JPH1059627A - Linear body winding bobbin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a linear body winding bobbin in which the wound linear body is hardly loosened. SOLUTION: An inside cylinder body 3 is provided inside a body portion 2a, the inside cylinder body 3 is made of material whose linear expansion coefficient is the negative linear expansion coefficient, and the absolute value of the linear expansion coefficient of the inside cylinder body is made to be larger than the absolute value of the linear expansion coefficient of the body portion 2a. At the time of winding, the outer peripheral face of the inside cylinder body 3 is closely stuck on the inner peripheral face of the body portion 2a, or has a slight gap. At the time of high temperature, the body portion 2a expands, but the inside cylinder portion 3 shrinks so that a gap 4 is produced. At the time of low temperature, the body portion 2a shrinks, but the inside cylinder body 3 expands so that a winding tension-increased state is caused, and no occurrence of winding disorder is allowed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bobbin for winding a linear body such as an optical fiber.

[0002]

2. Description of the Related Art A conventional bobbin for winding a linear body has a body made of a single material. For example, in a bobbin using an optical fiber as a linear body, an acrylonitrile-butadiene styrene resin (hereinafter, referred to as a bobbin) is used. ABS resin),
Polyethylene or the like is generally used. The linear expansion coefficients of these materials all have the same positive value as the linear expansion coefficient of the optical fiber, and have the property of expanding with an increase in temperature.

However, the absolute value of the ABS resin is 7.4 × 10 ⁻⁵ [1 ° C.] in comparison with the linear expansion coefficient of the optical fiber of 0.6 × 10 ⁻⁶ [1 / ° C.]. / ° C],
100 times or more. In some cases, the body of the bobbin is divided into several parts, but even in that case, the linear expansion coefficient of each part is a positive value as described above, and using a material with a large linear expansion coefficient I have.

When the temperature rises from the time the optical fiber is wound, the length of the optical fiber in the longitudinal direction expands and becomes longer, and the winding diameter of the optical fiber expands. When the temperature is lowered from the wound state, the length of the optical fiber in the longitudinal direction is contracted and shortened, and the winding diameter of the optical fiber is contracted. The expansion coefficient of the winding diameter of the wound optical fiber is substantially equal to the linear expansion coefficient of the optical fiber described above. On the contrary,
The diameter of the cross section of the optical fiber itself expands and contracts with an expansion coefficient substantially equal to the linear expansion coefficient of the optical fiber, and the winding width of the wound optical fiber expands and contracts.

FIG. 7 is an explanatory diagram of a conventional bobbin for winding a linear body. FIG. 7A is a cross-sectional view when cut along a plane passing through the bobbin axis, and FIG. 7B is a side cross-sectional view when cut along a plane perpendicular to the bobbin axis. FIG. 2 is a cross-sectional view taken along section lines A, A shown in FIG. In the figure, 1 is an optical fiber, 2 is a bobbin, 2a is a body, and 2b is a flange. The bobbin 2 has flanges 2b at both ends of a cylindrical body 2a.
And a linear body is wound around the outer periphery of the body 2a.

[0006] Usually, the optical fiber 1 is stored or transported while being wound on a bobbin 2. However, depending on storage conditions and transportation conditions, there may be a significant change in temperature, and if there is a change in temperature, there is a problem that loosening occurs.

FIG. 8 is a side sectional view of a conventional bobbin for winding a linear body at a low temperature. In the figure, the same parts as those in FIG. 7 are denoted by the same reference numerals, and description thereof will be omitted. Reference numeral 51 denotes a gap in the trunk diameter direction. As described above, the linear expansion coefficient of the material of the bobbin 2 is considerably larger than the positive linear expansion coefficient of the optical fiber 1. Therefore, at low temperatures, the trunk diameter of the trunk portion 2a is significantly smaller than the winding diameter of the optical fiber 1. For this reason, a gap 51 in the body diameter direction of the bobbin is generated between the body portion 2a and the optical fiber 1, and the wound optical fiber 1 is spilled, and loosening occurs. As described above, when the coefficient of linear expansion of the optical fiber 1 is smaller than the coefficient of linear expansion of the body 2a, there is a problem that loosening occurs at low temperatures.

