Contact network dropper string pressing structure and pressing method

Abstract

The present invention discloses a contact network suspension string crimping structure and crimping method, which relates to the technical field of contact network suspension string crimping, including a crimping tube, the crimping tube including a pair of symmetrically arranged crimping channels, one end of the stranded wire sequentially passing through the two crimping channels to form a hanging loop, each crimping channel including an arc segment and two straight segments, the arc segment being the fillet at the connection of the two straight segments, the two straight segments forming an obtuse angle, adjacent crimping channels not in contact and connected, and the two ports on the same side not in contact, and the stranded wire fixed in the crimping channel. The present invention ensures that the suspension string main line is not bent at the crimping tube through the cooperation of the crimping tube and the heart-shaped ring, reducing the bending stress and fatigue fracture risk of the stranded wire at this location.

Description

Technical Field

[0001] The present invention relates to the technical field of catenary wire crimping, and in particular to a catenary wire crimping structure and a crimping method. Background Art

[0002] The catenary dropper strings connect the contact wires and the load-bearing cables. When static, they maintain the contact wire's geometric shape. When a train passes at high speed, the vibrations of the contact wires are transmitted to the load-bearing cables through the dropper strings, transferring load and stabilizing the contact wire. The dropper strings also possess a certain electrical current-carrying capacity. Generally speaking, dropper strings are categorized as integrally adjustable, integrally non-adjustable, and rigid. Both integrally adjustable and integrally non-adjustable dropper strings utilize flexible stranded wire for length adjustment. Once the string length is determined, the stranded wire must be secured to the component. Typically, a crimping tube is used. The stranded wire is passed through the crimping tube, inserted into a heart-shaped ring, and then threaded back through the crimping tube before being connected to the terminal block. The two stranded wires contained within the crimping tube are compressed using a specialized tool and die, locking the strands in place and preventing them from sliding. This process is called the dropper string crimping process, and the shape of the crimping tube and the post-crimping state are collectively referred to as the dropper string crimping method.

[0003] After the conventional crimping tube is crimped onto the suspension string, the two suspension strings are arranged in parallel inside the crimping tube. However, since only one strand of the strands is directed in the direction of force, when the suspension string is subjected to force, the crimping tube will be in an inclined state, causing the strands to bend with a small bending radius at the outlet of the crimping tube, commonly known as "hard bend". After multiple cycles of vibration, the strands at this location are prone to fatigue fracture, such as Figure 9 As shown. Furthermore, because the two strands of wire in the traditional crimping method are parallel within the crimp tube, any time the suspension string is stressed and straightened, the main wire will inevitably form a hard bend at the crimp tube exit. Furthermore, the heart-shaped ring is located at the crimp tube exit, and since the heart-shaped ring separates the strands in two directions, the two strands also experience a small bend radius at the heart-shaped ring located at the other end of the crimp tube. Tests have shown that this area is also prone to fatigue fracture of the suspension string. Furthermore, due to the insufficient spacing between the strands of wire at the crimp tube exit and the stressed strands, the strands of wire that travel to the terminal often wear and break inside or outside the crimp tube during vibration. Summary of the Invention

[0004] The purpose of the present invention is to provide a contact network dropper string crimping structure and crimping method to solve the problems existing in the above-mentioned prior art, so that the main line of the dropper string is not bent at the crimping tube end, thereby reducing the radial shear force and fatigue fracture risk of the stranded wire at this position.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] The present invention provides a contact network suspension string crimping structure, including a crimping tube, the crimping tube including a pair of symmetrically arranged crimping channels, one end of the stranded wire sequentially passes through the two crimping channels to form a hanging loop, each of the crimping channels includes an arc segment and two straight segments, the arc segment is a chamfered corner at the connection of the two straight segments, the two straight segments form an obtuse angle, adjacent crimping channels are not in contact and connected, and the two ports on the same side are not connected, and the stranded wire is fixed in the crimping channel.

[0007] Preferably, the included angle between the two straight segments of the same crimping channel is 145° to 180°, and the included angle between the two ends of the straight segment located on the same opening side of the crimping tube is 0° to 45°.

[0008] Preferably, the two straight line segments are symmetrically arranged about the center line of the arc segment, and the length of the straight line segment is 2 mm to 14 mm.

