JP2010027427A - Cable for movement - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cable for movement which ensures that the cable never snakes from linear shape to wave shape along the axially extending direction, even when the cable is used over a long period under a severe condition where flexure and stretching of the cable are repeated. <P>SOLUTION: A cable 11 for movement is fabricated using a child twisted wire assembly 16 which is twisted while circularly arranging multiple wire cores 14 with a conductor 12 coated with an insulator 13 at a peripheral portion around a reinforcing string 15 as well as a parent twisted wire assembly 18 which is twisted while circularly arranging multiple child twisted wire assembly 16 at a peripheral portion around a reinforcing wire material 17, and the peripheral portion of the parent twisted wire assembly 18 is directly coated and fixed with a sheath 19 of thermoplastic resin. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a moving cable that is provided, for example, in a lifting device of a fire engine, and more particularly to a moving cable that prevents deterioration of the shape of a cable that is used under severe conditions of repeated bending and stretching.

  In general, power supply and communication methods for a fire truck with a ladder, a crane vehicle, and the like include a reel winding method and a curtain method, and a cabtire cable (hereinafter referred to as a cable) according to the application is used. As such a cable, as shown in FIG. 6, a wire core 63 composed of a conductor 61 and an insulator 62 that insulates and covers the outer periphery of the conductor 61, and a reinforcing inclusion 64 are interposed. Some have a sheath 65 which is arranged in a double annular shape on a concentric circle with a plurality of wire cores 63 as the center of the cross section, and sheathes the outer periphery. When such a cable 66 is used in a lifting device for a fire truck with a ladder, the cable 66 is repeatedly bent and stretched in accordance with the lifting operation, so that there is a risk of deformation or disconnection depending on long-term use. Therefore, highly durable cable characteristics are required.

  However, cables tend to be distorted gradually and become prone to deformation with long-term use. For example, as shown in FIG. 7, when a corrugated state in which the cable 66 is deformed from a straight shape to a wave shape along the axial direction, a so-called meander 67 is generated, the twist pitch is broken inside the cable 66 and the inherent flexibility of the cable is lost. As a result, the cable 66 is likely to come off from the pulley 68 or the like supporting the cable 66, and the cable 66 cannot be smoothly moved forward and backward. As a result, the cable 66 is damaged due to the meandering 67 and may cause disconnection or the like. was there.

  In particular, the use environment is severe in the cable of a fire truck with a ladder, and the cable is being overused. The cable of the fire truck with a ladder is a power line or a signal line that follows a very long lifting distance of the lifting device, and needs to withstand adverse effects due to tension, twisting, ironing, and the like. Furthermore, the cable applied to the fire truck with a ladder is required to have a highly reliable cable characteristic without being allowed to break, as can be understood from work related to human life. In recent years, ladders having a high height of, for example, 30m to 50m have been demanded, and accordingly, the need for cables to have highly reliable cable characteristics has arisen, and high performance capable of coping with adverse effects. Cable is sought.

Here, considering the cause of the meandering of the cable, the following can be considered.
(1) Since the adhesiveness between the sheath constituting the cable and the wire core (insulator) is poor, a shift occurs inside the cable, and this shift causes meandering.
(2) Due to the influence of the tension applied to the cable, the insulator and the sheath are displaced inside the cable, resulting in meandering.
(3) The sheath and the wire core are displaced due to clogging of the twisted pitch of the wire core provided inside the cable or loosening of the twisted pitch, resulting in meandering.
(4) When twisted by twisted twisting, the twisted wire tries to repel and return in the direction opposite to the twisting direction, so that a twisting force is applied in the direction opposite to the twisting direction, resulting in meandering.
This is the main cause of meandering.

  In addition, when twisted wires are covered and fixed with a sheath, the cable cores are reinforced and the durability of the cable is increased. However, meandering is not prevented, and sufficient cable characteristics are not yet obtained. is there.

