Flexible insulating signal transmission element and preparation method thereof

Abstract

The invention discloses a flexible insulation signal transmission element and a preparation method thereof, and relates to the technical field of wired signal transmission. The cable specifically comprises a signal line and a barrier layer, and the barrier layer comprises an insulating layer wrapping the peripheral wall of the signal line and a mineral layer wrapping the peripheral wall of the insulating layer. Wherein the signal line and the barrier layer form a signal transmission element with an outer diameter of less than 3 mm in a drawing and annealing alternating manner. The signal line is wrapped by the insulating layer and the mineral layer, the mineral layer is made of materials with high temperature resistance, the outer diameter of the cable is reduced in a drawing and annealing alternating mode, the insulating mineral cable can resist the high temperature of 300 DEG C or above, meanwhile, the flexibility of the cable is increased due to the reduced outer diameter, the flexibility of the cable can be greatly improved, and the service life of the cable is prolonged. Wiring in the installation space is facilitated, and the utilization rate of the installation space is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of wired signal transmission, and in particular to a flexible insulating signal transmission element and a preparation method thereof. Background Art

[0002] Insulated signal transmission components generally refer to components used to transmit signals in electronic and electrical systems. These components can provide electrical isolation between different circuits or systems to prevent current from flowing directly from one part to another. Insulated cables are a common way of signal transmission components.

[0003] At present, there are various types of signal transmission lines on the market, with different performances and applicable environments. Signal transmission lines suitable for use at high temperatures are mostly fluoroplastic or glass fiber sheathed. This type of transmission line has a thin core and good flexibility. It can be used when the ambient temperature does not exceed 300°C. If the temperature exceeds this, the insulation performance and mechanical strength of the signal transmission line will be reduced; if the temperature exceeds 300°C, mineral insulated cables can also be selected as signal transmission lines. This is a copper, stainless steel or nickel-based alloy tube as a sheath, which has the characteristics of high temperature resistance and is used to overcome the performance of signal transmission in high temperature environments.

[0004] Based on market demand and the customer's usage environment, the inventor concluded that customers need high-temperature resistant flexible insulated signal transmission lines. Although the high-temperature resistant signal transmission lines sold on the market use mineral insulated cables to solve the temperature problem, the environment used by some customers is complex and they need to route the lines in a complex environment. The outer diameter of the mineral insulated cables is more than 3.0 mm, which results in poor flexibility of the high-temperature resistant mineral cables, making it difficult to route the signal transmission lines in this environment. As a result, when customers use the transmission cables, it is difficult to route the lines in their complex environments. At the same time, due to its large diameter, it occupies too much installation space, affecting the layout of the remaining signal transmission lines.

[0005] Therefore, the present application aims to improve the flexibility of the signal transmission line and increase the utilization of the installation space. Summary of the invention

[0006] The main purpose of the present invention is to provide a flexible insulating signal transmission element and a preparation method thereof, aiming to improve the flexibility of the signal transmission line and improve the utilization rate of the installation space.

[0007] In order to achieve the above-mentioned purpose, the present invention proposes a flexible insulating signal transmission element, comprising a signal line; a barrier layer, which comprises an insulating layer wrapped around the outer peripheral wall of the signal line, and a mineral layer wrapped around the outer peripheral wall of the insulating layer; wherein the outer diameter of the barrier layer is less than 3 mm.

[0008] Furthermore, two ends of the signal line extend out from the ends of the barrier layer respectively, and are both connected to lead-out terminals.

[0009] Furthermore, the lead terminal is crimped and fixed to the signal line.

[0010] Furthermore, a connector is sleeved on the end of the barrier layer, and the connector is provided with a cavity for storing the signal line and the contact end of the lead terminal, and a sealing member can be arranged in the cavity to prevent the insulating layer from getting wet.

[0011] The present application also discloses a method for preparing a flexible insulating signal transmission element, the method comprising:

[0012] Step S1: Select a mineral pipe, and install an insulation layer and a signal line in the mineral pipe to form a mineral insulated cable;

[0013] Step S2: Drawing and annealing the mineral insulated cable to form a mineral insulated cable with an outer diameter less than 3 mm.

