A method for forming a pre-bent strand of a rotary sprocket

Abstract

The application relates to a kind of cable strand pre-bending forming methods simulating rotary cable saddle, and belongs to the field of cable strand pre-forming.The pre-forming bending section of cable strand is the cable strand section in rotary cable saddle, and the pre-forming process of rotary cable strand is according to wire unwinding-forming-winding-tape-marking-drawing-coiling, when wire unwinding to pre-forming bending section, wire is drawn to pre-bending forming die, wire is separated layer by layer according to inner and outer layer mode at rotary cable saddle, and wire bundle cross section is carded to be consistent with the size of the inner cavity of pre-bending forming die, the carded pre-bending section wire bundle is placed into the cavity of pre-bending forming die, to ensure that the outer layer wire is closely combined with the die, the bending section is fixed by clamp, and the pre-bending forming of rotary cable strand at rotary cable saddle is completed.

Description

Technical Field

[0001] This invention relates to a method for preforming strands, and more specifically to a method for pre-bending and forming strands. Background Technology

[0002] Suspension bridges have numerous advantages in terms of structural form, span capacity, and construction methods, and are widely used in the construction of large and medium-span bridges spanning rivers, seas, and canyons. However, with the further development of my country's transportation infrastructure, conventional suspension bridge designs are finding it increasingly difficult to adapt to more complex and unique terrain, geology, and construction conditions. Against this backdrop, new suspension bridge structural forms, such as the slewing cable suspension bridge, have emerged.

[0003] A slewing cable refers to a main cable arrangement where the main cable originates from an anchorage on one bank, passes around an anchorage on the opposite bank, and then returns and anchors back to the originating anchorage. The main cable strands pass continuously at the slewing anchorage, and the strands are slewing anchored using a slewing cable saddle system. This replaces the traditional discontinuous and dispersed anchoring method used in suspension bridges, fully utilizing the self-balancing characteristics of the main cable under constant load and optimizing the suspension bridge's anchorage structure and anchorage structure. The slewing cable erection structure is as follows: Figure 1 As shown.

[0004] The main features of the slewing cable and restraint system are: 1) The slewing side strands are continuous and compact, which can significantly reduce the requirements for the anchorage structure size compared with the traditional main cable's spread anchorage; 2) The slewing cable has two-plane turning in both vertical and horizontal planes. Compared with the traditional main cable strands, the strand and wire arrangement must meet the requirements of bidirectional turning in both vertical and horizontal planes.

[0005] like Figure 2 The diagram shows one method of main cable rotation.

[0006] like Figure 3 The diagram shows the structure of the slewing saddle.

[0007] like Figure 4 As shown Figure 3 The BB cross-sectional view of the structure shown illustrates the arrangement of the main cable wires within the slewing saddle.

[0008] In the above-mentioned turning maneuvers, for the cable strands in the vertical plane, the turning of the main cable saddle at the tower end and the anchorage section cable saddle cancels out the change in wire length within the cable strand caused by the sag of the main cable strand. However, for the turning maneuvers in the horizontal plane, this will lead to a significant difference in the wire length within the traditional cable strand, resulting in uneven stress on the main cable strand. Therefore, for the slewing cable strand, it is necessary to simulate the structure of the slewing cable saddle and pre-form it in the factory to ensure uniform stress on the main cable strand after installation. Summary of the Invention

[0009] The present application provides a strand pre-bending forming method for the bending of the strand of a rotating cable at a rotating cable saddle, which pre-bends the strand at the bending section of the rotating cable saddle to reduce or avoid the uneven stress of the pre-formed main cable strand.

[0010] The present application adopts the technical solution of a strand pre-bending forming method for simulating a rotating cable saddle, which comprises,

[0011] I. The length of the steel wire of the rotating strand is determined according to the design requirements, and the steel wire is wound on a wire reel.

[0012] II. The length L of the bending section of each layer of steel wire at the rotating cable saddle is determined according to the size of the rotating cable saddle N , N is the number of layers of the main cable, and the base number is from the inside to the outside, and the innermost layer is 1; according to the circular arc simulation, the length difference ΔL of the innermost layer steel wire and the outermost layer steel wire of the same root strand at the rotating cable saddle is calculated.

[0013] III. Marking of the rotating strand

[0014] The length of the bending section of each layer of steel wire calculated in step II is marked at the starting point and the ending point of the pre-bending forming section of the inner and outer steel wires of the rotating strand corresponding to the rotating cable saddle, and the starting point corresponds to the entrance of the rotating cable saddle, and the ending point corresponds to the exit of the rotating cable saddle.

