Polyurethane spring vibration isolator for rail transit and preparation method thereof

Abstract

The invention discloses a polyurethane spring vibration isolator for rail transit and a preparation method of the polyurethane spring vibration isolator, a polyurethane spring is arranged in the vibration isolator, polyurethane is a high polymer material and has good damping characteristic and aging resistance, rigidity cannot change along with time, and material performance is stable; the polyurethane spring achieves the damping effect through compression of internal foaming gaps, and the situation that the spring loses efficacy due to external environments such as water immersion can be effectively prevented; according to the spring vibration isolator, the steel spring is wrapped by the polyurethane material, on one hand, the polyurethane can play a certain vibration reduction role, meanwhile, the polyurethane is of a closed hole type, the waterproof performance and the oil stain resistance are good, the steel spring is protected, and the service life of the spring vibration isolator is prolonged; on the other hand, the polyurethane is used as a damping material in the spring vibration isolator, so that the vibration of the steel spring and the polyurethane material can be effectively reduced; in addition, the polyurethane material is used as an outer wrapping material and is filled in the lower base, so that the transverse displacement of the steel spring can be effectively limited.

Description

Technical Field

[0001] The invention belongs to the technical field of rail vibration reduction and noise reduction, and specifically relates to a polyurethane spring vibration isolator for rail transportation and a preparation method thereof. Background Art

[0002] In recent years, with the development of urban rail transit, while rail transit brings us convenience, the vibration and noise generated by rail transit also seriously affect people's quality of life. At the same time, it also has a certain impact on the stability, safety and service life of rail transit itself. Therefore, different vibration isolation measures need to be taken to reduce the impact of rail transit.

[0003] At present, the vibration isolators used for rail vibration reduction mainly include steel spring vibration isolators and rubber spring vibration isolators; the main vibration reduction element of rubber spring vibration isolators is rubber, which is not resistant to high temperature and oil pollution. In the underground tunnel environment of rail transit, it is easy to age, and the stiffness gradually increases over time, and the vibration reduction effect gradually decreases; the vibration reduction principle is to achieve the vibration reduction effect through the deformation of the rubber itself. In water-soaked areas or other conditions that affect the deformation of the rubber, the vibration reduction effect will fail.

[0004] The main vibration reduction components of the steel spring isolator are steel springs and damping fluid. Soaking the steel spring in damping fluid plays a role in dissipating the vibration energy of the isolator. Generally, the isolators in the tunnel are often submerged by accumulated water, causing leakage of the damping fluid and reducing the vibration reduction effect of the steel spring isolator.

[0005] Therefore, in order to effectively solve the vibration and noise problems caused by rail transit, the applicant has developed a polyurethane spring isolator after long-term research and experiments. It can be applied to ballastless track structure and has good vibration reduction effect. At the same time, it also has a height adjustment effect. The height of the polyurethane spring can be adjusted to adapt to different working conditions. Summary of the invention

[0006] In view of the above defects or improvement needs of the prior art, the inventors have conducted intensive research and designed a polyurethane spring isolator for rail transit and a preparation method thereof, wherein a polyurethane spring is arranged in the isolator, wherein the polyurethane is a polymer material with good damping characteristics and aging resistance, the stiffness does not change with time, and the material performance is stable; the polyurethane spring achieves the vibration reduction effect by compressing the internal foaming voids, which can effectively prevent the occurrence of spring failure caused by external environments such as immersion in water; by wrapping the steel spring with polyurethane material, on the one hand, the polyurethane can play a certain vibration reduction role, and at the same time, the polyurethane is a closed-cell type with good waterproof and oil-proof properties, which protects the steel spring and increases the service life of the spring isolator; on the other hand, the polyurethane is used as a damping material in the spring isolator, which can effectively reduce the vibration of the steel spring and the polyurethane material; in addition, the polyurethane material is used as an outer wrapping material and filled in the lower base, which can effectively limit the lateral displacement of the steel spring; thereby completing the present invention.

[0007] Specifically, the object of the present invention is to provide a polyurethane spring isolator for rail transit, which includes, from top to bottom, a locking plate 1, a height adjustment gasket 2, an upper cover plate 3, a polyurethane spring 5 and a lower base 7;

[0008] The polyurethane spring 5 includes a steel spring 51 and a high-strength polyurethane elastomer wrapped outside the steel spring 51.

