Cross-linked polyolefin insulated low-smoke halogen-free flame-retardant automotive ignition cables

Abstract

This invention discloses a cross-linked polyolefin insulated, low-smoke, halogen-free, flame-retardant automotive ignition cable, relating to the field of automotive electrical system technology. The cable includes a distributor connector and a spark plug connector installed at both ends. Two rubber blocks are movably mounted on the cable. Each rubber block is cylindrical, and an annular groove is formed on its circumference. Under no external force, the width of the annular groove is less than the width of the protrusion between the two annular grooves. This invention uses rubber blocks on the cable, allowing adjacent rubber blocks to interlock through the protrusion and the annular groove, preventing direct contact between the two cables. Furthermore, the rubber blocks maintain a gap between the cable and the engine block, preventing high engine temperatures from being directly transferred to the cable.

Description

Technical Field

[0001] This invention relates to the field of automotive electrical system technology, specifically to cross-linked polyolefin insulated, low-smoke, halogen-free, flame-retardant automotive ignition cables. Background Technology

[0002] Ignition cables, also known as spark plug wires, are the conductors that carry the high voltage generated by the ignition coil to the spark plugs. They are an essential part of traditional ignition systems, serving as the medium through which the ignition coil transfers its energy to the spark plugs. Traditional automotive high-voltage ignition cables typically use silicone rubber or EPDM rubber as insulation. While these materials have good high-temperature resistance and electrical insulation properties, they produce large amounts of dense smoke and toxic halogen gases during combustion, posing safety hazards. With increasingly stringent automotive safety standards and environmental requirements, higher demands are placed on the flame retardancy and low-smoke halogen-free characteristics of ignition cables. Existing technologies include research on low-smoke halogen-free cable materials, such as the 125℃ irradiated cross-linked low-smoke halogen-free flame-retardant polyolefin cable material for new energy vehicles disclosed in CN111205550A, and the highly flame-retardant cross-linked low-smoke halogen-free polyolefin insulation material disclosed in CN113372644A. One end of the ignition cable connects to the distributor, and the other end connects to the spark plug; the number of spark plugs is the same as the number of cylinders. The distance between the engine distributor and the spark plugs on each cylinder block varies, and the length of each ignition cable also varies. Due to the limited space inside the engine compartment, some ignition cables inevitably come into contact with each other. Vibrations generated during engine operation cause the ignition cables to rub against each other continuously, damaging their protective layer. The ignition cables are also prone to contact with the outer surface of the engine, and the high temperatures generated by the engine are directly transferred to the ignition cables. Summary of the Invention

[0003] The purpose of this invention is to provide a cross-linked polyolefin insulated, low-smoke, halogen-free, flame-retardant automotive ignition cable to overcome the aforementioned shortcomings in the prior art.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a cross-linked polyolefin insulated low-smoke halogen-free flame-retardant automotive ignition cable, comprising a cable, with a distributor socket and a spark plug socket respectively installed at both ends of the cable; two rubber blocks are movably installed on the cable; the rubber blocks are cylindrical and have annular grooves on their circumferential surfaces; under no external force, the width of the annular grooves is less than the width of the protrusion between the two annular grooves.

[0005] As a preferred embodiment of the present invention, the rubber block includes a first part that slides with the cable and a second part that rotates with the first part.

[0006] As a preferred embodiment of the present invention, the outer surface of the cable is formed with a raised strip arranged along its length, and the inner surface of the first part is formed with a strip-shaped groove that cooperates with the raised strip.

[0007] As a preferred embodiment of the present invention, the outer surface of the first part forms a uniform wave shape along its circumference, and the inner surface of the second part forms a uniform wave shape along its circumference.

[0008] As a preferred embodiment of the present invention, the cable and the first part form a gap fit.

[0009] As a preferred embodiment of the present invention, the protruding portion of the rubber block is provided with a plurality of annular rubber strips on both sides for increasing friction.

