Design method of butterfly-shaped optical cable mold
By optimizing the conical flow channel design of the butterfly optical cable mold and using Poiseuille's law and integral methods to calculate the total pressure loss, the problem of loose extraction force of the butterfly optical cable was solved, and the molding consistency and production efficiency of the optical cable sheath were improved.
Patent Information
- Application Number
- CN202511027796.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-24
- Publication Date
- 2025-10-17
AI Technical Summary
In the existing technology, the production process of butterfly-shaped optical cables has the problem of loose pulling force, which leads to low production efficiency of the outer sheath of the optical cable and easy movement between the reinforcing member and the outer sheath during construction and wiring, affecting product performance.
The relationship between flow rate and pressure loss in a straight circular flow channel is established using Poiseuille's law. The total pressure loss in a conical flow channel is calculated using differential and integral methods. Based on this model, the cone angle inside the mold is adjusted to optimize the flow channel design and enhance the insertion and extraction force.
By optimizing the cone angle inside the mold, the molding consistency and insertion/extraction force of the optical cable sheath were improved, increasing production efficiency and ease of operation, and reducing uneven material flow and retention in the mold.
Smart Images
Figure CN120805485A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of optical cable mold design, and particularly relates to a design method of a butterfly-shaped optical cable mold. BACKGROUND
[0002] As a key transmission medium of fiber to the home (FTTH), the butterfly-shaped optical cable is widely used in indoor and outdoor communication networks due to its flat structure which is convenient for wiring and fixing.
[0003] In the prior art, metal reinforcing elements are mostly used in the production of butterfly-shaped optical cables due to performance requirements of the optical cables. The metal reinforcing elements have a great influence on the improvement of mechanical properties, so that the optical cable can withstand greater longitudinal tension and avoid the breakage of optical fibers due to external stretching during wiring or long-term suspension. However, the reinforcing elements are directly extruded and formed during the production of the outer sheath of the butterfly-shaped optical cable. Due to the limitations of the outer sheath material itself and the phosphorus powder or zinc powder of the rust-proof coating on the surface of the metal reinforcing element, the reinforcing element is prone to have a loose pulling force. Although the production speed of the outer sheath can be reduced to temporarily increase the pulling force of the reinforcing element, the pulling force is still prone to fluctuation, which affects the production efficiency of the optical cable and causes the relative movement between the reinforcing element and the outer sheath during wiring or the production of the pre-terminated end, thereby affecting the performance of the product. SUMMARY
[0004] The present application aims to provide a design method of a butterfly-shaped optical cable mold, which solves the technical problem of loose pulling force of the butterfly-shaped optical cable in the prior art.
[0005] To achieve this purpose, the present application adopts the following technical solutions: The design method of the butterfly-shaped optical cable mold comprises the following steps: Step S1, providing an initial butterfly-shaped optical cable mold, a tapered flow channel is formed in the initial butterfly-shaped optical cable mold, and the flow channel parameters of the tapered flow channel are set, wherein the flow channel parameters of the tapered flow channel include an inner mold taper angle of the initial butterfly-shaped optical cable mold; Step S2, obtaining the flow rate Q in the straight circular flow channel according to the Poiseuille law, and performing formula transformation on the calculation formula of the flow rate Q to obtain the pressure loss ΔP of the straight circular flow channel; Step S3, after differential processing of the tapered flow channel, the total pressure loss ΔP of the tapered flow channel is calculated by using the integral method in combination with the Poiseuille law; Step S4, based on the total pressure loss ΔP of the tapered flow channel, the inner mold taper angle of the initial butterfly-shaped optical cable mold is adjusted to obtain an adjusted butterfly-shaped optical cable mold, so as to enhance the plug-in force of the butterfly-shaped optical cable mold.
[0006] Optionally, in the step S1, the flow channel parameters of the tapered flow channel further include an inlet radius, an outlet radius and a total length of the tapered flow channel. The inner taper angle of the mold of the conical flow channel is calculated by the following formula: ; In the formula, 2a is the inner taper angle of the mold, r1 is the inlet radius, r2 is the outlet radius, and L is the total length of the conical flow channel.