[0009] The top of the polyurethane spring 5 abuts against the upper cover plate 3, and the bottom of the polyurethane spring 5 abuts against the lower base 7;

[0010] The high-strength polyurethane elastomer fills the space between the upper cover plate 3 and the lower base 7 .

[0011] Wherein, the high-strength polyurethane elastomer is a closed-cell polyurethane elastomer.

[0012] The height of the polyurethane spring isolator is adjusted by adjusting the number and specifications of the height-adjusting pads 2, wherein the height-adjusting pads 2 have a variety of sizes and specifications, and the height of the polyurethane spring isolator is adjusted by setting the number and specifications of the height-adjusting pads 2;

[0013] Preferably, the thickness specifications of the height adjustment pad 2 include five types: 1mm, 2mm, 5mm, 10mm, and 14mm.

[0014] The vibration isolator further comprises a vertically arranged locking bolt 8, through which the locking plate 1, the height adjustment pad 2 and the upper cover plate 3 are connected as a whole.

[0015] A cylindrical upper baffle 31 is vertically arranged below the upper cover plate 3.

[0016] A cylindrical lower baffle 71 is vertically arranged above the lower base 7;

[0017] A rubber sealing ring 4 is connected between the upper baffle plate 31 and the lower baffle plate 71;

[0018] Preferably, the rubber sealing ring 4 is fixed to the upper baffle plate 31 and the lower baffle plate 71 through a sealing hoop 6 , thereby sealing the polyurethane spring 5 .

[0019] The bottom of the lower base 7 is provided with an inwardly recessed groove 72.

[0020] A horizontal limiter 9 is provided below the lower base 7 , and the horizontal limiter 9 is embedded into the slot 72 to provide horizontal limitation for the vibration isolator.

[0021] The present invention also provides a method for preparing a polyurethane spring isolator for rail transit, the method comprising the following steps:

[0022] Step 1, mixing polyol, isocyanate and catalyst to obtain a prepolymer, placing a steel spring in a mold, and then adding the prepolymer into the mold and performing a chain extension reaction to obtain a polyurethane spring 5;

[0023] Step 2, place the polyurethane spring 5 between the upper cover plate 3 and the lower base 7, and then install the sealing sleeve 6 and the rubber sealing ring 4;

[0024] Step 3, select the number and specifications of the height adjustment gaskets according to the required height of the vibration isolator installation position, and connect the locking plate 1, the height adjustment gasket 2 and the upper cover plate 3 into a whole through the locking bolts 8.

[0025] The beneficial effects of the present invention include:

[0026] (1) The polyurethane spring isolator for rail transit provided by the present invention, wherein the polyurethane spring is integrally formed by casting polyurethane and steel spring, i.e., a structural form in which the steel spring is wrapped in polyurethane, can effectively prevent the occurrence of spring failure caused by the external environment (such as immersion in water, etc.), thereby increasing the service life of the spring isolator; in addition, it can also effectively limit the lateral displacement of the steel spring;

[0027] (2) The polyurethane spring isolator for rail transit provided by the present invention, wherein polyurethane is used as a damping material in the spring isolator, which can effectively reduce the vibration of the steel spring and the polyurethane material;

[0028] (3) The number and specifications of the height-adjusting gaskets on the polyurethane spring isolator for rail transit provided by the present invention can be adjusted as needed to meet the requirements of different working conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1The overall structural schematic diagram of the polyurethane spring isolator for rail transit of the present application is shown;

[0030] Figure 2 A top view showing the overall structure of the polyurethane spring isolator for rail transit of the present application;

[0031] Figure 3 An exploded view of the polyurethane spring isolator for rail transit of the present application is shown;

[0032] Figure 4 A schematic diagram showing a height adjustment gasket in a polyurethane spring isolator for rail transit of the present application;

[0033] Figure 5 A schematic diagram of a locking plate in a polyurethane spring isolator for rail transit of the present application is shown.

[0034] Description of Figure Numbers:

[0035] 1-Locking plate

[0036] 2-Heightening spacer

[0037] 3-Upper cover

[0038] 31-Upper baffle

[0039] 4-Rubber sealing ring

[0040] 5-Polyurethane spring

[0041] 51-Steel Spring

[0042] 52-High strength polyurethane

[0043] 6-Sealing ferrule

[0044] 7- Lower base

[0045] 71-Lower baffle

[0046] 72-Slot

[0047] 8-Locking bolt

[0048] 9-Horizontal stopper DETAILED DESCRIPTION

[0049] The present invention is further described in detail below by the accompanying drawings and examples. Through these descriptions, the characteristics and advantages of the present invention will become clearer and more specific. Wherein, although various aspects of the embodiments are shown in the accompanying drawings, the drawings need not be drawn to scale unless otherwise specified.

