JPH11120839A - Sz stranded cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the increase in conductor resistance and waviness of a conductor core by setting a stranding pitch of a reversing part of an S-stranded part and a Z-stranded part to be shorter than a stranding pitch of an intermediate part sandwiched by the reversing part. SOLUTION: An S-stranded part 6 and a Z-standed part 7 are alternately and repeatedly twisted, and a stranding pitch of a reversing part 2 is set shorter than a stranding pitch of an intermediate part 3 which is sandwiched by the reversing part 2. Stranding pitches P4 and P6 shortened by the reversing part 2 are adjusted, by lengthening stranding pitches P5 and P7 of the intermediate part 3, and an average stranding pitch of the entire SZ stranded cable 1 is formed equal to a pitch of a unidirectional stranded cable, and a conductor core length is set equal to the unidirectional stranded cable, and conductor resistance does not increase. Since the pitches P4 and P6 are shortened, a conductor core 8 is densely arranged in the reversing part 2, and even if the SZ stranded cable 1 is twisted around, the conductor core does not become wavy. Therefore, a telecommunication cable having an outside diameter not less than 10 mm can be realized by the SZ stranded cable 1, and therefore, it can be quickly manufactured by an SZ stranding machine.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cable used for a communication cable or the like, and more particularly to an SZ twisted cable in which an S twisted portion and a Z twisted portion of a core wire are alternately repeated along the longitudinal direction of the cable. It is about.

[0002]

2. Description of the Related Art Among cables used for communication cables and the like, a unidirectionally twisted cable 51 has, as shown in FIG. Alternatively, they are twisted in one direction by Z twist.

The twist pitch P1 at this time is the same as the cycle length L1 of the quad twist core and the unit 52.

The one-way twisted cable 51
Is designed to be manufactured by rotating the feeding and winding drum, so that it is suitable for short products.

[0005] In the case of a long cable, SZ is manufactured by alternately rotating the collective dies left and right in the middle to give a twist.
Twisted cables are suitable.

[0006] As shown in FIG.
The quad twist core and the unit 56
Are formed such that the S twisted portion 57 and the Z twisted portion 58 are alternately repeated.

The S twisted portion 57 of the SZ twisted cable 55
P2 = 360 × L2 / θ2 (1) when the length of the S twisted portion 57 is L2 and the twist angle is θ2.

[0008] The twist pitch P3 of the Z twisted portion 58 is represented by P3 = 360 × L3 / θ3 (2) when the length of the Z twisted portion 58 is L3 and the twist angle is θ3.

Normally, the twist pitch P2, length L2 and twist angles θ2 and Z of the S twisted portion 57 represented by the equations (1) and (2)
Twist pitch P3, length L3 and twist angle θ of the twist portion 58
In general, the relationship with 3 is such that P2 = P3, L2 = L3, and θ2 = θ3.

By the way, when the communication cable is realized by using an SZ twisted cable instead of a unidirectional twisted cable, in the case of an SZ twisted cable having an outer diameter of 10 mm or less, the twist pitch is P2 = P3 = P1. Is configured.

In an SZ twisted cable having an outer diameter of 10 mm or more, the twist pitch is configured to satisfy P2 = P3 <P1.

In addition, S along the longitudinal direction of the cable
There is a concentric SZ twisted cable in which a twisted portion and a Z twisted portion are alternately repeated and twisted to form a layer, and are formed in a concentric multilayer structure.

[0013]

However, as described above, the twist pitch of the SZ twisted cable is P2 = P3 <P.
When it is configured to be 1, there is a problem that the length of the core wire core required for a certain length of the cable is longer than that of the unidirectionally twisted cable, and the conductor resistance is increased.

Conversely, when the twist pitches P2 and P3 are increased, the twist direction is from S twist to Z twist or from Z twist to S twist.
Since the twist pitch becomes larger than P2 and P3 at the reversal part which changes to twist, there is a problem that when the SZ twisted cable is twisted, undulation occurs in the core wire core inside the SZ twisted cable.