FIG. 9 is a front view of a conventional bobbin for winding a linear body at a high temperature. In the figure, the same parts as those in FIG. 7 are denoted by the same reference numerals, and description thereof will be omitted. 52 is a gap in the width direction of the bobbin. As described above, the linear expansion coefficient of the material of the bobbin 2 is considerably larger than the positive linear expansion coefficient of the optical fiber 1. Therefore, the displacement of the inner width of the bobbin 2 having the flange 2b, that is, the width of the body 2a due to the temperature change is considerably larger than the displacement of the winding width of the optical fiber 1. As a result, a gap 52 in the width direction of the bobbin is generated between the flange portion 2b and the winding width of the optical fiber 1, and the wound optical fiber 1 is spilled, and the winding is loosened.

FIG. 10 is a front view of a conventional bobbin for winding a linear body when the temperature changes from a low temperature to a high temperature. FIG.
10A is a front view of a state when the optical fiber is wound around a bobbin, FIG. 10B is a front view of a state at a low temperature, and FIG. 10C is a front view of a state at a high temperature. In the figure, the same parts as those in FIGS. 7 and 9 are denoted by the same reference numerals, and description thereof will be omitted. When the temperature decreases from the state where the optical fiber 1 is wound around the bobbin 2 as shown in FIG. 10A, the state shown in FIG. As described with reference to FIG. 8, the body diameter of the body portion 2 a is significantly smaller than the winding diameter of the optical fiber 1, a gap 51 in the body diameter direction is generated, and the wound optical fiber 1 is spilled and loosened. Occurs. In addition, the inner width of the bobbin 2 shrinks, and a compressive force is applied to the optical fiber 1 from the bobbin flange 2b, which promotes loosening and slightly reduces the winding width.

[0010] Subsequently, when the environment becomes high temperature, FIG.
The state shown in is shown. As described with reference to FIG. 9, a gap 52 in the width direction of the bobbin is generated between the flange portion 2 b and the winding width of the optical fiber 1, and the wound optical fiber 1 is spilled to cause loosening. . When such a temperature change is repeated, loosening of the winding is further promoted.

When the optical fiber is unwound, for example, when an optical cable is manufactured, the manufacturing conditions may fluctuate in the feeding process of the optical fiber 1 and the optical fiber 1 may be entangled with the manufacturing apparatus, leading to a disconnection. This is a major obstacle to improving the quality of the housed optical cable and improving the manufacturing efficiency.

[0012]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and has as its object to provide a bobbin for winding a linear body such as an optical fiber which is hardly loosened. It is the purpose.

[0013]

According to the first aspect of the present invention, there is provided a bobbin for winding a linear body, comprising an outer cylindrical body around which the linear body is wound, and an inner cylindrical body inside the outer cylindrical body. The outer cylindrical body is formed of a material having a positive coefficient of linear expansion in a body radial direction, and the inner cylindrical body is formed of a material having a negative coefficient of linear expansion in a body radial direction. The inner cylindrical body is characterized in that it has a gap at high temperature and adheres at low temperature.

According to a second aspect of the present invention, in the bobbin for winding a linear body according to the first aspect, a linear expansion coefficient of the outer cylindrical body in a body radial direction is equal to or larger than a linear expansion coefficient of the linear body. It is characterized by being.

According to a third aspect of the present invention, in the bobbin for winding a linear body according to the first aspect, a coefficient of linear expansion of the outer cylindrical body in a body radial direction is equal to a coefficient of linear expansion of the linear body. It is characterized by being substantially equal.

According to a fourth aspect of the present invention, in the bobbin for winding a linear body according to any one of the first to third aspects, the outer cylindrical body has a flange at an end and an inner periphery. A plurality of protrusions formed in the width direction on the surface are formed in the width direction, and the inner cylindrical body is housed between the flanges and formed on the outer peripheral surface in a circumferential direction facing the protrusions. A plurality of recesses are provided in the width direction, and the recesses are fitted into the protrusions.

