Wall bushing and forming device

Abstract

The utility model provides a wall bushing and a forming device. The wall bushing comprises a hollow insulator; the central guide rod comprises a first end part and a second end part, the central guide rod is arranged in the hollow insulator in a penetrating manner, and the central guide rod is connected with the hollow insulator; in the preparation process, the portion, between the first end and the second end, of the center guide rod is shaped after being arched upwards relative to the end of the center guide rod, and the upward-arching direction is opposite to the gravity direction. Through the design, the problem that the center guide rod droops can be solved.

Description

Technical Field

[0001] This application relates to the field of power transmission technology, specifically to a through-wall bushing and its forming device. Background Technology

[0002] Because wall bushings with voltage levels above 400kV have large axial dimensions and are generally arranged horizontally or nearly horizontally in practical applications, the central conductor used for conduction and current carrying will bend and sag under gravity. To control the electric field distribution, the diameter of the central conductor is required to be small, which also makes it prone to deformation. Furthermore, to ensure the long-term operational reliability of the wall bushing, the support insulator in the middle of the bushing is usually removed, leaving the central conductor suspended in the middle, which makes the middle section of the central conductor prone to sagging. Simultaneously, the middle section of the central conductor is generally located in the middle of the wall bushing. In the middle section, due to the high potential of the central conductor, the distance to the grounded external wall is shortest, resulting in the highest risk of discharge and high insulation requirements. Generally, it is required that the central conductor deviate as little as possible from the central axis of the wall bushing to reduce the risk of insulation material breakdown. Currently, the commonly used methods for controlling the deformation of the central conductor are to strengthen the cross-section of the central conductor or to arrange the central conductor axis eccentrically.

[0003] The first approach, strengthening the cross-section of the central guide rod, mainly involves increasing its stiffness by changing the material or improving its bending resistance by increasing the cross-sectional dimensions, thereby reducing the sag of the central guide rod. However, strengthening the cross-section of the central guide rod does not eliminate the sag in the middle; it only reduces the degree of sag. Furthermore, changes in the cross-section of the central guide rod inevitably lead to changes in the surrounding electric field. This makes its optimization design affect the design of other bushings such as capacitor equalizing plates and insulating materials, further complicating the product design process.

[0004] The second approach, eccentric arrangement, involves aligning the two ends of the central guide rod upwards. Initially, the axis of the central guide rod is offset from the axis of the through-wall bushing. The offset distance precisely cancels out the deflection (i.e., the amount of sag) of the central guide rod's middle section, ensuring that after a period of operation, the axis of the sagning central guide rod coincides with the axis of the through-wall bushing. However, this eccentric arrangement causes the central guide rod to operate off-center. When its length increases due to temperature rise, the elongation of the central guide rod is constrained by its fixed ends, resulting in compressive stress inside the central guide rod. This compressive stress, combined with the eccentric arrangement, easily leads to additional bending moments and eccentric instability. The additional bending moment exacerbates the deformation and offset of the central guide rod, while eccentric instability can suddenly cause a large deformation of the central guide rod, leading to insulation failure. Therefore, the eccentric arrangement method requires rigorous pre-design to accommodate the elongation of the central guide rod due to temperature increases. This necessitates a carefully designed, complex telescopic mechanism for the connection between the central guide rod and the end of the through-wall bushing, increasing R&D investment and product manufacturing costs. Utility Model Content

[0005] In view of this, this application provides a through-wall sleeve and a forming device, which can improve the problem of central guide rod sagging.

[0006] To address the above problems, the first aspect of this application provides a through-wall bushing, comprising: a hollow insulator; and a central guide rod, including a first end and a second end, wherein the central guide rod passes through the hollow insulator and is connected to the hollow insulator; wherein, during the manufacturing process, the central guide rod between the first end and the second end is arched upward relative to the end of the central guide rod and is shaped, with the direction of the arch being opposite to the direction of gravity.

[0007] By arching the central guide rod as described above, the sagging of the central guide rod under gravity can be counteracted, ultimately improving the problem of central guide rod sagging.

[0008] In one embodiment, the first height w of the first position point on the central guide rod relative to the end of the central guide rod satisfies the following condition:

[0009]

[0010] Where ρ is the linear density of the central guide rod, g is the gravitational acceleration, x is the distance from the first position point on the central guide rod to the first end along the first direction, L is the length between the two ends of the central guide rod, E is the Young's modulus of the central guide rod, I is the moment of inertia of the cross section of the central guide rod, and the first direction refers to the direction of the line connecting the two ends of the central guide rod.

[0011] The above settings ensure that the deflection of the central guide rod under gravity exactly cancels out the first height of the upper arch, guaranteeing that the distance between the central guide rod and the hollow insulator is equal everywhere after the central guide rod and the hollow insulator are installed and put into operation.

[0012] In one embodiment, the hollow insulator includes: a hollow insulating tube, with a central guide rod passing through the hollow insulating tube; a first end flange fixed to the first end of the central guide rod, connecting the central guide rod and the hollow insulating tube; and a second end flange sleeved on the second end of the central guide rod, connecting the central guide rod and the hollow insulating tube.