In the case of a concentric SZ twisted cable in which quad-twisted cores and units are concentrically formed in multiple layers, when the twist pitch of each layer is the same, all layers are twisted in accordance with the twist pitch of the outermost layer. When the pitch is set, the closer the layer is to the center, the larger the twist pitch with respect to the outer diameter of the layer becomes, and the undulation generated in the layer closer to the center becomes large, causing a problem that the entire SZ stranded cable undulates. . Conversely, if all layers have the same twist pitch in accordance with the twist pitch of the center layer, the closer the outer layer is, the smaller the twist pitch relative to the outer diameter of the layer becomes, and the conductor resistance of that layer increases. There was a problem that would.

Accordingly, the present invention has been devised in order to solve the above problems, and an object of the present invention is to provide an SZ twisted cable capable of preventing an increase in conductor resistance and preventing undulation of a core wire core. To provide.

[0017]

In order to solve the above-mentioned problems,
The present invention relates to an SZ twisted cable in which the S twisted portion and the Z twisted portion are alternately repeated along the longitudinal direction of the cable and twisted, and the twist pitch of the inverted portion of the S twisted portion and the Z twisted portion is set to each of the above. It is formed shorter than the twist pitch of the intermediate portion sandwiched between the reversing portions.

Preferably, the twist pitch of the reversing portion is in a range of approximately 10 to 15 times the cable diameter, and the twist pitch of the intermediate portion is in a range of approximately 50 to 60 times the cable diameter.

As described above, since the twist pitch at the reversing part is shortened, even if the SZ twisted cable is twisted, no undulation is generated in the core wire core therein. In addition, by forming the twist pitch at the intermediate portion to be long, the length of the core wire as the reversal portion and the entire intermediate portion can be formed substantially equal to that of the unidirectionally twisted cable. Can be prevented from increasing.

The S stranded portion and the Z
The layer is formed by alternately repeating the twist part and twisting,
In the concentric SZ twisted cable formed in a multilayer structure, the twist pitch of the inverted portion of the S twisted portion and the Z twisted portion of each layer is shorter than the twist pitch of the intermediate portion sandwiched between the inverted portions. While being formed, the above-mentioned layers are twisted by alternately repeating the S twisted portion and the Z twisted portion at different twist pitches.

When the twist pitch of the reversing part is approximately 10 to 15 times the outer diameter of each layer in the cable,
Desirably, the twist pitch of the intermediate portion is approximately 50 to 60 times the outer diameter of each layer in the cable.

According to the above construction, the relationship between the twist diameter and the outer diameter of each layer can be properly set by reducing the twist pitch of the layer closer to the center and increasing the twist pitch of the layer closer to the outer layer. Therefore, it is possible to prevent an increase in conductor resistance and to prevent undulation of the core wire core of each layer.

[0023]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a schematic diagram showing an embodiment of an SZ twisted cable according to the present invention and a diagram showing a change in twist pitch, FIG. 2 is a sectional view showing a quad twisted core, and FIG.
FIG. 2 is a sectional view showing a unit.

As shown in FIG.
Is formed with an S twisted portion 6 in which the quad twisted core 4 or the unit 5 is twisted rightward and a Z twisted portion 7 twisted leftward, and the S twisted portion 6 is formed along the longitudinal direction. The Z twisted portion 7 is alternately and repeatedly twisted, and the twist pitch of the inverted portion 2 of the S twisted portion 6 and the Z twisted portion 7 is larger than the twist pitch of the intermediate portion 3 sandwiched between the respective inverted portions 2. It is characterized by being formed short.

As shown in FIG. 2, the quad twist core 4 is
The four core wires 8 are arranged so as to be on a diagonal of a square and twisted.

As shown in FIG. 3, a plurality of units 5 are provided.
For example, five quad twisted cores 4 are arranged so as to be on the diagonal of a regular pentagon and twisted.

At both ends of the S twisted portion 6, the twist pitch P4 is equal to the twist pitch P of the conventional unidirectional twisted cable 51.
An S twist short pitch portion 9 shorter than 1 is formed, and an S twist long pitch portion 10 whose twist pitch P5 is longer than the conventional twist pitch P1 is provided in the intermediate portion 3 sandwiched between the S twist short pitch portions 9. Is formed.

