Cable bending simulation device and method for judging cable length change value

Abstract

The application relates to the technical field of aviation cables, in particular to a cable bending simulation device and a judgment method of cable length change value. The cable bending simulation device comprises a workbench, a first fixing member arranged on the workbench, a second fixing member also arranged on the workbench, and the first fixing member and the second fixing member are oppositely arranged, and the first fixing member and the second fixing member are respectively used for fixing two ends of a cable; and a moving table can drive the first fixing member to move relative to the second fixing member in three-axis directions. Through use of the cable bending simulation device, the bending state of the cable under different conditions can be simulated in advance, economic loss is reduced, and the reliability of an electric connector affected by cable bending can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of aerospace cables, and in particular, to a cable bending simulation apparatus and a method for determining a length change value of a cable. Background Art

[0002] Aircraft cable assembly is a link requiring strict quality control in the aircraft assembly process. After various cables on the aircraft are laid to each cabin through specified channels, they are installed and fixed by clamps. After the cables are fixed, affected by factors such as their own materials, length allowance and fixing mode, the internal harness segments of the cables present bending to different degrees. Under different bending states, the stress condition of the whole cable varies greatly, and the stress of wire cores at different positions inside the cable also differs greatly. If the cable continues to bear large stress after bending, the overall service life of the cable and the mating reliability of the electrical connector will be greatly reduced.

[0003] At present, after the on-board cable is installed, the bending of the cable affects the reliability of the electrical connector, and the on-board cable is not easy to disassemble after installation. In addition, for determining the length change after cable bending, only a reference range of technical requirements such as length and bending degree is given based on experience. However, due to the complex on-board installation conditions, the stress conditions inside the cable corresponding to different technical requirements are different, and there is no specific data support. Summary of the Invention

[0004] The purpose of the present invention is to overcome the problems existing in the prior art that after the cable is installed on the aircraft, the bending of the cable affects the reliability of the electrical connector, the cable is not easy to disassemble after being installed on the aircraft, and the degree of length change after cable bending is only based on experience without specific data support, and provides an apparatus for simulating the bending state of a cable and a method for determining the length change value of the cable.

[0005] In order to achieve the above objective of the invention, the present invention provides the following technical solution:

[0006] A cable bending simulation apparatus comprises a workbench, a moving platform is arranged on the workbench, a first fixing member is arranged on the moving platform, a second fixing member is further arranged on the workbench, the first fixing member and the second fixing member are arranged opposite to each other, the first fixing member and the second fixing member are respectively used for fixing two ends of a cable, and the moving platform can drive the first fixing member to move in three axial directions relative to the second fixing member.

[0007] The workbench serves as the foundation of the entire cable bending simulation apparatus, and carries the moving platform and the second fixing member. The moving platform can move in three axial directions relative to the second fixing member, and the three axial directions are the three axes of a Cartesian rectangular coordinate system. The first fixing member fixes one end of the cable on the moving platform, the second fixing member fixes the other end of the cable, and through the relative movement of the first fixing member in three axial directions relative to the second fixing member, different relative positions can be achieved, so as to simulate the bending states of the cable in different forms.

[0008] Since cables are not easily disassembled after installation on an aircraft, this cable bending simulation device can simulate the bending of the cable by setting the relative positions of the two ends of the cable after installation. This allows for early identification of the cable's reliability under corresponding bending conditions, preventing the cable from being unable to adapt to the bending conditions after installation on the aircraft, which could affect its service life or even cause damage or breakage. This effectively reduces economic losses and improves the reliability of electrical connectors affected by cable bending.

[0009] As a preferred embodiment of the present invention, the three axes are the three axes of a Cartesian coordinate system. The moving stage includes a first moving member arranged along the X-axis, a second moving member arranged along the Y-axis, and a third moving member arranged along the Z-axis. The second moving member is used to drive the first fixed member to move closer to or away from the second fixed member, and the third moving member is used to drive the first fixed member to rise or fall.