[0013] The above settings ensure the stability of the connection between the central guide rod and the hollow insulator.

[0014] In one embodiment, the through-wall sleeve further includes: a telescopic member located between the second end flange and the second end of the central guide rod, which slidably connects the second end and the second end flange so that the second end can slide relative to the second end flange in a first direction, the first direction referring to the direction of the line connecting the two ends of the central guide rod.

[0015] The above settings help to release the elongation of the center guide rod caused by temperature rise.

[0016] In one embodiment, the central guide rod is a hollow guide rod.

[0017] The above-mentioned configuration can reduce the weight and cost of the central guide rod, and also facilitate the fabrication of the central guide rod.

[0018] A second aspect of this application provides a forming apparatus for arching the central guide rod of a through-wall sleeve in any of the above embodiments. The forming apparatus includes: a first fixing member and a second fixing member spaced apart, the first fixing member supporting and fixing a first end of the central guide rod, and the second fixing member supporting and fixing a second end of the central guide rod; a force-applying member for applying a force to a first position point on the central guide rod to arch the central guide rod between the first end and the second end, the arching direction being opposite to the direction of gravity; and a shaping mechanism for shaping the central guide rod after it has arched.

[0019] The above-mentioned device is used to complete the shaping process of the central guide rod.

[0020] In one embodiment, the force-applying component includes a lifting platform disposed between the first fixing member and the second fixing member. The lifting platform is used to rise to abut against and arch the central guide rod, so that a first position point on the central guide rod rises to a first height.

[0021] The above-mentioned lifting platform configuration ensures stability when the guide rod is positioned at the center of the upper arch.

[0022] In one embodiment, the central guide rod is a hollow guide rod, and the shaping mechanism includes: a conveying pipe, which is connected to the central guide rod and is used to convey a heat medium to the central guide rod; a heater, which is disposed on the conveying pipe and is used to heat the heat medium; and a conveying pump, which is disposed on the conveying pipe and is used to provide power for conveying the heat medium through the conveying pipe.

[0023] The center guide rod can be better shaped by setting up delivery pipes, heaters, and delivery pumps.

[0024] In one embodiment, the shaping mechanism further includes a thermometer disposed on the conveying pipe for measuring the temperature of the heat medium in the conveying pipe.

[0025] Setting a thermometer allows for better control of the heating temperature.

[0026] In one embodiment, a pulley is provided at the bottom of one of the first fixing member and the second fixing member.

[0027] The pulley structure can protect the central guide rod.

[0028] Beneficial effects: This application improves the problem of central guide rod sagging by arching the central guide rod between the first and second ends of the central guide rod in the wall sleeve in the opposite direction of gravity.

[0029] Furthermore, this application provides a molding apparatus, which fixes the first end of the central guide rod with a first fixing member, fixes the second end of the central guide rod with a second fixing member, then arches the central guide rod upward with a force-applying member, and further shapes the arched central guide rod with a shaping mechanism, thereby enabling the preparation of the central guide rod.

[0030] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0031] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiments below. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0032] Figure 1 This is a structural schematic diagram of one embodiment of the through-wall sleeve of this application;

[0033] Figure 2 yes Figure 1 A schematic diagram of one embodiment of the central guide rod being shaped during its fabrication process;

[0034] Figure 3 This is a schematic diagram of the center guide rod constraint model in the prior art;

[0035] Figure 4 This is a schematic diagram of the bending moment of the central guide rod under gravity in existing technology;

[0036] Figure 5 This is a schematic diagram of the deflection of the central guide rod under gravity in existing technology;

[0037] Figure 6 This is a schematic flowchart of one embodiment of the method for preparing the through-wall sleeve of this application;

[0038] Figure 7 yes Figure 6 A schematic diagram of one embodiment of the central guide rod in the manufacturing process;

[0039] Figure 8This is a flowchart illustrating one embodiment of step S210;

[0040] Figure 9 yes Figure 8 A schematic diagram of one embodiment of step S211;

[0041] Figure 10 This is a flowchart illustrating one embodiment of step S310;

[0042] Figure 11 This is a partial structural schematic diagram of one embodiment of the molding apparatus of this application;

[0043] Figure 12 This is a top view schematic diagram of one embodiment of the molding apparatus of this application. Detailed Implementation

[0044] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0045] See Figure 1 and Figure 2 The first aspect of this application provides a through-wall bushing 10, which includes a hollow insulator 110 and a central guide rod 120. The central guide rod 120 includes a first end A and a second end B. The central guide rod 120 passes through the hollow insulator 110 and is connected to the hollow insulator 110. During the manufacturing process, the central guide rod 120 between the first end A and the second end B is arched upward relative to the end of the central guide rod 120 and is shaped. The direction of the arching S is opposite to the direction of gravity G.