For this reason, there is a cabtyre cable for a lifting device in which a winding wire body having a function of contributing to the twisting and bending rigidity of the cable is embedded at a position eccentric from the radial center of the cable. It is known (see Patent Document 1 below).
JP-A-7-220532

  However, since this type of cable is wound by the winding wire, it is difficult to form a straight line when it is stretched, and the cable is stretched between pulleys in a limited space of the lifting device. It was unsuitable for installation. Furthermore, since it is necessary to embed a winding wire body separately from the wire core, the increase in the number of parts, the number of manufacturing steps, and the like invites an increase in diameter and cost.

  Therefore, an object of the present invention is to provide a moving cable that does not deteriorate in shape even when used for a long time under severe conditions in which the cable is repeatedly bent and stretched.

  The present invention provides a child twisted body in which a plurality of wire cores whose conductors are covered with an insulator are annularly arranged and twisted around an outer periphery centering on a reinforcing yarn, and a plurality of the above-mentioned twisted bodies are arranged. The cable is a moving cable in which a parent twisted body is provided in a circular arrangement around the outer periphery around the reinforcing wire, and the outer periphery of the parent twisted body is directly covered and fixed with a thermoplastic resin sheath. Features.

  According to this configuration, since each core of the twisted body can be directly covered and fixed with a single sheath, the sheath extends to every corner of the core where the sheath is twisted at the time of covering, and between each core and the sheath. The contact area increases, and the adhesion between the sheath and the core increases. As a result, the movement cable has a high unity connection and is less likely to be displaced inside the cable. Therefore, even if the moving cable is twisted, the wire core inside the cable follows the movement, so that no deviation occurs, and no meandering occurs even if it is used for a long time.

  As an aspect of the present invention, the insulator can be configured by adding a ground color that is color-coded for each line core and a different color different from the ground color.

  In addition, when connecting the multiple wire cores provided in this moving cable to the equipment, each wire core is color-coded, so it is possible to identify and connect the wiring connection destination connection line at a glance. Can do.

  According to this invention, the contact area between the wire core and the sheath increases, and the adhesion between the two increases. As a result, the sense of unity between the wire core and the sheath is enhanced. Therefore, even if the moving cable is twisted, the wire core inside the cable follows the movement, so that it is difficult for deviation to occur, and the moving cable does not meander even if it is used for a long time. Furthermore, since the moving cable can omit the inner sheath, it can be reduced in diameter and weight, and can be configured compactly.

  An embodiment of the present invention will be described below with reference to the drawings.

  Drawing shows the case where it uses for the raising / lowering apparatus of the fire truck with a ladder as an example of the cable for a movement, FIG. 1 is the principal part expanded side view which showed the twisted state of the wire core of the cable for a movement, FIG. ) Is an enlarged cross-sectional view of the main part of the twisted body, FIG. 2 (B) is an enlarged cross-sectional view of the main part of the parent twisted body, and FIG. 2 (C) is an enlarged cross-sectional view of the moving cable. As shown in FIG. 2 (A), the moving cable 11 has a plurality of wire cores 14 in which the outer periphery of the conductor 12 is covered with an insulator 13 on the outer periphery around a reinforcing yarn 15 such as a polyester yarn. A small-diameter child twisted body 16 is formed by twisting in an annular arrangement, and a plurality of the child twisted bodies 16 are arranged around the reinforcing wire 17 as shown in FIG. 2 (B). A large-diameter parent twisted body 18 formed by twisting in an annular arrangement is prepared, and the outer periphery of the parent twisted body 18 is directly covered with a sheath 19 in a circular shape as shown in FIG. Constructed by creating fixed.

  The strand structure of the conductor 12 uses an annealed copper aggregate stranded wire with a fine pitch, and a tubular twist that does not add a twist at the time of twisting is suitable as a twisting method. Further, the insulator 13 is made of a thermoplastic resin material that can thinly coat the outer periphery of the small-diameter conductor 12 and that does not stretch so much even when subjected to an external force and has a characteristic that is difficult to break. For example, high density polyethylene that facilitates thin coating of about 0.25 mm may be used.