[0009] Preferably, the arc radius of the arc segment is at least 3 mm.

[0010] Preferably, the arc length of the arc segment is at least 2 mm.

[0011] Preferably, the wall thickness of the crimping channel is at least 1 mm, and the inner diameter of the crimping channel matches the outer diameter of the stranded wire and is 4 mm to 15 mm.

[0012] Preferably, the length of the crimping channel along the length direction of the stranded wire is 10 mm to 60 mm, and the width perpendicular to the length direction of the stranded wire is 8 mm to 50 mm.

[0013] Preferably, the material of the crimping channel includes metal or metal alloy.

[0014] Preferably, the crimping channel is an integrally formed part made of copper or copper alloy, and the stranded wire is fixed in the crimping channel by crimping.

[0015] The present invention also relates to a method for crimping a catenary dropper string, which is based on the above-mentioned catenary dropper string crimping structure and specifically comprises the following steps:

[0016] S1, cutting the cylindrical tube with an inner diameter of 8-16 mm into sections of set length for later use;

[0017] S2, compressing and deforming the tube to uniformly press the circular cross section of the tube segment into a waist-shaped cross section to form a flat tube, wherein the waist-shaped cross section is 15 mm long and 5 mm wide; expanding the ends of the flat tube to the same width, so that the lengths of the openings at both ends of the flat tube are greater than the length of the inner opening, thereby forming two side walls on the left and right sides of the flat tube, each of which is smoothly connected by a circular arc segment, and the angle between the axes of the two straight side walls on the same side is 145° to 180°, or the angle between the axes of the two straight side walls on the same opening side is 0° to 45°, thereby forming an expanded flat tube;

[0018] S3, passing the two ends of the stranded wire around the heart-shaped ring through the flared flat tube respectively, and making the opening of the flared flat tube contact the edge of the heart-shaped ring, and maintaining this position;

[0019] S4, use a mold to apply pressure to the upper and lower surfaces of the flared flat tube, press the flared flat tube and the stranded wire, and make the middle part of the flared flat tube fit with the stranded wire, so that two symmetrical and closed crimping multi-segment lines are formed in the middle part of the flared flat tube, and a pair of crimping channels are formed, and the crimping multi-segment lines each include an arc segment and two straight segments, the arc segment is a chamfered corner at the connection of the two straight segments, and the openings of the two arc segments are both facing the outside of the flared flat tube, and the sliding load of the stranded wire in the crimping channel is at least greater than 2kN.

[0020] Compared with the prior art, the present invention has achieved the following technical effects:

[0021] The main line of the suspension string of the present invention can ensure that the main line of the suspension string is not bent at the compression tube through the cooperation of the compression tube and the heart-shaped ring, thereby reducing the bending stress and fatigue fracture risk of the stranded wire at this part. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0023] Figure 1 Schematic diagram of the contact network dropper string pressing structure in an embodiment of the present invention Figure 1 ;

[0024] Figure 2 Schematic diagram of the contact network dropper string pressing structure in an embodiment of the present invention Figure 2 ;

[0025] Figure 3 Schematic diagram of the contact network dropper string pressing structure in an embodiment of the present invention Figure 3 ;

[0026] Figure 4 Schematic diagram of the contact network dropper string pressing structure in an embodiment of the present invention Figure 4 ;

[0027] Figure 5 Schematic diagram of the contact network dropper string pressing structure in an embodiment of the present invention Figure 5 ;

[0028] Figure 6 Schematic diagram of the use and assembly of the contact network dropper string pressing structure in the embodiment of the present invention Figure 1 ;

[0029] Figure 7 Schematic diagram of the use and assembly of the contact network dropper string pressing structure in the embodiment of the present invention Figure 2 ;

[0030] Figure 8 Figures a, b, c, d, and e are process flow charts of a method for crimping a catenary string in a second embodiment of the present invention;

[0031] Figure 9 This is a schematic diagram of the use and assembly of the contact network hanger string pressing structure in the prior art;

[0032] In the figure: 1-twisted wire, 2-crimping tube, 3-crimping channel, 4-straight segment, 5-arc segment, 6-heart-shaped ring, 7-main line of the suspension string, 8-suspension ring. DETAILED DESCRIPTION

[0033] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0034] The purpose of the present invention is to provide a contact network dropper string crimping structure and crimping method to solve the problems existing in the prior art, so that the main line of the dropper string is not bent at the crimping tube end, thereby reducing the radial shear force and fatigue fracture risk of the stranded wire at this position.

