A self-protecting, impact-resistant, low-heat-release control cable and its detection method

Abstract

The present invention relates to the field of cables, and in particular to a self-protecting, impact-resistant, low-heat-release control cable, comprising a conductor, an insulating layer, a filling layer, a heat-insulating layer, a shielding and fire-proofing layer, and an outer sheath arranged in sequence from the inside to the outside of the cable; the conductor is used to transmit electrical energy, the insulating layer is used to prevent the cable from directly contacting the external environment, the filling layer is used to fill the gap between the cable conductors, the heat-insulating layer is used to prevent the cable from overheating when working in a high-temperature environment, the shielding and fire-proofing layer is used to shield electromagnetic interference and protect the internal structure of the cable in the event of a fire, and the outer sheath is used to separate the internal structure of the cable from the external environment. The cable structure of the present invention is reasonable and simple, the cable materials are all low-calorific value materials, the heat release of the cable when burning is low, and the corrugated structure gives the cable itself better toughness and impact resistance, thereby enhancing the safety of the cable when in use.

Description

Technical Field

[0001] The invention relates to the field of cables, and in particular to a self-protecting, impact-resistant, low-heat-release control cable. Background Art

[0002] Under fire conditions, combustion performance is one of the main safety indicators of control cables. Product standards GB / T 9330 and GB / T 19666 only require flame retardancy, which cannot fully reflect the impact of cables on the surrounding environment under fire accidents. In recent years, the market has put forward higher requirements for the combustion performance of control cables, no longer limited to bundled flame retardancy, but also requiring cables to meet the B1 combustion performance specified in the classification standard GB 31247-2014. B1 control cables are mainly used for electrical connections of power distribution equipment.

[0003] For example, the prior art of CN114864158A discloses a Class B1 flame-retardant cable, which belongs to the field of cables. The Class B1 flame-retardant cable includes an outer sheath, multiple flame-retardant core heat-deformable parts, and a tensile rope. The outer sheath is made of flame-retardant material, is flat, and has an inner bend at the corner of the side wall; multiple flame-retardant cores are arranged in the outer sheath and arranged along the long axis of the outer sheath; the heat-deformable part is arranged along the inner wall of the inner bend, suitable for stretching the inner bend after heating; the tensile rope has an electrothermal effect, is arranged in the inner bend and is thermally connected to the heat-deformable part, suitable for heating the heat-deformable part, and the heat-deformable part is heated by energizing the tensile rope.

[0004] Another typical flame-retardant B1 grade cable disclosed in the prior art of CN110570981A, wherein the cable has a cable core mainly composed of multiple insulated conductors, and the cable core is coated with an inner ceramic fiber tape layer, an oxygen insulation layer, an outer ceramic fiber tape layer and a sheath layer from the inside to the outside, and the combined gap of the cable core coated by the inner ceramic fiber tape layer is filled with a ceramic fiber cotton filling layer.

[0005] Let's take a look at a Class B1 flame-retardant and fire-resistant cable disclosed in the prior art such as CN117423500A, which includes a protective device, a first wire and a second wire, the protective device includes a shell, a safety mechanism and a partition mechanism, the safety mechanism and the partition mechanism are arranged inside the shell; the first wire and the second wire are both Class B1 flame-retardant and fire-resistant wires; one end of the first wire is connected to the safety mechanism; one end of the second wire is connected to the safety mechanism to be electrically conductive with the first wire through the safety mechanism; the safety mechanism electrically separates the first wire from the second wire when the ambient temperature is greater than a preset temperature; the partition mechanism is used to separate the first wire from the second wire.

[0006] The existing B1-class control cables only consider the flame retardant properties of the cables in bundles, but do not consider factors such as heat release, smoke release and smoke toxicity that may cause harm to the outside world when the cables burn under fire conditions, and gradually fail to meet the requirements for fire safety. In order to solve the common problems in the field, the present invention is made. Summary of the invention

[0007] The purpose of the present invention is to propose a self-protecting, impact-resistant and low-heat-release control cable in view of the existing deficiencies.