[0010] By setting the three axes of the Cartesian coordinate system described above, the relative positions between the first and second fixed components can be described more simply and clearly. The first, second, and third moving components are set along the X, Y, and Z axes, respectively, making it easier to position the first fixed component when moving it, and thus making it easier to simulate different bending patterns of the cable.

[0011] As a preferred embodiment of the present invention, the second fixing member can be translated, and the translation direction of the second fixing member is parallel to the X-axis.

[0012] The translation direction of the second fixing member is parallel to the X-axis, that is, parallel to the first moving member. The translation of the second fixing member can simulate the bending shape of the cable at different positions in the X-axis direction, and at the same time, it increases the relative distance that the first and second fixing members can move in the X-axis direction, so as to simulate more bending states.

[0013] As a preferred embodiment of the present invention, a slider is connected to the second fixing member, and the worktable is provided with a slide rail, so that the slider can slide along the slide rail.

[0014] The slider carries the second fixing member and moves within the slide rail, facilitating its movement. Simultaneously, the slide rail ensures that the direction of movement of the second fixing member is parallel to the X-axis of the Cartesian coordinate system.

[0015] As a preferred embodiment of the present invention, a support is provided on the workbench, and a slide rail is provided on the upper part of the support.

[0016] The bracket creates a certain distance between the slide rail and the worktable, minimizing contact between the cable and the worktable or other workpieces during bending simulation, thus reducing the impact on the simulation of the cable bending shape.

[0017] As a preferred embodiment of the present invention, the first fixing member is connected to the moving platform through a base, and the base is a ball joint base.

[0018] The base can be tilted along the ball head inside, thus increasing the range of simulated bending. It can also be twisted to simulate more cable bending patterns.

[0019] As a preferred embodiment of the present invention, the first fixing member is a three-jaw chuck.

[0020] The three-jaw chuck can improve the alignment accuracy of the cable and better secure one end of the cable.

[0021] As a preferred embodiment of the present invention, the cable bending simulation device further includes a control system.

[0022] The control system issues commands to drive the mobile platform, and the control system is more precise than manual control, and can more accurately simulate cables with different bending shapes.

[0023] A method for determining the change in cable length, using the aforementioned cable bending simulation device, includes the following steps:

[0024] S1. Fixing the cable: Fix both ends of the cable to the second fixing member and the first fixing member respectively;

[0025] S2. Simulation of cable bending state: Adjust the second fixing member and the first fixing member to a preset relative position to make the cable bend;

[0026] S3. Select a section of the cable with a bending radius corresponding to the same center point;

[0027] S4. Calculate the length change ΔL of the selected cable segment, either inside or outside:

[0028]

[0029] In the formula, L represents the original length of the cable segment. The angle represents the central angle corresponding to the bending radius of this section of the cable; d represents the distance from the end face of any wire harness segment inside the cable to the center point of the cable end face; θ represents the angle between the line connecting the end face of any wire harness segment inside the cable to the center point of the cable end face and the bending radius of the cable.

[0030] When 0°≤θ≤90°, the wire core is located inside the curved channel and its length is shortened, so ΔL is a negative value; when 90°≤θ≤180°, the wire core is located outside the curved channel and its length is increased, so ΔL is a positive value.

[0031] S5. Calculate the overall length change of the cable: Add ΔL together to determine the overall length change of the cable.

[0032] When the cable bends, the bending radius at the center point of the cable is:

[0033]

[0034] Where R is the bending radius of the cable center point;

[0035] If the distance d from the end face of any wire bundle segment inside the cable to the center point of the cable end face and the bending radius r of the center point of the end face of any wire bundle segment inside the cable form a triangle with an included angle θ, then according to the Law of Cosines:

[0036]

[0037] Therefore, the theoretical line length after bending at any hole position can be calculated:

[0038]

[0039] From this, we can deduce the length change value after bending at any hole position:

[0040]

[0041] When a cable is bent, the side facing the center of the bend radius is considered the inner side, which is compressed; the side away from the center of the bend is considered the outer side, which is stretched.

