Wall bushing, preparation method of wall bushing and processing device

Abstract

The present application discloses a wall bushing, a preparation method of the wall bushing and a processing device, wherein the wall bushing comprises: a hollow insulator, which is a hollow structure with closed ends in the axial direction; a central guide rod, which is inserted through the hollow insulator; an adjusting member, which comprises a first end and a second end which are arranged opposite to each other in the axial direction, at least the first end and the second end of the adjusting member are fixedly connected to the outer peripheral surface of the central guide rod, and the adjusting member is subjected to internal tension in the axial direction. The design of the present application can improve the problem of sagging of the central guide rod.

Description

Technical Field

[0001] The present application relates to the field of power transmission technology, and in particular to a wall bushing, a preparation method of the wall bushing, and a processing device. Background Art

[0002] Since the axial dimension of wall bushings above 400kV is large and they are generally arranged horizontally or approximately horizontally, the central guide rod inside the wall bushing used for conducting current will bend and sag under the action of gravity; at the same time, in order to control the distribution of the electric field, the diameter of the central guide rod is small; and in order to ensure the long-term operation reliability of the wall bushing, the support insulator in the middle of the wall bushing is sometimes eliminated, so the central guide rod is suspended in the middle of the wall bushing. These factors together increase the possibility of sagging in the middle of the central guide rod.

[0003] The sagging of the middle part of the center guide rod will increase the risk of insulation material breakdown in the wall bushing and reduce the reliability of the wall bushing. Therefore, there is an urgent need to improve the problem of the sagging of the middle part of the center guide rod. Summary of the invention

[0004] The present application provides a wall sleeve, a preparation method of the wall sleeve, and a processing device, which can improve the problem of central guide rod sagging.

[0005] A first aspect of an embodiment of the present application provides a wall bushing, which includes: a hollow insulator, which is arranged in an axial direction as a hollow structure with closed two ends; a center guide rod, which passes through the hollow insulator; an adjusting member, which includes a first end and a second end arranged opposite to each other in the axial direction, at least the first end and the second end of the adjusting member are fixedly connected to the outer circumferential surface of the center guide rod, and the adjusting member is subjected to internal tension in the axial direction.

[0006] In the above-mentioned wall sleeve, since the adjusting member is subjected to internal tension in the axial direction, the adjusting member will have a tendency to shrink eccentrically in the axial direction, thereby driving the center guide rod to be eccentrically compressed until the resistance generated by the eccentric compression of the center guide rod is balanced with the residual internal tension on the adjusting member, that is, the pre-tension stress applied to the adjusting member can cause corresponding eccentric pre-compression stress to be generated at the lower part of the center guide rod, and the eccentric pre-compression stress can prevent the center guide rod from sagging. Therefore, the setting of the adjusting member in the present application can effectively prevent the center guide rod from sagging.

[0007] Wherein, the entire surface of the adjusting member facing the central guide rod is adhered to the central guide rod.

[0008] The above arrangement can ensure the connection strength between the adjusting member and the central guide rod, thereby ensuring the reliability of the connection between the adjusting member and the central guide rod.

[0009] Wherein, the adjusting member is a carbon fiber reinforced composite material cloth.

[0010] The above-mentioned adjusting member is made of carbon fiber reinforced composite material cloth, which can ensure the reliability of the adjusting member.

[0011] In which, the distance between the first end of the adjusting member and the adjacent end of the center guide rod in the axial direction is defined as a first distance, and the distance between the second end of the adjusting member and the adjacent end of the center guide rod in the axial direction is defined as a second distance, and the first distance is equal to the second distance.

[0012] The above arrangement can make the force transmitted by the adjusting member to the central guide rod symmetrical about the middle part of the central guide rod, thereby avoiding or reducing the sagging of the middle part of the central guide rod to the greatest extent.

[0013] The range of the first distance and the second distance is less than or equal to the product of the length of the central guide rod and 0.2.

[0014] The above arrangement can further ensure the connection reliability between the central guide rod and the adjusting member, and avoid peeling between the central guide rod and the adjusting member during long-term use.

[0015] Wherein, the internal tension is equal to FA F D 2 / 4I1, where F = 5ρgL 2 / [384I(D+b)(3 / (25I)-9 / (200I1))], ρ is the linear density of the central guide rod, g is the acceleration of gravity, L is the length of the central guide rod, I is the cross-sectional inertia moment of the central guide rod, D is the outer diameter of the central guide rod, b is the thickness of the adjusting member, I1 is the moment of inertia of the composite cross-section formed by the central guide rod and the adjusting member, A F It is the area of ​​the cross section of the adjusting member perpendicular to the axial direction.

[0016] The above arrangement can avoid sagging of the center guide rod to the greatest extent.

[0017] A second aspect of an embodiment of the present application provides a method for preparing a wall sleeve, which is used to prepare the wall sleeve described in any of the above items, and the method comprises: fixing the two ends of the center guide rod respectively by a first fixing member and a second fixing member; in a state where the adjusting member is subjected to the internal tension in the axial direction of the center guide rod, at least fixing the first end and the second end of the adjusting member on the outer circumferential surface of the center guide rod along the axial direction.

[0018] The above method can be used to prepare a wall sleeve that can prevent the central guide rod from sagging.

[0019] Wherein, the step of fixing at least the first end and the second end of the adjusting member on the outer peripheral surface of the center guide rod along the axial direction in a state where the adjusting member is subjected to the internal tension in the axial direction of the center guide rod comprises: gluing the first end of the adjusting member to a first position of the center guide rod; fastening the center guide rod and the adjusting member at the first position by using a first tensioner; tensioning the adjusting member by using a second tensioner at a second position spaced apart from the first position in the axial direction until the tension applied to the second tensioner in the axial direction is equal to a preset tension value; gluing the adjusting member between the first tensioner and the second tensioner to the center guide rod; taking the second position as a new first position and a position spaced apart from the new first position in the axial direction as a new second position, returning to the step of fastening the center guide rod and the adjusting member at the first position by using the first tensioner to the step of gluing the adjusting member between the first tensioner and the second tensioner to the center guide rod until the length of the adjusting member glued to the center guide rod is equal to the preset length.