[0046] Specifically, the central guide rod 120 is used for conducting electricity, and its first end A and second end B are connected to the hollow insulator 110. The central guide rod 120 passes through the hollow insulator 110, which provides insulation, preventing the central guide rod 120 from directly contacting the external wall. In traditional designs, the central guide rod is a straight rod during manufacturing. After installation with the hollow insulator, under gravity, both ends of the central guide rod are supported, but the central guide rod between the two ends is not supported, resulting in sagging. The sagging is more severe the further away from the ends, reaching its maximum value at the middle of the central guide rod. This sagging under gravity can also be referred to as deflection.

[0047] See Figure 2 ( Figure 2(The direction of gravity G in the diagram is only for illustrative purposes.) In the present application, during the fabrication process, the central guide rod 120 is arched upwards relative to the end of the central guide rod 120 between the first end A and the second end B. The direction of the upward arch is opposite to the direction of gravity G. That is to say, after the central guide rod 120 is fabricated, it is not a straight guide rod, but a curved guide rod. Since the central guide rod 120 has an upward arch in the direction of S after fabrication, the upward arch can be used to counteract the sagging of the central guide rod 120 under the action of gravity, and the problem of sagging of the central guide rod 120 can be improved. It should be noted that the first end A and the second end B mentioned above are not the two ends of the central guide rod 120, but rather the connection ends between the central guide rod 120 and the hollow insulator 110. The two ends of the central guide rod 120 mentioned in this application refer to the first end A and the second end B of the central guide rod 120. That is, as long as the central guide rod 120 between the two ends connected to the hollow insulator 110 is arched, there are no specific restrictions on the shape and length of the central guide rod 120 outside the hollow insulator 110.

[0048] In one embodiment, see Figure 1 The hollow insulator 110 includes a hollow insulating tube 111, a first end flange 112, and a second end flange 113. A central guide rod 120 passes through the hollow insulating tube 111; the first end flange 112 is fixed to the first end A of the central guide rod 120, connecting the central guide rod 120 and the hollow insulating tube 111; the second end flange 113 is sleeved on the second end B of the central guide rod 120, connecting the central guide rod 120 and the hollow insulating tube 111.

[0049] Specifically, the central guide rod 120 passes through the hollow insulating tube 111, and there is no contact between the central guide rod 120 and the hollow insulating tube 111, which can improve the insulation effect of the hollow insulating tube 111 on the central guide rod 120. The connection between the central guide rod 120 and the hollow insulating tube 111 is such that one end is fixed and the other end can slide. For example, the first end A of the central guide rod 120 is fixedly connected to the first end flange 112, and the second end B of the central guide rod 120 is slidably connected to the second end flange 113, that is, connected by a sleeve. The advantage of this is that the second end B of the central guide rod 120 can slide in the first direction X (the first direction X refers to the direction of the line connecting the two ends of the central guide rod 120). Because under the action of gravity, the drooping of the central guide rod 120 will cause the end of the central guide rod 120 to be displaced in the first direction X. By sliding, the end of the central guide rod 120 can be displaced to release the force of the central guide rod 120 on the first end flange 112 and the second end flange 113 in the first direction X, thereby ensuring the connection stability between the central guide rod 120 and the hollow insulator 110.

[0050] In some other embodiments, the connection between the central guide rod and the hollow insulating tube may not be achieved using end flanges. Instead, an insulating component is used to connect the hollow insulating tube and the central guide rod, with the insulating component and the hollow insulating tube being integrally formed.

[0051] In one embodiment, see Figure 1 The through-wall sleeve 10 also includes a telescopic member 130, which is located between the second end flange 113 and the second end B of the central guide rod 120, and slides between the second end B and the second end flange 113 so that the second end B can slide relative to the second end flange 113 in the first direction X.

[0052] Specifically, by providing a telescopic member 130 between the second end B of the central guide rod 120 and the second end flange 113, the second end B can slide relative to the second end flange 113 in the first direction X, thereby releasing the force exerted by the central guide rod 120 on the first end flange 112 and the second end flange 113, and further improving the connection stability between the central guide rod 120 and the hollow insulator 110.

[0053] Of course, in some other embodiments, a telescopic component may not be provided between the second end flange and the second end of the central guide rod, and sliding between the two may be achieved by applying lubricating oil between the second end flange and the second end of the central guide rod.

[0054] In one embodiment, see Figure 2 The central guide rod 120 is a hollow guide rod. A hollow guide rod reduces the overall weight of the central guide rod 120 with minimal loss of cross-sectional stiffness, thereby reducing sag and requiring less material, resulting in lower cost. Simultaneously, a hollow guide rod facilitates the fabrication of the upward arch of the central guide rod 120; details can be found in the embodiments described below. Of course, in some other embodiments, the central guide rod may also be a solid guide rod; this application does not impose specific limitations on this.