[0007] Optionally, in the step S2, the flow rate Q in the straight circular flow channel is calculated by the following formula: ; The pressure loss ΔP in the straight circular flow channel is calculated by the following formula: ; In the formula, Q is the flow rate in the straight circular flow channel, η is the viscosity of the fluid, ΔP is the pressure loss of the straight circular flow channel, and R is the radius of the straight circular flow channel.
[0008] Optionally, the step S3 includes: Step S31, dividing the conical flow channel into a plurality of micro-element segments, each of which is approximately a straight circular tube, to obtain a differential equation of the micro-element segment; Step S32, applying the Poiseuille law to each of the micro-element segments and replacing the integral variable to obtain an integral equation of the micro-element segment; Step S33, substituting the upper limit radius and the lower limit radius of the micro-element segment into the integral equation of the micro-element segment according to the power function integration rule to calculate the total pressure loss ΔP of the conical flow channel.
[0009] Optionally, in the step S31, the radius of the micro-element segment is dx; the length of the radius of the micro-element segment is dx; and the differential equation of the micro-element segment is as follows: .
[0010] Optionally, in the step S32, the integral variable u is replaced, and let when , when , ; and the integral equation of the micro-element segment is as follows: .
[0011] Optionally, in the step S33, the total pressure loss ΔP of the conical flow channel is calculated by the following formula: .
[0012] Optionally, the flow channel parameters of the conical flow channel further include an inlet radius, an outlet radius, and a total length of the conical flow channel; in the step S4, the mold inner taper angle of the initial butterfly cable mold is adjusted, specifically including: Under the condition of keeping the inlet radius and the outlet radius unchanged, the total pressure loss ΔP of the conical flow channel is reduced by increasing the mold inner taper angle.
[0013] Optionally, the initial butterfly cable mold includes a first mold sleeve and a second mold sleeve, the first mold sleeve is provided with two first sub-units, and the second mold sleeve is provided with two inner sub-units and outer sub-units with different heights. Among them, the height of the two first sub-units is H, the height of the inner sub-unit is H1, and the height of the outer sub-unit is H2.
[0014] Optionally, the height relationship between the inner sub-unit and the outer sub-unit is as follows: H1=ɛH2; In the formula, ε is a proportionality coefficient, and 0<ɛ<1.
[0015] Compared with the prior art, the present application has the following beneficial effects: The design method of the butterfly cable mold provided by the present application first establishes the mathematical relationship between the flow rate and the pressure loss in the straight circular flow channel by using the Poiseuille law, and further applies it to the conical flow channel through differentiation and integration, thereby obtaining the total pressure loss model of the conical flow channel; then, based on the model, the melt flow in the flow channel is made more uniform by adjusting the mold inner taper angle, and the pressure loss is reasonably distributed, thereby effectively improving the forming state of the cable sheath material in the mold. By optimizing the mold inner taper angle, the local resistance of the flow channel in the mold is reduced, thereby enhancing the overall plug-in force of the mold and improving the operation convenience and efficiency of the mold in the production process. The optimized flow channel design helps the material to flow more smoothly in the mold, reduces the uneven or stagnation of the melt in the mold, and thereby improves the forming consistency of the butterfly cable sheath. The method is based on a verifiable fluid mechanics model, has a strong theoretical basis and repeatability, and can be applied to the design and optimization of other types of cable molds or complex cavity molds. Therefore, the present application solves the technical problem of loose plug-in force of the butterfly cable in the prior art. BRIEF DESCRIPTION OF DRAWINGS
[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without any creative labor.
[0017] The structure, proportion, size and the like shown in the drawings of the specification are only used to cooperate with the content disclosed in the specification, to be understood and read by those skilled in the art, and do not have technical significance in defining the conditions under which the present application can be implemented, so any modification of the structure, change of the proportion relationship or adjustment of the size, without affecting the effects and purposes that can be achieved by the present application, should still fall within the scope of the technical content disclosed by the present application.
