foam can be made considerably small by supporting one rigid base plate with a plurality of polyurethane foams. This makes it possible to make the polyurethane foam more compact.

  In the open-cell polyurethane foam of the present invention, water is employed as a foaming agent for the urethane foam material, and urea bonds are formed during the foaming reaction of the urethane foam. The urea bond in the urethane foam is easy to aggregate and forms a portion having a relatively strong bonding force, that is, a hard segment, so that an appropriate hardness and compression residual strain are realized. Furthermore, a known means can be used as the means for adjusting the hardness. For example, the isocyanate index, which is the ratio of isocyanate groups to active hydrogen groups such as polyol, is increased or decreased, the apparent density is increased or decreased by adjusting the amount of foaming agent added, or the molecular weight is smaller than that of the polyol that forms the resin skeleton. Examples thereof include a method of adding a crosslinking agent having active hydrogen.

  In addition, the manufacturing method of polyurethane foam 20, a urethane foam raw material, a compounding quantity, etc. should just be employ | adopted normally, and if it satisfy | fills the said apparent density, compression rate, etc., it will not specifically limit. For example, as a manufacturing method of polyurethane foam 20, a urethane foam raw material, a blending amount and the like, those described in JP2011-24669A and JP7-268052A can be employed.

  The following examples illustrate the present invention more specifically. However, the present invention is not limited to this embodiment, and can be implemented in various modes with various modifications and improvements based on the knowledge of those skilled in the art.

  As the anti-vibration mats of Examples 1 to 3, the polyurethane foam shown in FIG. 3 is employed. In addition, as the anti-vibration mat of Comparative Example 1, a foam molded from an olefin resin is employed. In addition, the polyurethane foam employ | adopted as an anti-vibration mat of Examples 1-3 is made into the open cell polyurethane foam with a continuous cell.

Based on the method based on JISK7222: 2005, the apparent density (kg / m < ³ >) of the polyurethane foam of Examples 1-3 was measured. This measured value is shown in the “apparent density” column of FIG.

Based on a method based on JIS K 6400: 2012 (No D method pre-compression), the hardness (N / cm ² ) at 25% compression of the polyurethane foams of Examples 1 to 3 was measured. This measured value is shown in the “hardness” column of FIG.

  Based on the method based on JIS K 6400-4: 2004, the compression residual strain (%) of the polyurethane foams of Examples 1 to 3 and the olefin foam of Comparative Example 1 was measured. This measured value is shown in the column of “Compressive residual strain” in FIG.

By the method shown below, the cyclic compression residual strain (%) of the polyurethane foams of Examples 1 to 3 and the olefin-based foam of Comparative Example 1 was measured. Specifically, a polyurethane foam test piece (thickness 25 mm × width 50 mm × length 50 mm) having a load of 2.7 N / cm ² is applied to the entire pressure-receiving surface under the condition of 25 ° C. Compression is performed 100,000 times at an amplitude of 1 mm and a frequency of 5 Hz with a load of 2.7 N / cm ² . And the ratio of the difference of the thickness of the test piece before and after the test to the thickness of the test piece before the test is calculated. This calculated value is shown in the column of “Repetitive compression residual strain” in FIG.

The maximum surface pressure of the polyurethane foam of Example 1, that is, the maximum load per square centimeter is 0.4 kgf / cm ² , and the maximum surface pressure of the polyurethane foam of Example 2 is 0.8 kgf / cm ^2. It is. Then, a 1.5 m × 3 m × 25 mmt iron plate is placed on the polyurethane foam of each example having an upper surface area of 30000 cm ² as a rigid plate. In other words, a laid iron plate larger than the polyurethane foam is placed on the polyurethane foam of each example. At this time, the load capacity of the polyurethane foam of Example 1 is 12237 kg, and the load capacity of the polyurethane foam of Example 2 is 24475 kg. In addition, the thickness of the polyurethane foam of each Example is 50 mm.