[0055] First, based on the estimation of the first deflection of the central guide rod under gravity in existing technologies, refer to... Figure 3 The existing central guide rod 150 (distinguished from the central guide rod 120 of this application) also has a first end A and a second end B, wherein the first end A is subject to a fixed constraint, and the second end B is subject to a sliding constraint. This sliding constraint only allows the central guide rod 150 to slide in the horizontal direction, and does not allow it to slide or rotate in the vertical direction. See reference [link to relevant documentation]. Figure 4The central guide rod 150 is represented by the axis containing its centroid. Along the first direction X (the direction of the line connecting the first end A and the second end B) in the diagram, based on the fact that under gravity, the central guide rod 150 will experience a bending moment M that causes half of its cross-section to be under compression and the other half under tension, the bending moment M of the lower part of the central guide rod 150 is drawn below the central guide rod 150, and the bending moment M of the upper part is drawn above the central guide rod 150. It can be seen that the bending moment M of the central guide rod 150 is a quadratic curve, and the bending moment M of the first end A and the second end B of the central guide rod 150 is... The bending moment M at the center of the central guide rod 150 is Where ρ is the linear density of the central guide rod 150, which is the product of the area of ​​the cross section of the central guide rod 150 and the material density of the central guide rod 150; g is the acceleration due to gravity; and L is the length between the two ends of the central guide rod 150.

[0056] Furthermore, under the influence of gravity, the deformation of the central guide rod 150 is still relatively small compared to its length, which can be considered a small deformation case. Since the central guide rod 150 is generally made of alloy material, it has good elasticity. It can be assumed that it still conforms to the plane section assumption and the linear elastic assumption when subjected to bending moment M. Therefore, the following approximate equation can be used:

[0057]

[0058] Where, k is the curvature of the deformed central guide rod 150, y is the deflection of the first position point on the central guide rod 150 relative to the line connecting the two ends of the central guide rod 150 in the direction of gravity G, and y′ is the first derivative of the first deflection y, which is the cross-sectional rotation angle in radians, and its value is much less than 1 under the premise of small deformation. (2) The first position point is the second derivative of the first deflection y, and can be any point on the central guide rod 150 (see...). Figure 5 A coordinate system is established with the first end A as the origin, the first direction X as the horizontal axis (x-axis), and the gravity direction G as the vertical axis (y-axis). The direction from the first end A to the second end B is the positive direction of the horizontal axis, and the direction of gravity G is the positive direction of the vertical axis. Furthermore, the above formula takes the bending moment M drawn below the central guide rod 150 as positive, I as the moment of inertia of the section, and E as the Young's modulus of the central guide rod 150.

[0059] The hollow central guide rod 150 has a circular cross-section. For a circular cross-section, the moment of inertia I can be determined according to the following formula:

[0060]

[0061] Where D is the outer diameter of the center guide rod 150, d is the inner diameter of the center guide rod 150, and the inner diameter d is greater than 0.

[0062] Based on the bending moment M at the first end A of the central guide rod 150, the bending moment M at the second end B, the bending moment M at the middle, and the approximate formula for the curvature κ, we can obtain:

[0063]

[0064] Integrating the above equation, we can obtain the first deflection y under gravity:

[0065]

[0066] Secondly, based on the assessment of the second deflection caused by creep under long-term energized operation of the central guide rod 150, during the current flow process, the central guide rod 150 heats up due to its own resistance. Therefore, the central guide rod 150 will creep due to long-term heat and stress during operation, generating an additional second deflection. Currently, aluminum alloy is commonly used as the material for the central guide rod 150. The creep of aluminum alloys first undergoes a rapid development stage, during which the creep is very small and often negligible. This is followed by a gradually stabilizing second stage where the creep strain rate is approximately constant. For 6-series and 7-series aluminum alloys, this second stage occurs at temperatures above 145℃. However, according to GB / T 4109-2022, the average operating temperature of the center guide rod 150 should not exceed 130℃, and the maximum temperature should not exceed 140℃. Therefore, aluminum alloys will not experience the second stage of creep. The third stage is the destructive stage, but it only occurs at high temperatures (above 0.3 times the melting point; for example, 0.3 times the melting point of aluminum alloy is between 168℃ and 198℃, higher than the operating temperature of the center guide rod 150). Therefore, the center guide rod 150 will not experience the third stage of creep.

[0067] Furthermore, the material commonly used for the center guide rod 150 is generally 6-series aluminum alloy, based on a similar creep formula ε for 7-series aluminum alloys below 145°C. c =Aσ n t m The formula for estimating the creep of 6-series aluminum alloys was obtained by fitting the experimental data: ε c =9.4852×10 -18 σ -5.65 t 0.47344 Among them, ε c Let σ be the creep strain, σ be the uniaxial stress of the material, and t be the duration of high temperature. It should be noted that under gravity, the central guide rod 150 experiences shear stress in addition to axial stress. However, the deformation caused by shear stress in thin-walled rods with L > 8D is much lower than the deformation caused by axial stress; therefore, this application ignores creep caused by shear force. The service life of a typical through-wall sleeve is 30 years, or 262,800 hours. For a central guide rod with L = 10000 mm, D = 120 mm, and d = 100 mm, its maximum axial stress is 10.5 MPa, corresponding to an elastic strain of 1.3 × 10⁻⁶ MPa.-4 (The density and elastic modulus of aluminum alloy are taken as 2700 kg / m³) 3 The creep strain (79000MPa) located at the outer edge of the fixed ends is calculated to be 2.05×10⁻⁶ during its service life according to the formula. -9 Compared to the axial strain caused by gravity and temperature expansion and contraction, which can be ignored, the second deflection generated during use can be disregarded for the central guide rod 150.

