A method for manufacturing a high-pressure rubber bladder

Abstract

The application provides a preparation method of a high-pressure rubber capsule, and specifically comprises the following steps: Step 1, preparing an inner container; Step 2, preparing a lower mold plate of a mold, laying a capsule wall on the lower mold plate; Step 3, placing the inner container on the capsule wall, wrapping the side surface and the upper surface of the inner container with the capsule wall to form a raw material block, and embedding a steel pipe outside the side surface of the inner container; Step 4, covering an upper mold plate of the mold on the raw material block; Step 5, vulcanizing the raw material block together with the mold; Step 6, installing a valve on the embedded steel pipe; Step 7, inflating the rubber capsule by using the valve, and testing the strength of the rubber capsule. After the inner part of the rubber capsule prepared by the method is filled with water, the rubber capsule can be used for a surface impact load loading test, the test difficulty is reduced, the safety risk is low, and the test error is small. The method has the advantages of simple manufacturing process and low cost.

Description

Technical Field

[0001] This invention relates to the field of surface load testing equipment and facilities, and in particular to a method for preparing a high-pressure rubber bladder. Background Technology

[0002] There are two loading methods for testing the impact resistance of load-bearing components: static load and dynamic load. When using the static load method, the external force borne by the component does not change with time, and it cannot accurately reflect the impact resistance of the component. Therefore, it is necessary to carry out research on the application method of dynamic load.

[0003] Based on the ratio between the load application surface and the working surface of the component, dynamic loads can be divided into two types: concentrated loads and uniformly distributed loads, also known as surface impact loads. Surface impact loads are mainly tested using explosive methods, such as in equipment explosion resistance tests. However, this method has many problems, including high testing difficulty, numerous limitations, and significant safety risks, making it difficult to widely apply.

[0004] Therefore, there is a need for a method to prepare a high-pressure rubber bladder that can convert concentrated loads into uniformly distributed loads. Summary of the Invention

[0005] The purpose of this invention is to provide a method for preparing a high-pressure rubber bladder. The rubber bladder prepared by this method can be used for surface impact load testing. This method is simple to manufacture, low in cost, reduces the difficulty of testing, has low safety risks, and small test errors.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] 1. A method for preparing a high-pressure rubber bladder, characterized in that the preparation method specifically includes the following steps:

[0008] Step 1, Prepare the inner liner;

[0009] Step 2: Prepare the lower mold template, and lay the capsule wall on the lower mold template. The capsule wall includes multiple layers of adhesive material and multiple layers of reinforcing fabric arranged at intervals.

[0010] Step 3: Place the inner liner on top of the capsule wall, and use the capsule wall to wrap the sides and top surface of the inner liner to form a raw material block.

[0011] During the process of wrapping the sides of the inner liner, steel pipes are pre-embedded on the outside of the sides of the inner liner.

[0012] Step 4: Cover the raw material block with the upper template of the mold;

[0013] Step 5: Vulcanize the raw material block together with the mold to obtain a rubber bladder;

[0014] Step 6: After vulcanization is complete, remove the rubber bladder and install the valve on the pre-embedded steel pipe;

[0015] Step 7: Inflate the rubber bladder using the valve and test the strength of the rubber bladder.

[0016] Furthermore, in the above-mentioned method for preparing the high-pressure rubber bladder, in step 1, gypsum board is cut according to the size of the cavity inside the rubber bladder, the cut gypsum board is stacked, the height of all the stacked gypsum board is equal to the height of the cavity inside the rubber bladder, and all the stacked gypsum board is wrapped with tape to form the inner liner; the thickness of the gypsum board is 10mm.

[0017] Furthermore, in the above-mentioned method for preparing a high-pressure rubber bladder, in step 2, the lower template contacts a layer of rubber material on the bladder wall, the inner liner contacts a layer of rubber material on the bladder wall, the thickness of each layer of rubber material is 3mm-5mm, the thickness of each layer of reinforcing fabric is 1mm, the area of ​​the reinforcing fabric is greater than the area of ​​the rubber material, the rubber material is EPDM rubber, the reinforcing fabric is aramid 1313, and the total thickness of the rubber material and the reinforcing fabric on the bladder wall is equal to the wall thickness of the rubber bladder.