[0014] Furthermore, the step S2 further includes:

[0015] Step S2.1: The mineral insulated cable is drawn with an elongation within a range of 18%-24%. When the outer diameter of the mineral insulated cable is greater than 4.0 mm, the mineral insulated cable is annealed once after each drawing is completed;

[0016] Step S2.2: When the outer diameter of the mineral insulated cable is less than 4.0 mm, the mineral insulated cable is annealed once after every two drawing operations.

[0017] Furthermore, the annealing speed is 0.4-2.2 m / min, and the annealing temperature is 950° C.-1100° C.

[0018] Furthermore, the annealing speed gradually increases as the outer diameter of the mineral insulated cable becomes smaller.

[0019] Furthermore, the seal is sealed with glass powder, and the signal line extending from the end of the mineral insulated cable is heated for 30-50 cm to remove moisture, and the glass powder is sealed on the inner tank of the joint and heated by high-frequency heating. After the glass powder is melted, the joint is slowly cooled and solidified until the solidified glass powder fills the cavity of the joint.

[0020] Furthermore, the seal is sealed with a ceramic column, and the crimping position between the connector and the signal line is welded and sealed; after sealing, the ceramic column is installed in the connector, and the signal line extending from the end of the mineral insulated cable is heated for 30-50cm to remove moisture; the contact gaps between the ceramic column and the connector, and between the ceramic column and the signal line are brazed and sealed respectively.

[0021] The above technical solution has the following advantages:

[0022] The present invention adopts an insulating layer and a mineral layer to wrap the outside of the signal line. The material used for the mineral layer has high temperature resistance. The outer diameter of the cable is reduced by alternate drawing and annealing, so that the outer diameter of the insulated mineral cable is reduced to less than 3 mm. The insulated mineral cable has the ability to withstand high temperatures above 300°C, and its flexibility is increased due to the reduced outer diameter, which can greatly improve the flexibility of the cable, facilitate its wiring in the installation space, and improve the utilization rate of the installation space.

[0023] By alternating between drawing and annealing, and drawing once and annealing once for cables above 4 mm, and drawing twice and annealing once for cables below 4 mm, cable breakage during preparation can be avoided as much as possible, thereby increasing the yield of cable production. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The present invention is described in detail below with reference to specific embodiments and accompanying drawings, wherein:

[0025] Figure 1 It is a structural schematic diagram of the present invention.

[0026] Figure 2 It is a schematic diagram of the structure of the welding point of the sealing part of the present invention.

[0027] Figure 3 The figure is a process route diagram of the preparation method of the present invention.

[0028] In the figure: 1. signal line; 2. barrier layer; 3. connector; 4. seal; 5. lead terminal. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solution and advantages of the present invention clearer, the present invention is described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the following specific embodiments are only used to explain the present invention and do not constitute a limitation to the present invention.

[0030] Although fluoroplastic or glass fiber sheathed signal cables are widely used, the maximum operating temperature of such sheathed signal cables cannot exceed 300°C, and fluoroplastic is a polymer material that is not resistant to radiation. Although mineral insulation is resistant to high temperatures and radiation, its outer diameter is usually above 3.0mm and its flexibility is very poor. If its flexibility is to be improved, the outer diameter must be 3.0mm, or even below 2.0mm, which is very difficult and the core is easily broken or the sheath is cracked. In addition, magnesium oxide powder is very susceptible to moisture, and both ends of the cable need to be effectively sealed, but the current sealing method using epoxy resin materials can only be used at room temperature.

[0031] In view of the shortcomings of the above-mentioned prior art, a set of process routes was first developed to manufacture mineral insulated cables with a diameter of less than 2.0 mm; then, combined with the actual high-temperature and radiation application environment, the cables were prepared into complete signal transmission components.

[0032] like Figure 1 and Figure 2 As shown, a flexible insulating signal transmission element includes a signal line 1 and a barrier layer 2, wherein the barrier layer 2 includes an insulating layer wrapped around the outer wall of the signal line 1, and a mineral layer wrapped around the outer wall of the insulating layer; wherein the signal line 1 and the barrier layer 2 are formed into a signal transmission element with an outer diameter less than 3 mm by alternating drawing and annealing.

[0033] Specifically, the signal line 1 is used to transmit information, such as by electrical signal transmission or optical signal transmission, and is made of pure copper or pure nickel. The insulating layer is used to fill insulating materials, and silicone rubber, magnesium oxide powder, PE and PVC, etc. can be used. In this application, in order to improve the high temperature resistance effect, a prefabricated insulating porcelain column method or an automatic magnesium oxide filling method is adopted. The mineral layer is a pipe made of copper, stainless steel or nickel-based alloy tube, etc. The mineral layer is a sheath, which protects the entire insulating layer and the signal line 1.