[0008] In order to overcome the shortcomings of the prior art, the present invention adopts the following technical solutions:

[0009] A self-protecting, impact-resistant, low-heat-release control cable comprises a conductor, an insulating layer, a filling layer, a heat-insulating layer, a shielding and fire-proofing layer and an outer sheath which are sequentially arranged from the inside to the outside of the cable; the conductor is used to transmit electric energy, the insulating layer is used to prevent the cable from directly contacting the external environment, the filling layer is used to fill the gap between the cable conductors, the heat-insulating layer is used to prevent the cable from overheating when working in a high-temperature environment, the shielding and fire-proofing layer is used to shield electromagnetic interference and protect the internal structure of the cable in the event of a fire, and the outer sheath is used to separate the internal structure of the cable from the external environment;

[0010] A method for detecting whether a cable is qualified is also included, wherein the quality index of the cable is calculated by the following formula:

[0011] ZB=k3* ZB 1 +k 4 * ZB 2 +k 5 *ZB 3

[0012] in, ZB 1 is the electrical performance index of the cable, ZB 2 It is the anti-combustion performance index of the cable. ZB 3 is the anti-pollution performance index, k3 is the electrical performance weight of the cable, k 4 is the weight of the cable's flame retardancy performance, k 5 is the anti-pollution performance weight of the cable. When the quality index of the cable is greater than its corresponding specified threshold, the cable is unqualified;

[0013] The electrical performance indicators of the cable are obtained based on the measured values ​​and ideal values ​​of the parameters of the test circuit during the cable inspection;

[0014] The cable's flame resistance index is based on the heat generated by the cable during the test and the time the cable spends in different combustion stages;

[0015] The anti-pollution performance index of the cable is obtained based on the total volume of gas generated by the cable during the test and the volume ratio of harmful gases in the total gas.

[0016] Furthermore, the material of the conductor is annealed copper conductor, and the conductor is a second type twisted conductor structure; the thickness of the insulating layer is 0.6mm to 0.7mm, and the material of the insulating layer is low-smoke halogen-free flame-retardant polyolefin insulating material.

[0017] Furthermore, the cable includes multiple conductors, each of which is extruded with an insulating layer on the outside, and multiple conductors wrapped by the insulating layer are arranged inside the thermal insulation layer. The gaps between the thermal insulation layer and the conductors wrapped by the insulating layer and the gaps between the conductors wrapped by the insulating layer are filled by the filling layer. The conductors, the insulating layer and the filling layer together constitute the cable core of the cable. The material of the filling layer is a flame retardant inorganic material, which includes inorganic paper ropes and glass fiber yarns coated with hydroxides. The outer diameter of the filling layer is 1 mm to 3 mm.

[0018] Furthermore, the thermal insulation layer comprises two layers of glass fiber tapes, which are continuously overlapped and wrapped to form the thermal insulation layer, the thickness of the glass fiber tape is 0.2 mm, and the overlap rate is 10% to 20%; the material of the shielding fire insulation layer is copper tape, the production method of the copper tape is longitudinally wrapped and welded, the thickness of the copper tape is 0.4 mm to 0.6 mm, and the electrical conductivity of the copper tape at 20°C is less than or equal to 0.017593Ω·mm 2 / m.

[0019] Furthermore, the outer sheath material is a low-smoke, halogen-free, flame-retardant B1-grade polyolefin material, and the thickness of the outer sheath is 2.5 mm.

[0020] Furthermore, it also includes a method for preparing a self-protecting, impact-resistant, low-heat-release control cable:

[0021] S1, obtain the materials required for preparing each layer of the cable and classify them;

[0022] S2, an insulating layer is extruded on the outside of the conductor;

[0023] S3, continuously wrap two layers of glass fiber tape around the outside of the mold to form a heat insulation layer;

[0024] S4, taking out the mold, placing a plurality of conductors with extruded insulation layers inside the heat insulation layer, and filling the gaps between the plurality of conductors and the heat insulation layer with a flame retardant inorganic material to form a filling layer;

[0025] S5, preparing a copper strip by longitudinally wrapping and welding corrugation, and wrapping the copper strip around the heat insulation layer to form a shielding and fireproofing layer;

[0026] S6, an outer sheath is extruded outside the shielding and fireproof layer to obtain a self-protecting, impact-resistant and low heat release control cable.