According to a fifth aspect of the present invention, in the bobbin for winding a linear body according to any one of the first to fourth aspects, the outer cylindrical body has a flange at an end, and the inner cylindrical body has a flange. A cylindrical body is housed between the flanges, and the outer cylindrical body and the inner cylindrical body have a linear expansion coefficient that is anisotropic and has a smaller linear expansion coefficient in a width direction than in a trunk radial direction. It is characterized by being formed by.

[0018]

FIG. 1 is an explanatory view of a first embodiment of a bobbin for winding a linear body according to the present invention. FIG.
1A is a sectional side view at the time of winding, FIG. 1B is a sectional side view at a high temperature, and FIG. 1C is a sectional side view at a low temperature. In the figure, the same parts as those in FIG. 7 are denoted by the same reference numerals, and description thereof will be omitted. Reference numeral 3 denotes an inner cylindrical body, and reference numeral 4 denotes a gap in a body radial direction.

In FIG. 1A, this embodiment is
Compared to the conventional one described with reference to FIG.
a has an inner cylindrical body 3 inside the inner cylindrical body a.
The inner cylinder 3 is formed of a material having a negative coefficient of linear expansion, and the absolute value of the coefficient of linear expansion of the inner cylindrical body 3 is larger than the absolute value of the coefficient of linear expansion of the body 2a.

Although it depends on the temperature of the surrounding environment at the time of winding,
The outer peripheral surface of the inner cylindrical body 3 is in close contact with the inner peripheral surface of the body portion 2a or has a slight gap. In addition, the inner cylindrical body 3
Is housed between the flanges 2b, but the side surface of the end of the inner cylindrical body 3 and the flange 2b do not necessarily have to be in close contact with each other, and usually have a gap.

As shown in FIG. 1B, at a high temperature, the body 2a expands, but the inner cylindrical body 3 contracts and the body 2a expands.
A gap 4 in the trunk diameter direction is generated between a and the inner cylindrical body 3, and there is no influence of the inner cylindrical body 3. The linear expansion coefficient of the body 2a is
Since it is larger than the linear expansion coefficient of the wound optical fiber 1, the winding tension is increased and no winding disturbance occurs.

As shown in FIG. 1C, when the temperature is low, the body 2a contracts and the inner cylinder 3 expands. However, the absolute value of the linear expansion coefficient of the inner cylinder 3 is determined by the linear expansion coefficient of the body 2a. Since it is larger than the absolute value of the expansion coefficient, the body 2a and the inner cylindrical body 3 are in close contact with each other, and as a whole expand,
The winding tension is increased, and no winding disturbance occurs. In addition, even when the absolute value of the linear expansion coefficient of the inner cylindrical body is equal to or less than the absolute value of the linear expansion coefficient of the body portion 2a, if the linear expansion coefficient of the inner cylindrical body 3 is negative, the expansion of the inner cylindrical body 3 Since the shrinkage of the body portion 2a in the body diameter direction is suppressed, FIG.
As shown in the conventional bobbin 2 shown in FIG.
Occurs, the size is smaller than in the conventional case, and the loosening of the optical fiber 1 is reduced.

The flange 2b may be formed integrally with the body 2a, or may be integrated by screwing or fitting. The material of the flange 2b does not need to be the same as the material of the body 2a. In the case of a bobbin that does not require the flange portion 2b, only the body portion 2a is provided.

FIG. 2 is an explanatory view of a second embodiment of the bobbin for winding a linear body according to the present invention. 2A is a side sectional view at the time of winding, FIG. 2B is a side sectional view at a high temperature, and FIG. 2C is a side sectional view at a low temperature. In the figure, 11 is a bobbin, 11a is a body part, 12 is an inner cylindrical body, and 13 is a gap in the body radial direction. The optical fiber 1 is similar to the optical fiber 1 shown in FIG.
1, the body 11a, the flange, and the inner cylinder 12 have the same shape as the bobbin 2, the body 2a, the flange 2b, and the inner cylinder 3 shown in FIG. Are different, different codes are used.