Moreover, the maximum surface pressure of the olefin-based foam of Comparative Example 1 is 0.27 kgf / cm ² . Then, a 1.5 m × 3 m × 25 mmt laid iron plate is placed on the olefin-based foam of the comparative example having an upper surface area of 45000 cm ² . That is, a laid iron plate having the same size as the foam is placed on the olefin foam of Comparative Example 1. In this case, the load resistance of the olefin-based foam of Comparative Example 1 is 12150 kg. In addition, the thickness of the olefin foam of the comparative example is 150 mm.

  As can be seen from the results shown in FIG. 3, in the polyurethane foam of the example, the compression residual strain and the repeated compression residual strain are about 1/10 that of the olefin foam of the comparative example. From this, it can be seen that the polyurethane foams of the examples are much superior to the olefinic foams of the comparative examples with respect to the ease of restoration after being loaded. In other words, by adopting the polyurethane foam of the example as the vibration-proof mat, it is possible to realize a vibration-proof structure for mounting on heavy machinery that hardly deteriorates the vibration-proof performance even during long-term use.

  In addition, in the vibration isolating structure for mounting on heavy equipment in which the olefin-based foam of Comparative Example 1 having the same area as that of the laid iron plate is laid under the laid iron plate, the load resistance is about 12 tons. On the other hand, in the vibration isolating structure for mounting on heavy equipment in which the polyurethane foam of Example 1 having an area of 2/3 of the floor iron plate is laid under the floor iron plate, the load resistance is about 12 tons. As described above, according to the polyurethane foam of Example 1, it is possible to reduce the size of the vibration-proof mat when a heavy machine having the same weight is mounted. Furthermore, in the vibration isolating structure for mounting on heavy machinery in which the polyurethane foam of Example 2 that is 2/3 of the area of the laid iron plate is laid under the laid iron plate, the load resistance is about 24 tons. . As described above, according to the polyurethane foam of Example 2 having high hardness, it is possible to mount a heavy machine having a weight approximately twice that of the olefin-based foam of Comparative Example 1.

  In addition, a laying iron plate was placed on the polyurethane foam of the above example, and the vibration level when a heavy machine traveled on the laying iron plate was measured. The measurement test conditions and measurement results are shown in FIG. “Anti-vibration mat” shown in FIG. 4 indicates a polyurethane foam used as an anti-vibration mat laid under a laid iron plate. That is, in tests 1 to 4, the vibration level when a heavy machine travels on the laying iron plate placed on the polyurethane foam of Example 1 is measured. In Tests 5 and 6, the polyurethane foam of Example 3 is measured. The vibration level when the heavy machinery travels on the laid iron plate placed on the top is measured.

  The “area ratio” shown in FIG. 4 is the ratio of the area that receives the load of the polyurethane foam covering iron plate to the area of the bottom surface of the covering iron plate. In other words, in tests 1 to 4, polyurethane foam having an area of about 2/3 of the area of the iron plate is laid under the iron sheet, and in tests 5 and 6, the area of about 1/6 of the area of the iron plate. Polyurethane foam is laid under the iron plate. Further, the “compression ratio” shown in FIG. 4 is a ratio of the compression amount of the polyurethane foam when the base iron plate and the heavy machinery are mounted to the thickness of the polyurethane foam when the base iron plate and the heavy machinery are not mounted. It is.

  The “vibration level: anti-vibration mat not used” shown in FIG. 4 is the vibration level when the anti-vibration mat is not used, that is, when only the laying iron plate is laid and a heavy machine travels on the laying iron plate. Vibration level. In addition, “Vibration level: use of anti-vibration mat” shown in FIG. 4 is a vibration level when the anti-vibration mat is used, that is, a laying iron plate is placed on polyurethane foam as the anti-vibration mat. The vibration level when a heavy machine travels on the laid iron plate. For measurement of the vibration level, a vibrometer (Rion Co., Ltd .: VM-53), a level recorder (Rion Co., Ltd .: Level Recorder LR-07), and a data recorder (SONY: PV208AX) were used.

  As can be seen from Tests 1 and 3 to 5 shown in FIG. 4, the vibration level is reduced by 9 dB or more by using a vibration-proof mat having a compression rate of 5% or more and less than 40%. On the other hand, as can be seen from Test 2, even when a vibration isolating mat having a compression rate of 40% is used, the vibration level is reduced only by 4 dB. For this reason, it becomes possible to exhibit a high anti-vibration effect by setting the compression rate to 5% or more and less than 40%.