[0018] Furthermore, in the above-mentioned method for preparing a high-pressure rubber bladder, in step 3, the upper surface and four sides of the inner bladder are wrapped layer by layer from the inside out using the rubber material and the reinforcing cloth of the bladder wall. After one layer of rubber material is wrapped, the inner bladder and rubber material are wrapped with the reinforcing cloth, and the joints of the reinforcing cloth are sewn together. Then the next layer of rubber material is wrapped, until the outermost layer of rubber material is wrapped.

[0019] Furthermore, in the above-mentioned method for preparing a high-pressure rubber bladder, in step 3, two steel pipes are provided, and the two steel pipes are respectively pre-embedded on two opposite sides of the inner bladder. The length of the steel pipe is greater than the wall thickness of the rubber bladder, one end of the steel pipe is in contact with the inner bladder, and the other end of the steel pipe is located on the outside of the rubber bladder.

[0020] Furthermore, in the above-mentioned method for preparing a high-pressure rubber bladder, in step 3, a wing ring is provided on the steel pipe, and the wing ring is vertically arranged inside the bladder wall.

[0021] Furthermore, in the above-mentioned method for preparing a high-pressure rubber bladder, in step 4, the upper template includes four side plates and a top plate. The four side plates cover the four sides of the raw material block, and the top plate covers the upper surface of the raw material block. The four side plates and the top plate are fixed by multiple screws.

[0022] Furthermore, in the above-mentioned method for preparing high-pressure rubber bladders, in step 5, the raw material block together with the mold is sent into a vulcanizing furnace for vulcanization at a temperature of 110±10℃ for a time of 12±0.5 hours.

[0023] Furthermore, in the above-mentioned method for preparing a high-pressure rubber bladder, in step 6, after vulcanization is completed, the mold is disassembled, water is injected into the rubber bladder using the steel pipe, the gypsum board is soaked and crushed into gypsum board fragments, and the gypsum board fragments inside the rubber bladder are flushed out with water.

[0024] Furthermore, in the above-described method for preparing a high-pressure rubber bladder, in step 7, the rubber bladder can withstand an inflation pressure greater than or equal to 1.2 MPa.

[0025] Analysis reveals that this invention discloses a method for preparing a high-pressure rubber bladder. After filling the interior of the rubber bladder prepared by this method with water, it can be used for surface impact load testing. The water-filled rubber bladder can transform the concentrated load of the upper hammer into a uniformly distributed load through the internal fluid. Moreover, when the area required for the uniformly distributed load varies, it can be achieved by preparing rubber bladders with different planar dimensions, reducing the difficulty of the test, minimizing safety risks, and reducing test errors. This method is simple to manufacture and has low cost. Attached Figure Description

[0026] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. Wherein:

[0027] Figure 1 This is a schematic diagram of the structure of a gypsum board according to an embodiment of the present invention.

[0028] Figure 2 This is a schematic diagram of the structure of the lower template according to an embodiment of the present invention.

[0029] Figure 3 This is a schematic diagram of the inner liner of an embodiment of the present invention.

[0030] Figure 4 This is a schematic diagram of a structure for laying a bladder wall on a lower template according to an embodiment of the present invention.

[0031] Figure 5This is a schematic diagram of the structure of the inner liner when a layer of adhesive is wrapped around the upper surface and side surface of the inner liner according to an embodiment of the present invention.

[0032] Figure 6 This is a schematic diagram of the structure after the inner bladder is completely enclosed by the bladder wall according to an embodiment of the present invention.

[0033] Figure 7 This is a schematic diagram of the structure of a raw material block after it is placed into a mold according to an embodiment of the present invention.