[0018] Figure 1 A flowchart of a design method of a butterfly-shaped optical cable mold provided by an embodiment of the present application is shown in Figure 2 A cross-sectional structure diagram of a butterfly-shaped optical cable mold provided by an embodiment of the present application is shown in Figure 3 A structure diagram of a first mold sleeve in a butterfly-shaped optical cable mold provided by an embodiment of the present application is shown in Figure 4 A structure diagram of a second mold sleeve in a butterfly-shaped optical cable mold provided by an embodiment of the present application is shown in DETAILED DESCRIPTION
[0019] In order to make the purposes, features and advantages of the present application more obvious and easy to understand, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings of the embodiments of the present application. Obviously, the embodiments described below are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of the present application.
[0020] In the description of the present application, it should be understood that the terms "upper", "lower", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, and are only used to facilitate the description of the present application and simplify the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. It should be noted that when a component is considered to be "connected" to another component, it can be directly connected to the other component or there can be a component disposed therebetween.
[0021] The technical solutions of the present application will be further described below with reference to the drawings and through specific embodiments.
[0022] An embodiment of the present application provides a design method of a butterfly-shaped optical cable mold, as shown in Figures 1 to 4 including: Step S1, providing an initial butterfly cable mold, a tapered runner is formed in the initial butterfly cable mold, and the runner parameters of the tapered runner are set, wherein the runner parameters of the tapered runner include the mold internal taper angle, the inlet radius, the outlet radius, and the total length of the tapered runner; in this embodiment, the structure of the tapered runner is axisymmetricly contracted, and the internal passage cross section gradually shrinks along the axial direction. The tapered runner is used to guide the uniform flow of the outer sheath material (such as thermoplastic) to cover the metal reinforcing member in the optical cable.
[0023] The mold internal taper angle of the tapered runner is calculated by the following formula: In the formula, 2a is the mold internal taper angle, r1 is the inlet radius (unit: m), r2 is the outlet radius (unit: m), and L is the total length of the tapered runner (unit: m).
[0024] It should be noted that, compared with the traditional mold design method relying on experience, the present method provides accurate and controllable design basis for the tapered runner by defining the parameter model, which lays a foundation for theoretical calculation and simulation analysis of the molding process. Since the mold internal taper angle a is the core variable for controlling the pressure loss in the subsequent steps, the calculable and traceable taper angle expression provided in step S1 helps to accurately control the insertion force and adjust the mold performance in steps S3 and S4. Reasonably setting the taper angle helps to control the shear rate and flow velocity gradient of the material in the mold, reduces local turbulent flow and flow dead angle, and improves the uniformity and mechanical properties of the optical cable outer sheath.
[0025] Step S2, obtaining the flow rate Q in the straight circular runner according to the Poiseuille law, and performing formula transformation on the calculation formula of the flow rate Q to obtain the pressure loss ΔP of the straight circular runner. In this embodiment, the Poiseuille law is a well-known law, which will not be described here. According to the Poiseuille law, the mathematical relationship between the flow rate Q and the pressure loss ΔP in the straight circular runner is first established, which is used to simulate the actual situation of the optical cable sheath material flowing in the mold in a laminar flow state.
[0026] In specific applications, the designer can determine the viscosity η of the sheath material and set the geometric parameters R and L of the runner, combined with the actual molding requirements (such as the target flow rate Q), to calculate the theoretical pressure loss of the mold in the working state. This data will be used in the subsequent steps to evaluate whether the tapered runner is reasonable and whether the taper angle needs to be optimized.
[0027] In step S2, the flow rate Q in the straight circular runner is calculated by the following formula: The pressure loss ΔP in the straight circular runner is calculated by the following formula: ; Where Q is the flow rate in the straight circular channel (unit: m 3 / s); η is the viscosity of the fluid (unit: Pa·s), ΔP is the pressure loss of the straight circular flow channel (unit: Pa); R is the radius of the straight circular flow channel (unit: m); π is the pi.
[0028] It should be noted that the straight circular pipe pressure loss calculation formula established in step S2, although not directly used for tapered flow channels, provides a basic description of the material flow behavior under a "constant radius" and is the theoretical starting point for the differential integral derivation of tapered flow channels. Compared with the traditional reliance on experimental means to evaluate flow pressure, the present invention incorporates all key variables in the molding process, such as flow rate, viscosity, channel radius, etc., into quantitative formulas, which helps designers to perform simulation predictions under different materials and different structural conditions, thereby improving the efficiency and accuracy of the design. Through the pressure loss formula, designers can deduce the required system pressure based on the target molding speed, and conversely, they can also reversely infer whether the working pressure limit of the existing equipment can be met through the mold structure, thereby achieving coordinated optimization of the mold structure design and process conditions.