As shown in FIG. 2A, in this embodiment, the linear expansion coefficient of the body 11a is smaller than that of the optical fiber 1 in the first embodiment described with reference to FIG. The coefficient of expansion was made substantially equal, and the coefficient of linear expansion of the inner cylinder 12 was made negative. Depending on the temperature of the surrounding environment at the time of winding, the inner cylindrical body 12 is in close contact with the inside of the body portion 11a or has a slight gap.

As shown in FIG. 2B, at a high temperature, the body 11a expands but the inner cylinder 12 contracts, and a gap in the body radial direction is provided between the body 11a and the inner cylinder 12. 13
Occurs, and there is no influence of the inner cylindrical body 12. Since the coefficient of linear expansion of the body 11a is substantially equal to the coefficient of linear expansion of the wound optical fiber 1, no turbulence occurs and no extra tension is applied.

As shown in FIG. 2C, at a low temperature, the body 11a contracts and the inner cylinder 12 tends to expand.
The coefficient of linear expansion of the wound optical fiber 1 is
Since the linear expansion coefficient is substantially equal to 1a, there is theoretically no gap in the body diameter direction. However, as an actual product, the linear expansion coefficient of the optical fiber 1 and the linear expansion coefficient of the body 11a vary, In some cases, the temperature distribution is not uniform, and the temperature of the optical fiber 1 is higher. Therefore, using the inner cylindrical body 12 having a negative linear expansion coefficient, the inner cylindrical body 12 and the body portion 11a contract as a whole with a linear expansion coefficient equal to or slightly smaller than the linear expansion coefficient of the wound optical fiber 1. By doing so, there is no radial gap between the wound optical fiber 1 and the body portion 11a, so that there is no winding disturbance and no extra tension is applied to the optical fiber 1.

Even when the linear expansion coefficient of the inner cylindrical body 12 does not satisfy the above-mentioned condition, the inner cylindrical body 12
If the coefficient of linear expansion is negative, the expansion of the inner cylindrical body 12 suppresses the shrinkage of the body portion 11a in the body radial direction.
As in the conventional bobbin 2 shown in FIG. 1, even when a gap in the trunk diameter direction is generated between the wound optical fiber 1 and the trunk portion 11a at a low temperature, the size of the gap in the trunk diameter direction is larger than that in the related art. It becomes smaller, and the possibility of loosening of the optical fiber 1 is reduced.

In the first and second embodiments described above, loosening is prevented by reducing the gaps 4 and 13 in the body diameter direction. On the other hand, when the end side surface of the inner cylindrical body 3 is almost in close contact with the flange 2b at the temperature at the time of winding, the inner cylindrical body 3 also expands in the width direction at a low temperature, and the body 2a,
The compression force in the winding width direction due to the contraction of 11a can be reduced. However, at high temperatures, the inner cylinder 3, 1
2 shrinks in the width direction, so that the gap 52 in the width direction of the bobbin as shown in FIG. 9 cannot be prevented. Hereinafter, an embodiment for preventing the gap 52 in the width direction of the bobbin will be described.

FIG. 3 is a first explanatory view of a third embodiment of the bobbin for winding a linear body according to the present invention, and is a cross-sectional view at the time of winding. FIG. 4 is a second explanatory view of the third embodiment of the linear body winding bobbin of the present invention,
FIG. 4A is a cross-sectional view at a high temperature, and FIG. 4B is a cross-sectional view at a low temperature. In the figure, 21 is a bobbin, 21a is a body, 21b is a flange, 21c is a protrusion, 22 is an inner cylinder,
22a is a concave portion. The optical fiber 1 is wound around the body 21a, but is not shown.

As shown in FIG. 3, in this embodiment, a bobbin 21 has a flange 21b and a body 21a.
The inner cylindrical body 22 has a plurality of, in the illustrated example, two convex portions 21c formed in a circumferential direction on an inner peripheral surface of the inner cylindrical body 22.
A plurality of concave portions 22a formed in the circumferential direction corresponding to the convex portions 21c are accommodated in the interior surrounded by the body portion 21a and the flange portion 21b, and two or more concave portions 22a are provided in the width direction of the outer peripheral surface. The protrusion 21c and the recess 22a are fitted.