[0050] The present invention provides a polyurethane spring isolator for rail transit, such as Figure 1 , Figure 2 and Figure 3As shown in , the vibration isolator includes a locking plate 1, a height adjustment gasket 2, an upper cover plate 3, a polyurethane spring 5 and a lower base 7 from top to bottom;

[0051] The polyurethane spring 5 includes a steel spring 51 and a high-strength polyurethane elastomer wrapped around the outside and bottom of the steel spring 51.

[0052] In a preferred embodiment, a high-strength polyurethane elastomer is filled at the bottom of the steel spring 51 , and the height is not less than one third of the polyurethane spring 5 .

[0053] The steel spring 51 is filled with high-strength polyurethane elastomer on the outside, and the top of the steel spring 51 and the top of the high-strength polyurethane elastomer 52 are both in contact with the upper cover plate 3 .

[0054] The external high-strength polyurethane elastomer and the steel spring 51 jointly bear the force to reduce spring deformation.

[0055] The high-strength polyurethane elastomer at the bottom in contact with the steel spring plays a damping role in slowing down the vibration of the spring, and converts the kinetic energy of the spring into heat energy inside the polyurethane.

[0056] The steel spring 51 and the high-strength polyurethane elastomer 52 are integrally formed by casting technology. The steel spring 51 is located at the center of the polyurethane spring 5, and its height is less than that of the polyurethane spring 5, that is, a predetermined gap is left between the bottom and the lower base 7.

[0057] The steel spring 51 is fixed flush with the top surface of the mold, the mold is erected outside the steel spring, and the mold is fixed inside the steel spring 51 to ensure the height of the polyurethane when the bottom is poured.

[0058] Preferably, the steel spring 51 is made of 51CrV4, has a diameter of 20 to 40 mm, and a height of 40 to 150 mm. The pitch of the steel spring 51 is 20 to 40 mm.

[0059] Furthermore, the top and bottom ends of the steel spring 51 are both cut and ground to prevent the polyurethane from being punctured when the steel spring 51 is deformed.

[0060] In a preferred embodiment, the top of the polyurethane spring 5 abuts against the upper cover plate 3, and the bottom of the polyurethane spring 5 abuts against the lower base 7; that is, the polyurethane spring 5 bears the force between the upper cover plate 3 and the lower base 7, thereby providing buffering and vibration reduction for the force transmitted from the upper cover plate 3 to the lower base 7.

[0061] The high-strength polyurethane elastomer fills the space between the upper cover plate 3 and the lower base 7 to ensure sufficient buffering and vibration reduction effect. The polyurethane spring 5 is cylindrical, with a height of 100-200 mm and a diameter of 100-200 mm.

[0062] Preferably, the high-strength polyurethane elastomer is a closed-cell polyurethane elastomer, so as to achieve a vibration reduction effect by compressing the internal foaming voids. The closed-cell polyurethane elastomer in this application can have a variety of optional models, and the model that can meet the preparation method below can meet the performance requirements of this application.

[0063] Preferably, the height of the polyurethane spring isolator is adjusted by adjusting the number and specifications of the height-adjusting pads 2, wherein the height-adjusting pads 2 have a variety of sizes and specifications, and the height of the polyurethane spring isolator is adjusted by setting the number and specifications of the height-adjusting pads 2;

[0064] Preferably, the thickness specifications of the height adjustment pad 2 include five types: 1mm, 2mm, 5mm, 10mm, and 14mm.

[0065] Preferably, the vibration isolator further comprises a vertically arranged locking bolt 8, through which the locking plate 1, the height-adjusting pad 2 and the upper cover plate 3 are connected as a whole.

[0066] Preferably, if Figure 3 , Figure 4 and Figure 5 As shown in , the locking plate and the height-adjusting gasket have the same shape. The locking plate and the height-adjusting gasket are hexagonal, hollow in the middle, and have three semicircular notches for fixing with locking bolts 8.