[0010] As a preferred embodiment of the present invention, the number of annular grooves on the rubber block is two, and a rigid ring is fixedly installed on the circumferential surface of the protruding part in the middle of the rubber block near the distributor socket.

[0011] As a preferred embodiment of the present invention, the outer surface of the distributor connector is a protective sleeve made of rubber.

[0012] As a preferred embodiment of the present invention, an annular groove is provided on the outer wall of the distributor socket protective sleeve, and a non-stretchable pull wire is wound in the annular groove. One end of the pull wire is fixedly connected to the inner wall of the annular groove, and the other end is fixedly connected to a rigid ring.

[0013] As a preferred embodiment of the present invention, the insulation layer of the cable is made of cross-linked polyolefin through extrusion molding. In the above embodiment, the cross-linked polyolefin insulated low-smoke halogen-free flame-retardant automotive ignition cable provided by the present invention has rubber blocks installed on the cable. The rubber blocks on adjacent cables can be interlocked by the cooperation of the protrusion and the annular groove to prevent the two cables from directly contacting each other; and the rubber blocks can maintain a gap between the cable and the engine block, preventing the high temperature of the engine from being directly transferred to the cable. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0015] Figure 1 This is a three-dimensional view of the cross-linked polyolefin insulated low-smoke halogen-free flame-retardant automotive ignition cable of Example 1. Figure 2 for Figure 1 Enlarged view of point A in the middle; Figure 3 This is a front view of the cross-linked polyolefin insulated low-smoke halogen-free flame-retardant automotive ignition cable of Example 1. Figure 4 This is a schematic diagram of the initial state of the first and second parts of the rubber block in Example 1; Figure 5 This is a three-dimensional view of the cross-linked polyolefin insulated low-smoke halogen-free flame-retardant automotive ignition cable of Example 2. Figure 6 for Figure 5 Enlarged view of point B in the middle; Figure 7 This is a schematic diagram of the compression state of the first and second parts of the rubber block in Example 2; Explanation of reference numerals in the attached diagram: 1. Cable; 101. Raised bar; 2. Distributor socket; 3. Spark plug socket; 4. Rubber block; 401. Annular groove; 402. First part; 403. Second part; 5. Rigid ring; 6. Pull wire. Detailed Implementation

[0016] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0017] Example 1

[0018] like Figure 1 As shown, this embodiment provides a cross-linked polyolefin insulated low-smoke halogen-free flame-retardant automotive ignition cable, including cable 1. The insulation layer of cable 1 is made of cross-linked polyolefin extrusion molding. Distributor socket 2 and spark plug socket 3 are respectively installed at both ends of cable 1. Distributor socket 2 is connected to the distributor, and spark plug socket 3 is connected to the corresponding spark plug on the engine.

[0019] like Figure 1 and Figure 2 As shown, two rubber blocks 4 are movably installed on cable 1. Each rubber block 4 is cylindrical, and each has two annular grooves 401 on its circumference, meaning each rubber block 4 has three protrusions. Under no external force, the axis of the rubber block 4 is straight. The width of the annular grooves 401 is the same at all points, and the width of the annular grooves 401 is less than the width of the central protrusion of the rubber block 4. After the operator inserts the distributor connector 2 and spark plug connector 3 of each cable 1 into the corresponding distributor and spark plug, they arrange the cables 1 and align the rubber blocks 4 on adjacent cables 1. Specifically, they insert the protrusion of one rubber block 4 into the annular groove 401 of the other rubber block 4. Figure 3The state is shown. Because the width of the annular groove 401 is smaller than the width of the raised part in the middle of the rubber block 4, the two rubber blocks 4 will undergo extrusion deformation. The static friction generated between them makes it difficult to separate them after they are inserted. Thus, the cooperation of the rubber blocks 4 on the two cables 1 ensures that the two adjacent cables 1 always remain in a non-contact state. Several annular rubber strips are provided on both sides of the raised part of the rubber block 4 to increase the friction.