[0020] In the above scheme, the adjusting member of a preset length is pasted onto the central guide rod by means of segmented pasting, which can ensure that the internal tension of the adjusting member in the axial direction is equal everywhere.

[0021] Among them, the step of tensioning the adjusting member with a second tensioner at a second position spaced apart from the first position in the axial direction until the tension applied to the second tensioner in the axial direction is equal to a preset tension value comprises: applying adhesive on the center guide rod between the first position and the second position; covering the adhesive with a protective plate; locking the adjusting member and the second tensioner mounted on the center guide rod at the second position; driving the second tensioner to move away from the first tensioner until the tension applied to the second tensioner in the axial direction is equal to the preset tension value; and removing the protective plate.

[0022] The use of the protective plate in the above solution can prevent the adjusting member from being adhered to the central guide rod in advance during the process of tensioning the adjusting member.

[0023] Wherein, the first tensioner and the second tensioner are slidably connected by at least one group of screw rods arranged side by side, the screw rods extend along the axial direction, and a force gauge is arranged on the screw rods; the step of driving the second tensioner to move away from the first tensioner until the tension applied to the second tensioner in the axial direction is equal to the preset tension value comprises: driving the second tensioner to move away from the first tensioner until the sum of the readings of all the force gauges is equal to the preset tension value; and a nut is sleeved on the screw rod, and the nut is interposed between the first tensioner and the second tensioner; the step of driving the second tensioner to move away from the first tensioner comprises: rotating the nut until the nut abuts against the second tensioner; and continuing to rotate the nut to drive the second tensioner to move away from the first tensioner.

[0024] The use of the screw and the force gauge in the above solution can effectively ensure that after the adjusting member is fixedly connected to the central guide rod, the internal tension of the adjusting member in the axial direction reaches the expected value. At the same time, the use of the nut can ensure that the second tensioner moves away from the first tensioner stably.

[0025] A third aspect of an embodiment of the present application provides a processing device for processing any of the above-mentioned wall sleeves, the processing device comprising: a first fixing member and a second fixing member arranged at intervals, respectively used to fix the two ends of the center guide rod; a first tensioner, used to be sleeved on the center guide rod and lock the center guide rod and the adjusting member; a second tensioner, used to be sleeved on the center guide rod and locked with the adjusting member; a driving member, used to drive the second tensioner to move away from the first tensioner after the second tensioner is locked with the adjusting member, so that the adjusting member is subjected to the internal tension in the axial direction.

[0026] The above processing device can be used to prepare a wall sleeve that prevents the central guide rod from sagging.

[0027] Wherein, the processing device further includes: at least one group of screws arranged side by side, the screws extending along the axial direction, and the first tensioner and the second tensioner being slidably connected via the screws; and a force measuring device arranged on the screws.

[0028] The use of the screw and the force measuring device in the above solution can effectively ensure that after the adjusting member is fixedly connected to the central guide rod, the internal tension in the axial direction of the adjusting member reaches the expected value.

[0029] Wherein, the driving member comprises a nut, and the nut is sleeved on the screw rod and located between the first tensioner and the second tensioner.

[0030] The use of the nut in the above solution can ensure that the second tensioner moves stably away from the first tensioner.

[0031] Wherein, the first tensioner comprises: a first open ring, which is used to be sleeved on the central guide rod; a first locking member, which is arranged at the opening of the first open ring and is used to adjust the opening size of the first open ring to tighten or loosen the first open ring;

[0032] And / or, the second tensioner includes: a second open ring, used to be sleeved on the center guide rod; a second locking piece, arranged at the opening of the second open ring, used to adjust the opening size of the second open ring to tighten or loosen the second open ring; a clamp, arranged at the bottom of the second open ring away from the outer side of the annular surface of the first tensioner and connected to the second open ring, a gap is formed between the clamp and the second open ring in the vertical direction for the adjustment piece to pass through, and after the adjustment piece passes through the gap, the clamp is further used to lock the adjustment piece in the gap.

[0033] In the above scheme, the first tensioner includes a first open ring and a first locking member, and the first tensioner can be used to tighten the central guide rod and the adjusting member. The second tensioner includes a second open ring, a second locking member and a clamping plate, and the second tensioner can be used to reliably and smoothly tension the adjusting member.

[0034] The beneficial effect is: in the wall sleeve of the present application, since the adjusting member is subjected to internal tension in the axial direction, the adjusting member will have a tendency to shrink in the axial direction, thereby driving the center guide rod to be eccentrically compressed until the resistance generated by the eccentric compression of the center guide rod is balanced with the residual internal tension of the adjusting member, that is, the pre-tension stress applied to the adjusting member can cause corresponding eccentric pre-compression stress to be generated at the lower part of the center guide rod, and the eccentric pre-compression stress can prevent the center guide rod from sagging, so the setting of the adjusting member of the present application can effectively prevent the center guide rod from sagging.

[0035] At the same time, the present application also arranges that the entire surface of the adjusting member facing the central guide rod is adhered to the central guide rod, which can ensure the connection strength between the adjusting member and the central guide rod, and further ensure the reliability of the connection between the adjusting member and the central guide rod.

[0036] In addition, the present application also arranges the adjusting member to be a carbon fiber reinforced composite material cloth, which can ensure the reliability of the adjusting member. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work, among which:

[0038] Figure 1 This is a structural schematic diagram of an implementation method of a wall bushing of the present application;

[0039] Figure 2 yes Figure 1 A schematic diagram of the structure of the middle adjustment member and the center guide rod;

[0040] Figure 3 yes Figure 1 A schematic cross-sectional view of the middle adjusting member and the center guide rod perpendicular to the axial direction;

[0041] Figure 4 It is the bending moment diagram generated inside the center guide rod under the action of gravity;

[0042] Figure 5 It is a schematic flow chart of an implementation method of a method for preparing a wall bushing of the present application;

[0043] Figure 6 It is a schematic diagram of the processing device of the present application when processing a wall bushing;

[0044] Figure 7 yes Figure 6 Schematic diagram of the structure of the first tensioner;

[0045] Figure 8 yes Figure 6 The structural diagram of the second tensioner;

[0046] Fig. 9 It is the constraint diagram of the center guide rod;

[0047] Fig.10 It is a coordinate system established on the ideal axis of the central guide rod;

[0048] Fig.11 It is a schematic diagram of the internal bending moment of the composite rod composed of the central guide rod and the adjusting piece. DETAILED DESCRIPTION

[0049] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0050] It should be noted that the terms "first" and "second" in this application are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Thus, the features defined as "first" and "second" can explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally also includes steps or units that are not listed, or optionally also includes other steps or units inherent to these processes, methods, products or devices.