[0067] In this application, the upper cover plate and the lower base are both made of steel plates; the height-adjusting gasket and the locking plate are both made of steel, and the surfaces of the height-adjusting gasket, the locking plate, the upper cover plate and the lower cover plate are all treated with hot-dip galvanizing process.

[0068] In a preferred embodiment, a cylindrical upper baffle 31 is vertically arranged below the upper cover plate 3.

[0069] A cylindrical lower baffle 71 is vertically arranged above the lower base 7;

[0070] A rubber sealing ring 4 is connected between the upper baffle plate 31 and the lower baffle plate 71;

[0071] Preferably, the rubber sealing ring 4 is fixed to the upper baffle plate 31 and the lower baffle plate 71 through a sealing hoop 6 , thereby sealing the polyurethane spring 5 .

[0072] Preferably, a groove 72 recessed inwardly is provided at the bottom of the lower base 7.

[0073] A horizontal limiter 9 is provided below the lower base 7, and the vibration isolator is provided with horizontal limit by embedding the horizontal limiter 9 into the slot 72. The horizontal limiter 9 is made of aluminum alloy 6061.

[0074] The present invention also provides a method for preparing a polyurethane spring isolator for rail transit, the method comprising the following steps:

[0075] Step 1, mixing polyol, isocyanate and catalyst to obtain a prepolymer, placing a steel spring in a mold, and then adding the prepolymer into the mold and performing a chain extension reaction to obtain a polyurethane spring 5;

[0076] Step 2, place the polyurethane spring 5 between the upper cover plate 3 and the lower base 7, and then install the sealing sleeve 6 and the rubber sealing ring 4;

[0077] Step 3, select the number and specifications of the height adjustment gaskets according to the required height of the vibration isolator installation position, and connect the locking plate 1, the height adjustment gasket 2 and the upper cover plate 3 into a whole through the locking bolts 8.

[0078] Preferably, the polyol is one or a combination of more than one of polyether polyol, polyester polyol, polycarbonate polyol and polycaprolactone polyol;

[0079] The isocyanate is isophorone diisocyanate (IPDI) or dicyclohexylmethane diisocyanate (HMDI);

[0080] The catalyst is dibutyltin dilaurate.

[0081] Preferably, in step 1, under nitrogen protection, the dehydrated polyol, isocyanate and catalyst are mixed uniformly, reacted at 20-100° C. for 1-6 hours, and stirred at 50-300 rpm to obtain a prepolymer;

[0082] The ratio of polyol to isocyanate is 1:2 to 1:10; the water content of the polyol is less than 0.05%; the amount of the catalyst is 0% to 1% of the total mass of all raw materials, preferably 0.1wt%;

[0083] The inner diameter of the mold is consistent with the outer diameter of the polyurethane spring.

[0084] Preferably, the prepolymer is mixed with a diamine or diol chain extender at 45°C in a mold, and then the temperature is raised to 70°C for a chain extension reaction for 2 to 5 hours to obtain the polyurethane spring 5.

[0085] Example

[0086] Under nitrogen protection, the dehydrated polyol, isocyanate and catalyst were mixed evenly, reacted at 85°C for 5 hours with a stirring speed of 200 rpm to obtain a prepolymer;

[0087] Among them, the ratio of polyol to isocyanate is 1:5;

[0088] The water content of the polyol is less than 0.05%;

[0089] The amount of the catalyst is 0.3% of the total mass of all raw materials;

[0090] The polyol is a polyether polyol;

[0091] The isocyanate is isophorone diisocyanate (IPDI);

[0092] The catalyst is dibutyltin dilaurate;

[0093] The prepolymer and the diamine or diol chain extender are mixed in a mold at 45°C, and then the temperature is raised to 70°C for chain extension reaction for 4 hours to obtain a polyurethane spring 5, wherein the mold is cylindrical, 153 mm in height and 170 mm in diameter. Before adding the prepolymer to the mold, a steel spring with a spring wire diameter of 30 mm, a height of 130 mm and a pitch of 30 mm is added to the mold.

[0094] Place the polyurethane spring 5 between the upper cover plate 3 and the lower base 7, and then install the sealing sleeve 6 and the rubber sealing ring 4;

[0095] The locking plate 1, a height-adjusting pad 2 and the upper cover plate 3 are then connected as a whole through the locking bolts 8 to obtain a polyurethane spring vibration isolator for rail transit.

[0096] The following three tests were performed on the polyurethane spring isolator for rail transit.

