A bolt structure for preventing glue from entering the bolt sleeve of the pre-embedded blade root

Abstract

The present invention relates to a bolt structure for preventing glue from entering the bolt sleeve at the root of a pre-embedded blade, comprising a process bolt, a pre-embedded flange, a sealing ring, a bolt sleeve and a metal sealing ring. The sealing ring is arranged between the pre-embedded flange and the bolt sleeve, and the first-level sealing is achieved by squeezing the sealing ring between the bolt sleeve and the pre-embedded flange; the metal sealing ring is arranged on the shaft of the process bolt, and comprises an inner ring and an outer ring, the inner and outer rings are tightly fixed together, and the thermal expansion coefficient of the inner ring material is greater than the thermal expansion coefficient of the outer ring material; when the pre-embedded blade is infused with resin, the metal sealing ring is thermally expanded and bent toward the outer ring side, ultimately sealing the gap between the process bolt and the bolt sleeve, thereby preventing the resin from entering the bolt sleeve during infusion. The present invention utilizes the temperature difference during laying and infusion to form a secondary seal between the process bolt and the bolt sleeve through the metal sealing ring, greatly reducing the probability of glue entering the bolt sleeve, and facilitating the removal of the process bolt, thus avoiding damage to the bolt sleeve when removing the process bolt.

Description

Technical Field

[0001] The invention belongs to the technical field of pre-embedded blade profile infusion for wind turbine blades, and in particular relates to a bolt structure for preventing glue from entering a bolt sleeve at the root of a pre-embedded blade. Background Art

[0002] Compared to punched blades, pre-embedded blades eliminate a drilling step, minimize raw material waste, and achieve high molding efficiency. They have become the mainstream development direction in the wind turbine blade industry. During production, a bolt sleeve is embedded in the blade root. A rubber sealing ring is placed on the end of the bolt sleeve. The bolt sleeve is then mounted on the pre-embedded flange using process bolts. The rubber sealing ring is squeezed between the bolt sleeve and the pre-embedded flange to achieve a seal.

[0003] During the process of the bolt sleeve pressing the sealing ring, the sealing ring is located in the blind spot between the bolt sleeve and the embedded flange. Sometimes the sealing ring may slip or deviate, causing the sealing ring to fail. There is no effective means of observation or detection. After the sealing ring fails, resin will enter the bolt sleeve during blade infusion, causing the process bolts to stick to the threaded engagement area of ​​the bolt sleeve. The process bolts cannot be removed during the demolding stage, seriously affecting the production efficiency of the blade. In addition, the industry usually removes the process bolts by drilling holes at the injection bolt position. The bolt sleeve is easily damaged during the drilling process, and the bolt sleeve of the embedded blade cannot be replaced. In serious cases, the blade will be scrapped. Therefore, how to prevent the embedded blade bolt sleeve from being injected with glue becomes the key to the stable production of embedded blades. Summary of the Invention

[0004] In order to solve the above technical problems, the present invention provides a bolt structure for preventing glue from entering the bolt sleeve at the root of the embedded blade. The temperature difference between laying and pouring is utilized to form a secondary seal between the process bolt and the bolt sleeve through a metal sealing ring, which greatly reduces the probability of glue entering the bolt sleeve during pouring, and facilitates the removal of the process bolt, avoiding damage to the bolt sleeve when removing the process bolt.

[0005] The present invention is specifically achieved through the following technical solutions: a bolt structure for preventing glue from entering a pre-embedded blade root bolt sleeve proposed by the present invention comprises a process bolt, a pre-embedded flange, a sealing ring, a metal sealing ring and a bolt sleeve, wherein the sealing ring is arranged between the pre-embedded flange and the bolt sleeve, the bolt sleeve is pre-embedded in the blade root and located on one side of the pre-embedded flange, a process bolt mounting hole is provided on the pre-embedded flange, and the bolt hole of the bolt sleeve corresponds to the process bolt mounting hole; the process bolt is installed into the process bolt mounting hole from the other side of the pre-embedded flange and inserted into the corresponding bolt hole, and finally is tightened with the bolt sleeve thread, so that the bolt sleeve and the pre-embedded flange squeeze the sealing ring to achieve sealing;

[0006] The metal sealing ring is arranged on the shaft of the process bolt. After the process bolt is inserted into the embedded flange and the bolt sleeve and is screwed together with the bolt sleeve, the metal sealing ring is located at the junction of the bolt sleeve and the embedded flange.

[0007] The metal sealing ring includes an inner ring and an outer ring. The inner and outer rings are tightly fixed together to form a metal sealing ring. The thermal expansion coefficient of the inner ring material is greater than the thermal expansion coefficient of the outer ring material. When the embedded blades are poured, the metal sealing ring is heated and expanded and bends toward the outer ring side, and finally seals the gap between the process bolts and the bolt sleeve, thereby preventing resin from entering the bolt sleeve during pouring.