[0027] Furthermore, a method for detecting a self-protecting, impact-resistant, low-heat-release control cable is also provided, which is used to detect whether the cable is qualified, and comprises the following steps:

[0028] STEP 1, cut a part of the cable as a cable sample, and connect both ends of the cable sample to the test circuit;

[0029] STEP2, burn the cable sample and subject it to mechanical impact for a set period of time;

[0030] STEP3: Analyze various parameters of cable samples and test circuits during combustion and mechanical impact.

[0031] Numbers are collected;

[0032] STEP4: When the main circuit current of the test circuit, the voltage at both ends of the cable sample and the equivalent resistance of the cable sample are

[0033] When the corresponding specified threshold range is exceeded, combustion and mechanical impact are stopped;

[0034] STEP5, calculate the quality index of the cable;

[0035] STEP6, determine whether the quality index of the cable exceeds the corresponding specified threshold range. If so, the cable is judged to be unqualified. Otherwise, the cable is judged to be qualified.

[0036] The beneficial effects achieved by the present invention are:

[0037] 1. The cable includes conductor, insulation layer, filling layer, thermal insulation layer, shielding fire insulation layer and outer sheath from the inside to the outside. The cable structure is reasonable and simple. The cable materials are all low calorific value materials. The heat release of the cable is low when it burns, and the corrugated structure gives the cable itself better toughness and impact resistance, enhancing the safety of the cable when in use.

[0038] 2. By setting the quality index of the cable and using the quality index to comprehensively represent the various performances of the cable, it is helpful to quantify the quality of the cable and help the staff to judge whether the cable is qualified based on the quality index. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The present invention can be further understood from the following description in conjunction with the accompanying drawings. The components in the figures are not necessarily drawn to scale, but the emphasis is placed on illustrating the principles of the embodiments. In different views, the same reference numerals designate the same parts.

[0040] Figure 1 It is a schematic diagram of the structure of the present invention.

[0041] Figure 2 The present invention is a flow chart for preparing the self-protecting, impact-resistant, low-heat-release control cable of the present invention.

[0042] Figure 3 The present invention is a flow chart for detecting whether a cable is qualified.

[0043] Figure 4 The present invention is a flow chart for calculating the quality index of the cable.

[0044] Reference numerals: 1 conductor, 2 insulation layer, 3 filling layer, 4 heat insulation layer, 5 shielding and fireproof layer, 6 outer sheath. DETAILED DESCRIPTION

[0045] The following is an explanation of the embodiments of the present invention through specific embodiments. Those skilled in the art can understand the advantages and effects of the present invention from the contents disclosed in this specification. The present invention can be implemented or applied through other different specific embodiments, and the details in this specification can also be modified and changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. In addition, the drawings of the present invention are only simple schematic illustrations and are not depicted according to actual sizes. It is stated in advance. The following embodiments will further explain the relevant technical contents of the present invention in detail, but the disclosed contents are not intended to limit the scope of protection of the present invention.

[0046] Embodiment 1: According to Figure 1 , Figure 2 , Figure 3 and Figure 4 , this embodiment provides a self-protecting impact-resistant low heat release control cable, comprising a conductor, an insulating layer, a filling layer, a heat insulation layer, a shielding fire insulation layer and an outer sheath arranged in sequence from the inside to the outside of the cable; the conductor is used to transmit electric energy, the insulating layer is used to prevent the conductor from directly contacting the external environment, the filling layer is used to fill the gap between the conductors, the heat insulation layer is used to prevent the conductor from overheating when working in a high temperature environment, the shielding fire insulation layer is used to shield electromagnetic interference and protect the internal structure of the cable in the event of a fire, and the outer sheath is used to separate the internal structure of the cable from the external environment;

[0047] A method for detecting whether a cable is qualified is also included, wherein the quality index of the cable is calculated by the following formula:

[0048] ZB=k3* ZB1 +k 4 * ZB 2 +k 5 *ZB 3

[0049] in, ZB 1 is the electrical performance index of the cable, ZB 2 It is the anti-combustion performance index of the cable. ZB 3 is the anti-pollution performance index, k3 is the electrical performance weight of the cable, k 4 is the weight of the cable's flame retardancy performance, k 5 is the anti-pollution performance weight of the cable. When the quality index of the cable is greater than its corresponding specified threshold, the cable is unqualified.