  At the time of twisting, first, a core twisted body (four cores) 16 is formed by twisting, for example, four wire cores 14 together, and for example, 5 units of the core twisted body 16 are further twisted. A master-twisted body (20 wire cores) 18 that is collectively formed is formed. Also in this case, the tubular twisting that does not add twist at the time of twisting is performed to avoid the twisting twist. In addition, the twist pitch and the twist outer diameter are set to the conditions for twisting suitable for the number of wire cores and the number of units.

  The sheath 19 is provided as a covering protecting material for the moving cable 11, and the material of the sheath 19 is a high-hardness heat suitable for insulating the parent twisted body 18 to suppress meandering of the moving cable 11 due to twisting. A plastic resin material such as high hardness vinyl chloride is used. The sheath 19 is formed by directly covering and fixing each of the child twisted body 16 and the parent twisted body 18 with the sheath 19, so that the sheath 19 is wound around the outer circumference of a total of 20 wire cores 14 twisted together. It reaches every corner, the contact area between each core 14 and the sheath 19 increases, and the adhesion between the core 19 and the sheath 19 increases. For this reason, a sense of unity is enhanced inside the moving cable 11 and it is difficult for deviation inside the cable to occur. Therefore, even if the moving cable 11 is twisted, the wire core 14 of the internal twisted bodies 16 and 18 follows the movement, so that no deviation occurs, and as a result, no meandering occurs even when used for a long time.

  Furthermore, since the outer periphery of each twisted body 16, 18 only needs to be covered with one sheath, an inner sheath is not required. By omitting the inner sheath, the size of the moving cable 11 is reduced in size and weight, and becomes compact. Furthermore, since there is no inner sheath inside the cable, there is no separation between the outer sheath 19 and the wire core 14, enabling direct contact between the outer sheath 19 and the wire core 14, and generating a deviation. This is effective in preventing the occurrence of meandering.

  FIG. 3A is an enlarged side view of the main part showing the twisted body, FIG. 3B is a partially enlarged side view of the wire core, and FIG. 3C is an enlarged sectional view of the wire core. About the said wire core 14, the insulator 13 is colored so that it can identify separately for each color. Furthermore, in addition to being color-coded according to the wire core 14, the insulator 13 is configured by adding another color different from the ground color 31. As another example of the additional color configuration, for example, as shown in FIGS. 3A and 3B, the ground color 31 is different from the ground color 31 at positions 180 degrees different from the circumferential direction of the insulator 13. Different colors 32 such as black are elongated in stripes along the axial direction.

  The coloring ratio may be a coloring ratio that can be identified at a glance. As shown in FIG. 3 (C), if the area ratio in the circumferential direction is set to, for example, ground color 6: different color 4 or so, the wire core Even if 14 has a small diameter, it can be accurately identified. The coloring method of the different color 32 is not limited to two stripes in the circumferential direction, but may be one or a plurality of stripes, or any other distinguishable coloring form may be adopted. Thereby, when the 20 wire cores 14 provided in the moving cable 11 are wired and connected to a device (not shown), each wire core 14 is individually color-coded at the end of the moving cable 11, It is possible to identify and connect the wire corresponding to the wiring at a glance. And after manufacture of the cable 11 for a movement, the marking printing as information which specifies the cable for a movement is given to the outer surface of the sheath 19, and it completes.

  Next, the cable characteristics of the moving cable 11 configured as described above will be described. 4A is a front view of the cable movement bending tester, and FIG. 4B is a plan view of the main part of the cable movement bending tester. This cable movement bending test machine 41 repeatedly applies an external force similar to the external force that the movement cable 11 actually receives, and examines the degree of performance deterioration of the movement cable 11 after a predetermined time has elapsed.