[0097] Test 1: vertical static stiffness test;

[0098] First, preload the isolator twice, the preload speed is 2kN / s, the A load is 26kN, the B load is 46kN, the preload is to the B load, and it is maintained for 20s, and then maintained for another 20s after unloading. At the beginning of the test, the speed is uniformly loaded at 2kN / s to 13kN, 20kN, 26kN, 33.7kN, 41.4kN, and 46kN, and each stays for 20s. At the same time, the compression of the sample during loading is recorded (the compression is the average of the four dial gauge readings), and it is maintained for 20s after unloading and reloaded. Repeat this 3 times, and take the average of the 3 compressions, which is the average compression of the sample under A load and B load. Among them, the data of static load and compression are as follows:

[0099]

[0100]

[0101] According to the static stiffness K formula:

[0102] Where: X B Compression of the specimen when loaded with load B (mm)

[0103] X A Compression of the specimen when loaded with load A (mm)

[0104] The static stiffness values ​​of the test samples are shown in the following table:

[0105]

[0106] The measured static stiffness value is 6.21 kN / mm, which deviates from the designed static stiffness of 6.6 kN / mm by -5.9%, meeting the design allowable deviation requirement of ±10%.

[0107] Test 2: Dynamic detection test;

[0108] Install the vibration isolator on the testing machine and apply F 1 (10kN)~F 2 The load is applied to the center of the vibration isolator with a cyclic load of 60 kN, a loading frequency of 3 to 5 Hz, and 1000 load cycles. The last 100 load cycles are recorded and the actual load F applied in 10 consecutive cycles is selected. 1a 、F 2a and displacement of the loaded steel plate D 1a , D 2a (All are average values ​​of 3 displacement sensors). The dynamic load and displacement data are as follows:

[0109]

[0110] According to the dynamic stiffness formula:

[0111] Calculate the dynamic-static ratio at 4 Hz frequency according to the formula:

[0112] The dynamic stiffness of the test sample is 7.64kN / mm, and the dynamic-static stiffness ratio is 1.23, which meets the specification requirement of a dynamic-static ratio of less than 1.3.

[0113] Test three: fatigue test;

[0114] The vibration isolator is placed in a hydraulic fatigue testing machine, and the changes in performance parameters under long-term reciprocating loads within a certain range are measured to evaluate its durability.

[0115] Among them, the fatigue test load of a single vibration isolator is 26~68kN, the loading frequency is 4Hz, the number of load cycles is 5 million times, and the changes in the performance parameters of the vibration isolator are as follows:

[0116] Among them, the height of the isolator before the fatigue test was 198.04mm, and after 5 million fatigue tests, the height was 198.15mm, and the deformation was 0.11mm, which met the requirement of vertical permanent deformation less than 1mm.

[0117] Among them, after the vibration isolator underwent 5 million fatigue tests, the static stiffness was retested according to the static stiffness test process and requirements, and was 6.14kN / mm, with a deviation of -7.0% from the designed static stiffness of 6.6kN / mm, meeting the design allowable deviation requirement of ±10%.

[0118] Among them, the static stiffness changes by -1.1% compared with that before the fatigue test, which meets the requirement that the static stiffness change rate is less than ±5%.

[0119] Comparative Example 1

[0120] A rail transit rubber spring isolator similar to that in the embodiment is provided, the only difference being that the high-strength polyurethane elastomer 51 in the polyurethane spring 5 is replaced with rubber, and the polyurethane spring 52 is replaced with a steel plate, the specific model being TY / 340.

[0121] The following three tests were performed on the polyurethane spring isolator for rail transit.

[0122] Test 1: static stiffness test;

[0123] First, preload the isolator twice, the preload speed is 2kN / s, the A load is 26kN, the B load is 46kN, the preload is to the B load, and it is maintained for 20s, and then maintained for another 20s after unloading. At the beginning of the test, the speed is uniformly loaded at 2kN / s to 13kN, 20kN, 26kN, 33.7kN, 41.4kN, and 46kN, and each stays for 20s. At the same time, the compression of the sample during loading is recorded (the compression is the average of the four dial gauge readings), and it is maintained for 20s after unloading and reloaded. Repeat this 3 times, and take the average of the 3 compressions, which is the average compression of the sample under A load and B load. Among them, the data of static load and compression are as follows:

[0124]

[0125] According to the static stiffness K formula:

[0126] Where: X B Compression of the specimen when loaded with load B (mm)

[0127] X A Compression of the specimen when loaded with load A (mm)

[0128] The static stiffness values ​​of the test samples are shown in the following table:

[0129]

[0130] The measured static stiffness value is 7.44 kN / mm, which deviates from the designed static stiffness of 7.0 kN / mm by +6.2%, meeting the design allowable deviation requirement of ±10%, but is greater than the static stiffness deviation in the embodiment.