[0050] Furthermore, the conductor is made of annealed copper conductor, and the conductor is a second-type stranded conductor structure or a first-type solid conductor structure; the thickness of the insulating layer is 0.6 mm to 0.7 mm, and the insulating layer material is low-smoke halogen-free flame-retardant polyolefin insulating material.

[0051] Furthermore, the cable includes multiple conductors, each of which is extruded with an insulating layer on the outside, and multiple conductors wrapped by the insulating layer are arranged inside the thermal insulation layer. The gaps between the thermal insulation layer and the conductors wrapped by the insulating layer and the gaps between the conductors wrapped by the insulating layer are filled by the filling layer. The conductors, the insulating layer and the filling layer together constitute the cable core of the cable. The material of the filling layer is a flame retardant inorganic material, which includes inorganic paper ropes and glass fiber yarns coated with hydroxides. The outer diameter of the filling layer is 1 mm to 3 mm.

[0052] Preferably, the hydroxide is aluminum hydroxide or magnesium hydroxide; the flame retardant inorganic material includes inorganic paper rope and glass fiber coated with hydroxide, the inorganic paper rope can precipitate crystal water at high temperature, which can effectively reduce the cable core temperature, and the glass fiber can maintain its integrity in the flame, ensuring that the internal structure of the cable is tight and not loose.

[0053] Furthermore, the thermal insulation layer comprises two layers of glass fiber tapes, which are continuously overlapped and wrapped to form the thermal insulation layer, the thickness of the glass fiber tape is 0.2 mm, and the overlap rate is 10% to 20%; the material of the shielding fire insulation layer is copper tape, the production method of the copper tape is longitudinally wrapped and welded, the thickness of the copper tape is 0.4 mm to 0.6 mm, and the electrical conductivity of the copper tape at 20°C is less than or equal to 0.017593Ω·mm 2 / m. The glass fiber tape overlap rate refers to the proportion of the glass fiber tape used to wrap or strengthen the cable structure in the overlapping part during the cable manufacturing process.

[0054] Specifically, the glass fiber tape can maintain its own integrity at high temperatures, and its fluffy state can slow down the speed of heat transfer to the inside of the cable, which is beneficial to avoid burning of the insulating layer; the copper tape has excellent electrical conductivity and a high melting point, which can improve the shielding performance and has a good fire-proofing effect; the copper tape has a corrugated structure, which is beneficial to improve the toughness and impact resistance of the cable. When the cable is slightly bent, it can rebound by itself, and when it is impacted, it can disperse the impact force, thereby stabilizing the internal structure.

[0055] Furthermore, the outer sheath material is a low-smoke, halogen-free, flame-retardant B1-grade polyolefin material, and the thickness of the outer sheath is 2.5 mm.

[0056] Specifically, the outer sheath material is a low-smoke, halogen-free, flame-retardant B1 grade polyolefin material, which has a small heat release, no toxic gas release, and a stronger crusting ability. Its thickness of 2.5 mm can prevent the flame from directly burning through the outer sheath. At the same time, the extrusion extrusion method can make the outer sheath and the shielding and fire insulation layer tightly combined, reducing dripping while enabling the cable to form a stable whole, and greatly reducing the heat release rate and the total amount of heat release.

[0057] Furthermore, it also includes a method for preparing a self-protecting, impact-resistant, low-heat-release control cable:

[0058] S1, obtain the materials required for preparing each layer of the cable and classify them;

[0059] S2, an insulating layer is extruded on the outside of the conductor;

[0060] S3, continuously wrap two layers of glass fiber tape around the outside of the mold to form a heat insulation layer;

[0061] S4, taking out the mold, placing a plurality of conductors with extruded insulation layers inside the heat insulation layer, and filling the gaps between the plurality of conductors and the heat insulation layer with a flame retardant inorganic material to form a filling layer;

[0062] S5, preparing a copper strip by longitudinally wrapping and welding corrugation, and wrapping the copper strip around the heat insulation layer to form a shielding and fireproofing layer;

[0063] S6, an outer sheath is extruded outside the shielding and fireproof layer to obtain a self-protecting, impact-resistant and low heat release control cable.