[0029] In step S3 , after performing differential processing on the tapered flow passage, the total pressure loss ΔP of the tapered flow passage is calculated using an integration method in combination with Poiseuille's law.
[0030] In one embodiment, step S3 specifically includes: Step S31, the conical flow channel is divided into a plurality of micro-element segments, each micro-element segment is approximately a straight circular tube, and the differential equation of the micro-element segment is obtained; in step S31, the viscosity η of the fluid remains stable, and the radius of the micro-element segment is , the radius of the infinitesimal segment is d x ; The differential equation of the infinitesimal segment is as follows: ; In the formula, r( x ) is the infinitesimal segment at position x The radius at (unit: m); x The distance from the starting point to the entrance of the current micro-element segment (unit: m).
[0031] Step S32, apply Poiseuille's law to each infinitesimal segment, replace the integral variable, and obtain the integral equation of the infinitesimal segment; in step S32, replace the integral variable u, and let ,when hour, ;when hour, ; Integrate from 0 to L, the integral equation of the differential segment is as follows: .
[0032] Step S33, according to the power function integration rule, the upper limit radius and the lower limit radius of the micro-element segment are substituted into the integral equation of the micro-element segment, and the total pressure loss ΔP of the conical flow channel is calculated. The power function integration rule is a known rule, which will not be repeated here. In step S33, the total pressure loss ΔP of the conical flow channel is calculated by the following formula: .
[0033] It should be noted that step S31 converts the complex geometric structure into a mathematical problem that can be handled by calculus, realizing the "local equivalent straight pipe segment" approximation of any taper structure, and providing a basis for pressure loss modeling. Step S32 standardizes the complex structure integral problem into a one-dimensional power function integral, significantly simplifying the integral boundary conditions and expressions through variable substitution. Step S33 gives a calculable and adjustable total pressure drop model, which clearly indicates that the taper angle α is the core variable affecting the pressure loss; as a direct objective function of mold structure optimization, it provides theoretical support for the taper angle adjustment of step S4; the mathematical derivation is universal and can be adapted to different taper angles, material viscosities and target flow requirements.
[0034] Step S4, based on the total pressure loss ΔP of the conical flow channel, the mold inner taper angle of the initial butterfly optical cable mold is adjusted, and the adjusted butterfly optical cable mold is obtained to enhance the insertion force of the butterfly optical cable mold. In step S4, the mold inner taper angle of the initial butterfly optical cable mold is adjusted, which specifically includes: Under the condition of keeping the inlet radius and outlet radius unchanged, the total pressure loss ΔP of the conical flow channel is reduced by increasing the mold inner taper angle. The purpose of step S4 is to optimize and adjust the mold inner taper angle based on the total pressure loss ΔP of the conical flow channel to enhance the insertion force of the butterfly optical cable mold.
[0035] It should be noted that increasing the taper angle can effectively reduce the pressure drop per unit length of the conical flow channel; a more gentle pressure change avoids material stagnation or backflow in the mold, improves the smoothness of the mold from the optical cable, and enhances the insertion force. This optimization method does not change the mold inlet and outlet sizes, and maintains the consistency of the finished product size of the optical cable; compared with the traditional "sacrifice size to improve pulling force" method, it is more precise and scientific. Step S4 adjusts the mold inner taper angle to optimize the insertion performance of the butterfly optical cable mold, which is innovative in that it is based on theoretical modeling of structure parameter adjustment, does not change the appearance size of the flow optimization method, and provides a quantitative control mechanism between the taper angle-pressure drop-molding quality.