[0068] In summary, the first deflection y of the central guide rod 150 under the action of gravity is much greater than the second deflection generated by creep under long-term energized operation. Therefore, the second deflection is ignored, and the deflection of the central guide rod 150 is its first deflection y.

[0069] Based on the above assessment of the deflection of the central guide rod 150 in the prior art, in one embodiment, see [reference needed]. Figure 2 The first height w of the first position point on the central guide rod 120 relative to the end of the central guide rod 120 satisfies the following condition:

[0070]

[0071] Where ρ is the linear density of the central guide rod 120, which is equal to the product of the volume density and cross-sectional area of ​​the central guide rod 120; g is the acceleration due to gravity; x is the distance from the first position point on the central guide rod 120 to the first end A along the first direction X; L is the length between the two ends of the central guide rod 120; E is the Young's modulus of the central guide rod 120; I is the moment of inertia of the cross section of the central guide rod 120; and the first direction X refers to the direction of the line connecting the two ends of the central guide rod 120.

[0072] In this application, the central guide rod 120 is shaped into an upwardly arched curved shape during the manufacturing process. The first height w of the upward arch is basically consistent with the first deflection y of the central guide rod 150 under gravity in the prior art. Thus, the upward arch can be used to counteract the sag of the central guide rod 120 under gravity, and the problem of the central guide rod 120 sag can be avoided. Therefore, after the central guide rod 120 is installed and put into operation, its shape is approximately straight rather than curved. This ensures that the distance between the central guide rod 120 and the wall of the hollow insulating tube 111 is almost equal at all points, avoiding the risk of being punctured.

[0073] See Figure 6 and Figure 7 The second aspect of this application provides a method for preparing a wall sleeve 10, used to prepare the wall sleeve 10 of any of the above embodiments, the method comprising:

[0074] S100: Fix the first end A and the second end B of the center guide rod 120 by the first fixing member 210 and the second fixing member 220 respectively.

[0075] Specifically, both ends of the central guide rod 120 are fixed by fasteners, such as clamps. In order to ensure the effect of the central guide rod 120 being installed in the through-wall sleeve 10, during the preparation, the distance between the two fasteners after the first fastener 210 and the second fastener 220 fix the central guide rod 120 is the distance between the first end A and the second end B of the central guide rod 120 in the above embodiment.

[0076] S200: Apply a force to the central guide rod 120 between the first end A and the second end B to cause the central guide rod 120 between the first end A and the second end B to arch upward.

[0077] Specifically, the applied force is opposite to the gravitational force G, causing the central guide rod 120 between the first end A and the second end B to arch upward. The location where the force is applied can be a local location between the two ends or the entire area between the two ends.

[0078] S300: The center guide rod 120 is shaped.

[0079] Specifically, the shaping process is to maintain the upward arched shape of the central guide rod 120, i.e., it is curved, rather than returning to a straight shape when the upward arching force is removed, so that the upward arched shape of the central guide rod 120 can be maintained.

[0080] S400: Separate the central guide rod 120 from the first fixing member 210 and the second fixing member 220, and pass the central guide rod 120 through the hollow insulator 110 and connect it to the hollow insulator 110, so that the upward arching direction S of the central guide rod 120 after installation is opposite to the gravity direction G.

[0081] Specifically, it can be combined with Figure 1 and Figure 7 After separating the central guide rod 120 from the first fixing member 210 and the second fixing member 220, when installing the central guide rod 120 in the hollow insulator 110, the upward arching direction S of the central guide rod 120 needs to be opposite to the gravity direction G. This ensures that during subsequent operation, the upward arched part of the central guide rod 120 will gradually sag under the action of gravity and return to a straight shape, making the distance between the central guide rod 120 and the wall of the hollow insulating tube 111 equal at all points, avoiding the risk of puncture, and thus improving the sagging problem of the central guide rod 120. It is understandable that if the upward arching direction S is not opposite to the gravity direction G, especially when the upward arching direction S is the same as the gravity direction G, the sagging problem of the central guide rod 120 will be more serious. Therefore, whether the upward arching direction S is opposite to the gravity direction G is quite critical during installation.

[0082] In one embodiment, see Figure 7The above step S200 includes:

[0083] S210: Control the lifting platform (not shown) located below the central guide rod 120 to rise to lift the central guide rod 120, so that the central guide rod 120 between the first end A and the second end B arches upward.

[0084] Specifically, choosing a lifting platform as the force-applying device can ensure the stability of the upward arch, while also allowing for adjustment of the rising distance. This facilitates adjustment based on the first required rising height w of the central guide rod 120, thereby improving the equipment's versatility.

[0085] In one embodiment, see Figure 7 , Figure 8 and Figure 9 The above step S210 includes:

[0086] S211: Control the lifting platform to rise and abut against the first position point on the central guide rod 120.