[0064] Furthermore, a method for detecting a self-protecting, impact-resistant, low-heat-release control cable is also provided, which is used to detect whether the cable is qualified, and comprises the following steps:

[0065] STEP 1, cut a part of the cable as a cable sample, and connect both ends of the cable sample to the test circuit;

[0066] STEP2, burn the cable sample and subject it to mechanical impact for a set time period;

[0067] STEP3: Analyze various parameters of cable samples and test circuits during combustion and mechanical impact.

[0068] Numbers are collected;

[0069] STEP4: When the main circuit current of the test circuit, the voltage at both ends of the cable sample and the equivalent resistance of the cable sample are

[0070] When the corresponding specified threshold range is exceeded, the combustion and mechanical impact are stopped;

[0071] STEP5, calculate the quality index of the cable;

[0072] STEP6, determine whether the quality index of the cable exceeds its corresponding specified threshold range. If so, the cable is judged to be unqualified. Otherwise, the cable is judged to be qualified.

[0073] Specifically, the above-mentioned specified threshold range is set by those skilled in the art with reference to industry specifications.

[0074] Furthermore, the calculation of cable quality indicators in STEP5 includes the following steps:

[0075] STEP51, calculate the electrical performance indicators of the cable according to the following formula:

[0076]

[0077] in, ZB 1 is the electrical performance index of the cable, T is the detection time of the cable sample, is the measured value of the main circuit current of the test circuit of the cable sample at the tth moment during the detection period, I is the ideal value of the main circuit current of the test circuit, is the measured value of the voltage across the cable sample at the tth moment during the test, U is the ideal value of the voltage across the cable sample, is the measured value of the equivalent resistance of the cable sample at the tth moment during the test, and R is the ideal value of the equivalent resistance of the cable sample;

[0078] Specifically, the detection time of the cable is the time from the start of burning of the cable to the time when the main circuit current of the test circuit, the voltage at both ends of the cable sample and the equivalent resistance of the cable sample all exceed their corresponding specified threshold ranges;

[0079] Specifically, the test circuit is set by a person skilled in the art, and I, R, and U are ideal values ​​set by a person skilled in the art when designing the test circuit;

[0080] STEP52, calculate the cable's anti-combustion performance index according to the following formula:

[0081]

[0082] in, ZB 2 is the anti-combustion performance index of the cable, H is the total heat generated by the cable sample during the test, k1 is the intensive combustion weight, k2 is the initial combustion weight, e is the natural constant, h is the total heat generated by the cable sample during the initial combustion, and time is the time experienced by the cable sample during the initial combustion; the initial combustion period is the combustion stage when the heat generated per unit time during the combustion of the cable sample is not greater than the corresponding threshold; the time experienced during the initial combustion period is the time experienced when the heat generated per unit time during the combustion of the cable sample is not greater than the threshold. The total heat generated by the cable sample during the test can be measured using a calorimeter (such as a bomb calorimeter) to measure the combustion heat of the cable sample. The cable sample is completely burned, and then the change in system temperature before and after the combustion is measured to calculate the combustion heat; or the standard test method for determining the combustion heat of solid, liquid and gaseous fuels of ASTM (American Society for Testing and Materials) and the International Organization for Standardization (ISO) is used. The total heat generated by the cable sample during the initial combustion period is measured in a similar way to the total heat generated during the test period.

[0083] Specifically, a combustion limit threshold is set, and the combustion limit threshold is used to distinguish whether the cable is in the initial combustion stage or the intense combustion stage. When the heat generated per unit time during the combustion of the cable sample is greater than the threshold, it is judged that the cable is converted from the initial combustion state to the intense combustion state. The heat generated by the cable during combustion can be measured by a heat release instrument; preferably, the peak value of the heat release rate during the combustion of the outer sheath material is less than or equal to 30kW, and the combustion limit threshold can be 20kW;

[0084] STEP53, calculate the cable's anti-pollution performance index according to the following formula:

[0085]

[0086]

[0087] in, ZB 3 is the anti-pollution performance index, A is the total volume of gas generated by the cable during the test, B is the number of types of harmful gases generated by the cable during the test, C is b LEVEL is the volume ratio of the bth harmful gas generated by the cable during the test to the gas generated during the test. b is the level parameter of the bth type of harmful gas, level parameter LEVEL b It is the reciprocal of the direct damage concentration (IDLH) of harmful gases, and the direct damage concentration is obtained by national regulations;