[0015] IV. The specifications of the pre-bending forming die are determined according to the bending arc length of the rotating cable saddle and the height H of the bending arc length, the pre-bending forming die has an arc-shaped die cavity for bending and shaping the steel wire, the arc-shaped inner diameter R1 of the arc-shaped die cavity is consistent with the arc-shaped inner diameter of the rotating cable saddle; the height H corresponding to the arc-shaped radius R1 of the arc-shaped die cavity is consistent with the height corresponding to the arc-shaped inner diameter of the rotating cable saddle; the arc-shaped outer diameter R2 of the arc-shaped die cavity satisfies R2=R1+(1.1-1.5)h, h is the height of the inner strand of the rotating cable saddle in the inner and outer layer direction; the width of the arc-shaped die cavity and the rotating cable saddle in the radial section is consistent.

[0016] V. Pre-forming the rotating strand

[0017] The preforming of the rotating strand includes a straight preforming section and a curved preforming section, wherein the curved preforming section is the strand section in the rotating saddle. The preforming process of the rotating strand is wire unwinding, forming, wrapping, marking, traction and coiling. The several steel wires constituting the rotating strand are unwound from the wire reels. For the straight preforming section, the wire bundle is shaped and then directly pulled to the winding reel for winding after being wrapped with a wrapping belt. When the steel wire is unwound to the curved preforming section, the steel wire is pulled to the pre-bending forming die, and the wrapping belt on the wire bundle is removed. The wire bundle is divided into layers according to the inner and outer layers in the rotating saddle, and the cross section of the wire bundle is carded to be consistent with the size of the inner cavity of the pre-bending forming die. The front and rear ends of the wire bundle are temporarily fixed to maintain the current cross section shape.

[0018] Then, the carded pre-bending section wire bundle is placed in the cavity of the pre-bending forming die to ensure that the outer layer of the steel wire is tightly attached to the die and that the cross section shape of the wire bundle is consistent with the cross section shape of the steel wire in the rotating saddle. The bending extension trend of the wire bundle in the pre-bending forming die cavity is consistent with the bending trend of the steel wire in the rotating saddle.

[0019] Six, clamp fixing of the preformed curved section of the rotating strand

[0020] The positions of the inner and outer layers of the steel wire in the pre-bending forming die are adjusted so that the starting point mark on the steel wire corresponds to the starting position of the pre-bending forming die, and the end point mark corresponds to the end position of the pre-bending forming die. Then, the pre-bending section of the rotating strand is fixed by using a clamp, and after fixing, it is pulled forward to the winding reel for winding, and then the processing of the straight preforming section of the rotating strand is continued.

[0021] As one of the embodiments of the present application, in step two,

[0022] (N-3)d), wherein d is the diameter of the steel wire, R1 is the rotating inner diameter of the circular arc where the innermost layer of the rotating strand is located, and θ is the central angle of the circular arc where the rotating saddle is located.

[0023] d), wherein N is the number of layers corresponding to the outermost layer of the steel wire.

[0024] As one of the embodiments of the present application, in step six, when adjusting the position of the steel wire, a partition plate is used to cut between the current layer of steel wire and the adjacent layer of steel wire, and then the position of the current layer of steel wire is adjusted. This can avoid interference with the steel wire of the adjacent layer when the current steel wire moves.

[0025] As one of the embodiments of the present application, in step six, the starting and ending positions of the preformed bending section of the rotating strand are fixed by clamp one, the fixed length of clamp one is 100mm-200mm, the middle section of the preformed bending section of the rotating strand is fixed by clamp two, the fixed length of clamp two is 30mm-80mm, and the distance between the clamps is 1-3m.

[0026] As one of the embodiments of the present application, a spacer is arranged between the outermost 1-4 layers of steel wires of the preformed bending section of the rotating strand, the spacer is located at the middle position of the preformed bending section, and the spacer fills the bending gap between the outer steel wire layers, the extension length of the spacer along the length direction of the rotating strand is 50-80mm, and the width along the radial cross section width direction of the bending section of the rotating strand is not less than the outer diameter of the strand.

[0027] As one of the embodiments of the present application, the preformed bending section in the rotating strand has several sections, and each bending section.