[0008] The aforementioned pre-embedded blade root bolt sleeve prevents glue from entering the bolt structure, the shaft of the process bolt includes a large diameter section and a small diameter section, a step is formed at the junction of the large diameter section and the small diameter section, and one end of the metal sealing ring is arranged close to the step.

[0009] The aforementioned pre-embedded blade root bolt sleeve prevents glue from entering the bolt structure, the front half of the metal sealing ring is arranged close to the step and fixed to the outer periphery of the process bolt shaft, and the rear half can be slightly radially displaced relative to the process bolt shaft.

[0010] The aforementioned bolt structure for preventing glue from entering the pre-embedded blade root bolt sleeve is provided with an external thread on the minor diameter section of the process bolt for cooperating with the internal thread of the bolt hole to realize threaded connection.

[0011] The aforementioned bolt structure for preventing glue from entering the embedded blade root bolt sleeve, after the process bolts are assembled, the end of the front half of the metal sealing ring is located in the process bolt installation hole, and the end of the rear half is located in the bolt hole.

[0012] In the aforementioned bolt structure for preventing glue from entering the pre-embedded blade root bolt sleeve, the gap between the metal sealing ring and the inner wall of the bolt sleeve is no more than 2 mm, preferably no more than 1 mm.

[0013] The aforementioned bolt structure for preventing glue from entering the embedded blade root bolt sleeve has a groove on the end face of the embedded flange close to the bolt sleeve, and the sealing ring is installed in the groove to achieve sealing between the embedded flange and the bolt sleeve.

[0014] In the aforementioned bolt structure for preventing glue from entering the pre-embedded blade root bolt sleeve, the inner ring material may be a manganese-nickel-copper alloy, and the outer ring material may be a nickel-iron alloy, but the present invention is not limited thereto.

[0015] Compared with the prior art, the present invention has obvious advantages and beneficial effects. By means of the above technical solution, the present invention can achieve considerable technological advancement and practicality, and has a wide range of utilization value. It has at least the following advantages:

[0016] The present invention adds a metal sealing ring on the basis of the existing sealing ring between the bolt sleeve at the root of the embedded blade and the embedded flange, thereby realizing a secondary seal between the process bolt and the bolt sleeve. When the original sealing ring fails, it can play a sealing role to prevent the resin from flowing into the bolt sleeve during resin pouring, causing the threaded engagement area of ​​the process bolt and the bolt sleeve to stick together. Even if the sealing ring fails, the poured resin will accumulate between the metal sealing ring and the port of the bolt sleeve close to the embedded flange, which is convenient for cleaning the resin and removing the process bolts without damaging the bolt sleeve. It is easy to install and does not require additional operating steps. The present invention has a simple structure and is easy to operate. The process bolts can be reused, which reduces the risk of glue entering the bolt sleeve when the embedded blade is poured with resin. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of the present invention.

[0018] Figure 2 It is a schematic diagram of the metal sealing ring forming the second level seal.

[0019] 1-process bolt; 2-embedded flange; 3-sealing ring; 4-metal sealing ring; 5-bolt sleeve; 6-process bolt mounting hole; 7-bolt hole; 8-large diameter section; 9-small diameter section; 10-step; 11-external thread; 12-inner ring; 13-outer ring; 14-end of the front half of the metal sealing ring; 15-end of the back half of the metal sealing ring. DETAILED DESCRIPTION

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with specific embodiments. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0021] In order to overcome the defects of the prior art, the present invention provides a bolt structure for preventing glue from entering the bolt sleeve at the root of the embedded blade, which includes a process bolt 1, an embedded flange 2, a sealing ring 3, a metal sealing ring 4 and a bolt sleeve 5. The bolt sleeve 5 is embedded in the root of the blade and is located on one side of the embedded flange. A plurality of process bolt mounting holes 6 are provided on the embedded flange. The bolt holes 7 of the bolt sleeve correspond one-to-one with the process bolt mounting holes 6 on the embedded flange. The number of bolt sleeves is equal to the number of process bolt mounting holes and the number of process bolts. The process bolt is installed into the process bolt mounting hole from the other side of the embedded flange and inserted into the corresponding bolt hole, and finally tightened with the bolt sleeve thread, so that the bolt sleeve and the embedded flange squeeze the sealing ring 3 to achieve the first level of sealing. In one embodiment, a groove is provided on the end face of the embedded flange close to the bolt sleeve, and the sealing ring is installed in the groove to achieve sealing between the embedded flange and the plurality of bolt sleeves.

[0022] The metal sealing ring is set on the shaft of the process bolt. After the process bolt is inserted into the embedded flange and the bolt sleeve and tightened with the bolt sleeve thread, the metal sealing ring is exactly located at the junction of the bolt sleeve and the embedded flange. Figure 1 and Figure 2 shown.