[0088] S is the cross-sectional area of ​​the gas collection pipeline, T is the detection time of the cable sample, and V is the flow rate of the gas generated by the cable during the detection period when it passes through the gas collection pipeline;

[0089] Specifically, the gas flow rate can be detected by a flow meter;

[0090] Specifically, different harmful gases have different levels, and different levels correspond to different level parameters. The larger the level parameter, the greater the harmfulness of the harmful gas. The level parameter is set by a person skilled in the art. The type of the harmful gas can be obtained by performing spectral analysis on the gas generated during the combustion process, and the volume proportion of the harmful gas in the gas generated during the detection period can be obtained by analyzing the gas generated during the detection period using spectral analysis technology.

[0091] STEP54, calculate the quality index of the cable according to the following formula:

[0092] ZB=k3* ZB 1 +k 4 * ZB 2 +k 5 *ZB 3

[0093] in, ZB 1 is the electrical performance index of the cable, ZB 2 It is the anti-combustion performance index of the cable. ZB is the anti-pollution performance index, k3 is the electrical performance weight of the cable, k 4 is the weight of the cable's flame retardancy performance, k 5is the weight of the cable's anti-pollution performance.

[0094] Specifically, k1, k2, k3, k 4 , k 5 It is set by those skilled in the art;

[0095] Specifically, the greater the electrical performance index of the cable, the worse the electrical performance of the cable; the greater the anti-performance index of the cable, the worse the anti-combustion performance of the cable; the greater the anti-pollution index of the cable, the greater the pollution caused by the cable when it burns; the greater the quality index of the cable, the worse the quality of the cable;

[0096] Specifically, the materials of each layer of the cable have their own qualification standards. However, in the actual testing process, different parts of the cable may burn to different degrees, and different cable layers may be mixed together during the burning process, making it difficult to directly test the quality of each layer of the cable. Therefore, a quality indicator is set. When the quality indicator of the cable is within its corresponding specified threshold range, the cable is considered qualified. Judging directly by the performance of the cable itself is conducive to simplifying the testing steps and improving the accuracy of the judgment.

[0097] The beneficial effects of this solution are as follows: 1. The cable includes a conductor, an insulating layer, a filling layer, a heat insulation layer, a shielding fire insulation layer and an outer sheath from the inside to the outside. The cable structure is reasonable and simple. The cable materials are all low calorific value materials. The heat release of the cable during combustion is low, and the corrugated structure gives the cable itself better toughness and impact resistance, thereby enhancing the safety of the cable during use.

[0098] 2. By setting the quality index of the cable and using the quality index to comprehensively represent the various performances of the cable, it is helpful to quantify the quality of the cable and help the staff to judge whether the cable is qualified based on the quality index.

[0099] Embodiment 2: This embodiment should be understood to include all the features of any of the above embodiments, and further improve on the basis thereof, and also includes a production and detection system for a self-protection, impact-resistant, low-heat-release control cable, including a production system and a detection system, the production system is used to produce a self-protection, impact-resistant, low-heat-release control cable, and the detection system is used to detect whether the cable produced by the production system is qualified;

[0100] The production system includes a stranding machine, an extrusion machine, a wrapping machine, and a copper strip production module. The stranding machine is used to strand the conductors. The extrusion machine is used to extrude the materials of each layer of the cable onto the cable. The wrapping machine is used to wrap the glass fiber tape to form the insulation layer. The copper strip production module is used to produce copper strips according to the longitudinal wrap welding corrugation process.

[0101] The detection system includes a test circuit, a detection device, a sampling module, a calculation module and a comparison module. The test circuit is used to test the electrical properties of the cable sample. The detection device is used to burn and mechanically impact the cable sample. The sampling module is used to collect various parameters generated by the cable during the detection process. The calculation module is used to calculate the quality index of the cable according to the sampling data of the sampling module. The judgment module is used to judge whether the cable is qualified according to the calculation result of the calculation module.