[0034] Figure 8 This is a schematic diagram of the assembly of a steel pipe and a wing ring according to an embodiment of the present invention.

[0035] Figure 9 This is a graph showing the pressure and time borne by the rubber bladder when the upper hammer head is at a height of 0.3m in Embodiment 1 of the present invention.

[0036] Figure 10 This is a graph showing the pressure and time borne by the rubber bladder when the upper hammer head is at a height of 0.5m in Embodiment 1 of the present invention.

[0037] Explanation of reference numerals in the attached drawings: 1. Gypsum board; 2. Inner liner; 3. Adhesive; 4. Reinforcing fabric; 5. Lower template; 6. Side plate; 7. Steel pipe; 8. Wing ring; 9. Raw material block; 10. Top plate. Detailed Implementation

[0038] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. Various examples are provided by way of explanation and not by way of limitation. Indeed, those skilled in the art will recognize that modifications and variations can be made to the invention without departing from its scope or spirit. For example, a feature shown or described as part of one embodiment may be used in another embodiment to produce yet another embodiment. Therefore, it is desirable that the invention encompass such modifications and variations falling within the scope of the appended claims and their equivalents.

[0039] In the description of this invention, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," and "bottom," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and do not require the invention to be constructed and operated in a specific orientation; therefore, they should not be construed as limitations on the invention. The terms "connected," "linked," and "set up" used in this invention should be interpreted broadly. For example, they can refer to a fixed connection or a detachable connection; a direct connection or an indirect connection through intermediate components; a wired connection, a radio connection, or a wireless communication signal connection. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0040] The accompanying drawings illustrate one or more examples of the invention. The detailed description uses numerals and letters to refer to features in the drawings. Similar or analogous reference numerals in the drawings and description have been used to refer to similar or analogous parts of the invention. As used herein, the terms “first,” “second,” and “third,” etc., are used interchangeably to distinguish one component from another and are not intended to indicate the location or importance of individual components.

[0041] like Figures 1 to 10 As shown in the embodiment of the present invention, a method for preparing a high-pressure rubber bladder is provided, the method specifically including the following steps:

[0042] Step 1, prepare the inner liner 2.

[0043] like Figure 1 As shown, a 10mm thick gypsum board 1 is cut according to the dimensions of the cavity inside the rubber bladder, as follows: Figure 3 As shown, the cut plasterboard 1 is stacked, and the height of all the stacked plasterboard 1 is equal to the height of the cavity inside the rubber bladder. All the stacked plasterboard 1 are then wrapped with tape to form the inner liner 2. The inner liner 2 made of plasterboard 1 can be broken and flushed out of the rubber bladder in subsequent steps by soaking in water, thus forming a cavity inside the rubber bladder. The manufacturing method is simple and low in cost.

[0044] Step 2, prepare the lower mold plate 5, as shown in the figure. Figure 2 As shown, Figure 4 As shown, the bladder wall is laid on the lower template 5. The bladder wall consists of multiple layers of rubber material 3 and multiple layers of reinforcing fabric 4 spaced apart. The lower template 5 is in contact with one layer of rubber material 3 of the bladder wall, and the inner liner 2 is in contact with one layer of rubber material 3 of the bladder wall. The thickness of each layer of rubber material 3 is 3mm-5mm (e.g., 3mm, 3.2mm, 3.4mm, 3.6mm, 3.8mm, 4mm, 4.2mm, 4.4mm, 4.6mm, 4.8mm, 5mm), and the thickness of each layer of reinforcing fabric 4 is 1mm. The area of ​​the reinforcing fabric 4 is larger than that of the rubber material 3 to facilitate sewing of the reinforcing fabric 4 in subsequent processes. The rubber material 3 is EPDM rubber, and the reinforcing fabric 4 is aramid 1313 (hexagonal mesh high-temperature resistant reinforced aramid base fabric). The total thickness of the rubber material 3 and the reinforcing fabric 4 of the bladder wall is equal to the wall thickness of the rubber bladder.