[0036] In an embodiment, due to uneven extrusion pressure distribution during the outer sheath production process, the overall situation is that the inner side reinforcement outer sheath size is larger than the outer side reinforcement outer sheath size, and this difference makes it only possible to increase the small outer diameter size to maintain the overall size to meet product requirements when controlling the outer sheath size, but this difference will lead to an increase in the use of outer sheath material. As shown in Figures 2 to 4 As shown in FIG. 1, the initial butterfly cable mold includes a first mold sleeve and a second mold sleeve. The first mold sleeve is provided with two first sub-units, and the second mold sleeve is provided with two inner and outer sub-units with different heights. In this embodiment, when the sizes of the two first sub-units are both H, the height consistency of the formed optical cable is maintained between 95.2% and 97.1%. The design of sub-units with different heights helps to balance the stress distribution in the mold and avoid significant deformation during the molding process. The height-adjustable mold design makes it more flexible to adapt to the production needs of different specifications and different types of optical cables.
[0037] It should be noted that by adopting the design of inner and outer sub-units with different heights, the pressure distribution in different areas of the mold can be achieved, which helps to uniformly form the optical cable outer sheath. This design can effectively avoid uneven molding caused by excessive or insufficient local pressure in the mold, and improve the physical properties and consistency of the optical cable sheath.
[0038] Specifically, the height relationship between the inner and outer sub-units is as follows: H1=ɛH2; In this embodiment, when ɛ=0.97~0.98, the height consistency of the formed optical cable reaches 99.6%.
[0039] It should be noted that by finely adjusting the height ratio of the inner and outer sub-units in the mold (for example, when ɛ=0.97 to 0.98), the mold maintains stable molding quality over multiple production cycles, ensuring that the height consistency of the optical cable outer sheath can reach 99.6%. By reasonably designing the height difference between the inner and outer sub-units, the waste of mold material can be effectively reduced while maintaining the size requirements of the outer sheath. By precisely controlling the height ratio, the flow pressure in the mold is effectively optimized, reducing the residence and uneven flow of the melt caused by excessive local flow resistance, thereby improving the quality of the optical cable sheath.
[0040] Working principle: the design method of the butterfly-shaped optical cable mold provided by the application firstly establishes the mathematical relationship between the flow and pressure loss in the straight circular runner by using the Poiseuille law, and further applies it to the tapered runner through differentiation and integration means, so as to obtain the total pressure loss model of the tapered runner; then based on the model, by adjusting the inner taper angle of the mold, the melt flow in the runner is more uniform, the pressure loss is reasonably distributed, and the forming state of the optical cable sheath material in the mold is effectively improved. By optimizing the inner taper angle of the mold, the local resistance of the runner in the mold is reduced, thereby enhancing the overall plug-in force of the mold and improving the operation convenience and efficiency of the mold in the production process. The optimized runner design helps the material flow more smoothly in the mold, reduces the uneven or stagnation of the melt in the mold, thereby improving the forming consistency of the butterfly-shaped optical cable sheath. The method is based on a verifiable fluid mechanics model, has strong theoretical basis and repeatability, and can be applied to the design and optimization of other types of optical cable molds or complex cavity molds. Therefore, the application solves the technical problem of loose pull-out force of the butterfly-shaped optical cable in the prior art.
[0041] In another embodiment, the equivalent length L of the tapered runner eff The following formula is used for calculation: L eff =L0(1+k(1-ε)) (approximate linearity, k is a structure coefficient); The equivalent length L eff is substituted into the taper angle formula to obtain: ; Finally, substitute ΔP formula to obtain: ; In the formula, L0 is the reference tapered runner length when ε=1 (symmetrical structure).
[0042] When ε increases (tends to 1), H1 and H2 tend to be consistent, the mold structure is more symmetrical, resulting in L eff decreases, then α increases, and finally ΔP decreases; when ε decreases (far from 1), the asymmetry of the mold is enhanced, resulting in L eff increases, then α decreases, and finally ΔP increases. Therefore, by controlling the asymmetry of the mold structure through ε, the material flow path length can be optimized, and finally ΔP can be precisely controlled.
[0043] The above-described embodiments are only used to illustrate the technical solutions of the present application, and are not intended to limit the present application; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that the technical solutions recorded in the foregoing embodiments can still be modified, or some technical features can be replaced by equivalent replacements; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.