[0034] The two ends of the signal line 1 extend from the ends of the barrier layer 2 respectively, and are both connected to the lead-out terminals 5. The lead-out terminals 5 are crimped and fixed to the signal line 1; in addition, the lead-out terminals 5 and the ends of the signal line 1 can also be connected by welding or threading, and the lead-out terminals 5 facilitate the connection of the two ends of the signal line 1 to realize signal transmission.

[0035] The end of the barrier layer 2 is sleeved with a connector 3, and the connector 3 is provided with a cavity for storing the contact end of the signal line 1 and the lead terminal 5. A seal 4 can be arranged in the cavity to prevent the insulating layer from getting wet, wherein the contact end of the signal line 1 and the lead terminal 5 is located in the connector 3. Specifically, the connector 3 is sleeved on the outside of the cable. After the signal line 1 and the lead terminal 5 are fixed, the connector 3 can be slid from the outside of the cable to the contact end of the signal line 1 and the lead terminal 5, and the cavity of the connector 3 is wrapped around the contact end. The connector 3 can be sealed by the seal 4 to prevent the magnesium oxide powder of the insulating layer from getting wet. The seal 4 can be made of high-purity magnesium oxide powder or a ceramic column.

[0036] A method for preparing a flexible insulating signal transmission element, the method comprising:

[0037] Step S1: Select a mineral pipe, and install an insulating layer and a signal line 1 in the mineral pipe to form a mineral insulated cable;

[0038] Step S2: Drawing and annealing the mineral insulated cable to form a mineral insulated cable with an outer diameter less than 3 mm.

[0039] Specifically, step S2.1: the mineral insulated cable is drawn with an elongation within a range of 18%-24%. When the outer diameter of the mineral insulated cable is greater than 4.0 mm, the mineral insulated cable is annealed once after each drawing is completed;

[0040] Step S2.2: When the outer diameter of the mineral insulated cable is less than 4.0 mm, the mineral insulated cable is annealed once after every two drawing operations, the annealing speed is 0.4-2.2 m / min, and the annealing temperature is 950°C-1100°C; the annealing speed gradually increases as the outer diameter of the mineral insulated cable becomes smaller.

[0041] When the seal 4 is sealed with glass powder, the signal line 1 extending from the end of the mineral insulated cable is heated at a distance of 130-50cm to remove moisture, and the glass powder is sealed on the inner tank of the joint 3 and heated by high-frequency heating, that is, a coil is placed on the outside of the joint 3, and eddy currents are generated through an alternating magnetic field to heat and melt the glass powder; after the glass powder is melted, the joint 3 is slowly cooled and solidified until the solidified glass powder fills the cavity of the joint 3.

[0042] When the seal 4 is sealed with a ceramic column, the position where the connector 3 and the signal line 1 are crimped is welded and sealed; after sealing, the ceramic column is installed into the connector 3, and the signal line 1 extending from the end of the mineral insulated cable is heated at a distance of 130-50cm to remove moisture; the contact gaps between the ceramic column and the connector 3, and between the ceramic column and the signal line 1 are brazed and sealed respectively.

[0043] The present application uses the above method to prepare a mineral insulated cable, and the specific preparation method is as follows:

[0044] Embodiment 1:

[0045] (1) According to the setting of the finished product outer diameter of 1.3mm, the mineral layer selects I ncone l 600 tube with an outer diameter of 10.3mm, and the insulation layer and signal line 1 respectively select prefabricated insulating porcelain columns and pure nickel core rods. The tube is assembled with prefabricated insulating porcelain columns and pure nickel core rods with specifications of 6.5mm*1mm*4.0mm. The calculation meets the assembly requirements, and the outer diameter of the core rod is 2.8-3.2mm.