[0042] During the bending process of a cable, different bending radii correspond to different central angles. This simulation of cable bending shows the central angles corresponding to the bending radii of cables on the same plane. The difference is subtle, so it can be considered as the angle of the center of the circle corresponding to the bending radius of the cable in the same plane. same.

[0043] By using this method to determine cable length changes, specific data on the length changes at various points after a cable bend can be obtained, rather than relying solely on experience. Once the exact extent of the length change after bending is determined, the stress on the cable can be adjusted accordingly, appropriately extending its service life and improving the reliability of electrical connector connections.

[0044] As a preferred embodiment of the present invention, in step S2, the first fixing member is first adjusted to reach its predetermined position, then the position of the first fixing member in the front-back direction is adjusted, and finally the relative positions of the second fixing member and the first fixing member in the left-right direction are adjusted.

[0045] The forward / backward direction represents the direction in which the first fixing member approaches or moves away from the second fixing member, while the left / right direction represents the direction in which the first fixing member deviates relative to the second fixing member. During the cable bending simulation, the relative positions of the second and first fixing members must be the same as the relative positions of the electrical connectors at both ends of the cable on an aircraft in actual operation.

[0046] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0047] 1. The cable bending simulation device described above is used to simulate the bending of cables. The base of the cable bending simulation device is a ball joint base, and there are slide rails and sliders below the second fixing member. The moving table can move relative to the second fixing member in three-axis directions, which allows the cable bending simulation device to simulate various forms of cable bending. Before the cable is officially installed on the aircraft, a preliminary simulation can be performed to identify the reliability of the cable under different bending states in advance, and avoid the cable from being in the corresponding bending state again after it is installed on the aircraft, which can reduce economic losses.

[0048] 2. By using the above method for judging the change in cable length, the specific change in length of any wire bundle segment inside the cable after bending can be calculated. Based on the specific change in cable length after bending, the stress on the cable can be adjusted accordingly, the service life of the cable can be appropriately extended, and the reliability of the electrical connector will be improved. Attached image description:

[0049] Figure 1 This is a schematic diagram of the structure of a cable bending simulation device in Example 1;

[0050] Figure 2 This is a schematic diagram of the structure of the first fastener in Embodiment 1;

[0051] Figure 3 This is a schematic diagram of the connection of the second fastener in Embodiment 1;

[0052] Figure 4 This is a schematic diagram of the specific structure of the second fastener in Embodiment 1;

[0053] Figure 5 The implementation steps of the method for determining the change value of cable length in Example 2 are as follows:

[0054] Figure 6 The method for determining the change value of cable length in Example 2 is described in detail below. The specific meaning of θ for the cable is as follows.

[0055] The markings in the diagram are: 1-moving stage, 101-first moving part, 102-second moving part, 103-third moving part, 2-worktable, 3-control system, 4-second fixed part, 401-slider, 402-slide rail, 403-bracket, 5-first fixed part, 6-base, 7-cable. Detailed Implementation

[0056] The present invention will be further described in detail below with reference to experimental examples and specific embodiments. However, this should not be construed as limiting the scope of the above-mentioned subject matter of the present invention to the following embodiments; all technologies implemented based on the content of the present invention fall within the scope of the present invention.

[0057] Example 1

[0058] like Figure 1-4 As shown, a cable bending simulation device includes a worktable 2, a movable stage 1 on the worktable 2, a first fixing member 5 on the movable stage 1, and a second fixing member 4 on the worktable 2. The first fixing member 5 and the second fixing member 4 are arranged opposite to each other. The first fixing member 5 and the second fixing member 4 are respectively used to fix the two ends of the cable 7. The movable stage 1 can drive the first fixing member 5 to move relative to the second fixing member 4 in three-axis directions.