[0102] The beneficial effects of this embodiment are as follows: through the production and testing system, the quality of the produced cables can be tested immediately after they are produced by the production system. After the test is completed, the staff can make on-site adjustments to the production system based on the test results, which is beneficial to improve the integration of the system and facilitate the staff to adjust the system.

[0103] The above disclosed contents are only preferred feasible embodiments of the present invention, and do not limit the protection scope of the present invention. Therefore, all equivalent technical changes made by using the contents of the present invention specification and drawings are included in the protection scope of the present invention. In addition, the elements therein can be updated with the development of technology. The above units are only examples. Those skilled in the art can use corresponding units according to different designs according to actual needs when implementing this solution.

Claims

1. A detection method for a self-protecting, impact-resistant, low-heat-release control cable, characterized in that: The structure of the cable includes a conductor, an insulating layer, a filling layer, a heat-insulating layer, a shielding and fire-proofing layer and an outer sheath which are arranged in sequence from the inside to the outside of the cable; the conductor is used to transmit electric energy, the insulating layer is used to prevent the cable from directly contacting the external environment, the filling layer is used to fill the gaps between the cable conductors, the heat-insulating layer is used to prevent the cable from overheating when working in a high-temperature environment, the shielding and fire-proofing layer is used to shield electromagnetic interference and protect the internal structure of the cable in the event of a fire, and the outer sheath is used to separate the internal structure of the cable from the external environment; The detection method calculates the quality index of the cable by the following formula , ZB=k3*ZB1+k4*ZB2+k5*ZB3 Among them, ZB1 is the electrical performance index of the cable, ZB2 is the anti-combustion performance index of the cable, ZB3 is the anti-pollution performance index, k3 is the electrical performance weight of the cable, k4 is the anti-combustion performance weight of the cable, and k5 is the anti-pollution performance weight of the cable. When the quality index of the cable is greater than its corresponding specified threshold, the cable is unqualified; the electrical performance index of the cable is obtained based on the measured value and ideal value of the parameters of the test circuit of the cable during the detection period; the anti-combustion performance index of the cable is obtained based on the heat generated by the cable during the detection period and the time occupied by the cable in different combustion stages; the anti-pollution performance index of the cable is obtained based on the total volume of gas generated by the cable during the detection period and the volume proportion of harmful gas in the total gas; The cable detection method comprises the following steps: STEP 1, cut a part of the cable as a cable sample, and connect both ends of the cable sample to the test circuit; STEP2, burn the cable sample and subject it to mechanical impact for a set time period; STEP3: Analyze various parameters of cable samples and test circuits during combustion and mechanical impact. Numbers are collected; STEP4: When the main circuit current of the test circuit, the voltage at both ends of the cable sample and the equivalent resistance of the cable sample are When the corresponding specified threshold range is exceeded, the combustion and mechanical impact are stopped; STEP5, calculate the quality index of the cable, including the following steps: STEP51, calculate the electrical performance indicators of the cable according to the following formula: in, is the electrical performance index of the cable, T is the detection time of the cable sample, is the measured value of the main circuit current of the test circuit of the cable sample at the tth moment during the detection period, I is the ideal value of the main circuit current of the test circuit, is the measured value of the voltage across the cable sample at the tth moment during the test, U is the ideal value of the voltage across the cable sample, is the measured value of the equivalent resistance of the cable sample at the tth moment during the test, and R is the ideal value of the equivalent resistance of the cable sample; The detection time of the cable is the time from the beginning of burning of the cable to the time when the main circuit current of the test circuit, the voltage at both ends of the cable sample and the equivalent resistance of the cable sample all exceed their corresponding specified threshold ranges; STEP52, calculate the cable's anti-combustion performance index according to the following formula: in, is the anti-combustion performance index of the cable, H is the total heat generated by the cable sample during the test, For intense burning weights, is the initial combustion weight, e is a natural constant, h is the total heat generated by the cable sample during the initial combustion period, and time is the time experienced by the cable sample during the initial combustion period; the initial combustion period is the combustion stage when the heat generated per unit time during the combustion of the cable sample is not greater than the corresponding threshold; the time experienced during the initial combustion period is the time experienced when the heat generated per unit time during the combustion of the cable sample is not greater than the threshold; STEP53, calculate the cable's anti-pollution performance index according to the following formula: A= in, is the anti-pollution performance index, A is the total volume of gas generated by the cable during the test, B is the number of types of harmful gases generated by the cable during the test, is the volume ratio of the bth harmful gas generated by the cable during the test to the gas generated during the test, is the grade parameter of the bth type of harmful gas, the grade parameter It is the reciprocal of the harmful concentration IDLH of harmful gases, which is obtained according to national regulations; S is the cross-sectional area of ​​the gas collection pipeline, T is the detection time of the cable sample, and V is the flow rate of the gas generated by the cable during the detection period when it passes through the gas collection pipeline; STEP6, determine whether the quality index of the cable exceeds its corresponding specified threshold range. If so, the cable is judged to be unqualified. Otherwise, the cable is judged to be qualified.