[0023] Preferably, the shaft of the process bolt includes a large diameter section 8 and a small diameter section 9. A step 10 is formed at the junction of the large and small diameter sections. The metal sealing ring is disposed on the process bolt shaft with one end abutting the step. The small diameter section of the process bolt is also provided with an external thread 11 for mating with the internal thread of the bolt hole to achieve a threaded connection between the process bolt and the bolt sleeve.

[0024] The metal sealing ring comprises an inner ring 12 and an outer ring 13, each made of two materials with different thermal expansion coefficients: the inner ring is made of a material with a larger thermal expansion coefficient, and the outer ring is made of a material with a smaller thermal expansion coefficient. The inner and outer rings are tightly fixed together to form the metal sealing ring. The inner and outer rings can be fixed by bonding or welding. In one embodiment, the inner ring can be made of a manganese-nickel-copper alloy, and the outer ring can be made of a nickel-iron alloy, but the present invention is not limited to this.

[0025] In one embodiment, the metal sealing ring is fixed to the outer periphery of the process bolt shaft by bonding. In other embodiments, the metal sealing ring can also be fixed to the outer periphery of the process bolt shaft by welding, but the present invention is not limited thereto.

[0026] The metal sealing ring is defined as comprising a front half and a rear half. The front half is arranged close to the step and is bonded and fixed to the outer periphery of the process bolt shaft. The rear half does not need to be fixed and can be slightly displaced radially relative to the process bolt shaft.

[0027] Furthermore, after the process bolts are assembled, the end 14 of the front half of the metal sealing ring is located in the process bolt mounting hole of the embedded flange, and the end 15 of the rear half is located in the bolt hole of the bolt sleeve, and the gap between the outer ring of the metal sealing ring and the inner wall of the bolt sleeve is no more than 2 mm, preferably no more than 1 mm.

[0028] To reduce resin viscosity and speed up resin infusion, the pre-embedded flange mold is opened and heated before infusion. The resin reaction requires a certain temperature and releases heat during the reaction, resulting in a significant temperature difference between the process bolts during layup and infusion. The process bolts are generally at room temperature (10-25°C) during layup. During infusion, the pre-embedded flange mold is opened and heated, causing the process bolts to reach 45°C. The heat released by the resin reaction can reach as high as 80°C. At this time, the blade root's surface temperature can reach over 60°C due to the heat released by the resin. Therefore, there is a significant temperature difference between the process bolts during layup and infusion. During infusion, the rising temperature of the process bolts causes the metal sealing ring bonded to the process bolt shaft to expand due to the heat. The metal sealing ring bends toward the outer ring, which has a lower thermal expansion coefficient. This seals the gap between the process bolt and the bolt sleeve, forming a secondary seal and preventing resin from entering the bolt sleeve during infusion. After the pouring is completed, the mold heating is turned off, and the embedded flange, process bolts, bolt sleeves and metal sealing rings return to room temperature. The metal sealing ring returns to its original shape and no longer bends toward the outer ring. There is a gap between the metal sealing ring and the bolt sleeve. At this time, the resin has been cured and no longer flows, and the bolt will no longer be filled with glue.

[0029] The method for preventing glue from entering the bolt sleeve of the embedded blade root by using the above structure includes:

[0030] (1) Install the sealing ring 3 into the groove on the end face of the embedded flange 2, align the bolt hole of the bolt sleeve 5 with the process bolt installation hole 6 of the embedded flange, insert the process bolt 1 into the process bolt installation hole of the embedded flange, and then insert it into the corresponding bolt hole 7. During the process of tightening the process bolt and the bolt sleeve, the sealing ring is pressed between the embedded flange and the bolt sleeve to form the first level of sealing. After the process bolt and the bolt sleeve are tightened, the metal sealing ring on the outer periphery of the process bolt is exactly located at the junction of the bolt sleeve and the embedded flange, with one end of the metal sealing ring located in the process bolt installation hole of the embedded flange and the other end located in the bolt hole.

[0031] (2) After all the bolt sleeves at the root of the embedded blade are installed, the embedded flange mold is opened and heated to prepare for resin infusion. The heat released by the mold heating and the resin curing reaction causes the temperature of the process bolt to rise, causing the metal sealing ring on the process bolt to expand due to the heat and bend toward the outer ring to press against the bolt sleeve, eventually sealing the gap between the process bolt and the bolt sleeve to form a second-level seal. When infusing the resin, if the sealing ring fails due to slippage, displacement, etc., the second-level seal can prevent the resin from entering the bolt sleeve and causing the threaded engagement area of ​​the process bolt and the bolt sleeve to stick.