The body 21a is formed by the body 2a shown in FIG.
Although they are different in shape from each other, they are formed of the same material, and have a positive linear expansion coefficient that is considerably larger than the linear expansion coefficient of the optical fiber 1. On the other hand, the inner cylindrical body 22
It is formed of a material similar to the inner cylindrical body 3 shown in FIG. 1, is formed of a material having a negative linear expansion coefficient, and has a width of the bobbin 21 when the body 21 a and the inner cylindrical body 22 are combined. The linear expansion coefficient in the direction is set to be the linear expansion coefficient of the optical fiber 1 (approximately may be approximately zero). For example, the absolute value of the linear expansion coefficient of the inner cylindrical body 22 and the linear expansion coefficient of the body 21 a The absolute value of the coefficient is made substantially equal.

Although it depends on the temperature of the surrounding environment at the time of winding,
In the illustrated example, the outer peripheral surface of the inner cylindrical body 22 is a body part 21a.
And the end face of the inner cylindrical body 22 and the flange 2
1b, a slight gap is provided.

At the time of high temperature shown in FIG.
a expands and the inner cylindrical body 22 attempts to contract, but the bobbin 2
1 in the width direction are balanced with each other, and the expansion and contraction are small enough not to affect the loosening of the winding. Regarding the body diameter direction, between the convex portion 21c and the concave portion 22a, and the convex portion 21c
A gap is formed between the inner peripheral surface of the body portion 21a except for the outer peripheral surface of the inner cylindrical body 22 except for the concave portion 22a. The expansion and contraction in the body diameter direction are the same as those in the first embodiment described with reference to FIG.

At the time of low temperature shown in FIG.
a shrinks and the inner cylindrical body 22 tries to expand, but the bobbin 21
Are balanced with each other in the width direction, and the expansion and contraction are small enough not to affect the loosening of the winding. In the width direction of the bobbin 21, there is no gap between the end surface of the inner cylindrical body 22 and the flange portion 21b. However, in FIG. A gap is provided in advance between the flange 21b. The body diameter direction is the same as that of the first embodiment described with reference to FIG.

In order to manufacture the body 21a and the inner cylindrical body 22 fitted with the projections 21c and the recesses 22a, one is manufactured, and then the other is molded on the inner or outer circumference thereof through a release agent. Alternatively, instead of providing both the protrusion 21c and the recess 22a in the circumferential direction over the entire circumference 360 degrees,
The convex portion 21c is provided in an internal tooth shape, the outer peripheral portion other than the concave portion 22a is provided in an external tooth shape, and the inner cylindrical body 22 is inserted into the body portion 21a such that the convex portion 21c and the concave portion 22a are alternated. Thereafter, the inner cylindrical body 22 may be rotated by a predetermined angle so that the convex portion 21c and the concave portion 22a are fitted.

In the above description, the absolute value of the linear expansion coefficient of the inner cylindrical body 22 is substantially equal to the absolute value of the linear expansion coefficient of the body portion 21a. Is almost balanced, but as long as the polarities of the linear expansion coefficients are opposite, a force in the direction of the balance can be generated. FIG.
As in the second embodiment described with reference to the above, the linear expansion coefficient of the body portion 21a may be substantially equal to the linear expansion coefficient of the optical fiber 1.

FIG. 5 shows a modification of the third embodiment of the linear body winding bobbin of the present invention, and is a sectional view at the time of winding. In the figure, 31 is a bobbin, 31a is a body, 31b is a flange, 31c is a protrusion, 32 is an inner cylinder,
32a is a concave portion. This embodiment is a modification of the third embodiment described with reference to FIGS.
Bobbin 31, body 31a, flange 31b, projection 31c,
The inner cylindrical body 32 and the recess 32a are shown in FIGS.
Are the same as the bobbin 21, the body 21a, the flange 21b, the projection 21c, the inner cylinder 22, and the recess 22a shown in FIG. 1, but on the assumption that the inner cylinder 32 is a cylinder having an air core. Protrusions 31c are provided at one position on each of the left and right sides near the end in the width direction of the body portion 31a, and a concave portion 32a provided on the outer peripheral surface of the inner cylindrical body 32 is fitted into the convex portion 31c. The number of nails was reduced.