[0046] (2) Drawing is carried out within the range of the elongation of the mineral insulated cable. The specific values ​​are 8.5, 7.7, 7.0, 6.4, 5.8, 5.3, 4.8, 4.4, 4.1, 3.8, 3.5, 3.2, 2.9, 2.7, 2.5, 2.3, 2.1, 1.9, 1.75, 1.6, 1.5, 1.38, 1.29, 1.2, 1.1, 1.0 (unit: mm). The mineral insulated cable is drawn on a stretching machine. When the outer diameter is above 4.0 mm, annealing is performed in a tubular furnace once for each drawing; when the outer diameter is less than 4.0 mm, annealing is performed once for each two drawing. The annealing temperature is 950℃-1100℃, the annealing speed is 0.4-2.2m / min, the initial annealing speed is 0.4m / min, and it gradually increases with the outer diameter of the cable, until the cable reaches 2.5mm, the annealing speed is 2.2m / min. As the annealing speed increases, the annealing time can be reduced to prevent over-annealing, which causes excessive grain growth of the cable material and uneven organization, thereby affecting the physical and chemical properties of the cable.

[0047] (3) After multiple drawing and annealing, the finished cable has an outer diameter of 1.0±0.03mm. After passing the test, take cables with lengths of 10m, 15m and 20m, remove the mineral layers at both ends, and expose the signal line 1 with a length of 20-25mm.

[0048] (4) When the outer diameter of the mineral cable is 1.0 mm, the diameter of the signal line 1 is about 0.4 mm, which is difficult to meet the wiring requirements. A nickel tube or copper tube with a diameter of 1.4-1.6 mm and a length of 20-30 mm needs to be crimped onto the signal line 1 as a lead-out wire. When crimping, ensure that the starting end of the nickel tube or copper tube is 2-3 mm away from the cable sheath to prevent the nickel tube or copper tube of the terminal from contacting the mineral layer.

[0049] (5) Put the stainless steel connector 3 on the cable, crimp it with a mold, and fix the connector 3 to the cable.

[0050] (6) Use a heat gun to remove moisture from the cable cutout at a distance of 30-50 cm and measure the insulation resistance. After the cable insulation treatment is qualified, seal the glass powder on the inner tank of the joint 3 and heat the glass powder by high-frequency heating. After the glass powder melts, slowly cool and solidify. Repeat this 3-4 times until the solidified glass powder completely fills the inside of the joint 3 cavity.

[0051] (7) After sealing is completed, grind joint 3, immerse it in water for 1 hour, and measure the insulation resistance at room temperature and the high temperature above 300°C.

[0052] Embodiment 2:

[0053] (1) According to the setting of the finished product outer diameter of 1.6 mm, the mineral layer selects 316L pipe with an outer diameter of 12.7 mm, and the insulation layer and signal line 1 select prefabricated insulating porcelain columns and pure copper core rods respectively. The pipe is assembled with prefabricated insulating porcelain columns and pure copper core rods with specifications of 9.5 mm*1 mm*5.0 mm. The calculation meets the assembly requirements, and the outer diameter of the core rod is 2.8-3.2 mm.

[0054] (2) Drawing is done within the range of the elongation of the mineral insulated cable. The specific values ​​are 11.4, 10.3, 9.4, 8.5, 7.7, 7.0, 6.4, 5.8, 5.3, 4.8, 4.4, 4.1, 3.8, 3.5, 3.2, 2.9, 2.7, 2.5, 2.3, 2.1, 1.9, 1.75, 1.6 (unit: mm). The mineral insulated cable is drawn on a stretching machine. When the outer diameter is above 4.0 mm, annealing is done in a tubular furnace once for each drawing; when the outer diameter is less than 4.0 mm, annealing is done once for each two drawing. The annealing temperature is 950℃-1100℃, and the annealing speed is 0.4-2.2m / min.

[0055] (3) After multiple drawing and annealing, the cable is finished and tested to be qualified. Take cables with lengths of 10m, 15m and 20m respectively, peel off the mineral layers at both ends, and expose the signal line 1 with a length of 20-25mm.

[0056] (4) After the finished cable, the diameter of signal line 1 is 0.6mm smaller, which is difficult to meet the wiring requirements. A nickel tube or copper tube with a diameter of 1.4-1.6mm and a length of 20-30mm needs to be crimped on the signal line 1 as a lead-out line. When crimping, ensure that the starting end of the nickel tube or copper tube is 2-3mm away from the cable sheath.

[0057] (5) Place the stainless steel connector 3 on the cable and crimp it with a mold to fix the connector 3 to the cable.