[0051] See also Figures 1 to 3 In one embodiment of the present application, the wall bushing 100 includes a hollow insulator 110 , a center guide rod 120 and an adjusting member 130 .

[0052] The hollow insulator 110 is configured as a hollow structure with closed ends along the axial direction X, and the central guide rod 120 is inserted through the hollow insulator 110 for conducting current. In one embodiment, the hollow insulator 110 includes a hollow insulating tube 111, a first end flange 112, and a second end flange 113. The central guide rod 120 is inserted through the hollow insulating tube 111, and the two do not contact each other. The first end flange 112 is sleeved on one end of the central guide rod 120 to connect the central guide rod 120 and the hollow insulating tube 111. The second end flange 113 is fixed to the other end of the central guide rod 120 to connect the central guide rod 120 and the hollow insulating tube 111.

[0053] The adjusting member 130 includes a first end 131 and a second end 132 which are arranged opposite to each other in the axial direction X. At least the first end 131 and the second end 132 of the adjusting member 130 are fixedly connected to the outer circumference of the central guide rod 120 , and the adjusting member 130 is subjected to internal tension in the axial direction X.

[0054] Specifically, only the first end 131 and the second end 132 of the adjusting member 130 may be fixedly connected to the outer peripheral surface of the center guide rod 120, and other parts of the adjusting member 130 may not be fixedly connected to the outer peripheral surface of the center guide rod 120; or the entire adjusting member 130 may be fixedly connected to the outer peripheral surface of the center guide rod 120, that is, the entire surface of the adjusting member 130 facing the center guide rod 120 is fixedly connected to the center guide rod 120, so as to ensure the connection strength between the adjusting member 130 and the center guide rod 120, and avoid the center guide rod 120 and the adjusting member 130 from peeling off during long-term use.

[0055] In one embodiment, the adjusting member 130 is adhered to the center guide rod 120 by an adhesive such as epoxy resin, so that at least the first end 131 and the second end 132 of the adjusting member 130 are fixedly connected to the outer peripheral surface of the center guide rod 120; in another embodiment, at least the first end 131 and the second end 132 of the adjusting member 130 can be fixedly connected to the outer peripheral surface of the center guide rod 120 by auxiliary parts such as tape.

[0056] In the above-mentioned wall sleeve 100, since the adjusting member 130 is subjected to internal tension in the axial direction X, the adjusting member 130 will have a tendency to shrink in the axial direction X, thereby driving the center guide rod 120 to be eccentrically compressed until the resistance generated by the eccentric compression of the center guide rod 120 is balanced with the residual internal tension exerted on the adjusting member 130, that is, the pre-tension stress applied to the adjusting member 130 can cause corresponding eccentric pre-compression stress to be generated at the lower part of the center guide rod 120, and the eccentric pre-compression stress can prevent the center guide rod 120 from sagging. Therefore, the setting of the adjusting member 130 in the present application can effectively prevent the center guide rod 120 from sagging.

[0057] Continue reading Figure 1 as well as Figure 2 In one embodiment, the entire surface of the adjusting member 130 facing the center guide rod 120 is adhered to the center guide rod 120 by an adhesive such as epoxy resin to ensure the connection strength between the center guide rod 120 and the adjusting member 130 to avoid peeling off the adjusting member 130 and the center guide rod 120 during long-term use.

[0058] The adjusting member 130 may be a pulling film or a pulling rod. In one embodiment, the adjusting member 130 is a carbon fiber reinforced composite material (CFRP). The carbon fiber reinforced composite material is a composite material formed by using carbon fiber or carbon fiber fabric as a reinforcement and resin, ceramic, metal, cement, carbon or rubber as a matrix. It has a higher specific strength and specific rigidity among many lightweight materials, and the lightweight effect is very obvious. Therefore, the material of the adjusting member 130 is a carbon fiber reinforced composite material, which can ensure the reliability of the adjusting member 130 and further prevent the central guide rod 120 from sagging.

[0059] Continue reading Figure 1 and Figure 2, the distance between the first end 131 of the adjusting member 130 and the end of the adjacent center guide rod 120 in the axial direction X is defined as the first distance L1, and the distance between the second end 132 of the adjusting member 130 and the end of the adjacent center guide rod 120 in the axial direction X is defined as the second distance L2, and the first distance L1 is equal to the second distance L2. Specifically, the middle part of the center guide rod 120 is the part that is most prone to sagging. By setting the first distance L1 equal to the second distance L2, the bending moment M generated by the center guide rod 120 under the action of gravity can be eliminated under the action of the adjusting member 130, thereby avoiding or reducing the sagging of the middle part of the center guide rod 120 to the greatest extent. It should be noted that the ends of the center guide rod 120 mentioned above refer to the positions on the center guide rod 120 that are connected to the first end flange 112 and the second end flange 113.

[0060] Continue reading Figure 1 and Figure 2 , along the axial direction X in the figure, under the action of gravity, a bending moment M will be generated inside the central guide rod 120, which makes the cross section of the central guide rod 120 half compressed and half tensile. The horizontal axis of the central guide rod 120 represents the central guide rod 120, and the bending moment M of the tension of the lower part of the central guide rod 120 is drawn below the central guide rod 120, and the bending moment M of the tension of the upper part is drawn above the central guide rod 120, then the following is obtained: Figure 4 The bending moment diagram of the central guide rod 120 under the action of gravity is shown in FIG. It can be seen that the bending moment M of the central guide rod 120 is a quadratic curve, and the bending moment M at both ends of the central guide rod 120 is The bending moment M in the middle of the central guide rod 120 is Wherein, ρ is the linear density of the central guide rod 120 , which can be obtained based on the product of the area of ​​the positive cross section of the central guide rod 120 and the material density of the central guide rod 120 , g is the gravitational acceleration, and L is the length between the two ends of the central guide rod 120 .