[0131] Test 2: Dynamic test;

[0132] Install the vibration isolator on the testing machine and apply F 1 (10kN)~F 2 The load is applied to the center of the vibration isolator with a cyclic load of 60 kN, a loading frequency of 3 to 5 Hz, and 1000 load cycles. The last 100 load cycles are recorded and the actual load F applied in 10 consecutive cycles is selected. 1a 、F 2a and displacement of the loaded steel plate D 1a , D 2a (All are average values ​​of 3 displacement sensors). The dynamic load and displacement data are as follows:

[0133]

[0134] According to the dynamic stiffness formula:

[0135] Calculate the dynamic-static ratio at 4 Hz frequency according to the formula:

[0136] The dynamic stiffness of the test sample is 9.37 kN / mm, and the dynamic-static stiffness ratio is 1.26, which meets the requirement of the specification that the dynamic-static ratio is less than 1.3, but is greater than the dynamic-static stiffness ratio in the embodiment.

[0137] Test three: fatigue test;

[0138] The vibration isolator is placed in a hydraulic fatigue testing machine, and the changes in performance parameters under long-term reciprocating loads within a certain range are measured to evaluate its durability.

[0139] Among them, the fatigue test load of a single vibration isolator is 26~68kN, the loading frequency is 4Hz, the number of load cycles is 5 million times, and the changes in the performance parameters of the vibration isolator are as follows:

[0140] Among them, the height of the vibration isolator before the fatigue test was 89.97 mm, and the height after 5 million fatigue tests was 89.32 mm, and the deformation was 0.65 mm, which met the requirement of permanent deformation less than 1 mm, but was greater than the deformation in the embodiment.

[0141] Among them, after the vibration isolator has undergone 5 million fatigue tests, the static stiffness is retested to be 7.61kN / mm according to the static stiffness test process and requirements, which deviates from the designed static stiffness of 7.0kN / mm by +8.7%, meeting the design allowable deviation requirement of ±10%, but is greater than the deviation in the embodiment.

[0142] The static stiffness changes by -2.3% compared with the static stiffness before the fatigue test, which meets the requirement that the static stiffness change rate is less than ±5%, but is greater than the static stiffness change rate in the embodiment.

[0143] Comparative Example 2

[0144] A rail transit steel spring isolator similar to that in the embodiment is provided, except that the high-strength polyurethane elastomer 52 in the polyurethane spring 5 is replaced with a damping fluid, and the specific model is GZQ-R71V-345

[0145] The following two tests are performed on the steel spring isolator for rail transit.

[0146] Test 1: static stiffness test;

[0147] First, preload the vibration isolator twice, the preload speed is 2-3kN / s, the A load is 26kN, the B load is 46kN, the preload is to the B load, and it is maintained for 20s, and then maintained for another 20s after unloading. At the beginning of the test, the speed is uniformly loaded at 2kN / s to 13kN, 20kN, 26kN, 33.7kN, 41.4kN, and 46kN, and each stays for 20s. At the same time, the compression of the sample during loading is recorded (the compression is the average of the four dial gauge readings), and it is maintained for 20s after unloading and reloaded. Repeat this 3 times, and take the average of the 3 compressions, which is the average compression of the sample under A load and B load. Among them, the data of static load and compression are as follows:

[0148]

[0149] According to the static stiffness K formula:

[0150] Where: X B Compression of the specimen when loaded with load B (mm)

[0151] X A Compression of the specimen when loaded with load A (mm)

[0152] The static stiffness values ​​of the test samples are shown in the following table:

[0153]

[0154] The measured static stiffness value is 7.29 kN / mm, which deviates from the designed static stiffness of 6.6 kN / mm by +9.5%, meeting the design allowable deviation requirement of ±10%, but is greater than the static stiffness deviation in the embodiment.

[0155] Test 2: Fatigue test;

[0156] The vibration isolator is placed in a hydraulic fatigue testing machine, and the changes in performance parameters under long-term reciprocating loads within a certain range are measured to evaluate its durability.