2. A self-protecting, impact-resistant, low-heat-release control cable that meets the quality indicators of the detection method described in claim 1, characterized in that: The structure of the cable includes a conductor, an insulating layer, a filling layer, a heat-insulating layer, a shielding and fire-proofing layer and an outer sheath which are arranged in sequence from the inside to the outside of the cable; the conductor is used to transmit electric energy, the insulating layer is used to prevent the cable from direct contact with the external environment, the filling layer is used to fill the gaps between the cable conductors, the heat-insulating layer is used to prevent the cable from overheating when working in a high-temperature environment, the shielding and fire-proofing layer is used to shield electromagnetic interference and protect the internal structure of the cable in the event of a fire, and the outer sheath is used to separate the internal structure of the cable from the external environment.

3. A self-protecting, impact-resistant, low-heat-release control cable according to claim 2, characterized in that: The material of the conductor is annealed copper conductor, and the conductor is a second-class stranded conductor structure; the thickness of the insulating layer is 0.6 mm to 0.7 mm, and the material of the insulating layer is low-smoke halogen-free flame-retardant polyolefin insulating material.

4. A self-protecting, impact-resistant, low-heat-release control cable according to claim 3, characterized in that: The cable includes multiple conductors, each of which is extruded with an insulating layer on the outside, and multiple conductors wrapped by the insulating layer are arranged inside the thermal insulation layer. The gaps between the thermal insulation layer and the conductors wrapped by the insulating layer and the gaps between the conductors wrapped by the insulating layer are filled by the filling layer. The conductors, the insulating layer and the filling layer together constitute the cable core of the cable. The material of the filling layer is a flame-retardant inorganic material, which includes an inorganic paper rope and glass fiber coated with hydroxide, and the outer diameter of the filling layer is 1mm to 3mm.

5. A self-protecting, impact-resistant, low-heat-release control cable according to claim 4, characterized in that: The heat insulation layer comprises two layers of glass fiber tapes, which are continuously overlapped and wrapped to form the heat insulation layer. The thickness of the glass fiber tape is 0.2 mm, and the overlap rate is 10% to 20%. The material of the shielding fire insulation layer is copper tape, which is produced by longitudinally wrapping welding corrugation. The thickness of the copper tape is 0.4 mm to 0.6 mm, and the electrical conductivity of the copper tape at 20°C is less than or equal to 0.017593 · / m.

6. A self-protecting, impact-resistant, low-heat-release control cable according to claim 5, characterized in that: The material of the outer sheath is low-smoke halogen-free flame-retardant B1 grade polyolefin material, and the thickness of the outer sheath is 2.5 mm.

7. A self-protecting, impact-resistant, low-heat-release control cable according to claim 6, characterized in that: A method for preparing a self-protecting, impact-resistant, low-heat-release control cable: S1, obtain the materials required for preparing each layer of the cable and classify them; S2, an insulating layer is extruded on the outside of the conductor; S3, continuously wrap two layers of glass fiber tape around the outside of the mold to form a heat insulation layer; S4, taking out the mold, placing a plurality of conductors with extruded insulating layers inside the heat insulation layer, and filling the gaps between the plurality of conductors and the heat insulation layer with a flame retardant inorganic material to form a filling layer; S5, preparing a copper strip by longitudinally wrapping and welding corrugation, and wrapping the copper strip around the heat insulation layer to form a shielding and fireproofing layer; S6, an outer sheath is extruded outside the shielding and fireproof layer to obtain a self-protecting, impact-resistant and low heat release control cable.

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