[0061] Continue reading Figure 2 as well as Figure 4 In one embodiment, the positions P and Q where the bending moment M of the central guide rod 120 is alternately positive and negative are used as the starting point and the end point of the connection between the adjusting member 130 and the central guide rod 120. According to the calculation of the existing technical specifications, the distance between the position P and the end of the adjacent central guide rod 120 and the distance between the position Q and the end of the adjacent central guide rod 120 are both equal to 0.211L (the specific calculation process is: (1 / 2-3 0.5 / 6)L=0.211L), and considering the fixed distance required for the force transmission of the adjusting member 130 itself, in one embodiment, the first distance L1 and the second distance L2 are both set to be equal to 0.2L. It can be understood that at this time, the length of the adjusting member 130 is equal to 0.6L.

[0062] In another embodiment, in order to increase the connection strength between the central guide rod 120 and the adjusting member 130 and further ensure the connection reliability between the central guide rod 120 and the adjusting member 130, the range of the first distance L1 and the second distance L2 is set to be less than the product of the length L of the central guide rod 120 and 0.2. In other embodiments, the range of the first distance L1 and the second distance L2 can also be set to be greater than 0.2L; or the first distance L1 and the second distance L2 can also be set to be unequal. In short, the first distance L1 and the second distance L2 can be set according to actual needs, and this application does not impose specific restrictions.

[0063] See 5 and Figure 6 In one embodiment of the present application, the processing device includes a first fixing member 210 and a second fixing member 220, a first tensioner 250, a second tensioner 260 and a driving member (not shown), wherein the first fixing member 210 and the second fixing member 220 are arranged at intervals and are respectively used to fix the two ends of the central guide rod 120; the first tensioner 250 is used to be sleeved on the central guide rod 120 and lock the central guide rod 120 with the adjusting member 130; the second tensioner 260 is used to be sleeved on the central guide rod 120 and lock with the adjusting member 130; the driving member is used to drive the second tensioner 260 to move away from the first tensioner 250 after the second tensioner 260 is locked with the adjusting member 130, so that the adjusting member 130 is subjected to internal tension in the axial direction X. The following is a process of preparing the above-mentioned wall sleeve 100 using the processing device:

[0064] S110 : Fixing the two ends of the central guide rod 120 by means of the first fixing member 210 and the second fixing member 220 respectively.

[0065] Specifically, the first fixing member 210 and the second fixing member 220 are used to fix the central guide rod 120 , and at the same time, except for the two ends, the rest of the central guide rod 120 is suspended.

[0066] The first fixing member 210 and the second fixing member 220 can both be tools such as a vise. In one embodiment, a pulley 230 is provided at the bottom of at least one of the first fixing member 210 and the second fixing member 220. The pulley 230 can slide to release the external force on the central guide rod 120 in the axial direction X, thereby avoiding damage to the central guide rod 120. In one embodiment, a pad 240 is provided at the bottom of the first fixing member 210, and a pulley 230 is provided at the bottom of the second fixing member 220. It can be understood that the setting of the pad 240 keeps the position of the first fixing member 210 stationary, so as to ensure the stability of the central guide rod 120 during the processing, thereby ensuring the processing effect. Of course, in other embodiments, the bottoms of the first fixing member 210 and the second fixing member 220 can also be provided with pads 240.

[0067] S120 : fixing at least the first end 131 and the second end 132 of the adjusting member 130 to the outer circumferential surface of the central guide rod 120 along the axial direction X in a state where the adjusting member 130 is subjected to internal tension in the axial direction X of the central guide rod 120 .

[0068] Specifically, after the adjusting member 130 is fixed on the outer circumference of the central guide rod 120, the adjusting member 130 is subjected to internal tension in the axial direction X, and the internal tension can be used to eliminate the sagging of the middle part of the central guide rod 120, thereby slowing down or preventing the sagging of the central guide rod 120. In the specific process of step S120, the adjusting member 130 is stretched first, and then the adjusting member 130 in the stretched state is fixed on the outer circumference of the central guide rod 120.

[0069] Continue to combine Figure 6 In one embodiment, step S120 includes:

[0070] S121 : Adhere the first end portion 131 of the adjusting member 130 to the first position of the central guide rod 120 .

[0071] Among them, an adhesive such as epoxy resin can be applied to the first position of the center guide rod 120, and then the first end 131 of the adjusting member 130 can be adhered to the first position of the center guide rod 120, or an adhesive such as epoxy resin can be applied to the first end 131 of the adjusting member 130, and then the first end 131 of the adjusting member 130 can be adhered to the first position of the center guide rod 120.

[0072] In one embodiment, the distance between the first position of the central guide rod 120 and the adjacent end of the central guide rod 120 is approximately equal to one fifth of the length L of the central guide rod 120 , that is, the first distance L1 is approximately equal to 0.2L.

[0073] S122: Using the first tensioner 250 to tighten the central guide rod 120 and the adjustment member 130 at the first position.

[0074] Specifically, in order to prevent the adjusting member 130 from being separated from the central guide rod 120 during the subsequent tensioning of the adjusting member 130 , the first tensioner 250 is used to fasten the central guide rod 120 and the adjusting member 130 at the first position.

[0075] In one embodiment, at a first position, the first tensioner 250 is sleeved on the periphery of the central guide rod 120 and the adjusting member 130, and then the central guide rod 120 and the adjusting member 130 are locked, so that no matter how the adjusting member 130 is stretched subsequently, the first end 131 of the adjusting member 130 will not be separated from the central guide rod 120.

[0076] See also Figure 6 as well as Figure 7In one embodiment, the first tensioner 250 includes a first open ring 251 and a first locking member 252 .

[0077] The first open ring 251 is used to be sleeved on the central guide rod 120; the first locking member 252 is arranged at the opening of the first open ring 251, and is used to adjust the opening size of the first open ring 251 to tighten or loosen the first open ring 251, so that when the central guide rod 120 and the adjusting member 130 need to be tightened, the first open ring 251 is locked by the first locking member 252. In one embodiment, the first locking member 252 includes a bolt and a nut. The present application does not limit the specific structure of the first locking member 252, as long as the first locking member 252 can adjust the opening size of the first open ring 251 and lock it.

[0078] S123: At a second position spaced apart from the first position in the axial direction X, the adjusting member 130 is tensioned by the second tensioner 260 until the tension applied to the second tensioner 260 in the axial direction X is equal to a preset tension value.