  When a polyurethane foam having a high hardness (polyurethane foam of Example 3) is used as the vibration isolating mat, the compression ratio becomes 5% or more and less than 40% by reducing the area ratio. To be adjusted. Further, when the hardness cannot be changed, for example, when only a single type of polyurethane foam can be prepared, the compression ratio becomes 5% or more and less than 40% by changing the area ratio. You may adjust. Thus, by changing at least one of the hardness and the area ratio, the compression rate can be made 5% or more and less than 40%, and vibrations of heavy machinery can be appropriately absorbed.

  In addition, the anti-vibration structure for heavy equipment is usually installed outdoors, when water is absorbed by the polyurethane foam of the embodiment used as the anti-vibration mat, and when it is dried after absorbing water The physical properties of the polyurethane foam were measured. Specifically, the physical properties of the polyurethane foam of Example 2 which was left outdoors for 2 months to absorb water (after the WET test) and the polyurethane foam after the WET test was dried (after the DRY test). Was measured according to the following method. For comparison, the same physical properties of the polyurethane foam of Example 2 before the WET test were measured.

Based on the method based on JIS K 6400-2: 2012 (D method without pre-compression), the hardness (N / cm ² ) at 25% compression was measured. This measured value is shown in the “hardness” column of FIG.

  Tensile strength (MPa) was measured according to a method based on JIS K 6400-5: 2012 (dumbbell No. 2 type). This measured value is shown in the column of “Tensile strength” in FIG.

  Elongation (%) was measured according to a method based on JIS K 6400-5: 2012 (dumbbell No. 2 type). This measured value is shown in the column of “elongation” in FIG.

  The compressive residual strain (%) was measured in accordance with a method based on JIS K 6400-4: 2004. Specifically, a polyurethane foam test piece having a size of 25 mm thickness × 50 mm width × 50 mm length was compressed to 50% of the original test piece thickness, and the condition was kept at 70 ° C. for 22 hours. put. And the ratio of the difference of the thickness of the test piece before and behind the test with respect to the thickness of the test piece before compression is calculated. This value is shown in the “compressed residual strain” column of FIG.

The compression residual strain (%) was measured repeatedly by the method described below. Specifically, a polyurethane foam test piece having a thickness of 25 mm × width of 50 mm × length of 50 mm was subjected to a load of 2.7 N / cm ² in the thickness direction at 25 ° C., and an amplitude of 2 mm, Compressed 100,000 times at a frequency of 5 Hz to a thickness of 10% of the original specimen thickness. And the ratio of the difference of the thickness of the test piece before and behind the test with respect to the thickness of the test piece before compression is calculated. This value is shown in the column of “Repetitive compression residual strain” in FIG.

The vibration transmissibility (dB) was calculated from the measurement data obtained according to the method based on JIS K 6385: 2001 (resonance method) according to the following formula.
τ = 20 × log [| 1 / {1- (f / f0) 2} |]
Here, τ is a vibration transmissibility (dB). Further, f is a frequency (Hz) generated from the vibration source, and f0 is a natural frequency (Hz) when vibration-proofing is supported. The vibration transmissibility indicates vibration transmission characteristics, and the smaller the value, the less difficult it is to transmit vibration. This measurement was performed on a polyurethane foam test piece (thickness 25 mm × width 100 mm × length 100 mm) compressed to 15% of the original thickness and vibration during measurement. Is a resonance point at 1 to 50 Hz. This measured value is shown in the column of “vibration transmissibility” in FIG.

  As can be seen from the results shown in FIG. 5, in the polyurethane foam of Example 2, the physical properties are reduced with respect to hardness, tensile strength, and elongation by absorbing water. However, by absorbing water after absorbing water, each physical property value is almost returned to the value before water absorption. In addition, with respect to repeated compressive residual strain and vibration transmissibility, it is difficult for strain to remain in the polyurethane foam by absorbing water, and vibration is difficult to transmit. And even if the absorbed water is dried, it is difficult for distortion to remain, and vibration is difficult to transmit. Furthermore, regarding the compressive residual strain, the value of the compressive residual strain is substantially returned to the value before water absorption by drying the water after absorbing the water. Thus, even when the polyurethane foam of the example is used outdoors, the vibration characteristics, ease of restoration, etc. are hardly deteriorated, and the vibration isolating structure for mounting on heavy equipment used outdoors is used. It can be seen that it is suitable for anti-vibration mats.