[0035] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0036] Example 1

[0037] like Figures 1 to 7As shown, in this embodiment, a contact network suspension string crimping structure is provided, including a crimping tube 2, the crimping tube 2 includes a pair of crimping channels 3 symmetrically arranged, one end of the stranded wire 1 passes through the two crimping channels 3 in sequence to form a hanging ring, each crimping channel 3 includes an arc segment 5 and two straight segments 4, the arc segment 5 is a chamfered corner at the connection of the two straight segments 4, the two straight segments 4 form an obtuse angle, adjacent crimping channels 3 are not in contact and connected, and the two ports on the same side are not connected, and the stranded wire 1 is fixed in the crimping channel 3.

[0038] As an optional solution, the angle between the two straight segments 4 of the same crimping channel 3 in this embodiment is 145° to 180°, preferably 164°, and the angle between the two ends of the straight segment 4 located on the same opening side of the crimping tube 2 is 0° to 45°, preferably 16°, similar to a hyperbola. This embodiment proposes a non-parallel arrangement of stranded wires within the crimping tube, and further proposes a hyperbola-like arrangement of stranded wires for the suspension string. The stress state of the suspension string is verified, so that the main line of the suspension string always coincides with the loading direction when loaded, and the stranded wire 1 has no hard bends. The crimping method of this embodiment optimizes the shape of the matching heart-shaped ring 6. Specifically, the angle and length of the two straight segments of the heart-shaped ring 6 are modified so that it can be aligned with the crimping tube, facilitating the crimping operation while protecting the stranded wire 1.

[0039] As an optional solution, in this embodiment, the two straight line segments 4 are symmetrically arranged about the center line of the arc segment 5, and the length of the straight line segment 4 is 2 mm to 14 mm.

[0040] As an optional solution, in this embodiment, the arc radius of the arc segment 5 is at least 3 mm.

[0041] As an optional solution, in this embodiment, the arc length of the arc segment 5 is at least 2 mm.

[0042] As an optional solution, in this embodiment, the wall thickness of the crimping channel 3 is at least 1 mm to ensure the connection strength. The inner diameter of the crimping channel 3 matches the outer diameter of the stranded wire 1 after crimping and is 4 mm to 15 mm.

[0043] As an optional solution, in this embodiment, the length of the crimping channel 3 along the length direction of the stranded wire 1 is 10 mm to 60 mm, preferably 30 mm, and the width perpendicular to the length direction of the stranded wire 1 is 8 mm to 50 mm, preferably 20 mm.

[0044] As an optional solution, the material of the crimping channel 3 in this embodiment includes metal or metal alloy, which is convenient for crimping and forming and ensures a certain connection strength.

[0045] As an optional solution, in this embodiment, the crimping channel 3 is preferably an integrally formed part made of copper or copper alloy. The stranded wire 1 is fixed in the crimping channel 3 by crimping, and the sliding load of the stranded wire 1 in the crimping channel 3 is at least greater than 2kN, meeting the force requirements of the stranded wire 1 when serving as the main line 7 of the suspension string.

[0046] The crimping structure of the crimping channel 3 of this embodiment eliminates the hard bending of the stranded wire 1 at the outlet of the traditional suspension string under stress; and the two groups of stranded wires 1 are in a separated state, avoiding wear between the stranded wires 1; at the same time, the stranded wire leading to the terminal block is at a large distance from the main line of the suspension string, and at the same time, the width of the bayonet of the matching heart-shaped ring 6 is increased to match it with the opening of the crimping channel 3, which can avoid mutual friction between the stranded wires 1 outside the crimping tube 2; in addition, the overall dimensions of the crimping tube 2 and the heart-shaped ring 6 match the traditional crimping method, and can be directly adapted to the suspension ring 8, wire clamps, terminal blocks, suspension string main line 7, bolts and nuts, etc. used in the current suspension string, which is convenient for engineering application.