[0032] (3) After the injection is completed, turn off the mold heating and wait for the embedded flange, process bolts, bolt sleeves and metal sealing ring to cool to room temperature. The metal sealing ring returns to normal and no longer bends toward the outer ring, no longer seals between the process bolts and the bolt sleeve. There is a gap between the metal sealing ring and the bolt sleeve. At this time, the process bolts can be removed normally. If the sealing ring fails to seal, the resin is blocked between the metal sealing ring and the bolt sleeve near the port of the embedded flange. Use a file or other tool to clean up the remaining resin.

[0033] The installation structure of the process bolts, the embedded flange and the bolt sleeve is a well-known technology in the field, and the present invention will not elaborate on it in detail. The present invention adds a metal sealing ring on the basis of the existing sealing ring between the embedded blade root bolt sleeve and the embedded flange, and uses the temperature difference between the process bolts during laying and pouring to achieve a secondary seal between the process bolts and the bolt sleeve. When the original sealing ring fails, it can play a sealing role to prevent the resin from flowing into the bolt sleeve during the resin pouring, causing the threaded engagement area of ​​the process bolt and the bolt sleeve to stick together. Even if the sealing ring fails, the resin will gather between the metal sealing ring and the port of the bolt sleeve near the embedded flange, which is convenient for cleaning the bolt sleeve and will not damage the bolt sleeve. It is easy to install and does not require additional operating steps.

[0034] The above description is merely an embodiment of the present invention and does not constitute any form of limitation to the present invention. The present invention may also have other forms of embodiments based on the above structures and functions, which are not listed one by one. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments by any person skilled in the art based on the technical essence of the present invention without departing from the scope of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A bolt structure for preventing glue from entering the bolt sleeve at the root of a pre-embedded blade, comprising a process bolt (1), a pre-embedded flange (2), a sealing ring (3), and a bolt sleeve (5), wherein the sealing ring (3) is arranged between the pre-embedded flange (2) and the bolt sleeve (5), and is characterized in that It also includes a metal sealing ring (4), the bolt sleeve is embedded in the root of the blade and is located on one side of the embedded flange, the embedded flange is provided with a process bolt installation hole (6), and the bolt hole (7) of the bolt sleeve corresponds to the process bolt installation hole (6); the process bolt is installed into the process bolt installation hole from the other side of the embedded flange and inserted into the corresponding bolt hole, and finally tightened with the bolt sleeve thread, so that the bolt sleeve and the embedded flange squeeze the sealing ring (3) to achieve sealing; The metal sealing ring is arranged on the shaft of the process bolt. After the process bolt is inserted into the embedded flange and the bolt sleeve and is screwed together with the bolt sleeve, the metal sealing ring is located at the junction of the bolt sleeve and the embedded flange. The metal sealing ring includes an inner ring and an outer ring. The inner and outer rings are tightly fixed together to form a metal sealing ring. The thermal expansion coefficient of the inner ring material is greater than the thermal expansion coefficient of the outer ring material. When the embedded blades are poured, the metal sealing ring is heated and expanded and bends toward the outer ring side, and finally seals the gap between the process bolts and the bolt sleeve, thereby preventing resin from entering the bolt sleeve during pouring.

2. The bolt structure for preventing glue from entering the pre-embedded blade root bolt sleeve according to claim 1 is characterized in that The shaft of the process bolt comprises a large diameter section (8) and a small diameter section (9); a step (10) is formed at the junction of the large diameter section and the small diameter section; one end of the metal sealing ring is arranged close to the step (10).

3. The bolt structure for preventing glue from entering the pre-embedded blade root bolt sleeve according to claim 2 is characterized in that The front half of the metal sealing ring is arranged close to the step and fixed on the outer periphery of the process bolt shaft, and the rear half can be radially displaced relative to the process bolt shaft.

4. The bolt structure for preventing glue from entering the pre-embedded blade root bolt sleeve according to claim 2 is characterized in that The small diameter section of the process bolt is also provided with an external thread for cooperating with the internal thread of the bolt hole to realize threaded connection.

5. The bolt structure for preventing glue from entering the pre-embedded blade root bolt sleeve according to claim 3 is characterized in that After the process bolts are assembled, the end of the front half of the metal sealing ring is located in the process bolt installation hole (6), and the end of the rear half is located in the bolt hole (7).

6. The bolt structure for preventing glue from entering the pre-embedded blade root bolt sleeve according to claim 1 is characterized in that A groove is provided on the end surface of the embedded flange close to the bolt sleeve, and the sealing ring (3) is installed in the groove to achieve sealing between the embedded flange and the bolt sleeve.

7. The bolt structure for preventing glue from entering the pre-embedded blade root bolt sleeve according to claim 1 is characterized in that The inner ring is made of manganese-nickel-copper alloy, and the outer ring is made of nickel-iron alloy.

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