[0079] Specifically, the distance between the first position and the second position can be designed according to the requirements. At the second position, the second tensioner 260 is used to tension the adjusting member 130, so that the adjusting member 130 is in a stretched state, and when the tension applied to the second tensioner 260 in the axial direction X is equal to the preset tension value, the second tensioner 260 is controlled to stop tensioning the adjusting member 130.

[0080] Combination Figure 6 as well as Figure 8 The second tensioner 260 includes a second open ring 261 , a second locking member 262 and a clamping plate 263 .

[0081] The second open ring 261 is used to be sleeved on the central guide rod 120; the second locking member 262 is arranged at the opening of the second open ring 261, and is used to adjust the opening size of the second open ring 261, so as to tighten or loosen the second open ring 261; the clamping plate 263 is arranged at the bottom of the second open ring 261 away from the outer side of the annular surface of the first tensioner 250 and is connected to the second open ring 261, and a gap (not shown) is formed between the clamping plate 263 and the second open ring 261 in the vertical direction for the adjustment member 130 to pass through, and the adjustment member 130 can pass through the gap in the vertical direction, and after the adjustment member 130 passes through the gap, the clamping plate 263 is further used to lock the adjustment member 130 in the gap. Furthermore, the bottom of the second open ring 261 can be set as a hollow structure, that is, the bottom of the second open ring 261 is provided with a cavity 2631, so that the material consumption of the second tensioner 260 is reduced while not affecting the passing of the adjustment member 130, thereby reducing the cost.

[0082] Specifically, in step S123, the second open ring 261 is sleeved on the central guide rod 120, and the clamping plate 263 is set away from the first tensioner 250, and then the free end of the adjusting member 130 is led out from the gap between the second open ring 261 and the central guide rod 120, passes through the gap between the clamping plate 263 and the second open ring 261 in the vertical direction, and the adjusting member 130 is locked in the gap by the clamping plate 263, and then the second tensioner 260 is driven to move away from the first tensioner 250 until the tension applied to the second tensioner 260 in the axial direction X is equal to the preset tension value. It can be understood that in the process of the second tensioner 260 moving away from the first tensioner 250, the adjusting member 130 is stretched.

[0083] Among them, see Figure 7 as well as Figure 8 The main body of the second open ring 261 can have the same structure as the first open ring 251, except that a fixing plate (not shown) corresponding to the clamping plate 263 is also connected to the bottom of the second open ring 261, so that the adjusting member 130 can be locked in the gap between the fixing plate and the clamping plate 263 by using the clamping plate 263; the second locking member 262 can have the same structure as the first locking member 252.

[0084] S124 : Adhere the adjustment member 130 between the first tensioner 250 and the second tensioner 260 to the central guide rod 120 .

[0085] Specifically, when the tension applied to the second tensioner 260 in the axial direction X is equal to the preset tension value, the adjustment member 130 between the first tensioner 250 and the second tensioner 260 is adhered to the central guide rod 120 by an adhesive such as epoxy resin.

[0086] S125: Set the original second position as the new first position, and a position spaced apart from the new first position on the axial direction X as the new second position, and return to the step of using the first tensioner 250 to tighten the center guide rod 120 and the adjusting member 130 at the first position to the step of sticking the adjusting member 130 between the first tensioner 250 and the second tensioner 260 to the center guide rod 120, until the length of the adjusting member 130 stuck to the center guide rod 120 is equal to the preset length.

[0087] Specifically, the second tensioner 260 is moved from the original second position to the new second position, and the first tensioner 250 is moved from the original first position to the original second position (i.e., the new first position), the center guide rod 120 and the adjusting member 130 are locked at the new first position, and the adjusting member 130 is tensioned at the new second position until the requirements are met, and then the adjusting member 130 between the new first position and the new second position is pasted onto the center guide rod 120, and then the process from step S122 to step S125 is repeated until the length of the adjusting member 130 pasted onto the center guide rod 120 is equal to the preset length.

[0088] In one embodiment, when the length of the adjusting member 130 attached to the central guide rod 120 is equal to the preset length, the portion of the adjusting member 130 not attached to the central guide rod 120 is removed by, for example, shearing. In one embodiment, the length of the adjusting member 130 attached to the central guide rod 120 is equal to 0.6L.

[0089] The above embodiment adheres the adjusting member 130 of a preset length to the central guide rod 120 by pasting in sections, which can ensure that the internal tension of the adjusting member 130 in the axial direction X is equal everywhere, and can also prevent the long screw 280 from becoming unstable during the pasting process of the adjusting member 130 and causing damage to the equipment. Of course, in other embodiments, the adjusting member 130 of a preset length can also be pasted to the central guide rod 120 by only one pasting process, in which case it is only necessary to set the distance between the second position and the first position in step S123 to be equal to the preset length.

[0090] In one embodiment, continue to refer to Figure 6 , step S123 specifically includes:

[0091] S1231: Apply adhesive to the central guide rod 120 between the first position and the second position.

[0092] The adhesive may be epoxy resin, and the present application does not impose any specific restrictions on the material of the adhesive.

[0093] S1232: Cover the adhesive with the protection plate 270.

[0094] Specifically, in order to prevent the adjusting member 130 from being adhered to the central guide rod 120 in advance during the process of tensioning the adjusting member 130 , the protective plate 270 is used to cover the adhesive.

[0095] In one embodiment, the material of the protection plate 270 is polytetrafluoroethylene. It can be understood that the length of the protection plate 270 in the axial direction X is smaller than the distance between the first position and the second position.

[0096] S1233: At the second position, the adjusting member 130 is locked with the second tensioner 260 sleeved on the central guide rod 120 .

[0097] Specifically, at the second position, the adjusting member 130 and the second tensioner 260 are locked by using the clamping plate 263 .

[0098] S1234: driving the second tensioner 260 to move away from the first tensioner 250 until the tension applied to the second tensioner 260 in the axial direction X is equal to a preset tension value.

[0099] S1235 : Remove the protection plate 270 .

[0100] After the protection plate 270 is removed, step S124 may be performed to adhere the adjustment member 130 between the first tensioner 250 and the second tensioner 260 to the central guide rod 120 .