[0047] The main wire 7 of the suspension string in this embodiment has no bends at the end of the crimping tube 2, which reduces the bending stress of the stranded wire 1 at this location and reduces the risk of fatigue fracture of the stranded wire 1 at this location; the stranded wire 1 at the transition location between the heart-shaped ring of the suspension string and the crimping tube is aligned and has no bends, which reduces the bending stress of the stranded wire 1 at this location and reduces the risk of fatigue fracture of the stranded wire 1 at this location; the stranded wire of the current-carrying ring of the suspension string maintains a distance from the stranded wire of the main wire of the suspension string at the crimping tube location, which reduces the risk of wear between the strands.

[0048] Example 2

[0049] like Figure 8 As shown, this embodiment provides a method for pressing a catenary dropper string, which is based on the catenary dropper string pressing structure of the first embodiment, and specifically includes the following steps:

[0050] S1, cutting the cylindrical tube with an inner diameter of 12 mm into sections of set length for later use;

[0051] S2, pressing and deforming the tube, uniformly pressing the circular cross section of the tube segment into a waist-shaped cross section to form a flat tube, wherein the waist-shaped cross section is 15 mm long and 5 mm wide; expanding the ends of the flat tube to the same width, so that the length of the openings at both ends of the flat tube is greater than the length of the inner opening, thereby forming two side walls of the flat tube that are smoothly connected by a circular arc segment, with the angle between the axis of the side walls of the two straight segments 4 on the same side being 145° to 170°, or the angle between the axis of the side walls of the two straight segments 4 on the same opening being 10° to 30°, thereby forming an expanded flat tube;

[0052] S3, passing the two ends of the stranded wire 1 through the heart-shaped ring 6 through the expanded flat tube respectively, and making the opening of the expanded flat tube contact the edge of the heart-shaped ring 6, and maintaining this position;

[0053] S4, use a mold to apply pressure to the upper and lower surfaces of the flared flat tube, press the flared flat tube and the stranded wire 1, and make the middle part of the flared flat tube fit with the stranded wire 1, so that two symmetrical and closed crimping multi-segment lines are formed in the middle of the flared flat tube, and a pair of crimping channels 3 are formed. The crimping multi-segment lines each include an arc segment 5 and two straight line segments 4. The arc segment 5 is a chamfered corner at the connection of the two straight line segments 4, and the openings of the two arc segments 5 are both facing the outside of the flared flat tube, and the sliding load of the stranded wire 1 in the crimping channel 3 is at least greater than 2KN, meeting the force requirements of the stranded wire 1 when serving as the main line 7 of the suspension string.

[0054] When in use, the two ends of the main line of the suspension string 7 are respectively connected to a crimping tube 2 and a heart-shaped ring 6 to form a hanging ring, and then the two heart-shaped rings 6 are respectively hung on the suspension rings 8 at the upper and lower ends. The suspension rings 8 are connected to the contact wire and the load-bearing cable (or elastic suspension cable) through the contact wire suspension string clamp. The stranded wire bent out of the crimping tube 2 is then connected to the contact wire suspension string clamp and the load-bearing cable (elastic suspension cable) suspension string clamp through the wiring terminal to form a complete set of suspension strings.

[0055] Example 3

[0056] like Figure 9 As shown, this embodiment provides a method for pressing a catenary dropper string, which is based on the catenary dropper string pressing structure of the first embodiment, and specifically includes the following steps:

[0057] S1, copper tube cutting, cut the copper tube with an outer diameter of 14mm and an inner diameter of 12mm into 30mm long tube sections.

[0058] S2, press the circular cross-section pipe section into a waist-shaped hole cross-section structure of 5mm (diameter)*15mm (length).

[0059] S3, uses a special mold to expand the inside and outside to make the waist-shaped hole into a trumpet structure with symmetrical front and rear ports, and makes the opening angle of the trumpet 16°, forming a double V-shaped flat tube structure.

[0060] S4, passing the heart-shaped ring 6 and the stranded wire 1 through the double V-shaped flat tube structure according to the assembly position requirements.