[0059] The three axes are in a Cartesian coordinate system. The moving stage 1 includes a first moving member 101 along the X-axis, a second moving member 102 along the Y-axis, and a third moving member 103 along the Z-axis. The second moving member 102 is used to move the first fixed member 5 closer to or away from the second fixed member 4, and the third moving member 103 is used to raise or lower the first fixed member 5. Figure 1 As shown. Each moving part has limiting members at both ends to prevent components of the moving platform 1 from detaching during movement. The second fixing member 4 is used for lateral limiting members that fit the track on parts of each moving part to ensure that the second fixing member 4 does not detach obliquely. The form of the moving part is determined according to the specific situation; for example, in this embodiment, a track is used.

[0060] like Figure 1 As shown, the workbench 2 is a hollow cubic frame, and its size is determined according to the length of the curved cable to be simulated. A movable platform 1 is provided on one side of the top of the workbench 2 and its two adjacent sides, and a second fixing member 4 is provided on the remaining side of the top of the workbench 2.

[0061] The second fixing member 4 is P-shaped and includes an open ring. The opening is located at the junction of the ring and the middle section of the straight segment. The straight segment has a circular hole for connecting the device below the second fixing member 4, such as... Figure 4 As shown. The inner diameter of the ring of the second fixing member 4 is slightly smaller than the outer diameter of the cable 7, which is used to ensure the fixing of the cable 7. The second fixing member 4 can be translated, and the translation direction of the second fixing member 4 is parallel to the X-axis of the Cartesian coordinate system mentioned above, that is, parallel to the first moving member 101. The second fixing member 4 is connected to a slider 401, and the worktable 2 is provided with a slide rail 402, and the slider 401 can slide along the slide rail 402. The worktable 2 is provided with a bracket 403, and the slide rail 402 is located on the upper part of the bracket 403, as shown. Figure 3As shown. Bracket 403 is parallel to the X-axis.

[0062] The first fixing member 5 is connected to the movable platform 1 via the base 6. The base 6 is a ball joint base, which allows the cable 7 to bend at multiple angles and also to twist. Figure 2 As shown, the base 6 is concave, with protrusions on two opposite sides of its concave portion, and is fixed to the third movable component 103, as shown. Figure 1 As shown. The base 6 moves on the third moving part 103. The first fixing part 5 is a three-jaw chuck, as shown. Figure 2 As shown, this allows for better fixation of cable 7 and also ensures greater precision during cable bending simulation.

[0063] like Figure 1 As shown, the cable bending simulation device also includes a control system 3. The control system 3 issues commands to control the movement of the mobile platform 1, and is more precise than manual movement.

[0064] Example 2

[0065] like Figure 5 As shown, a method for determining the change in cable length, using a cable bending simulation device as described in Example 1, includes the following steps:

[0066] S1. Fix the cable: Fix both ends of the cable 7 to the second fixing member 4 and the first fixing member 5 respectively;

[0067] S2, cable bending state simulation: Adjust the second fixing part 4 and the first fixing part 5 to a preset relative position so that the cable 7 is in a bending state;

[0068] S3. Select a section of cable 7 with a bending radius corresponding to the same center point;

[0069] S4. Calculate the length change ΔL of the selected segment of cable 7, either inside or outside:

[0070]

[0071] In the formula, L represents the original length of the cable segment 7. The angle represents the central angle corresponding to the bending radius of this section of cable 7; d represents the distance from the end face of any wire harness segment inside cable 7 to the center point of the end face of cable 7; θ represents the angle between the line connecting the end face of any wire harness segment inside cable 7 to the center point of the end face of cable 7 and the bending radius of cable 7; the specific position of θ is as follows: Figure 6 As shown.

[0072] When 0°≤θ≤90°, the wire core is located inside the bend channel, and its length is shortened, so ΔL is a negative value; when 90°≤θ≤180°, the wire core is located outside the bend channel, and its length is increased, so ΔL is a positive value; when the cable 7 is bent, the side facing the center point of the bending radius of the cable 7 is the inside, and the inside will be compressed; the side away from the bending center point of the cable 7 is the outside, and the outside will be stretched.

[0073] S5. Calculate the overall length change of cable 7: Add ΔL together to determine the overall length change of cable 7.