The Z twist portion 7 is formed at both ends with a Z twist short pitch portion 11 whose twist pitch P6 is shorter than the conventional twist pitch P1, and an intermediate portion 3 sandwiched between the Z twist short pitch portions 11. Further, a Z twist length pitch portion 12 whose twist pitch P7 is longer than the conventional twist pitch P1 is formed.

The S-twist short pitch section 9 and the Z-twist short pitch section 11 constitute the reversing section 2 including the vicinity of the position where the twist direction is reversed.

That is, in the SZ stranded cable 1, each of the above-described portions is composed of the S-twisted short pitch portion 9, the S-twisted long pitch portion 10,
The twisted short pitch portion 9, the Z twisted short pitch portion 11, the Z twisted long pitched portion 12, the Z twisted short pitched portion 11, and the S twisted short pitched portion 9 are repeated in this order.

The twist pitch P4 of the S twist short pitch portion 9 is:
When the length of the S twist short pitch portion 9 is L4 and the twist angle, which is the rotation angle with respect to the traveling distance, is θ4, P4 = 360 × L4 / θ4 (3)

The twist pitch P5 of the S twist long pitch portion 10
Is the length of the S twist length pitch section 10 as L5 and the twist angle as θ
When it is set to 5, P5 = 360 × L5 / θ5 (4)

The twist pitch P6 of the Z twist short pitch portion 11
Is the length of the Z twist short pitch portion 11 as L6 and the twist angle as θ
When it is set to 6, P6 = 360 × L6 / θ6 (5)

The twist pitch P7 of the Z twist long pitch portion 12
Is L7 for the length of the Z twist length pitch section 12 and θ for the twist angle.
When it is set to 7, P7 = 360 × L7 / θ7 (6)

The relationship of the twist pitch of each part of the above-described SZ twisted cable 1 is such that the S twist short pitch portion 9 shown in the formula (3) and the Z twist short pitch portion 11 shown in the formula (5) are equal, and P4
= P6 <P1.

The twist pitch P4 (P6) of the reversing part 2 composed of the S-twisted short pitch portion 9 and the Z-twisted short pitch portion 11
Is set in the range of approximately 10 to 15 times the diameter R1 of the SZ twisted cable.

The S twist length pitch portion 10 shown in the formula (4) is equal to the Z twist length pitch portion 12 shown in the formula (6).
= P7 <P1.

The twist pitch P5 (P7) of the intermediate portion 3 composed of the S twist length pitch portion 10 and the Z twist length pitch portion 12
Is set in the range of approximately 50 to 60 times the diameter R1 of the SZ twisted cable.

The average twist pitch P8 of the entire SZ twisted cable 1 is P8 = 360 × (2L4 + L5 + 2L6 + L7) / (2
θ4 + θ5 + 2θ6 + θ7) (7)

The lengths L4, L5, L6, and L7 of the respective portions are set so that the average twist pitch P8 represented by the equation (7) is substantially equal to the conventional twist pitch P1.

S twist short pitch section 9 and Z twist short pitch section 1
The lengths L4 and L6 of 1 are short and are set to be equal to each other,
Length L of S twist length pitch portion 10 and Z twist length pitch portion 12
5, L7 are long and are set equally.

Incidentally, the average twist pitch P8 is not limited to being formed substantially the same as the conventional twist pitch P1, and the twist pitch P4 of the S twist short pitch portion 9 and the Z twist short pitch portion 11 is not limited.
If P6 is formed smaller than the predetermined pitch, the average twist pitch P8 may be set to be larger than the conventional twist pitch P1 as appropriate.

Next, the SZ stranded cable 1 having the above configuration
The operation of will be described.

As described above, the twist pitches P4 and P6 shortened in the reversing section 2 are replaced by the twist pitches P5 and P5 in the intermediate section 3.
By adjusting the length of P7 to be longer, the average twist pitch P8 of the entire SZ twisted cable 1 is formed so as to be substantially equal to the twist pitch P1 of the conventional one-way twisted cable. Even with the large diameter SZ twisted cable 1 described above, the length of the core wire core 8 as the whole SZ twisted cable 1 is the same as that of the conventional one-way twisted cable 51.
And the conductor resistance does not increase as compared with the cable 51.