[0061] S5. Use a special crimping die to press the copper tube and stranded wire 1 from the top and bottom directions until the middle of the crimping tube 2 is crimped closed. The sliding load of stranded wire 1 inside the crimping tube 2 is at least greater than 2kN, meeting the design standard.

[0062] Throughout this specification, references to terms such as "one embodiment," "certain embodiments," "illustrative embodiments," "this embodiment," "specific examples," or "some examples" indicate that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, illustrative uses of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0063] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the method and core concept of the present invention. At the same time, those skilled in the art will find that the specific implementation methods and application scopes may vary based on the concept of the present invention. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims

1. A contact network hanger string crimping structure, characterized by: The crimping tube comprises a pair of non-parallel crimping channels symmetrically spaced apart, one end of the stranded wire sequentially passes through the two crimping channels to form a hanging loop, each crimping channel comprises an arc segment and two straight segments, the arc segment is a rounded corner at the connection of the two straight segments, the two straight segments form an obtuse angle, an angle is formed between two ports of the straight segments on the same opening side of the crimping tube, adjacent crimping channels are not in contact and communication, and the two ports on the same side are not in communication, the stranded wire is fixed in the crimping channel and is in a non-parallel state; The crimping method of the crimping tube comprises the following steps: S1, cutting the cylindrical tube with an inner diameter of 8-16 mm into sections of set length for later use; S2, compressing and deforming the tube to uniformly press the circular cross section of the tube segment into a waist-shaped cross section to form a flat tube, wherein the waist-shaped cross section is 15 mm long and 5 mm wide; expanding the ends of the flat tube to the same width, so that the lengths of the openings at both ends of the flat tube are greater than the length of the inner opening, thereby forming two side walls on the left and right sides of the flat tube, each of which is smoothly connected by a circular arc segment, and the angle between the axes of the two straight side walls on the same side is 145° to 180°, or the angle between the axes of the two straight side walls on the same opening side is 0° to 45°, thereby forming an expanded flat tube; S3, passing the two ends of the stranded wire around the heart-shaped ring through the flared flat tube respectively, and making the opening of the flared flat tube contact the edge of the heart-shaped ring, and maintaining this position; S4, use a mold to apply pressure to the upper and lower surfaces of the flared flat tube, press the flared flat tube and the stranded wire, and make the middle part of the flared flat tube fit with the stranded wire, so that two symmetrical and closed crimping multi-segment lines are formed in the middle part of the flared flat tube, and a pair of crimping channels are formed, and the crimping multi-segment lines each include an arc segment and two straight segments, the arc segment is a chamfered corner at the connection of the two straight segments, and the openings of the two arc segments are both facing the outside of the flared flat tube, and the sliding load of the stranded wire in the crimping channel is at least greater than 2kN.

2. The contact network hanger string pressing structure according to claim 1, characterized in that: The included angle between the two straight sections of the same crimping channel is 145° to 180°, and the included angle between the two ports of the straight section located on the same opening side of the crimping tube is 0° to 45°.

3. The contact network hanger string pressing structure according to claim 1, characterized in that: The two straight line segments are symmetrically arranged about the center line of the arc segment, and the length of the straight line segment is 2 mm to 14 mm.

4. The contact network hanger string pressing structure according to claim 1, characterized in that: The arc radius of the arc segment is at least 3 mm.

5. The contact network hanger string pressing structure according to claim 1, characterized in that: The arc length of the arc segment is at least 2 mm.

6. The contact network hanger string crimping structure according to claim 1, characterized in that: The wall thickness of the crimping channel is at least 1 mm, and the inner diameter of the crimping channel matches the outer diameter of the stranded wire and is 4 mm to 15 mm.

7. The contact network hanger string crimping structure according to claim 1, characterized in that: The length of the crimping channel along the length direction of the stranded wire is 10 mm to 60 mm, and the width perpendicular to the length direction of the stranded wire is 8 mm to 50 mm.

8. The contact network dropper string crimping structure according to claim 1, characterized in that: The material of the crimping channel includes metal or metal alloy.

9. The contact network hanger string crimping structure according to claim 1, characterized in that: The crimping channel is an integrally formed part made of copper or copper alloy, and the stranded wire is fixed in the crimping channel by crimping.

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