  Specifically, as shown in FIG. 4 (A), a movable carriage 43 that reciprocates in the horizontal direction along a horizontally long opening window 42 opened in the center of the cable moving bending test machine 41 is provided. On the front side of the carriage 43, an upper pulley 44 and a lower pulley 45 are disposed so as to protrude in an oblique vertical position. Then, the moving cable 11 is stretched over the upper and lower pulleys 44, 45, and one end of the stretched cable is fixed to the main body fixing portion 47 via a fixed position pulley 46 arranged on the left side when viewed from the front, and the other end is viewed from the front. A fixed load is applied to the moving cable 11 by being connected to a weight 49 via a fixed position pulley 48 arranged on the right side. By reciprocating the movable carriage 43 in this cable load state, the cable movement bending tester 41 sets the conditions to approximate the actual use state by rubbing the moving cable 11.

  Further, as shown in FIG. 4 (B), the moving cable 11 has the same protruding length from the front surface 41a of the tester main body when the mounting positions of the upper and lower pulleys 44 and 45 are set to the same protruding length. Only the tension applied by the ladder and the load is applied. Actually, in the use state of the moving cable 11 in the fire truck with a ladder, since three forces of torsion, ironing, and tension are applied, an accurate evaluation cannot be obtained unless the torsion is applied. Therefore, in order to perform the movement and bending while twisting, the protrusion amount is varied so that the upper pulley 44 and the lower pulley 45 are stepped in the front-rear direction. The moving cable 11 is stretched over the upper and lower pulleys 44 and 45 having such a step structure, and one end of the cable is fixed so that the twist does not escape.

  Table 1 shows an example of the structure of the moving cable 11.

次に、この表１の移動用ケーブル１１の完成品から約５ｍの試料を採り、これを直径１２０ｍｍの上下プーリ４４，４５に掛け渡し、該ケーブル１１の一方端を固定した状態で他方端に５ｋｇの錘４９を吊るし、移動台車４３を毎秒０．３３ｍの速さで１ｍ以上の距離を左右同一場所において、１０回／分の割合で往復させた試験条件で移動用ケーブル１１に対する評価を行った。

Next, a sample of about 5 m is taken from the finished product of the moving cable 11 shown in Table 1, and is passed over the upper and lower pulleys 44 and 45 having a diameter of 120 mm, and the one end of the cable 11 is fixed to the other end. The moving cable 43 is evaluated under the test conditions in which a 5 kg weight 49 is suspended and the moving carriage 43 is reciprocated at a rate of 0.33 m per second at a distance of 1 m or more at the same place on the left and right at a rate of 10 times / minute. It was.

  As a result, the moving cable 11 does not meander even if the moving carriage 43 is reciprocated 80,000 times (10 times / minute), which is a movement amount corresponding to long-term use of the cable, and finally the moving carriage 43 is No meandering was observed even after 200,000 reciprocations. Thereby, it was recognized that the moving cable 11 maintains stable cable performance. At this time, it was recognized that the marking printed on the outer surface of the moving cable 11 was deformed in a slightly twisted state by continuing the long-time test. However, the outer shape of the moving cable 11 maintains the original straight shape, and no deformation wrinkles occur in the outer shape. This indicates that the outer diameter of the moving cable 11 is small, the flexibility is excellent, and the twist pitch inside the cable is not easily broken. In particular, inside the cable, the sheath 19 with respect to each stranded wire core 14 spreads to every corner, the wire core 14 and the sheath 19 are sufficiently in close contact with each other, and the cause of the deviation can be accurately eliminated to prevent meandering. Can be guessed.

  As an example of the test cable to be compared with the moving cable 11, a cable having a two-layer structure in which twisted wires are circularly arranged on the inner side and the outer side on a concentric circle, for example, shown in FIG. 6. Similarly, as a result of the test using the cable moving / bending test machine 41 shown in FIG. 4 using the cable 66, when the moving carriage 43 is reciprocated about 10,000 times at the earliest time and about 20,000 times at the later time. It was confirmed that meandering began to occur. This is considered to be a deviation between the wire core 63 and the sheath 65 inside the cable.