[0087] Specifically, Figure 9 In this process, the first position point can be any position point between the two ends of the central guide rod 120. For example, the first position point can be the middle of the central guide rod 120. At the same time, this step does not limit the number of lifting platforms. That is to say, one lifting platform can be used to abut against the central guide rod 120, or multiple lifting platforms can be used to abut against different positions of the central guide rod 120.

[0088] S212: Control the lifting platform to continue rising until it reaches the first position point and rises to a first height w, where the first height w satisfies the following condition:

[0089]

[0090] Where ρ is the linear density of the central guide rod 120, g is the gravitational acceleration, x is the distance from the first position point on the central guide rod 120 to the first end A along the first direction X, L is the length between the two ends of the central guide rod 120, E is the Young's modulus of the central guide rod 120 at the stable operating temperature (since the maximum temperature of the central guide rod 120 during operation does not exceed 140℃, the elastic modulus reduction is not serious, and the Young's modulus at room temperature can be used as an approximation), I is the moment of inertia of the cross section of the central guide rod 120, and the first direction X refers to the direction of the line connecting the two ends of the central guide rod 120.

[0091] Specifically, Figure 7 In the middle, it rises through the lifting platform (not shown) until it rises to the first position point and reaches the first height w. Then, the first height w of the central guide rod 120 arches upward and the first deflection y of the central guide rod 120 under the action of gravity cancel each other out, so that the central guide rod 120 is straight under the action of gravity after installation and operation.

[0092] In one application scenario, the first position point is the middle of the central guide rod 120, and the corresponding first height is... Substituting the aforementioned parameters, the calculated value is 8.4 mm.

[0093] In one implementation, see Figure 10 The above step S300 includes:

[0094] S310: The center guide rod 120 is heated to shape it.

[0095] Specifically, the material of the center guide rod 120 is metal or alloy, so the center guide rod 120 can be shaped by aging treatment, wherein the center guide rod 120 can be shaped into an upward arch by heating.

[0096] In one embodiment, combined with Figure 1 and Figure 10 The central guide rod 120 is a hollow guide rod. The above step S310 includes:

[0097] S311: Input heat medium into the central guide rod 120.

[0098] Specifically, the central guide rod 120 is a hollow guide rod, and a heat medium can be introduced into the central guide rod 120 to heat the entire central guide rod 120. The heat medium can be a high-boiling-point oil that does not corrode the central guide rod 120.

[0099] S312: Heat the heat medium and, after the temperature of the heat medium reaches a preset temperature threshold, control the heat medium to maintain the temperature for at least a first duration.

[0100] Specifically, aging treatment typically requires maintaining a certain temperature for a certain period of time to complete the creep of the material, thereby achieving a shaping effect. Heating is a common method of aging treatment. Therefore, it is necessary to control the duration for which the heat medium is maintained after being heated to a preset temperature threshold (the preset temperature threshold is the temperature required for the creep of the central guide rod 120 material). The first duration is the creep duration required for the central guide rod 120 material. The preset temperature threshold and the first duration may differ for different materials, and no specific restrictions are imposed here.

[0101] In one application scenario, the material of the central guide rod 120 is aluminum alloy. 180℃ is a suitable temperature for aging treatment of aluminum alloy. At this temperature, it can be approximately assumed that the creep deformation at various points on the central guide rod 120 is linearly related to its stress. In actual use, the central guide rod 120 will undergo elastic deformation under the action of gravity, and its elastic deformation is also proportional to its stress. This indicates that after aging treatment, there will be no excessive internal stress due to deformation coordination issues. Furthermore, the pre-bending shape of the central guide rod 120 will be similar to the deformation generated under its own gravity. In actual operation, the axis of the central guide rod 120 will coincide with the ideal axis.

[0102] The creep strain of the central guide rod 120 at various positions reaches the self-weight strain ε m =σ m / E requires the first duration t h It should satisfy: σ m / E=1.22×10 -6 σ m 0.9252 t h 0.3161 σ is approximately considered m ≈σ m 0.9252 ,but Where, σ m Let be the stress at a certain location of the aluminum alloy under its own weight, and let E be the elastic modulus of the aluminum alloy, with E taken as 79000 MPa. Then, the first time interval t can be calculated. h =1639s=27min.

[0103] See Figure 11 and Figure 12 The third aspect of this application provides a forming apparatus 20 for arching the central guide rod 120 of the through-wall sleeve 10 in any of the above embodiments. The forming apparatus 20 includes: a first fixing member 210 and a second fixing member 220 spaced apart, a force-applying member 230, and a shaping mechanism 240. The first fixing member 210 is used to support and fix the first end A of the central guide rod 120, and the second fixing member 220 is used to support and fix the second end B of the central guide rod 120. The force-applying member 230 is used to apply a force to a first position point on the central guide rod 120 to arch the central guide rod 120 between the first end A and the second end B, with the arching direction S opposite to the gravity direction G. The shaping mechanism 240 is used to shape the central guide rod 120 after it has arched.