[0101] After removing the protective plate 270 , the protective plate 270 may be soaked in alcohol or other organic solvents to prevent the adhesive from solidifying on the protective plate 270 . At the same time, the protective plate 270 needs to be dried before the next use of the protective plate 270 .

[0102] Continue reading Figure 6 In one embodiment, the processing device also includes at least one group of screws 280 and force gauges 290 arranged side by side. Specifically, the first tensioner 250 and the second tensioner 260 are slidingly connected by at least one group of screws 280 arranged side by side. The screw 280 extends along the axial direction X, and the force gauge 290 is arranged on the screw 280. At this time, step S1234 includes: driving the second tensioner 260 to move away from the first tensioner 250 until the sum of the readings of all the force gauges 290 is equal to the preset tension value.

[0103] Specifically, the number of screws 280 can be three, four, five or more. In one embodiment, the number of screws 280 is four, wherein two screws 280 connect the first tensioner 250 and the second tensioner 260 on one side of the central guide rod 120, and the other two screws 280 connect the first tensioner 250 and the second tensioner 260 on the other side of the central guide rod 120.

[0104] Continue to combine Figure 6 , Figure 7 as well as Figure 8In one embodiment, the screw 280 is slidably connected to the first open ring 251 and the second open ring 261. Specifically, the first open ring 251 and the second open ring 262 are correspondingly provided with through holes 2511. The number of through holes 2511 on the first open ring 251 and the number of through holes 2511 on the second open ring 262 are equal to the number of screws 280. The screw 280 sequentially passes through the through holes 2511 on the first open ring 251 and the through holes 2511 on the second open ring 262, thereby realizing the sliding connection of the screw 280 to the first open ring 251 and the second open ring 262.

[0105] At the same time, a force gauge 290 is provided on each screw rod 280. In the process of driving the second tensioner 260 to move away from the first tensioner 250, when the sum of the readings of all the force gauges 290 is equal to the preset tension value, it means that the internal tension of the adjustment member 130 between the first position and the second position in the axial direction X has reached the expected value, and therefore the driving of the second tensioner 260 to move away from the first tensioner 250 is stopped.

[0106] Continue reading Figure 6 In one embodiment, the driving member of the processing device includes a nut (not shown). Specifically, a nut is sleeved on the screw rod 280, and the nut is located between the first tensioner 250 and the second tensioner 260. At this time, the step of driving the second tensioner 260 to move away from the first tensioner 250 includes: rotating the nut until the nut abuts against the second tensioner 260; continuing to rotate the nut to drive the second tensioner 260 to move away from the first tensioner 250.

[0107] Specifically, after the nut is rotated until it abuts against the second tensioner 260 , the nut is continuously rotated. During the process of continuing to rotate the nut, the second tensioner 260 is pushed and moves away from the first tensioner 250 .

[0108] Continue reading Figure 1 In one embodiment, the internal tension T of the adjusting member 130 in the axial direction X is equal to FA F D 2 / 4I1, where F = 5ρgL 2 / [384I(D+b)(3 / (25I)-9 / (200I1))], ρ is the linear density of the center guide rod 120, g is the acceleration of gravity, L is the length between the two ends of the center guide rod 120, I is the cross-sectional inertia moment of the center guide rod 120, D is the outer diameter of the center guide rod 120, b is the thickness of the adjusting member 130, I1 is the inertia moment of the composite cross-section formed by the center guide rod 120 and the adjusting member 130, A F It is the area of ​​the cross section of the adjusting member 130 perpendicular to the axial direction X.

[0109] Specifically, it is estimated below that the deflection δ of the middle part of the center guide rod without setting the adjustment member of the present application, the deflection δ of the middle part of the center guide rod mainly includes two parts, one part is the deflection caused by gravity, and the other part is the deflection caused by creep under long-term energized operation.

[0110] First, let's introduce the deflection caused by gravity:

[0111] Since the center guide rod is a hollow structure, the cross section of the center guide rod perpendicular to the axial direction is a circular cross section. The length between the two ends of the center guide rod is defined as L, the outer diameter is D, and the inner diameter is d. The cross-sectional area of ​​the center guide rod perpendicular to the axial direction is defined as A, then A=π(D 2 -d 2 ) / 4, and the Young's modulus of the material used for the central guide rod is recorded as E. The support equipment at both ends of the central guide rod generally does not allow the ends of the central guide rod to rotate. Therefore, the constraint diagram of the central guide rod is as follows: Fig. 9 As shown, one end of the center guide rod is a sliding constraint and the other end is a fixed constraint, wherein the sliding constraint means that the center guide rod is allowed to slide in the axial direction (the axial direction of the center guide rod is set as the horizontal direction hereinafter), but rotation and vertical movement (vertical refers to the direction perpendicular to the horizontal direction) are not allowed.

[0112] As mentioned above, see Figure 4 , under the action of gravity, a bending moment M will be generated inside the central guide rod 120, which makes the cross section of the central guide rod 120 half compressed and half tensile. At the same time, the present application believes that under the action of gravity, the deformation of the central guide rod is still small compared to its length, which can be regarded as a small deformation. At the same time, since the central guide rod is generally made of alloy material, it has good elasticity. It can be considered that it still meets the plane section assumption and linear elastic assumption when it is subjected to bending moment, so the following approximate equation can be used:

[0113] к≈w (2) =-M / EI

[0114] Among them, κ is the curvature of the center guide rod after deformation, w is the sag (i.e. deflection) of a point on the center guide rod in the vertical direction relative to its ideal axis (the straight line passing through the two ends of the center guide rod), and w is a function of the coordinate along the axial direction of the center guide rod; w (1) is the first-order derivative of w with respect to the coordinate along the axial direction, that is, the cross-sectional rotation angle; w (2) is the second derivative of w with respect to the coordinate along the axial direction. At the same time, in the above formula, the bending moment M drawn below the center guide rod is positive. I is the moment of inertia of the cross section of the center guide rod about the horizontal axis passing through the centroid of the plane where it is located. For the annular cross section of the center guide rod, I = (1-a 4 )πD 4 / 64, where a=d / D.

[0115] At the same time, the ideal axis of the center guide rod is established. Fig.10 Coordinate system shown.