[0028] As one of the embodiments of the present application, in step five, the pre-bending forming die comprises a plurality of circular arc section forming dies and a reference base plate, the plurality of circular arc section forming dies are arranged at intervals along the circular arc, each circular arc section forming die is fixedly connected with the reference base plate, the reference base plate is a flat plate, the length of the reference base plate is consistent with the straight line distance between the inlet and outlet of the rotating cable saddle, the circular arc section forming die at one end starts from one end of the reference base plate, and the circular arc section forming die at the other end ends at the other end of the reference base plate.

[0029] Further, a gap is left between two adjacent circular arc section forming dies to reserve the installation space of the clamp.

[0030] Compared with the prior art, the present application has the advantages that: the present application simulates the structure of the rotating cable saddle according to the bending form of the rotating strand at the rotating cable saddle, preforms the bending section of the rotating strand, and ensures that the main cable strand is uniformly stressed after erection. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 It is a schematic diagram of the rotating main cable of the rotating cable suspension bridge;

[0032] Figure 2 It is a rotating mode of a main cable;

[0033] Figure 3 It is a schematic diagram of the structure of the rotating cable saddle;

[0034] Figure 4 It is Figure 3 the BB sectional view in the structure shown;

[0035] Figure 5 It is a pre-bending forming principle diagram of the rotating strand;

[0036] Figure 6 The marking method of the cable strand in the bending forming section;

[0037] Figure 7 The arrangement of the cable strand steel wires at the rotating cable saddle in the embodiment of the present application;

[0038] Figure 8 The structure of the pre-bending forming device in the embodiment of the present application;

[0039] Figure 9 The Figure 8 The AA cross-sectional view;

[0040] Figure 10 The pre-forming process of the main cable strand straight section in the embodiment of the present application (front view);

[0041] Figure 11 The pre-forming process of the main cable strand straight section in the embodiment of the present application (top view);

[0042] Figure 12 The pre-forming process of the main cable strand bending section in the embodiment of the present application (front view);

[0043] Figure 13 The pre-forming process of the main cable strand bending section in the embodiment of the present application (top view);

[0044] Figure 14 The cross-sectional shape of the cable strand steel wires after carding in the embodiment of the present application, which is consistent with the arrangement shape of the steel wires at the rotating cable saddle;

[0045] Figure 15 The cross section of the cable strand after being fixed by the temporary fixture in the embodiment of the present application;

[0046] Figure 16 The arrangement of the cable strand steel wires in the pre-bending forming device of the main cable strand in the embodiment of the present application, which is consistent with the arrangement shape of the steel wires at the rotating cable saddle;

[0047] Figure 17 The process of the cable strand steel wires entering the pre-bending forming device in the embodiment of the present application;

[0048] Figure 18 The fixation of the cable strand in the pre-bending section in the embodiment of the present application;

[0049] Figure 19 The spacer between the steel wire layers of the cable strand pre-bending section;

[0050] Figure 20 The schematic diagram of the spacer arranged between the steel wire layers of the cable strand pre-bending section for spacing;

[0051] Figure 21 Figure 1 is a side view of a first fixture for a pre-bending section of a strand;

[0052] Figure 22 Figure 1 is a side view of a first fixture for a pre-bending section of a strand;

[0053] Figure 23 Figure 1 is a side view of a first fixture for a pre-bending section of a strand;

[0054] Figure 24 Figure 1 is a side view of a first fixture for a pre-bending section of a strand;

[0055] In the figure, main cable 1, rotating cable saddle 2, rotating saddle 3, tower cable saddle 4, scattering saddle 5, pre-formed simulation mold 6, connecting plate 7, reference base plate 8, wire feeding disc 9, wrapping tape 10, reel 11, fixture one 12, fixture two 13, gasket 14. DETAILED DESCRIPTION

[0056] The application will be further described in conjunction with the following examples, which are exemplary and intended to explain the application, and should not be construed as limiting the application. The description in the examples is corresponding to the drawings, and the description of the orientation is also based on the description of the drawings, and should not be construed as limiting the protection scope of the application.

[0057] Example 1

[0058] This example simulates the structure of the rotating cable saddle, and pre-forms the rotating cable saddle in the factory to ensure that the rotating strands are uniformly stressed after erection.

[0059] Implementation scheme:

[0060] (1) The winding and production of the steel wires of the strand are performed according to the design requirements, and the length and specification of the steel wires are determined by the design unit in combination with the specific bridge design.

[0061] (2) The bending length of the strand at the rotating cable saddle is determined according to the size of the rotating strand and the rotating cable saddle groove.