[0045] Place the lower template 5 on an open surface. Lay the first layer of rubber compound 3 on the lower template 5, and then lay a reinforcing fabric 4 on top of the rubber compound 3, ensuring the area of ​​the reinforcing fabric 4 is larger than the area of ​​the rubber compound 3. Then, lay a second layer of rubber compound 3 on top of the reinforcing fabric 4, and repeat this process with another layer of reinforcing fabric 4. The rubber compound 3 and reinforcing fabric 4 are laid alternately until the total thickness of the rubber compound 3 and reinforcing fabric 4 meets the wall thickness requirement of the rubber bladder. The thickness of each layer of rubber compound 3 and the number of layers of rubber compound 3 and reinforcing fabric 4 are determined based on the wall thickness of the rubber bladder. For example, if the wall thickness of the rubber bladder is 10mm, then a 3mm thick rubber compound 3 is selected, and a total of 3 layers of rubber compound 3 and 2 layers of reinforcing fabric 4 are laid to meet the required wall thickness of the rubber bladder.

[0046] Step 3, as follows Figure 5 As shown, the inner liner 2 is placed on top of the capsule wall, and the capsule wall wraps around the sides and top surface of the inner liner 2 to form the raw material block 9. During the wrapping of the sides of the inner liner 2, steel pipes 7 are pre-embedded on the outside of the sides of the inner liner 2.

[0047] like Figure 6 As shown, the inner liner 2 is wrapped in layers of adhesive material 3 and reinforcing cloth 4 from the inside out. After one layer of adhesive material 3 is wrapped, the inner liner 2 and adhesive material 3 are wrapped with reinforcing cloth 4, and the joints of reinforcing cloth 4 are sewn together. Then the next layer of adhesive material 3 is wrapped until the outermost layer of adhesive material 3 is wrapped.

[0048] Preferably, two steel pipes 7 are provided, which are pre-embedded on two opposite sides of the inner liner 2. The length of the steel pipe 7 is greater than the wall thickness of the rubber bladder. One end of the steel pipe 7 contacts the inner liner 2, and the other end is located on the outside of the rubber bladder. One steel pipe 7 is used to inflate or fill the rubber bladder with air, and the other steel pipe 7 is used to vent or drain the rubber bladder, facilitating the reuse of the rubber bladder.

[0049] Preferably, such as Figure 8 As shown, a wing ring 8 is provided on the steel pipe 7. The wing ring 8 is vertically set inside the bladder wall. The wing ring 8 can improve the connection strength between the steel pipe 7 and the rubber bladder and prevent the steel pipe 7 from slipping out of the rubber bladder under pressure during the inflation or water injection process.

[0050] Step 4, as follows Figure 7 As shown, the upper mold plate is placed over the raw material block 9. The upper mold plate includes four side plates 6 and a top plate 10. The four side plates 6 cover the four sides of the raw material block 9, and the top plate 10 covers the upper surface of the raw material block 9. The four side plates 6 and the top plate 10 are fixed by multiple screws. The inner cavity formed by the four side plates 6 and the top plate 10 is consistent with the shape of the rubber bladder, and the raw material block 9 is in close contact with the surrounding mold.

[0051] Step 5: Vulcanize the raw material block 9 together with the mold to obtain a rubber bag. Put the raw material block 9 together with the mold into a vulcanizing furnace for vulcanization. The vulcanization temperature is 110±10℃ and the time is 12±0.5 hours.

[0052] Step 6: After vulcanization is complete, remove the rubber bladder and install the valve on the pre-embedded steel pipe 7.

[0053] After vulcanization, the mold is disassembled, and water is injected into the rubber bladder through steel pipe 7 to soak and break the gypsum board 1 into fragments. These fragments are then flushed out of the rubber bladder with water. Valves are then installed on both steel pipes 7. During the test, the rubber bladder is inflated with air or water to create high pressure inside. The pressure inside the rubber bladder is controlled by the valves, ensuring controllable pressure and improving safety during the test.