  Specifically, since the twisted wire has a two-layer structure with different directions, when twist is applied, one is loose and the other is tight. In addition, since the outermost layer is based on a large outer diameter, the ground pitch tends to collapse. As a result, it is considered that the sheath is twisted in the direction in which the ground is loosened, and the sheath and the wire core (insulator) are displaced due to the collapse of the ground pitch, resulting in meandering.

  Furthermore, even when the cable configuration is changed from an annealed copper assembly strand to an annealed copper composite strand (C & C composite strand) and the cable moving and bending test is performed, when the cable is reciprocated 40,000 times, the cable slightly swells and snakes. Confirmed that occurred. In other words, it was found that the improvement of the conductor is strong against disconnection, but the effect of preventing meandering cannot be obtained.

  Furthermore, even when the cable movement / bending test is performed with the sheath hardness increased, when the moving carriage 43 is reciprocated approximately 40,000 times at the earliest time from the start of the test and about 50,000 times at the later time, the cable is disconnected. Slight swells and meandering were confirmed. In other words, the sheath is hard and does not twist, but due to the structure of the stranded wire, there is not much spread depth (sag) to the center in the radial direction in the sheath coating, and the insulator does not play even though the sheath does not move. It is presumed that it was misaligned and led to meandering.

  Therefore, when the moving cable 11 of the present invention and the conventional cable (see FIG. 6) are compared, it is clearly recognized that the effect is different with respect to the meandering prevention measures for the cable.

  Furthermore, the case where the suitability of the adhesiveness between the wire core 14 and the sheath 19 is considered will be described with reference to FIG. 5A is an enlarged cross-sectional view of the sheath showing the cross-sectional shape of the sheath after the test result of the present invention, and FIG. 5B is an enlarged cross-sectional view of the sheath showing the cross-sectional shape of the sheath after the test result of the cable of FIG. FIG.

  As a result, as can be seen from FIG. 5 (A), the sheath 19 of the present invention penetrates sufficiently from the outer peripheral surface of the cable toward the center, and the sheath 19 wraps the outer peripheral surface 14a of the twisted wire core 14. It is recognized that it is coated. For this reason, the contact area between the insulator 13 and the sheath 19 located on the outer surface of the wire core 14 is increased, and this is considered to limit the occurrence of deviation between the two and prevent the meandering of the cable. .

  On the other hand, in the sheath 65 of the conventional example shown in FIG. 5B, the ratio of falling from the outer peripheral surface of the cable toward the center is constant, and the outer peripheral surface 63a of the wire core 63 can be sufficiently adhered by the sheath 65. It is recognized that it is not done.

From these test results, the following was found.
(1) It is difficult to think about meandering only by the influence of tension. When tension and ironing are applied, twisting is induced to cause meandering. Therefore, it is necessary to take measures against the tension due to the interposed state of the sheath.
(2) Pitch breakage of the stranded wire due to twisting is one factor that induces meandering and disconnection. Therefore, as an example of the twist preventing means, it was recognized that increasing the hardness of the sheath 19 is effective for preventing twist.
(3) As a means for preventing the twisted wire pitch from being twisted, it is more effective to deepen the sheath 19 than to increase the hardness of the covering material.
(4) It has been found that by making the depth of the sheath sufficiently deep, it is difficult to cause a deviation between the wire core 14 and the sheath 19, thereby preventing meandering.
(5) A twisted wire having a two-layer structure in which the wire cores are annularly arranged on the inner side and the outer side on a concentric circle has a large outer diameter due to the outer layer as shown in FIG. Therefore, it is necessary to change the design so that the twisted outer diameter becomes smaller (see FIG. 2B). As a result, the parent twisted body 18 in which the child twisted body 16 is collectively twisted is used.

  Next, the results of testing the temperature resistance performance of the moving cable 11 are shown. First, as a low-temperature test, a sample of 500 mm is taken from the finished product of the moving cable 11, the collected moving cable 11 is left in a low-temperature environment for 1 hour, and then bent 90 degrees to bend the sheath. And the presence or absence of cracks was examined. As a result, it was confirmed that the moving cable 11 can be bent even in a low temperature environment of −10 ° C., and cracks do not occur even in a low temperature environment of −30 ° C., thereby maintaining good cable characteristics.