  Hereinafter, various aspects of the present invention will be listed.

(1) It is composed of a plate-like open-cell polyurethane foam which is a thermosetting resin and a rigid base plate placed on the open-cell polyurethane foam, and when a heavy machine travels or works on the rigid base plate A vibration isolating structure for mounting on heavy machinery capable of absorbing vibration by the open cell polyurethane foam,
The apparent density (JIS K 7222: 2005) of the open cell polyurethane foam is 100 to 600 kg / m ³ ,
The non-overlay thickness, which is the thickness of the open cell polyurethane foam when the rigid floor plate and heavy machinery are not overlaid, is 20 to 120 mm,
A compression ratio at the time of loading, which is a compression ratio of the open-cell polyurethane foam when the rigid floor plate and heavy machinery are loaded, is 5% or more and less than 40% of the thickness when not mounted. Anti-vibration structure for heavy equipment mounting.

(2) Hardness of the open-cell polyurethane foam (JIS K 6400: 2012 D method without pre-compression) so that the compression ratio at the time of loading is 5% or more and less than 40% of the thickness at the time of non-mounting. And the ratio of the area of the open cell polyurethane foam that receives the load of the rigid base plate to the area of the lower surface of the rigid base plate is set.

(3) One piece of the rigid base plate is placed on a plurality of the open cell polyurethane foams,
Item (1) or Item (2) is characterized in that the area of the plurality of open-cell polyurethane foams subjected to the load of the one rigid sheet is smaller than the area of the lower surface of the one sheet. Anti-vibration structure for heavy equipment mounting.

  (4) The compression residual strain (JIS K 6400-4: 2004) of the open-cell polyurethane foam is 2% or less, as described in any one of the items (1) to (3) Anti-vibration structure for heavy equipment mounting.

(5) The open-cell polyurethane foam is
At least, a mixture of polyol, polyisocyanate and foaming agent is formed into a three-dimensional network shape,
The antivibration structure for mounting on heavy machinery according to any one of (1) to (4), wherein the foaming agent contains at least water.

10: Anti-vibration structure for heavy equipment mounting 20: Open cell polyurethane foam 22: Rigid flooring (laying iron)

Claims (3)

It is composed of a plate-like open-cell polyurethane foam that is a thermosetting resin, and a rigid base plate placed on the open-cell polyurethane foam, and the vibration when a heavy machine travels or works on the rigid base plate An anti-vibration structure for mounting on heavy machinery that can be absorbed by open-cell polyurethane foam,
The apparent density (JIS K 7222: 2005) of the open cell polyurethane foam is 100 to 600 kg / m ³ ,
The non-overlay thickness, which is the thickness of the open cell polyurethane foam when the rigid floor plate and heavy machinery are not overlaid, is 20 to 120 mm,
The maximum surface pressure of the open-cell polyurethane foam is 0.4 kgf / cm ² or more,
Wherein the open-celled polyurethane foam on the mounting when the compression ratio is a compression ratio when the rigid floor plate and heavy equipment is placing above, the 5% or more of the non-top Notoki thickness and state, and are less than 40%,
One piece of the rigid base plate is placed on a plurality of the open cell polyurethane foams,
An anti-vibration structure for mounting on a heavy machine , wherein an area of the plurality of open-cell polyurethane foams subjected to the load of the one rigid base plate is smaller than an area of a lower surface of the single rigid base plate . 2. The vibration isolation for mounting on heavy machinery according to claim 1, wherein the open-cell polyurethane foam has a compressive residual strain (based on JIS K 6400-4: 2004 , left at 25 ° C. ) of 2% or less. Construction.   The natural frequency of the open-cell polyurethane foam when the compression ratio at the time of loading is 5% or more and less than 40% of the thickness at the time of non-mounting is 14 Hz or less. Or the vibration isolating structure for heavy machinery mounting of Claim 2.

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