FIG. 6 is an explanatory view of a bobbin for winding a linear body according to a fourth embodiment of the present invention. FIG. 6A is a front view at the time of winding, and FIG. 6B is a front view at a high temperature. In the drawing, 41 is a bobbin, 41a is a body, and 41b is a flange. Bobbin 41, body 41a, flange 41b
Has the same shape as the bobbin 2, the body 2a, and the flange 2b shown in FIG. 1 respectively, but has different characteristics because of different expansion coefficient characteristics. Although hidden in the figure, it has an inner cylindrical body almost in close contact with the inner peripheral surface of the body 41a and having the same shape as the inner cylindrical body 3 shown in FIG. 1, but has different expansion coefficient characteristics.

In this embodiment, based on the first and second embodiments described with reference to FIGS. 1 and 2, the cylindrical body portion 41a and the inner cylinder hidden in the figure are:
It is made of a material having a linear expansion coefficient having anisotropy and having a smaller linear expansion coefficient in the width direction than in the body radial direction. Even when the cylindrical body 41a and the inner cylindrical body change in the body diameter direction due to a temperature change, the inner width of the body 41a is hardly changed. As a result, the gap in the width direction of the bobbin 41 between the flange 41b and the winding width of the optical fiber 1 is reduced.

In the third embodiment or the modified example thereof described with reference to FIGS. 3 to 5, if anisotropy is similarly provided, the function of the key nail is combined. ,
The change in the inner width of the body portion can be further reduced, and the selection range of the linear expansion coefficients of the constituent materials of the body portions 21a, 31a and the inner cylindrical bodies 22, 32 can be expanded.

In each of the above embodiments, the elastic modulus of the constituent material of the body and the inner cylindrical body is not mentioned, but not only the coefficient of linear expansion but also strictly considering the elastic modulus. Materials are selectively employed.

The inner cylinders 3, 12, and 32 shown in FIGS. 1, 2, and 5 are cylinders having an air core therein, and the inner cylinder 22 shown in FIGS. And a cylindrical body having no air core inside. Thus, the inner cylinder is
As long as it has the outer shape of the circumferential surface, it may be a cylindrical body having no air core therein, and the term “inner cylindrical body” includes such a body. Therefore, even if a cylindrical body having no air core therein is used as the inner cylindrical body 3, 12, 32 shown in FIG. 1, FIG. 2, and FIG. The inner cylindrical body 22 may have an air core inside. The flange of the bobbin and the inner cylindrical body having no air core inside are provided with a shaft hole for passing a central axis, or the central axis is directly fixed, and used. Was omitted.

In the above description, an example in which the optical fiber 1 is used as a linear body has been described. However, other linear bodies having the same characteristics can achieve the same function and effect. In the case where the linear body has a negative linear expansion coefficient, even if the above-described configuration is used, the outer cylindrical body at a low temperature is formed by the inner cylindrical bodies 3, 12, 22, and 32 having the negative linear expansion coefficient. Due to the contraction of the diameter, there is an effect that it is possible to prevent the loosening of the winding due to the formation of a gap between the wound linear body and the outer cylindrical body. In addition, if the positive and negative of the linear expansion coefficient of the body and the inner cylindrical body are reversed in accordance with the reversal of the linear expansion coefficient of the linear body, the change will be reversed at low and high temperatures. The same operation and effect can be obtained simply by forming.