[0074] In step S2, firstly, the first fixing member 5 is adjusted to reach its predetermined position. Then, the position of the first fixing member 5 in the front-back direction is adjusted. Finally, the relative positions of the second fixing member 4 and the first fixing member 5 are adjusted in the left-right direction. The front-back direction refers to the direction in which the first fixing member 5 moves closer to or further away from the second fixing member 4, and the left-right direction refers to the direction in which the first fixing member 5 deviates from the second fixing member 4. Ultimately, the relative positions of the second fixing member 4 and the first fixing member 5 must correspond to the relative positions of the electrical connectors at both ends of the cable on the aircraft in actual operation.

[0075] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for judging the length change value of a cable, using a cable bending simulation device, the cable bending simulation device comprising a workbench (2), a moving table (1) provided on the workbench (2), a first fixing member (5) provided on the moving table (1), a second fixing member (4) provided on the workbench (2), the first fixing member (5) and the second fixing member (4) being oppositely arranged, the first fixing member (5) and the second fixing member (4) being respectively used for fixing two ends of a cable (7), the moving table (1) being capable of driving the first fixing member (5) to move relative to the second fixing member (4) in three-axis directions; characterized in that, Includes the following steps: S1. Fixing the cable (7): Fix both ends of the cable (7) to the second fixing member (4) and the first fixing member (5) respectively; S2, simulation of the bending state of the cable (7): adjust the second fixing member (4) and the first fixing member (5) to a preset relative position so that the cable (7) is in a bending state; S3. Select a section of the cable (7) with a bending radius corresponding to the same center point; S4, calculating the length variation of the inner side or of the outer side of the cable (7) of the selected section : ， In the formula L represents the length of the cable (7) in the section, represents the central angle of the circle corresponding to the bending radius of the cable (7) in the section, represents the distance from the end face of any wire harness section in the cable (7) to the center point of the end face of the cable (7), represents the angle between the line connecting the end face of any wire harness section in the cable (7) to the center point of the end face of the cable (7) and the bending radius of the cable (7), when When the wire core is located inside the curved channel, its length is shortened. It is a negative value; when When the wire core is located outside the curved channel, its length increases. It is a positive value; S5. Calculate the overall length change of the cable (7): Add them together to determine the overall length change of the cable (7).

2. The method for determining the change in cable length as described in claim 1, characterized in that, The three axes are the three axes of the Cartesian rectangular coordinate system. The moving stage (1) includes a first moving part (101) set along the X-axis, a second moving part (102) set along the Y-axis and a third moving part (103) set along the Z-axis. The second moving part (102) is used to drive the first fixed part (5) to move closer to or away from the second fixed part (4). The third moving part (103) is used to drive the first fixed part (5) to rise or fall.

3. The method for determining the change in cable length as described in claim 2, characterized in that, The second fixing member (4) is capable of translation, and the translation direction of the second fixing member (4) is parallel to the X-axis.

4. The method for determining the change in cable length as described in claim 3, characterized in that, The second fixing member (4) is connected to a slider (401), and the worktable (2) is provided with a slide rail (402). The slider (401) can slide along the slide rail (402).

5. The method for determining the change in cable length as described in claim 4, characterized in that, The workbench (2) is provided with a support (403), and the slide rail (402) is located on the upper part of the support (403).

6. The method for determining the change in cable length as described in claim 1, characterized in that, The first fixing member (5) is connected to the moving platform (1) via a base (6), and the base (6) is a ball joint base.

7. The method for determining the change in cable length as described in claim 1, characterized in that, The first fixing member (5) is a three-jaw chuck.

8. A method for determining the change in cable length as described in any one of claims 1 to 7, characterized in that, It also includes the control system (3).

9. The method for determining the change in cable length as described in claim 1, characterized in that, In step S2, the first fixing member (5) is first adjusted to rise and fall to its predetermined position, then the position of the first fixing member (5) in the front-back direction is adjusted, and finally the relative position of the second fixing member (4) and the first fixing member (5) in the left-right direction is adjusted.

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