[0116] Finally, according to the boundary conditions and related equations, we know that w (2) =ρg[–L 2 / 24+0.5(x–0.5L) 2 ] / EI,w (1) =ρg[–xL 2 / 24+0.5(x 3 / 3–0.5Lx 2 +L 2 x / 4)] / EI,w=ρg[–x 2 L 2 / 48+0.5(x 4 / 12–Lx 3 / 6+L 2 x 2 / 8)] / EI. It can be obtained that under the action of gravity, the deflection of the middle part of the central guide rod is ρgL 4 / 384EI.

[0117] The following describes the deflection caused by creep of the center guide rod under long-term energized operation:

[0118] During the power-on process, the center guide rod generates heat due to its own resistance. The metal will creep during long-term heat and stress, generating additional plastic strain, which will cause the sagging amount of the center guide rod to gradually increase over time. Currently, the material commonly used for the center guide rod is aluminum alloy. According to literature research, the creep of aluminum alloy will first experience a first stage of rapid development; when the operating temperature is higher than 145°C, it will enter a second stage of gradual stability with a creep strain rate that is approximately constant; when the operating temperature is higher than 0.3 times the melting point (168°C to 198°C), it will enter the third stage of destruction. According to existing technical specifications, the average operating temperature of the center guide rod should not exceed 130°C, and the maximum temperature should not exceed 140°C. Therefore, this application does not consider the creep of the center guide rod in the second and third stages.

[0119] The commonly used center guide rod material is generally 6 series aluminum alloy, and its creep formula is approximately: ε c =9.4852×10 -18 σ 5.65 t 0.47344 Among them, ε cis the creep strain, dimensionless; σ is the axial stress of the center guide rod, measured in MPa; t is the duration of high temperature, measured in h. It should be noted that although the center guide rod is subjected to axial stress and shear stress under the action of gravity, the deformation caused by the shear stress of the thin-walled rod with L>8D is much lower than the deformation caused by its axial stress, so the creep caused by the shear stress can be ignored. The service life of a general wall bushing is 30 years. For a center guide rod with L=10000mm, D=120mm, and d=100mm, its maximum axial stress is 10.5MPa. According to the formula, the creep strain within its service life is 2.05×10 -9 , can be ignored. Therefore, for general wall bushings, the present application does not need to consider the deflection caused by creep of the center guide rod under long-term energized operation.

[0120] In summary, the calculation formula for the middle deflection δ of the center guide rod is: δ=ρgL 4 / 384EI. For a center guide rod with L of 10000mm, D of 120mm, and d of 100mm, δ is 8.4mm.

[0121] Combination Figure 1 and Figure 6 As shown, after the central guide rod 120 is prestressed by the adjusting member 130 of the present application, that is, after the adjusting member 130 is fixedly connected to the central guide rod 120, the non-gravity bending moment generated by the composite rod composed of the central guide rod 120 and the adjusting member 130 is as follows: Fig.11 shown.

[0122] Fig.11 The bending moment area marked with “-” in the middle is the area where the adjustment member 130 is installed. The area of ​​the cross section of the adjustment member 130 perpendicular to the axial direction X is A. F , the elastic modulus of the adjusting member 130 is E F , the bending moment corresponding to the middle part of the composite rod is M p , the internal pressure is N. Among them, L1 = L2, when both are 0.2L, M P =2M0 / 5; when both are other lengths, M P =L1M0 / (0.5L), M0 is the initial bending moment caused by the external stress (detailed description below). Since the common material of the central guide rod 120 is aluminum alloy, and the elastic modulus E of the adjusting member 130 is F Generally, it is 1 / 3 to 1 / 4 of the aluminum alloy material, and the thickness of the adjusting member 130 is relatively small, so it can be considered that the centroid of the composite cross section formed by the central guide rod 120 and the adjusting member 130 does not change much, and the moment of inertia of the composite cross section I1≈I+E F D 2 A F / (4E) (the centroid height of the adjusting member 130 is also neglected here, and it is assumed that the centroid of the adjusting member is close to the bottom surface of the central guide rod 120).

[0123] During the preparation of the wall sleeve 100, the second tensioner 260 tensions the adjusting member 130 with a tension force F until the adjusting member 130 is elongated and stabilized, and then the adjusting member 130 is adhered to the outer peripheral surface of the central guide rod 120. At this time, the tension force F is borne by the second tensioner 260. In this stage, N=0, M P =0. After the second tensioner 260 is removed, the tension force of the adjusting member 130 is transmitted to the central guide rod 120, and the two jointly bear the force to achieve deformation coordination. The adjusting member 130 and the central guide rod 120 can be regarded as a composite section that is jointly stressed. At this time, the actual tension on the composite section is F. After the entire processing device is removed, the internal tension on the adjusting member 130 in the axial direction X is T. According to the equilibrium condition, the initial bending moment M0 caused by the external stress is F(D+b) / 2, then M P =F(D+b) / 5, so at a position greater than 0.2L from the end of the central guide rod 120 in the middle of the central guide rod 120, T / A F =F(D+b) 2 / (4I1)≈FD 2 / (4I1), T=FA F D 2 / (4I1).

[0124] At the same time, this application uses the virtual displacement method to calculate the upward deflection δ generated in the center guide rod 120 span after the prestress is applied P , the calculation formula is: P =L 2 F(D+b)(3 / 25I-9 / 200I1) / (5E).

[0125] In order to apply the prestress, the upward deflection δ of the central guide rod 120 in the span P It can offset the middle deflection δ of the central guide rod 120 under the action of gravity, so that δ P =δ, we can get F = 5ρgL 2 / [384I(D+b)(3 / (25I)-9 / (200I1))].

[0126] Therefore, the internal tension T of the adjusting member 130 in the axial direction X is calculated and set by the above embodiment: T=FA F D 2 / (4I1), F=5ρgL 2 / [384I(D+b)(3 / (25I)-9 / (200I1))], which can effectively prevent the central guide rod 120 from sagging.

[0127] In one embodiment, when the sum of the readings of all the force gauges 290 is equal to F during the process of driving the second tensioner 260 to move away from the first tensioner 250, it indicates that the internal tension T on the adjusting member 130 between the first position and the second position in the axial direction X has reached the expected value, and therefore the driving of the second tensioner 260 to move away from the first tensioner 250 is stopped.