[0020] It should be noted that the rubber blocks 4 near the distributor are interlocked to prevent the cables 1 from contacting each other in the densely distributed area near the distributor. After the operator arranges the cables 1, ensuring that the cables 1 do not contact the engine block, another rubber block 4 is adjusted to a position close to the cables 1 in the spark plug area, and then the rubber blocks 4 are interlocked. In this way, adjacent cables 1 are shaped through the interlocking of two pairs of rubber blocks 4, and the two cables 1 will not contact each other. Due to the protection of the rubber blocks 4, the shaped cables 1 will not contact the engine block.

[0021] like Figure 2 and Figure 4 As shown, the rubber block 4 includes a first part 402 that slides with the cable 1 and a second part 403 that rotatably engages with the first part 402; a clearance fit is formed between the cable 1 and the first part 402. A raised strip 101 is formed on the outer surface of the cable 1 along its length, and a strip-shaped groove is formed on the inner surface of the first part 402 that engages with the raised strip 101. A uniform wave shape is formed on the outer surface of the first part 402 along its circumference, and a uniform wave shape is formed on the inner surface of the second part 403 along its circumference. Specifically, as... Figure 4 As shown, in the initial state, the crest region on the inner side of the second part 403 corresponds to the trough region on the outer side of the first part 402, and there is no radial compression force between the first part 402 and the second part 403. After the operator installs each cable 1 and adjusts the position of each corresponding rubber block 4, the second part 403 is rotated so that the crest region on the inner side of the second part 403 corresponds to the crest region on the outer side of the first part 402. In this way, a radial compression force is generated between the first part 402 and the second part 403, which also generates a radial compression force between the first part 402 and the cable 1. This increases the static friction between the rubber block 4 and the cable 1, ensuring that the position of the rubber block 4 relative to the cable 1 remains constant. In summary, in this embodiment, because the rubber block 4 and the cable 1 are in a clearance fit, it is relatively convenient to adjust the position of the rubber block 4. After adjustment, rotating the first part 402 can prevent the rubber block 4 from sliding relative to the cable 1.

[0022] Example 2

[0023] like Figure 5 , Figure 6 and Figure 7 As shown, in this embodiment, a rigid ring 5 is fixedly installed on the circumferential surface of the protruding part in the middle of the rubber block 4 near the distributor connector 2, that is, the rigid ring 5 is fixedly connected to the middle part of the second part 403. The outside of the distributor connector 2 is a protective sleeve made of rubber. An annular groove is formed on the outer wall of the protective sleeve. A non-stretchable pull wire 6 is wound in the annular groove. One end of the pull wire 6 is fixedly connected to the inner wall of the annular groove, and the other end is fixedly connected to the rigid ring 5. The technical points of this embodiment are described in detail below: Since the distributor interface is relatively short, its dustproof and waterproof effect is poor compared with the spark plug interface. In this embodiment, a pull wire 6 is wound on the protective sleeve of the distributor connector 2. When one end of the pull wire 6 is subjected to tension, it will tighten the protective sleeve, so that the protective sleeve fits tightly with the distributor interface, improving the dustproof and waterproof effect. In the initial state, the pull wire 6 is in a slack state and will not tighten the protective sleeve. The operator adjusts the position of the rubber block 4 and inserts the corresponding rubber block 4 and then rotates the second part 403. When the second part 403 rotates, it drives the rigid ring 5 on it to rotate synchronously. The rigid ring 5 then pulls the pull wire 6, causing the pull wire 6 to gradually change from a slack state to a taut state. During this process, the inner crest of the second part 403 continuously contacts the outer crest of the first part 402 until the pull wire 6 is fully taut, and the second part 403 can no longer rotate. In this state, the protective sleeve is deformed due to being tightened by the pull wire 6, and it has a tendency to recover. This causes the pull wire 6 to pull the rigid ring 5 in the opposite direction. Under the action of the pull wire 6, the rigid ring 5 undergoes axial deformation, that is, the protruding part in the middle of the rubber block 4 will shift towards the distributor side under the action of the rigid ring 5, thereby clamping the other rubber block 4 and increasing the static friction between the two adjacent rubber blocks 4. On the other hand, the rigid ring 5 causes the second part 403 to have a rotational tendency under the action of the pull wire 6. However, due to the obstruction of the crest position of the first part 402, the second part 403 cannot overcome the static friction between itself and the crest of the first part 402. The two will squeeze each other at the crest, causing the first part 402 to deform and increasing the static friction between the first part 402 and the cable 1.