[0062] According to the circular arc simulation, the length difference between the inner and outer layers of the steel wires of the same rotating strand at the rotating cable saddle is calculated, and the calculation process is as follows, see Figure 5 ,

[0063] The first layer steel wire length L1 of the rotating cable saddle = θ / 180 x π x (R1+0.5d)

[0064] The second layer steel wire length L2 of the rotating cable saddle = θ / 180 x π x (R1+0.5d)

[0065] The third layer steel wire length L3 of the rotating cable saddle = θ / 180 x π x (R1+0.5d)

[0066] Length of the fourth layer wire of the rotating cable saddle

[0067] Length of the fifth layer wire of the rotating cable saddle

[0068] Length of the sixth layer wire of the rotating cable saddle

[0069] Length of the seventh layer wire of the rotating cable saddle

[0070] Length of the Nth layer wire of the rotating cable saddle

[0071] Wherein, d is the diameter of the wire, R1 is the inner diameter of the rotating cable strand.

[0072] The calculation formula is based on the rotating main cable with 7 layers

[0073] The total number of layers of the main cable is N, and the calculation formula of ΔL of the outermost layer and the first layer wire is

[0074]

[0075] (3) Marking of the rotating cable strand

[0076] Before the pre-forming of the rotating cable strand in the bending section of the rotating cable saddle, according to the length difference above, according to the marking points of the rotating cable saddle on the cable strand, marks are made on the upper layer of the cable strand wire (the outer layer of the rotating cable saddle) and the lower layer of the cable strand wire (the inner layer of the rotating cable saddle) at the starting point (the entry point of the corresponding rotating cable saddle) and the ending point (the exit point of the corresponding rotating cable saddle) of the pre-bending forming section of the rotating cable strand, which facilitates the inspection after pre-bending forming, as shown in Figure 6 .

[0077] (4) According to the bending arc length and the height of the bending arc length of the rotating cable saddle, the specifications of the pre-bending forming mold are determined, the pre-bending forming mold has an arc-shaped mold cavity for wire bending and shaping, the arc-shaped inner diameter R1 of the arc-shaped mold cavity is consistent with the arc-shaped inner diameter of the rotating cable saddle; the height H corresponding to the arc-shaped radius R1 of the arc-shaped mold cavity is consistent with the height corresponding to the arc-shaped inner diameter of the rotating cable saddle; the arc-shaped outer diameter R2 of the arc-shaped mold cavity satisfies: R2=R1+(1.1-1.5)h, h is the height of the inner cable strand in the inner and outer layer direction of the rotating cable saddle; the width of the arc-shaped mold cavity and the rotating cable saddle in the radial section is consistent, as shown in Figure 8 , 9 .

[0078] (5) The pre-bending forming device has the following parts:

[0079] ①The reference base plate 8 for determining the inner diameter R1 of the preformed circular arc segment, the height H and the length of the circular arc segment (inner arc length) is 10mm-20mm in thickness, the length of the reference base plate is not less than the straight line length between the start point and the end point of the bending segment of the rotating strand, and the width is not less than 2 times the cross-sectional width of the strand, so as to ensure that the reference base plate does not warp, deform or lose stability during use. The reference base plate 8 needs to be finished, and the flatness thereof should reach 0.5mm / 1000mm. The reference base plate is vertically placed on the ground.

[0080] ②The pre-bending forming die (the structure of the pre-bending forming die is shown in Figure 6 The inner cavity of the die needs to be machined, and the dimensional error of the machined cavity is not greater than 0.1mm. The die is composed of three to five circular arc segments with the same center and the same diameter, and the wall thickness is 30mm-100mm, so as to ensure a certain rigidity and provide sufficient constraint rigidity for the preforming of the strand. A certain gap is reserved between the circular arc segments of the pre-bending forming die, so as to facilitate the installation of the mounting clamp after forming. The start point and the end point of the pre-bending forming die are basically consistent with the start point and the end point of the rotating saddle.

[0081] ③A certain thickness of steel plate or rigid support is used to connect the pre-bending forming die and the reference base plate. The connecting plate or connecting support has a certain rigidity, and needs to ensure that the preforming circular arc device does not lose stability and does not deform during preforming operation. In the manufacturing process, the reference base plate and the connecting device are welded or bolted, the connecting device and the preforming die can be integrally machined or welded. After welding, the flatness of the base plate should reach 1mm / 1000mm.