[0104] Specifically, the first fixing member 210 and the second fixing member 220 fix the two ends of the central guide rod 120. The force-applying member 230 applies force to the central guide rod 120, causing the central guide rod 120 to arch upward. The direction of the arching S is opposite to the direction of gravity G. Then, the shaping mechanism 240 shapes the shape of the arch of the central guide rod 120 so that the central guide rod 120 can have an arched shape after it is manufactured. This can, to a certain extent, offset the sagging of the central guide rod 120 under the action of gravity, thereby improving the sagging problem of the central guide rod 120.

[0105] In one embodiment, see Figure 11 The force-applying component 230 includes a lifting platform, which is disposed between the first fixing component 210 and the second fixing component 220. The lifting platform is used to rise to abut against and arch the central guide rod 120, so that the first position point on the central guide rod 120 rises to a first height w.

[0106] Specifically, the lifting platform can ensure stability when the central guide rod 120 is in the upper arch, and the lifting platform can adjust the height of the central guide rod 120 when the central guide rod 120 is in the upper arch. Therefore, the lifting platform can better adjust the upper arch shape of the central guide rod 120.

[0107] Of course, in some other implementations, the central guide rod can also be arched upwards using jacks or overhead cranes.

[0108] In one embodiment, see Figure 11 The central guide rod 120 is a hollow guide rod, and the shaping mechanism 240 includes a conveying pipe 241, a heater 242, and a conveying pump 243. The conveying pipe 241 is connected to the central guide rod 120 and is used to convey the heat medium to the central guide rod 120; the heater 242 is installed on the conveying pipe 241 and is used to heat the heat medium; the conveying pump 243 is installed on the conveying pipe 241 and is used to provide power for the conveying pipe 241 to convey the heat medium.

[0109] Specifically, the delivery pipe 241 is connected to both ends of the central guide rod 120. The delivery pipe 241 is filled with a heating medium, and the delivery pump 243 provides the power to deliver the heating medium, allowing the heating medium to circulate thermally within the delivery pipe 241 and the central guide rod 120. The heater 242 provides heat, ensuring that the heating medium is continuously heated. Therefore, the shaping mechanism 240 can ensure that the central guide rod 120 completes its upward arching shaping under continuous heating by means of the thermal circulation of the heating medium when the central guide rod 120 arches upward under the force applied by the force member 230.

[0110] Of course, in some other implementations, the heating and forming can also be carried out by electrically heating the central guide rod.

[0111] In one embodiment, see Figure 12The shaping mechanism 240 also includes a thermometer 244, which is installed on the conveying pipe 241 and used to measure the temperature of the heat medium in the conveying pipe 241. By monitoring the temperature of the heat medium in the conveying pipe 241 with the thermometer 244, it is possible to better ensure that the central guide rod 120 completes the upward arch shaping at the preset temperature.

[0112] In one embodiment, a pulley 250 is provided at the bottom of one of the first fixing member 210 and the second fixing member 220.

[0113] Specifically, the first fixing member 210 and the second fixing member 220 can be clamps, such as bench vises. A pulley 250 is provided at the bottom of one of the first fixing members 210 and the second fixing member 220. The pulley 250 is slidable, ensuring that during the heating process of the central guide rod 120, when the first fixing member 210 and the second fixing member 220 are subjected to a force in the first direction X generated by the thermal expansion and contraction of the central guide rod 120, the pulley 250 can release this force. On the one hand, this simulates the situation where the central guide rod 120 is installed on the hollow insulator 110, making the fabrication of the central guide rod 120 closer to the application scenario. On the other hand, the release of this force by the pulley 250 prevents damage to the central guide rod 120 by the first fixing member 210 and the second fixing member 220. Alternatively, a pad 260 can be provided at the bottom of the first fixing member 210 or the second fixing member 220 without a pulley 250 to fix the relative position of the fixing member to the ground.

[0114] In a specific application scenario, refer to Figure 11 and Figure 12 This application provides a method for manufacturing a central guide rod 120, which is made of aluminum alloy. The method is as follows:

[0115] S01: Draw a line on the ground and set the pad vise and the sliding vise (the first fixing member 210 is the pad vise and the second fixing member 220 is the sliding vise) on the same straight line, wherein the pad vise is fixed to the ground and the sliding vise can slide relative to the ground, and the sliding direction is limited to the first direction X.

[0116] S02: Insert cast iron pipes 270 into both ends of the central guide rod 120. The ends of the cast iron pipes 270 inside the central guide rod 120 should reach or slightly exceed the edge of the anchoring section of the central guide rod 120. After installation, fill the gap between the central guide rod 120 and the cast iron pipes 270 with sealing rings. The insertion of the cast iron pipes 270 into both ends of the central guide rod 120 facilitates subsequent connection with the oil delivery hose (i.e., the delivery pipe 241).

[0117] S03: Fix both ends of the center guide rod 120 with a bench vise, and align the vise clamping position as closely as possible with the first end A and the second end B of the center guide rod 120.

[0118] S04: Place a lifting platform (i.e., force-applying component 230) below the middle of the central guide rod 120, and control the lifting platform to rise until it lifts the central guide rod 120, causing the central guide rod 120 to arch upwards to a first height w. The first height w can be calculated based on the specific parameters of the central guide rod 120 actually used.