  On the other hand, as an example of the combustion test, a 60-degree inclined combustion test (see JIS, C, 3005) was performed. In this 60-degree inclined combustion test, a sample having a length of about 300 mm collected from the finished product of the moving cable 11 is supported with an inclination of about 60 degrees with respect to the horizontal, and the tip of the reducing flame is about 20 mm from the lower end of the sample. It is investigated whether or not the sample naturally disappears within 60 seconds after the flame is taken out until it burns within 30 seconds. As a result, it disappeared immediately after ignition in about 2 seconds, and it was confirmed that there was no problem in the combustion test.

  In consideration of temperature resistance characteristics such as flame retardancy, the use of flame-resistant polyethylene can significantly improve low-temperature resistance and flame resistance, but on the other hand, water used as a flame retardant A large amount of oxide is contained in the coating material, and this hydroxide causes a decrease in mechanical strength, induces the generation of cracks in the sheath, and deteriorates durability and is not preferable. Therefore, after selecting a material that has a certain level of low temperature resistance and flame resistance but does not deteriorate durability, it is a meander-resistant wire formed by twisting in multiple stages of a child twisted body and a parent twisted body. By creating a core assembly and covering the outer periphery with a sheath, it is possible to create a moving cable that prevents meandering.

  As described above, each of the twisted wire cores can be directly covered and fixed with the sheath, so that the sheath is spread to every corner of the twisted portion at the time of covering, and the contact area between each wire core and the sheath To increase the adhesion. As a result, the sense of unity is enhanced inside the moving cable, and displacement inside the cable is less likely to occur. As a result, even if the moving cable is twisted under severe usage conditions, the cable core inside the cable follows the movement, so there is no deviation inside the cable, and there is no meandering even if it is used for a long time. Demonstrate cable characteristics.

  The moving cable 11 of the present invention is not limited to the configuration of the above-described embodiment, and can be applied based on the technical idea described in the claims. For example, in the embodiment, the moving cable 11 is applied to a fire truck with a ladder. However, the moving cable 11 is not limited to this, and can be widely used for other purposes as a moving cable for industrial equipment, broadcasting equipment, and the like. .

The principal part expanded side view which showed the twisted state of the cable for a movement. (A) is the principal part expanded sectional view of a child twisted body, (B) is the principal part expanded sectional view of a parent twisted body, (C) is an expanded sectional view of a cable for movement. (A) is a principal part expanded side view which shows a child twisted body, (B) is a partial expanded side view of a wire core, (C) is an expanded sectional view of a wire core. (A) is a front view of a cable movement bending test machine, (B) is a principal part top view of a cable movement bending test machine. (A) is an expanded sectional view of the sheath showing the sectional shape of the sheath after the test results of the present invention, and (B) is an enlarged sectional view of the sheath showing the sectional shape of the sheath after the conventional test results. The longitudinal cross-sectional view of the conventional cabtire cable. The principal part expansion perspective view which shows the cable with which meandering generate | occur | produced.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Moving cable 12 ... Conductor 13 ... Insulator 14 ... Wire core 15 ... Reinforcement thread 16 ... Child twisted body 17 ... Reinforcement wire 18 ... Parent twisted body 19 ... Sheath 32 ... Different color

Claims (2)

A plurality of wire cores whose conductors are covered with an insulator are annularly arranged around the outer periphery around the reinforcing yarn to provide a twisted body that is twisted together,
Providing a parent twisted body in which a plurality of the child twisted bodies are arranged in a ring around the outer periphery around the reinforcing wire and twisted together,
A moving cable in which the outer periphery of the parent twisted body is directly covered and fixed by a sheath of a thermoplastic resin. The moving cable according to claim 1, wherein the insulator is configured by adding a ground color that is color-coded for each wire core and a different color different from the ground color.

Images