[0082] (6) The preforming of the rotating strand includes preforming of the straight line segment and the preforming of the bending segment. The preforming process of the rotating strand is as follows: steel wire unwinding-forming-wrapping tape-marking-pulling-winding. The steel wires constituting the rotating strand are respectively unwound from the wire reels. For the preforming of the straight line segment, the steel wire bundle is shaped after the steel wire is unwound from the wire reel, and then the steel wire bundle is directly pulled to the winding reel and wound on the winding reel. As shown in Figures 10-11 When the steel wire is unwound to the preforming bending segment, the steel wire is pulled to the pre-bending forming die, and the wrapping tape on the steel wire bundle is removed at the same time. The steel wire is divided layer by layer according to the inner and outer layers in the rotating saddle, and the cross section of the steel wire bundle is combed to be consistent with the inner cavity size of the pre-bending forming die. Temporary fixation is performed at the front and rear ends of the steel wire bundle to maintain the current cross-sectional shape, as shown in Figures 14-16After the pre-bending section is shown, the pre-bending section is put into the cavity of the pre-bending forming die, the outer layer of the steel wire is tightly attached to the die, and the cross-sectional shape of the steel wire is consistent with the cross-sectional shape of the steel wire at the rotating cable saddle; the bending extension trend of the steel wire in the cavity of the pre-bending forming die is consistent with the bending trend of the steel wire at the rotating cable saddle.

[0083] (7) The pre-bending section of the rotating cable is fixed by a clamp

[0084] The positions of the inner and outer layers of the steel wire in the pre-bending forming die are adjusted, so that the starting mark on the steel wire corresponds to the starting position of the pre-bending forming die, and the ending mark corresponds to the ending position of the pre-bending forming die; if the mark on the pre-bent steel wire is detected to be inconsistent with the design, the thin steel plate is cut into the layer of steel wire and the adjacent layer of steel wire, and the carding is performed again.

[0085] Then the pre-bending section of the rotating cable is fixed by a clamp, the clamps at the starting and ending positions are large-rigidity special clamps (clamp one) with a length of 100mm-200mm (the clamp structure is shown in Figure 21 、 22 ), and the bolts are tightened so that the steel wire cannot move freely, the middle section clamps are ordinary pre-forming clamps (clamp two) with a length of 30mm-80mm (the clamp structure is shown in Figure 23 、 24 ), and the distance between the clamps is 2m, as shown in Figure 18 . After being fixed, it is pulled forward and wound on the reel, as shown in Figures 12-13 , and then the processing of the pre-forming straight section of the rotating cable is continued.

[0086] In order to prevent the outer layer of the steel wire from moving, positioning isolation spacers can be arranged between the outermost 1-4 layers of the steel wire in the pre-bending section (the length of the spacer along the length direction of the cable is 50-80mm, and the width along the diameter direction of the cable is not less than the outer diameter of the cable), and the spacer is made of flexible material such as high-strength polyester fiber tape according to the design thickness, as shown in Figure 19 、 20 .

[0087] In the pre-bending forming section of the rotating cable, 3-8 layers of high-strength polyester fiber adhesive tape are wrapped around the band.

[0088] In addition to the above embodiments, the present application also includes other embodiments, and any technical solutions formed by equivalent transformation or equivalent replacement shall fall within the protection scope of the claims of the present application.