[0054] Step 7: Inflate the rubber bladder using the valve and test its strength.

[0055] The rubber bladder prepared using the above method can withstand an inflation pressure greater than or equal to 1.2 MPa.

[0056] The high-pressure rubber bladder prepared by the above method can transform the concentrated load of the upper hammer head into a uniformly distributed planar load through the internal fluid. Using the high-pressure rubber bladder for surface impact load loading tests has the advantages of high safety, small test error, and low test difficulty.

[0057] In one embodiment of the present invention, a rubber bladder with a suitable wall thickness is prepared according to the pressure requirements using the above method. The projected plane area of ​​the rubber bladder is 1.25m × 1.25m, the weight of the upper hammer m1 is 700kg, and the inside of the rubber bladder is filled with water, the weight of the water inside the rubber bladder m2 is 200kg.

[0058] A planar impact load test was conducted using a rubber bladder. The bladder was fixed to the specimen. When the upper hammer fell from a height of 0.3m above the top of the bladder, the falling time was calculated to be 0.247s according to t = (2h / g)¹ / ² (the test data was recorded using a data line for physical triggering, so the recorded pressure arrival time was slightly earlier than the falling time by about 0.07ms). Therefore, the velocity formula yielded v₁ as 2.426m / s. Figure 9 A graph showing the pressure and time experienced by the rubber bladder.

[0059] Assuming all constraints remain stationary, the vast majority of the potential energy of the upper hammer will be converted into the kinetic energy of the water. Based on the principle of equal impulse, the velocity along the vertical direction can be obtained as v1 = m1 × v1 / m. 2 = 8.491 m / s.

[0060] Because of the constraint of the test piece under the rubber bladder, the water's ability to move vertically is converted into pressure, which is calculated according to the following formula.

[0061] F = 1 / 2 × μ × ρ × v 2 ×A×Cd Formula 1

[0062] In Formula 1, ρ is the density of water, 1000 kg / m³. 3 v is the relative velocity (8.491 m / s), and A is the area of ​​the contact surface (1.25 m × 1.25 m = 1.563 m). 2 Cd is the drag coefficient of 0.6, and μ is the power amplification factor of 1.8.

[0063] The force exerted by the rubber bladder on the specimen in the vertical direction can be calculated using Formula 1 as 57.46 kN.

[0064] Finally, based on the pressure calculation formula P = F / A = 0.039 MPa, it can be similarly calculated that when the hammer falls from a height of 0.5 m, the pressure exerted by the rubber bladder on the specimen is 0.065 MPa. According to the definition that all pressures of water are equal, a planar impact load can be achieved using the rubber bladder.

[0065] The experimental results show that when the upper hammer falls from a height of 0.3m, the pressure exerted by the rubber bladder on the specimen is 0.041MPa, which is 1.051 times the theoretically calculated value; when the upper hammer falls from a height of 0.5m... Figure 10 The graph shows the pressure and time exerted by the rubber bladder. The pressure exerted by the rubber bladder on the specimen is 0.056 MPa, which is 0.861 times the theoretically calculated value. The error value does not exceed 15%, which meets the test requirements. Further theoretical calculations and experiments will be carried out to verify the results obtained from the test.

[0066] As can be seen from the above description, the embodiments of the present invention achieve the following technical effects:

[0067] A method for preparing a high-pressure rubber bladder is disclosed. After filling the interior of the prepared rubber bladder with water, it can be used for surface impact load tests. The water-filled bladder can transform the concentrated load of the upper hammer into a uniformly distributed load through the internal fluid. Furthermore, when different areas of the uniformly distributed load are required, rubber bladders with different planar dimensions can be prepared, reducing the difficulty of the test, minimizing safety risks, and reducing test errors. This method is simple to implement and low in cost.