[0024] In summary, this embodiment cleverly connects the distributor socket 2 protective sleeve to the rubber block 4 via the pull wire 6. When the operator rotates the second part 403 within a predetermined range, the rubber block 4 not only tightens the distributor socket 2 protective sleeve but also increases the static friction between adjacent rubber blocks 4. Simultaneously, the static friction between the rubber block 4 and the cable 1 also increases synchronously. The above description only illustrates certain exemplary embodiments of the present invention. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A cross-linked polyolefin insulated low-smoke halogen-free flame-retardant automotive ignition cable, comprising a cable (1), wherein distributor sockets (2) and spark plug sockets (3) are respectively installed at both ends of the cable (1), characterized in that, Two rubber blocks (4) are movably installed on the cable (1); the rubber blocks (4) are cylindrical and an annular groove (401) is provided on the circumferential surface of the rubber blocks (4); under no external force, the width of the annular groove (401) is less than the width of the protrusion between the two annular grooves (401).

2. The cross-linked polyolefin insulated low-smoke halogen-free flame-retardant automotive ignition cable according to claim 1, characterized in that, The rubber block (4) includes a first part (402) that slides with the cable (1) and a second part (403) that rotates with the first part (402).

3. The cross-linked polyolefin insulated low-smoke halogen-free flame-retardant automotive ignition cable according to claim 2, characterized in that, The outer surface of the cable (1) forms a protrusion (101) arranged along its length direction, and the inner surface of the first part (402) forms a strip-shaped groove that cooperates with the protrusion (101).

4. The cross-linked polyolefin insulated low-smoke halogen-free flame-retardant automotive ignition cable according to claim 3, characterized in that, The outer surface of the first part (402) forms a uniform wave shape along its circumference, and the inner surface of the second part (403) forms a uniform wave shape along its circumference.

5. The cross-linked polyolefin insulated low-smoke halogen-free flame-retardant automotive ignition cable according to claim 4, characterized in that, The cable (1) and the first part (402) form a gap fit.

6. The cross-linked polyolefin insulated low-smoke halogen-free flame-retardant automotive ignition cable according to claim 1, characterized in that, The rubber block (4) has several annular rubber strips on both sides of the protruding part to increase friction.

7. The cross-linked polyolefin insulated low-smoke halogen-free flame-retardant automotive ignition cable according to claim 1, characterized in that, The number of annular grooves (401) on the rubber block (4) is two, and a rigid ring (5) is fixedly installed on the circumferential surface of the protruding part in the middle of the rubber block (4) near the distributor socket (2).

8. The cross-linked polyolefin insulated low-smoke halogen-free flame-retardant automotive ignition cable according to claim 7, characterized in that, The distributor socket (2) is covered with a rubber protective sleeve.

9. The cross-linked polyolefin insulated low-smoke halogen-free flame-retardant automotive ignition cable according to claim 8, characterized in that, The outer wall of the distributor socket (2) protective sleeve is provided with an annular groove, and a non-stretchable pull wire (6) is wound in the annular groove. One end of the pull wire (6) is fixedly connected to the inner wall of the annular groove, and the other end is fixedly connected to the rigid ring (5).

10. The cross-linked polyolefin insulated low-smoke halogen-free flame-retardant automotive ignition cable according to claim 9, characterized in that, The insulation layer of the cable (1) is made by cross-linked polyolefin extrusion molding.

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