[0128] The above description is only an embodiment of the present application and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly used in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A wall bushing, characterized in that: The wall bushing comprises: Hollow insulators are arranged axially as hollow structures with both ends closed; A central guide rod, passing through the hollow insulator; The adjusting member comprises a first end and a second end which are arranged opposite to each other in the axial direction. At least the first end and the second end of the adjusting member are fixedly connected to the outer peripheral surface of the central guide rod, and the adjusting member is subjected to internal tension in the axial direction.

2. The wall bushing according to claim 1, characterized in that: The entire surface of the adjusting member facing the central guide rod is adhered to the central guide rod.

3. The wall bushing according to claim 1, characterized in that: The adjusting piece is made of carbon fiber reinforced composite material cloth.

4. The wall bushing according to claim 1, characterized in that: The distance between the first end of the adjusting member and the adjacent end of the center guide rod in the axial direction is defined as a first distance, and the distance between the second end of the adjusting member and the adjacent end of the center guide rod in the axial direction is defined as a second distance, and the first distance is equal to the second distance.

5. The wall bushing according to claim 4, characterized in that: The range of the first distance and the second distance is less than or equal to the product of the length of the central guide rod and 0.

2.

6. The wall bushing according to claim 1, characterized in that: The internal tension is equal to FA F D 2 / (4I1), Where F = 5ρgL 2 / [384I(D+b)(3 / (25I)-9 / (200I1))], ρ is the linear density of the central guide rod, g is the acceleration of gravity, L is the length of the central guide rod, I is the cross-sectional inertia moment of the central guide rod, D is the outer diameter of the central guide rod, b is the thickness of the adjusting member, I1 is the moment of inertia of the composite cross-section formed by the central guide rod and the adjusting member, A F It is the area of ​​the cross section of the adjusting member perpendicular to the axial direction.

7. A method for preparing a wall bushing, used for preparing the wall bushing according to any one of claims 1 to 6, characterized in that: The method comprises: Fixing the two ends of the central guide rod by a first fixing member and a second fixing member respectively; In a state where the adjusting member is subjected to the internal tension in the axial direction of the central guide rod, at least the first end portion and the second end portion of the adjusting member are fixed to the outer peripheral surface of the central guide rod along the axial direction.

8. The preparation method according to claim 7, characterized in that: The step of fixing at least the first end portion and the second end portion of the adjusting member on the outer peripheral surface of the central guide rod along the axial direction in a state where the adjusting member is subjected to the internal tension in the axial direction of the central guide rod comprises: Adhere the first end of the adjusting member to the first position of the central guide rod; Using a first tensioner to fasten the central guide rod and the adjusting member at the first position; At a second position spaced apart from the first position in the axial direction, tensioning the adjusting member by a second tensioner until the tension applied to the second tensioner in the axial direction is equal to a preset tension value; Adhere the adjusting member between the first tensioner and the second tensioner to the central guide rod; The second position is taken as the new first position, and a position spaced apart from the new first position in the axial direction is taken as the new second position, and the step of fastening the center guide rod and the adjusting member at the first position using the first tensioner is returned to the step of sticking the adjusting member between the first tensioner and the second tensioner to the center guide rod until the length of the adjusting member stuck to the center guide rod is equal to the preset length.

9. The preparation method according to claim 8, characterized in that: The step of tensioning the adjusting member by a second tensioner at a second position spaced apart from the first position in the axial direction until the tension applied to the second tensioner in the axial direction is equal to a preset tension value comprises: Applying adhesive on the central guide rod between the first position and the second position; Covering the adhesive with a protective plate; At the second position, the adjusting member is locked with the second tensioner sleeved on the central guide rod; driving the second tensioner to move away from the first tensioner until the tension applied to the second tensioner in the axial direction is equal to the preset tension value; Remove the protective plate.

10. The preparation method according to claim 9, characterized in that: The first tensioner and the second tensioner are slidably connected by at least one set of screws arranged side by side, the screws extend along the axial direction, and a force measuring device is arranged on the screws; The step of driving the second tensioner to move away from the first tensioner until the tension applied to the second tensioner in the axial direction is equal to the preset tension value comprises: driving the second tensioner to move away from the first tensioner until the sum of the readings of all the force gauges is equal to the preset tension value; And, a nut is sleeved on the screw rod, and the nut is interposed between the first tensioner and the second tensioner; The step of driving the second tensioner to move away from the first tensioner comprises: Rotating the nut until the nut abuts against the second tensioner; The nut is continuously rotated to drive the second tensioner to move away from the first tensioner.

11. A processing device for processing the wall bushing according to any one of claims 1 to 6, characterized in that: The processing device comprises: A first fixing member and a second fixing member are arranged at intervals and are used to fix two ends of the central guide rod respectively; A first tensioner, used for being sleeved on the central guide rod and locking the central guide rod and the adjusting member; A second tensioner, used for being sleeved on the central guide rod and for being locked with the adjusting member; A driving member is used for driving the second tensioner to move away from the first tensioner after the second tensioner is locked with the adjusting member, so that the adjusting member is subjected to the internal tension in the axial direction.

12. The processing device according to claim 11, characterized in that: The processing device also includes: at least one set of screws arranged side by side, the screws extending along the axial direction, and the first tensioner and the second tensioner being slidably connected via the screws; A force measuring device is arranged on the screw rod.

13. The processing device according to claim 12, characterized in that: The driving member comprises a nut, which is sleeved on the screw rod and located between the first tensioner and the second tensioner.

14. The processing device according to claim 11, characterized in that: The first tensioner comprises: A first open ring, used for sleeved on the central guide rod; A first locking member, disposed at the opening of the first open ring, and used to adjust the opening size of the first open ring to tighten or loosen the first open ring; And / or, the second tensioner comprises: A second open ring, used for sleeved on the central guide rod; A second locking member, disposed at the opening of the second open ring, and used to adjust the opening size of the second open ring to tighten or loosen the second open ring; A clamping plate is arranged at the bottom of the second open ring away from the outer side of the annular surface of the first tensioner and is connected to the second open ring. A gap is formed between the clamping plate and the second open ring in the vertical direction for the adjusting member to pass through. After the adjusting member passes through the gap, the clamping plate is further used to lock the adjusting member in the gap.

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