[0119] S05: The non-corrosive, high-boiling-point oil (i.e., the heat medium) is heated and transported by a temperature-controlled heater (i.e., heater 242) and a high-temperature water pump (i.e., transfer pump 243). The heating temperature is controlled at around 180°C. The oil is introduced into the cast iron pipe 270 on one side of the central guide rod 120 through the oil delivery hose and output back to the temperature-controlled heater from the cast iron pipe 270 on the other side. The reading of the thermometer 244 is observed. When the reading of the thermometer 244 stabilizes at around 180°C, the timing begins.

[0120] S06: After 30 minutes, turn off the temperature-controlled heater and high-temperature water pump, allowing the central guide rod 120 and hot oil to slowly cool to room temperature. Once room temperature is reached, collect the oil and store it properly. Measure whether the upward arching distance of the central guide rod 120 meets the standard. If it does not meet the standard, repeat steps S01 to S05. It is understood that the heating time of 30 minutes in this step exceeds the theoretical calculation value, ensuring the shaping effect of the central guide rod 120. In some other embodiments, the heating time can also be set to 27 minutes, 28 minutes, 31 minutes, etc., as long as the shaping process of the central guide rod can be achieved; no specific restrictions are made here.

[0121] S07: Clean the inside of the center guide rod 120 at room temperature and air dry it naturally or blow it at a lower temperature to obtain the center guide rod 120 with an upward arch shape.

[0122] Using the above preparation method, when the central guide rod 120 is installed inside the hollow insulator 110, under the action of gravity, the middle section of the central guide rod 120 will gradually descend to be basically level with the height of both ends, thereby improving the problem of the central guide rod 120 drooping.

[0123] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural contradiction, the various technical features mentioned in the various embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A through-wall sleeve, characterized in that, The through-wall sleeve includes: Hollow insulators; A central guide rod, including a first end and a second end, is inserted through the hollow insulator and connected to the hollow insulator; During the manufacturing process, the central guide rod between the first end and the second end is arched upwards relative to the end of the central guide rod and is shaped, with the direction of the arch being opposite to the direction of gravity.

2. The through-wall sleeve according to claim 1, characterized in that, The first height w of the first position point on the central guide rod relative to the end of the central guide rod arches upwards, satisfying the following condition: Wherein, ρ is the linear density of the central guide rod, g is the gravitational acceleration, x is the distance from the first position point on the central guide rod to the first end along the first direction, L is the length between the two ends of the central guide rod, E is the Young's modulus of the central guide rod, I is the moment of inertia of the cross section of the central guide rod, and the first direction refers to the direction of the line connecting the two ends of the central guide rod.

3. The through-wall sleeve according to claim 1, characterized in that, The hollow insulator includes: A hollow insulating tube, wherein the central guide rod passes through the hollow insulating tube; The first end flange is fixed to the first end of the central guide rod and connects the central guide rod to the hollow insulating tube; The second end flange is fitted onto the second end of the central guide rod, connecting the central guide rod to the hollow insulating tube.

4. The through-wall sleeve according to claim 3, characterized in that, The through-wall sleeve also includes: The telescopic component is located between the second end flange and the second end of the central guide rod, and slidably connects the second end to the second end flange so that the second end can slide relative to the second end flange in a first direction, the first direction being the direction of the line connecting the two ends of the central guide rod.

5. The through-wall sleeve according to claim 1, characterized in that, The central guide rod is a hollow guide rod.

6. A forming apparatus for arching the central guide rod of a through-wall sleeve as described in any one of claims 1-5, characterized in that, The molding apparatus includes: A first fixing member and a second fixing member are spaced apart. The first fixing member is used to support and fix the first end of the central guide rod, and the second fixing member is used to support and fix the second end of the central guide rod. A force-applying component is used to apply a force to a first position point on the central guide rod, so that the central guide rod between the first end and the second end arches upward, with the arching direction opposite to the direction of gravity. A shaping mechanism is used to shape the central guide rod after it has been arched upwards.

7. The molding apparatus according to claim 6, characterized in that, The force-applying component includes: A lifting platform is disposed between the first fixing member and the second fixing member. The lifting platform is used to rise to abut against and arch the central guide rod, so that the first position point on the central guide rod rises to a first height.

8. The molding apparatus according to claim 6, characterized in that, The central guide rod is a hollow guide rod, and the shaping mechanism includes: A delivery pipe, connected to the central guide rod, is used to deliver a heat medium to the central guide rod; A heater, disposed on the conveying pipe, is used to heat the heat medium; A delivery pump, installed on the delivery pipe, is used to provide power for delivering the heat medium through the delivery pipe.

9. The molding apparatus according to claim 8, characterized in that, The shaping mechanism also includes: A thermometer is installed on the delivery pipe to measure the temperature of the heat medium in the delivery pipe.

10. The molding apparatus according to claim 6, characterized in that, One of the first fixing member and the second fixing member is provided with a pulley at its bottom.

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