Claims
1. A design method for a butterfly-shaped optical cable mold, characterized in that: include: Step S1, providing an initial butterfly-shaped optical cable mold, opening a tapered flow channel in the initial butterfly-shaped optical cable mold, and setting flow channel parameters of the tapered flow channel: wherein the flow channel parameters of the tapered flow channel include a mold inner cone angle; Step S2, obtaining the flow rate Q in the straight circular flow channel according to Poiseuille's law, and performing a formula transformation on the calculation formula of the flow rate Q to obtain the pressure loss ΔP of the straight circular flow channel; Step S3, performing differential processing on the tapered flow channel, and then combining Poiseuille's law with an integral method to calculate the total pressure loss ΔP of the tapered flow channel; Step S4: adjusting the inner cone angle of the initial butterfly-shaped optical cable mold based on the total pressure loss ΔP of the tapered flow channel to obtain an adjusted butterfly-shaped optical cable mold to enhance the insertion and extraction force of the butterfly-shaped optical cable mold.
2. The design method of the butterfly-shaped optical cable mold according to claim 1, characterized in that: In step S1, the flow channel parameters of the tapered flow channel further include an inlet radius, an outlet radius, and a total length of the tapered flow channel; The inner cone angle of the tapered runner mold is calculated using the following formula: ； Where 2α is the inner cone angle of the mold, r1 is the inlet radius, r2 is the outlet radius, and L is the total length of the tapered flow channel.
3. The design method of the butterfly-shaped optical cable mold according to claim 2, characterized in that: In step S2, the flow rate Q in the straight circular flow channel is calculated using the following formula: ； The pressure loss ΔP in a straight circular flow channel is calculated using the following formula: ； Where Q is the flow rate in the straight circular flow channel, η is the viscosity of the fluid, ΔP is the pressure loss in the straight circular flow channel, and R is the radius of the straight circular flow channel.
4. The method for designing a butterfly-shaped optical cable mold according to any one of claims 1 to 3, characterized in that: The step S3 comprises: Step S31, dividing the tapered flow channel into a plurality of micro-element segments, each of which is approximately a straight circular tube, and obtaining a differential equation of the micro-element segment; Step S32, applying Poiseuille's law to each of the infinitesimal segments, using integral variable substitution to obtain an integral equation for the infinitesimal segment; Step S33 , according to the power function integration rule, the upper limit radius and the lower limit radius of the infinitesimal segment are substituted into the integral equation of the infinitesimal segment to calculate the total pressure loss ΔP of the tapered flow channel.
5. The method for designing a butterfly-shaped optical cable mold according to claim 4, wherein: In step S31, the radius of the microelement segment , the radius of the infinitesimal segment is d x ; The differential equation of the infinitesimal segment is as follows: 。 6. The method for designing a butterfly-shaped optical cable mold according to claim 5, characterized in that: In step S32, the integral variable u is used for substitution, and ,when hour, ;when hour, ; Integrating from 0 to L, the integral equation of the infinitesimal segment is as follows: 。 7. The method for designing a butterfly-shaped optical cable mold according to claim 6, wherein: In step S33, the total pressure loss ΔP of the tapered flow channel is calculated using the following formula: 。 8. The method for designing a butterfly-shaped optical cable mold according to claim 1, wherein: The flow channel parameters of the tapered flow channel also include an inlet radius, an outlet radius, and a total length of the tapered flow channel. In step S4, the inner cone angle of the initial butterfly-shaped optical cable mold is adjusted, specifically including: Under the condition of keeping the inlet radius and the outlet radius unchanged, the total pressure loss ΔP of the tapered flow channel is reduced by increasing the inner cone angle of the mold.
9. The method for designing a butterfly-shaped optical cable mold according to claim 1, wherein: The initial butterfly-shaped optical cable mold includes a first mold sleeve and a second mold sleeve, wherein the first mold sleeve is provided with two first subunits, and the second mold sleeve is provided with two inner subunits and an outer subunit of different heights; The height of the two first subunits is set to H, the height of the inner subunit is set to H1, and the height of the outer subunit is set to H2.
10. The method for designing a butterfly-shaped optical cable mold according to claim 9, wherein: The height relationship between the inner subunit and the outer subunit is as follows: H1=ɛH2; Where ɛ is the proportional coefficient, and 0<ɛ<1.