Claims

1. A method for pre-bending and forming cable strands to simulate a slewing cable saddle, characterized in that: include, 1. Determine the length of the steel wire in the slewing cable strand according to the design requirements, and coil the steel wire on the wire feeding spool; II. Determine the length L of the bent section of each layer of steel wire at the slewing saddle based on the dimensions of the slewing saddle. N N is the number of layers of the main cable, with the innermost layer being 1, based on the circular arc simulation. The length difference ΔL between the innermost and outermost steel wires of the same strand at the slewing cable saddle is calculated. III. Revolving Strand Marking According to the length of the bending section of each layer of steel wire calculated in step two, mark the starting point and the ending point of the pre-bent forming section of the inner and outer layers of steel wire corresponding to the slewing saddle of the slewing cable strand. The starting point corresponds to the entrance of the slewing saddle, and the ending point corresponds to the exit of the slewing saddle. The marked steel wire is then coiled onto the wire unwinding reel. IV. Based on the bending arc length and the height H of the bending arc length of the slewing saddle, determine the specifications of the pre-bending forming mold. The pre-bending forming mold has an arc-shaped mold cavity for bending and shaping the steel wire. The arc-shaped inner diameter R1 of the arc-shaped mold cavity is consistent with the arc-shaped inner diameter of the slewing saddle. The height H corresponding to the arc radius R1 of the arc-shaped mold cavity is consistent with the height corresponding to the arc-shaped inner diameter of the slewing saddle. The arc-shaped outer diameter R2 of the arc-shaped mold cavity satisfies: R2 = R1 + (1.1~1.5)h, where h is the height of the inner strand of the slewing saddle in the inner and outer layer directions. The width of the arc-shaped mold cavity and the slewing saddle is consistent in the radial section. V. Pre-forming of slewing cable strands The preforming of the slewing cable strand includes a preforming straight section and a preforming curved section. The preforming curved section corresponds to the cable strand section inside the slewing cable saddle. The preforming process of the slewing cable strand is as follows: wire feeding—forming—wrapping—marking—traction—coiling. Several wires constituting the slewing cable strand are fed out from each wire reel. For the preforming straight section, after the wires are fed out from the feeding reel, the wire bundle is shaped and fixed with wrapping tape, and then directly pulled to the reel for winding. When the wires are fed to the preforming curved section, the wires are pulled towards the pre-bending forming mold, and the wrapping tape on the wire bundle in this section is removed. The wires are separated layer by layer according to the inner and outer layers at the slewing cable saddle, and the cross-section of the wire bundle is combed to match the inner cavity size of the pre-bending forming mold. The front and rear ends of the wire bundle in this section are temporarily fixed to maintain the current cross-sectional shape. Then, the combed pre-bent section of the steel wire bundle is placed into the cavity of the pre-bending forming mold, ensuring that the outer steel wire fits tightly with the mold and that the cross-sectional shape of the steel wire bundle is consistent with the cross-sectional shape of the steel wire at the saddle of the slewing cable strand; the bending extension trend of the steel wire bundle in the cavity of the pre-bending forming mold is consistent with the bending trend of the steel wire at the saddle of the slewing cable strand.

6. Fix the pre-formed bending section of the slewing cable strand with clamps. Adjust the positions of the inner and outer steel wires in the pre-bending forming mold so that the starting point mark on the steel wire corresponds to the starting position of the pre-bending forming mold and the ending point mark corresponds to the ending position of the pre-bending forming mold. Then, use a clamp to fix the pre-bending section of the rotary strand in segments. After fixing, pull forward and wind it onto the reel. Then continue to process the pre-forming straight section of the rotary strand.

2. The method according to claim 1, characterized in that: In step two, In the formula, d is the diameter of the steel wire, R1 is the inner diameter of the arc where the innermost steel wire in the slewing strand is located, and θ is the central angle of the arc where the slewing saddle is located. In the formula, N is the number of layers corresponding to the outermost steel wire layer.

3. The method according to claim 1, characterized in that: In step six, when adjusting the position of the steel wire, a separator is used to cut between the current steel wire layer and the adjacent steel wire layer, and then the position of the current steel wire layer is adjusted.

4. The method according to claim 1, characterized in that: In step six, the starting and ending positions of the preformed bending section of the slewing cable strand are fixed with clamp one, the fixing length of clamp one is 100mm~200mm, and the middle section of the preformed bending section of the slewing cable strand is fixed with clamp two, the fixing length of clamp two is 30mm~80mm, and the spacing between the clamps is 1-3m.

5. The method according to claim 1, characterized in that: A shim is placed between the outermost 1 to 4 layers of steel wire in the preformed bending section of the slewing strand. The shim is located in the middle of the preformed bending section. The shim extends 50 to 80 mm along the length of the slewing strand and its width along the radial cross-sectional width of the slewing strand bending section is not less than the outer diameter of the strand.

6. The method according to claim 1, characterized in that: The pre-formed bending section in the slewing cable strand has several segments.

7. The method according to claim 1, characterized in that: In step five, the pre-bending forming mold includes multiple arc segment forming molds and a reference base plate. The multiple arc segment forming molds are arranged at intervals along the arc. Each arc segment forming mold is fixedly connected to the reference base plate. The reference base plate is a flat plate. The length of the reference base plate is consistent with the straight-line distance between the inlet and outlet of the slewing cable saddle. The arc segment forming mold at one end starts at one end of the reference base plate, and the arc segment forming mold at the other end terminates at the other end of the reference base plate.

8. The method according to claim 7, characterized in that: A gap is left between two adjacent arc segment forming molds.

Images