[0058] (6) The joint 3 and the cable are welded and sealed by flame brazing; after sealing, the ceramic column is installed into the joint 3, and the cable cut is dehumidified by a hot drying gun at a distance of 30-50cm, and the insulation resistance is measured. After the cable insulation treatment is qualified, the contact gaps between the ceramic column and the joint 3 and the ceramic column and the lead terminal 5 are brazed and sealed respectively, and the welding method is induction brazing, as shown in the following example. Figure 2 shown.

[0059] (7) After sealing is completed, grind joint 3, immerse it in water for 1 hour, and measure the insulation resistance at room temperature and the high temperature above 300°C.

[0060]

[0061] Comparative Examples 1 and 2 in the table respectively select polyimide (PI) cable and polyetheretherketone (PEEK) cable, which are high-temperature signal transmission lines available on the market. It can be seen from the chart that when the temperature exceeds 400°C, the cable insulation layers of Comparative Examples 1 and 2 are in a melted or burnt state, while the insulation layers of the mineral insulated cables prepared in Examples 1 and 2 of the present application are not melted or burnt, and their high-temperature resistance is better than that of the signal transmission lines on the market. At the same time, the outer diameters of the cables prepared in Examples 1 and 2 of the present application are both less than 2 mm, which makes the cables more flexible while being resistant to high temperatures, and saves more installation space for wiring operations.

[0062] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A flexible insulating signal transmission element, characterized in that: include: Signal line (1); A barrier layer (2), comprising an insulating layer wrapped around the outer peripheral wall of the signal line (1), and a mineral layer wrapped around the outer peripheral wall of the insulating layer; Wherein, the outer diameter of the barrier layer (2) is less than 3 mm.

2. The flexible insulating signal transmission element according to claim 1, characterized in that: Both ends of the signal line (1) extend out from the ends of the barrier layer (2) respectively, and are both connected to lead-out terminals (5).

3. The flexible insulating signal transmission element according to claim 2, characterized in that: The lead-out terminal (5) is crimped and fixed to the signal line (1).

4. The flexible insulating signal transmission element according to claim 2, characterized in that: The end of the barrier layer (2) is sleeved with a connector (3), and the connector (3) is provided with a cavity for storing the contact ends of the signal line (1) and the lead terminal (5), and a sealing member (4) can be arranged in the cavity to prevent the insulating layer from getting wet.

5. The method for preparing the flexible insulating signal transmission element according to claim 4, characterized in that: The preparation method comprises: Step S1: selecting a mineral pipe, placing an insulating layer and a signal line (1) in the mineral pipe to form a mineral insulated cable; Step S2: Drawing and annealing the mineral insulated cable to form a mineral insulated cable with an outer diameter less than 3 mm.

6. The method for preparing the flexible insulating signal transmission element according to claim 5, characterized in that: The step S2 further comprises: Step S2.1: The mineral insulated cable is drawn with an elongation within a range of 18%-24%. When the outer diameter of the mineral insulated cable is greater than 4.0 mm, the mineral insulated cable is annealed once after each drawing is completed; Step S2.2: When the outer diameter of the mineral insulated cable is less than 4.0 mm, the mineral insulated cable is annealed once after every two drawing operations.

7. The method for preparing the flexible insulating signal transmission element according to claim 5, characterized in that: The annealing speed is 0.4-2.2 m / min, and the annealing temperature is 950°C-1100°C.

8. The method for preparing the flexible insulating signal transmission element according to claim 7, characterized in that: The annealing speed gradually increases as the outer diameter of the mineral insulated cable becomes smaller.

9. The method for preparing the flexible insulating signal transmission element according to claim 5, characterized in that: The sealing member (4) is sealed with glass powder. The signal line (1) extending from the end of the mineral insulated cable is heated to remove moisture at a distance of 30-50 cm. The glass powder is sealed on the inner tank of the joint (3) and heated by high-frequency heating. After the glass powder is melted, the joint (3) is slowly cooled and solidified until the solidified glass powder fills the cavity of the joint (3).

10. The method for preparing the flexible insulating signal transmission element according to claim 5, characterized in that: The sealing member (4) is sealed by a ceramic column, and the position where the joint (3) and the signal line (1) are crimped is welded and sealed; after sealing, the ceramic column is installed in the joint (3), and the signal line (1) extending from the end of the mineral insulated cable is heated to remove moisture at a distance of 30-50 cm; and the contact gaps between the ceramic column and the joint (3) and between the ceramic column and the signal line (1) are brazed and sealed respectively.

Images