[0045]

EXAMPLE In the structure of the first embodiment shown in FIG. 1, the outer diameter of the body 2a of the bobbin 2 is 140mmφ, the inner diameter is 134mmφ, the inner width is 100mm, the flange diameter of the flange 2b is 280mmφ, The thickness was 10 mm. ABS resin was used as a material for forming the body 2a and the flange 2b. Its linear expansion coefficient is 7.4 × 10 ⁻⁵ [1 / ° C.], and its elastic modulus is 23.
0 [kg / mm ² ]. The outer diameter of the inner cylindrical body 3 is 13
4 mmφ, inner diameter was 128 mmφ, and inner width was 100 mmφ. A liquid crystal polymer was used as a material for forming the inner cylindrical body 3. Its coefficient of linear expansion is −9 × 10 ⁻⁶ [1 / ° C.], and its elastic modulus is 23000 [kg / mm ² ].

As the optical fiber 1 to be wound, a glass part having a glass diameter of 125 μmφ was coated with an ultraviolet curable resin, the outer diameter was 250 μm, and the elastic modulus was 7,300 kg / kg.
mm ² ] and a coefficient of linear expansion of 0.6 × 10 ⁻⁶ [1 / ° C.]. This optical fiber 1 was wound around the body 2a of the above-described bobbin 2, and a heat cycle of -60 ° C to + 80 ° C was performed.

Bobbin 2 having inner cylindrical body 3 described above
The conventional bobbin 2 without the inner cylindrical body 3 described with reference to FIGS. 7 to 10 shows that the winding did not loosen at all even after the elapse of 20 cycles in which each temperature holding time was 2 hours. In this case, the optical fiber 1 jumped out due to loose winding. However, while a heat cycle is applied to the bobbin 2 having the inner cylindrical body 3 described above, the runout width is 5 mm,
When vibration of 5 Hz was applied, the winding was loosened due to expansion and contraction of the bobbin 2 in the inner width direction.

Therefore, in the circumferential direction of both the body portion 2a and the inner cylindrical body 3, similar to the convex portion 31c and the concave portion 32a of the modification of the third embodiment described with reference to FIG. Uneven portions having a height of 2.5 mm and a width of 3 mm were provided near both ends of the bobbin 2 and fitted, so that the expansion and contraction of the bobbin 2 in the width direction were canceled by the expansion and contraction of each material. At this time,
Even when a heat cycle of 60 ° C. to + 80 ° C. and the above-described vibration were applied, the bobbin 2 did not expand or contract in the width direction and did not loosen.

Further, similarly to the bobbin 41 and the inner cylindrical body of the fourth embodiment described with reference to FIG.
a, a structure in which the linear expansion coefficients of both materials of the inner cylindrical body 3 are made to have anisotropy and the linear expansion coefficient in the width direction of the bobbin 2 becomes substantially zero is prepared. A heat cycle of + 80 ° C. and a vibration of 5 mm and a vibration of 5 Hz were applied. Even in this case, the inner width of the bobbin 2 did not expand or contract, and the winding did not loosen.

[0050]

As is clear from the above description, according to the first aspect of the present invention, there is provided an outer cylindrical body around which a linear body is wound, and an inner cylindrical body inside the outer cylindrical body.
The outer cylinder is formed of a material having a positive coefficient of linear expansion in the body diameter direction, and the inner cylinder is formed of a material having a negative coefficient of linear expansion in the body diameter direction. Since there is a gap at high temperature and close contact at low temperature, it is possible to prevent loosening due to a gap between the wound linear body and the outer cylinder due to shrinkage of the outer cylindrical body at low temperature. This has the effect.

According to the second aspect of the present invention, since the linear expansion coefficient of the outer cylindrical body in the body diameter direction is equal to or greater than the linear expansion coefficient of the linear body, the winding tension is increased at a high temperature. And there is an effect that winding disturbance does not occur.

According to the third aspect of the present invention, since the linear expansion coefficient of the outer cylindrical body in the body diameter direction is substantially equal to the linear expansion coefficient of the linear body, the tension applied to the linear body at a high temperature is increased. There is an effect that can be reduced.