[0068] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing a high-pressure rubber bladder, characterized in that, The preparation method specifically includes the following steps: Step 1: Prepare the inner liner. Cut the plasterboard according to the size of the cavity inside the rubber bladder. Stack the cut plasterboards so that the height of all the stacked plasterboards is equal to the height of the cavity inside the rubber bladder. Wrap all the stacked plasterboards with tape to form the inner liner. Step 2: Prepare the lower mold template, and lay the capsule wall on the lower mold template. The capsule wall includes multiple layers of adhesive material and multiple layers of reinforcing fabric arranged at intervals. Step 3: Place the inner liner on top of the capsule wall, and use the capsule wall to wrap the sides and top surface of the inner liner to form a raw material block. During the process of wrapping the side of the inner liner, a steel pipe is pre-embedded on the outside of the side of the inner liner, and a wing ring is provided on the steel pipe. The wing ring is vertically arranged inside the liner wall. Step 4: Cover the raw material block with the upper template of the mold; Step 5: Vulcanize the raw material block together with the mold to obtain a rubber bladder; Step 6: After vulcanization is complete, remove the rubber bladder and install the valve on the pre-embedded steel pipe; Step 7: Inflate the rubber bladder using the valve and test the strength of the rubber bladder; The prepared rubber bladder was used for surface impact load loading test. After being filled with water, the rubber bladder transformed the concentrated load into a uniformly distributed load.

2. The method for preparing a high-pressure rubber bladder according to claim 1, characterized in that, In step 1, the thickness of the gypsum board is 10 mm.

3. The method for preparing a high-pressure rubber bladder according to claim 1, characterized in that, In step 2, the lower template contacts a layer of adhesive material on the bladder wall, and the inner liner contacts a layer of adhesive material on the bladder wall. Each layer of adhesive material has a thickness of 3mm-5mm, and each layer of reinforcing fabric has a thickness of 1mm. The area of ​​the reinforcing fabric is larger than the area of ​​the adhesive material. The rubber compound is EPDM rubber, and the reinforcing fabric is aramid 1313. The total thickness of the rubber material and the reinforcing fabric in the bladder wall is equal to the wall thickness of the rubber bladder.

4. The method for preparing a high-pressure rubber bladder according to claim 1, characterized in that, In step 3, the upper surface and four sides of the inner liner are wrapped layer by layer from the inside out using the adhesive material and the reinforcing fabric of the bladder wall. After one layer of adhesive material is wrapped, the inner liner and adhesive material are wrapped with the reinforcing fabric, and the joints of the reinforcing fabric are sewn together. Then the next layer of adhesive material is wrapped until the outermost layer of adhesive material is wrapped.

5. The method for preparing a high-pressure rubber bladder according to claim 1, characterized in that, In step 3, two steel pipes are provided, and the two steel pipes are respectively pre-embedded on two opposite sides of the inner liner. The length of the steel pipe is greater than the wall thickness of the rubber bladder. One end of the steel pipe is in contact with the inner liner, and the other end of the steel pipe is located on the outside of the rubber bladder.

6. The method for preparing a high-pressure rubber bladder according to claim 1, characterized in that, In step 4, the upper template includes four side plates and a top plate. The four side plates cover the four sides of the raw material block, and the top plate covers the upper surface of the raw material block. The four side plates and the top plate are fixed by multiple screws.

7. The method for preparing a high-pressure rubber bladder according to claim 1, characterized in that, In step 5, the raw material block, along with the mold, is fed into a vulcanizing furnace for vulcanization. The vulcanization temperature is 110±10℃ and the time is 12±0.5 hours.

8. The method for preparing a high-pressure rubber bladder according to claim 2, characterized in that, In step 6, after vulcanization is completed, the mold is disassembled, water is injected into the rubber bladder through the steel pipe, the gypsum board is soaked and crushed into gypsum board fragments, and the gypsum board fragments are flushed out of the rubber bladder with water.

9. The method for preparing a high-pressure rubber bladder according to claim 1, characterized in that, In step 7, the rubber bladder can withstand an inflation pressure greater than or equal to 1.2 MPa.

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