Further, since the twist pitches P4 and P6 of the reversing portion 2 are shortened, the core wire cores 8 are provided densely in the reversing portion 2, and even if the SZ twisted cable 1 is twisted, 8 does not undulate.

As a result, a communication cable having an outer diameter of 10 mm or more can be realized by the SZ twisted cable 1, so that it is possible to manufacture the communication cable by using an SZ twisting machine instead of a drum twister type twisting machine. Therefore, the twist production speed can be increased, and the production time and cost can be reduced.

FIG. 4 is a perspective view showing a concentric SZ twisted cable.

Referring to FIG. 4, another embodiment of the SZ twisted cable according to the present invention will be described. This SZ
The twisted cable 16 has a quad twisted core 4 or a unit 5 formed in a concentric multilayer structure.
The twist pitch of the reversal portion between the S twist portion and the Z twist portion of 18, 19 is formed to be shorter than the twist pitch of the intermediate portion sandwiched between the reversal portions, and is formed at a different twist pitch in each layer. It is characterized by being.

The twist pitch of the reversal part is set to each layer 17,
In the range of approximately 10 to 15 times the outer diameters R2, R3, and R4 of 18, 19, the twist pitch of the intermediate portion can be adjusted for each layer 17, 18, 1
9 are formed so as to be approximately 50 to 60 times the outer diameters R2, R3 and R4. That is, the layer 1 near the center
The twist pitch increases from 7 to the outer layer 19.

As a result, when viewed from each of the layers 17, 18, and 19, the twist pitch is set to be appropriate for the outer diameters R2, R3, and R4, and the same operation as the above-described SZ twisted cable 1 is performed. Obtainable.

In the SZ stranded cable 16 as a whole, the twist pitch of the layer 17 near the center is reduced, and the layer 1 near the outer layer is reduced.
By increasing the twist pitch of the layer 9, it is possible to prevent an increase in the conductor resistance of the layer 17 closer to the center and to prevent the core wire of the layer 19 closer to the outer layer from undulating.

[0053]

In summary, according to the present invention, the outer diameter is 1
Even with an SZ stranded cable of 0 mm or more, an excellent effect of preventing an increase in conductor resistance and preventing undulation of the core wire core is exhibited.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an embodiment of an SZ twisted cable according to the present invention and a diagram showing a change in twist pitch thereof.

FIG. 2 is a cross-sectional view showing a quad twist core.

FIG. 3 is a sectional view showing a unit.

FIG. 4 is a perspective view showing a concentric SZ twisted cable.

FIG. 5 is a schematic view showing a conventional one-way twisted cable.

FIG. 6 is a schematic diagram showing a conventional SZ twisted cable and a diagram showing a change in twist pitch thereof.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 SZ twisted cable 2 Inversion part 3 Intermediate part 6 S twisted part 7 Z twisted part

Claims (4)

[Claims] In an SZ twisted cable in which an S twisted portion and a Z twisted portion are alternately repeated along the longitudinal direction of the cable and twisted, the twist pitch of an inverted portion of the S twisted portion and the Z twisted portion is set to the above-mentioned value. An SZ twisted cable formed shorter than a twist pitch of an intermediate portion sandwiched between the reversing portions. 2. The twist pitch of the reversing part is in a range of about 10 to 15 times the cable diameter, and the twist pitch of the intermediate part is in a range of about 50 to 60 times the cable diameter. The SZ stranded cable as described. 3. A concentric SZ twisted cable which is formed by concentrically forming a multilayer by forming layers by alternately repeating S-twisted portions and Z-twisted portions along the longitudinal direction of the cable to form layers. The twist pitch of the reversal portion between the S twist portion and the Z twist portion is formed shorter than the twist pitch of the intermediate portion sandwiched between the reversal portions, and the S twist portion and the Z twist portion have different twist pitches in the respective layers. An SZ twisted cable characterized by being alternately and repeatedly twisted with a twisted portion. 4. The twist pitch of the reversing portion is approximately 10 to 15 times the outer diameter of each layer in the cable, and the twist pitch of the intermediate portion is the outer diameter of each layer in the cable. 4. The SZ stranded cable according to claim 3, wherein the range is approximately 50 to 60 times.