In the invention described in claim 4, the outer cylindrical body has a flange at the end and a plurality of circumferentially formed convex portions on the inner peripheral surface in the width direction. Since the body is accommodated between the flanges and has a plurality of circumferentially formed concave portions facing the convex portions on the outer peripheral surface and formed in the circumferential direction, and the concave portions are fitted into the convex portions, the flange is provided. Since the expansion and contraction of the inner width between the portions can be prevented, at the time of high temperature, the winding can be prevented from being loosened due to the formation of a gap between the wound linear body and the flange portion, and at the time of low temperature, the wound wire can be prevented. There is an effect that loosening of the winding due to compression of the body by the flange can be prevented.

According to the fifth aspect of the present invention, the outer cylinder has a flange at an end, the inner cylinder is housed between the flanges, and the outer cylinder and the inner cylinder have a linear expansion coefficient. Since it is formed of a material having anisotropy and having a smaller linear expansion coefficient in the width direction than the linear expansion coefficient in the body diameter direction, it is possible to prevent expansion and contraction of the inner width between the flanges, so at high temperatures, In addition to preventing winding looseness due to the formation of a gap between the wound linear body and the flange, the effect of preventing winding looseness due to compression of the wound linear body by the flange at low temperatures can be prevented. is there.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a first embodiment of a bobbin for winding a linear body according to the present invention.

FIG. 2 is an explanatory view of a second embodiment of the bobbin for winding a linear body according to the present invention.

FIG. 3 is a first explanatory view of a third embodiment of the linear body winding bobbin of the present invention, and is a cross-sectional view at the time of winding.

FIG. 4 is a second explanatory view of the third embodiment of the linear body winding bobbin of the present invention, FIG. 4 (A) is a cross-sectional view at a high temperature, and FIG. It is sectional drawing at the time.

FIG. 5 is a modified example of the third embodiment of the linear body winding bobbin of the present invention, and is a cross-sectional view at the time of winding.

FIG. 6 is an explanatory diagram of a fourth embodiment of a bobbin for winding a linear body according to the present invention.

FIG. 7 is an explanatory view of a conventional bobbin for winding a linear body.

FIG. 8 is a side sectional view of a conventional bobbin for winding a linear body at a low temperature.

FIG. 9 is a front view of a conventional bobbin for winding a linear body at a high temperature.

FIG. 10 is a front view of a conventional bobbin for winding a linear body when the temperature changes from a low temperature to a high temperature.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Optical fiber, 2, 11, 21, 31, 41 ... Bobbin, 3, 12, 22, 32 ... Inner cylindrical body, 4, 13, 5
1 ... clearance in the trunk diameter direction, 52 ... clearance in the width direction of the bobbin.

Claims (5)

[Claims] An outer cylindrical body around which the linear body is wound;
An inner cylinder is provided inside the outer cylinder, and the outer cylinder is formed of a material having a positive linear expansion coefficient in a body radial direction,
The linear shape is characterized in that the inner cylindrical body is formed of a material having a negative coefficient of linear expansion in a body radial direction, and the outer cylindrical body and the inner cylindrical body have a gap at a high temperature and adhere at a low temperature. Bobbin for body winding. 2. The bobbin according to claim 1, wherein a coefficient of linear expansion of the outer cylindrical body in a body radial direction is equal to or greater than a coefficient of linear expansion of the linear body. 3. The bobbin according to claim 1, wherein a coefficient of linear expansion of the outer cylindrical body in a body radial direction is substantially equal to a coefficient of linear expansion of the linear body. 4. The outer cylindrical body has a flange portion at an end and a plurality of convex portions formed in a circumferential direction on an inner peripheral surface in a width direction, and the inner cylindrical body includes the flange portion. And a plurality of recesses formed in the width direction, the recesses being formed in the outer peripheral surface and facing the protrusions in the circumferential direction on the outer peripheral surface, and the recesses are fitted in the protrusions. Item 1 or 3
The bobbin for winding a linear body according to any one of the above. 5. The outer cylindrical body has a flange at an end, the inner cylindrical body is housed between the flanges, and the outer cylindrical body and the inner cylindrical body have anisotropic linear expansion coefficients. 5. A material having a characteristic and having a coefficient of linear expansion in a width direction smaller than a coefficient of linear expansion in a body radial direction.
The bobbin for winding a linear body according to any one of the above.