[0157] Among them, the fatigue test load of a single vibration isolator is 26~68kN, the loading frequency is 4Hz, the number of load cycles is 5 million times, and the changes in the performance parameters of the vibration isolator are as follows:

[0158] Among them, the height of the vibration isolator before the fatigue test was 289.64mm, and the height was 290.05mm after 5 million fatigue tests, and the deformation was 0.41mm, which met the requirement of deformation less than 2mm, but was greater than the deformation change in the embodiment.

[0159] Among them, after the vibration isolator underwent 5 million fatigue tests, the static stiffness was retested to be 7.02kN / mm according to the static stiffness test process and requirements. The deviation from the designed static stiffness of 6.6kN / mm was +5.4%, which met the design allowable deviation requirement of ±10%.

[0160] Among them, the static stiffness changes by -3.7% compared with the static stiffness before the fatigue test, which meets the requirement that the static stiffness change rate is less than ±5%, but is greater than the static stiffness change in the embodiment.

[0161] The present invention has been described above in conjunction with preferred embodiments, but these embodiments are only exemplary and serve only as an illustration. On this basis, the present invention may be subjected to a variety of substitutions and improvements, all of which fall within the scope of protection of the present invention.

Claims

1. A polyurethane spring isolator for rail transit, characterized in that: The vibration isolator comprises, from top to bottom, a locking plate (1), a height-adjusting gasket (2), an upper cover plate (3), a polyurethane spring (5) and a lower base (7); The polyurethane spring (5) comprises a steel spring (51) and a high-strength polyurethane elastomer (52) wrapped around the steel spring.

2. The polyurethane spring isolator for rail transit according to claim 1, characterized in that: The top of the polyurethane spring (5) abuts against the upper cover plate (3), and the bottom of the polyurethane spring (5) abuts against the lower base (7); The high-strength polyurethane elastomer completely fills the space between the upper cover plate (3) and the lower base (7).

3. The polyurethane spring isolator for rail transit according to claim 1, characterized in that: The high-strength polyurethane elastomer is a closed-cell polyurethane elastomer.

4. The polyurethane spring isolator for rail transit according to claim 1, characterized in that: The height of the polyurethane spring vibration isolator is adjusted by adjusting the number and specifications of the height-adjusting pads (2); the height-adjusting pads (2) have a variety of sizes and specifications; and the height of the polyurethane spring vibration isolator is adjusted by setting the number and specifications of the height-adjusting pads (2); Preferably, the thickness dimensions of the height-adjusting pad (2) include five types: 1 mm, 2 mm, 5 mm, 10 mm, and 14 mm.

5. The polyurethane spring isolator for rail transit according to claim 1, characterized in that: The vibration isolator also includes a vertically arranged locking bolt (8), through which the locking plate (1), the height adjustment pad (2) and the upper cover plate (3) are connected into a whole.

6. The polyurethane spring isolator for rail transit according to claim 1, characterized in that: A cylindrical upper baffle (31) is vertically arranged below the upper cover plate (3). A cylindrical lower baffle (71) is vertically arranged above the lower base (7); A rubber sealing ring (4) is connected between the upper baffle plate (31) and the lower baffle plate (71); Preferably, the rubber sealing ring (4) is fixed to the upper baffle (31) and the lower baffle (71) via a sealing sleeve (6), thereby sealing the polyurethane spring (5).

7. The polyurethane spring isolator for rail transit according to claim 1, characterized in that: An inwardly recessed groove (72) is provided at the bottom of the lower base (7). A horizontal limiter (9) is arranged below the lower base (7), and horizontal limit is provided for the vibration isolator by embedding the horizontal limiter (9) into the slot (72).

8. A method for preparing a polyurethane spring isolator for rail transit, characterized in that: The method comprises the following steps: Step 1, mixing polyol, isocyanate and catalyst to obtain a prepolymer, placing a steel spring in a mold, and then adding the prepolymer into the mold and performing a chain extension reaction to obtain a polyurethane spring (5); Step 2, placing the polyurethane spring (5) between the upper cover (3) and the lower base (7), and then installing the sealing hoop (6) and the rubber sealing ring (4); Step 3, selecting the number and specifications of the height-adjusting gaskets according to the required height of the vibration isolator installation position, and connecting the locking plate (1), the height-adjusting gasket (2) and the upper cover plate (3) into a whole through the locking bolts (8).

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