JPH0646241B2 - Light Rotor Kyaki Letter - Google Patents

Description

The present invention relates to an optical rotary rear accumulator suitable for optical connection between a rotating body and a non-rotating body.

"Prior Art" When optical communication is performed with a moving device such as a stacker crane or a reclaimer and a fixed device that remotely controls or monitors the operating state of the moving device, for example, the moving device side is equipped with a cable reel. An optical rotary accumulator is attached to the cable reel to enable optical communication between a rotating body and a non-rotating body.

Known as such an accumulator is disclosed in JP-A-56
There are inventions such as -145076, 59-43777, and 59-53010.

In each of the accumulators of the above-mentioned conventional example, as shown in FIG. 6, a hollow shaft 1 and an outer case 2 are assembled so as to be rotatable relative to each other with a winding space 3 interposed between their inner and outer circumferences. An optical tape cable (hereinafter, simply referred to as an optical cable) 4 is spirally wound around the outer circumference of the hollow shaft 1 in the working space 3, and both ends of the spiral, that is, a winding start end and a winding end are the hollow shaft 1 and the outer case 2. It consists of one fixed to each.

In the case of the accumulator described above, one of the hollow shaft 1 and the outer case 2 (for example, the outer case 2) is a rotating body,
The other one is a non-rotating body.

The amount of rotation between the rotating body and the non-rotating body is the maximum tightening state when the optical cable 4 is wound around the outer circumference of the hollow shaft 1 by the relative rotation between them, and the optical cable 4 is wound by the relative rotation opposite to the above. It is determined within the range of the maximum unwound state when unwound.

Usually, the rotation amount at this time is 50 rotations or more.

Further, one end of the optical cable 4 is pulled out through the hollow shaft 1 and out of the hollow shaft 1, and the other end is also pulled out of the outer case 2, so that the cable between the moving device and the fixing device is attached to the accumulator mounted on the cable reel. You will be able to connect.

"Problems to be solved by the invention" The important problems of the optical rotary accumulator described above are
How to enable the accumulation of a high rotation amount and how to obtain a long life of the optical cable.

Generally speaking for rotary accumulators, it is better to make a material with high rigidity into a spiral shape by preforming and to store it in the winding space, which improves the amount of rotation and life, but does not have rigidity. Moreover, it is difficult to take such a measure for an optical cable which is inferior in strength.

In the case of an optical rotary rear accumulator, in general, the outer diameter of the hollow shaft is increased and the inner diameter of the outer case is increased to satisfy the rotation amount and the service life, but this tends to increase the size of the accumulator. It is not desirable because it accompanies it.

The following phenomena can be mentioned as a special feature of the optical rotary accumulator.

In the accumulator of FIG. 6 described above, the hollow shaft 1
When the optical cable 4 is wound around the outer periphery of the optical cable 4 and then unwound as shown in FIG. 7, the outermost loop of the spiral optical cable 4 tends to be layered before forming the inner peripheral surface of the outer case 2. Show.

When the optical cable 4 is unwound from this state, the spiral optical cable 4 is pushed up by the unwinding loop from the inner layer, the above-mentioned layered state becomes more dense, and the frictional resistance increases.

When the optical cable 4 is forcibly unwound from this state, the loops of the optical cable 4 are superposed in a number of layers and integrated, and the integrated product swells like rolling in the outer case 2, but the spiral outer diameter is almost the same. Does not grow.

Finally, as shown in FIG. 7, an S-shaped curve 5 due to the cable rigidity is generated in the inner layer of the optical cable 4, and the optical cable 4 buckles at point X.

In view of the above problems, the present invention is to provide an optical rotary rear cumulator capable of accumulating a high rotation amount and ensuring a long life of the optical cable including prevention of buckling.

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present invention has a hollow shaft and an outer case, which are relatively rotatably assembled to each other with a winding space interposed between the inner and outer circumferences of the hollow shaft and the outer case. In an optical rotary rear accumulator in which an optical tape cable is spirally wound around the outer periphery of a hollow shaft in the space for use, and both ends of the spiral are fixed to the hollow shaft and the outer case, respectively, the inner diameter of the outer case is D ₁ , When the natural loop diameter of the optical tape cable is D and the innermost loop inner diameter of the optical tape cable in the unwound state is D ₂ , D ₁ ≧ 1.3D, D ₂ ≦
It is characterized by satisfying 1.1D.

[Embodiment] An embodiment of the optical rotary rear accumulator according to the present invention will be described below with reference to the drawings.

In FIGS. 1 to 3, 11 is a hollow shaft made of metal, and 12 is an outer case made of metal or synthetic resin (including FRP).

The hollow shaft 11 and the outer case 12 are relatively rotatably assembled with a winding space 13 interposed between the inner and outer circumferences thereof.

14 An optical tape cable (hereinafter simply referred to as an optical cable), which has a tape-shaped flat cross-sectional shape.
As shown in FIG. 4, the optical fiber core wire 15 and the FRP wire 16 which are adjacent to each other are paired and these double pairs are covered with a plastic (including FRP) coating layer 17. .

The optical cable 14 is spirally wound around the outer circumference of the hollow shaft 11 in the winding space 13, and a winding start end 14a and a winding end 14b that are both ends of the spiral are wound on the hollow shaft 11 and the outer case 12, respectively. It is fixed.

Reference numeral 18 is a bearing interposed in the fitting portion between the hollow shaft 11 and the outer case 12.

19 draws one end of the optical cable 14 out of the hollow shaft 11,
The slit formed in the hollow shaft 11 and 20 are the optical cable 14
To pull the other end of the
It is a slit formed in the.

21 A stopper for fixing the winding start end 14a and the winding end end 14b of the optical cable 14.

The optical rotary rear cumulator according to the present invention, like the conventional example, the hollow shaft 11, the outer case 12 is a rotating body,
The other is used as a non-rotating body, and the optical Rotaria accumulator is attached to a cable reel equipped in, for example, a stacker crane or a reclaimer.

In such a use mode, when the outer case 12 that rotates together with the cable reel is a rotating body, the hollow shaft 11 is a non-rotating body, and the outer case 12 rotates in the direction of arrow M in FIG. 3,
The spiral optical cable 14 is tightened, and when the outer case 12 rotates in the direction of arrow N in FIG. 2, the optical cable 14 is unwound.

In the present invention, the inner diameter D ₁ ≧ 1.3D of the outer case 12 is set on the basis of the natural loop diameter D of the optical cable 14, and the outermost loop 14x of the optical cable in the unwound state is set.
A means for holding the inner diameter D ₂ of D ₂ is set so that D ₂ ≦ 1.1 D.

The natural loop diameter D mentioned here is the diameter when the optical cable 14 is just circular as shown in FIG.

The natural loop diameter D tends to increase as the rigidity of the optical cable 14 increases and the weight per unit length decreases, and conversely, the rigidity of the optical cable 14 decreases and the weight per unit length increases. It tends to become smaller.

Further, when the optical cable 14 has the same rigidity, the natural loop diameter D decreases when the optical cable weight / unit length increases, and when the optical cable weight / unit length is the same, the natural loop diameter D increases. The diameter D becomes large.

The reason that D ₁ ≧ 1.3D in the present invention is to avoid the following situation.

That is, when the optical cable 14 is unwound when D ₁ <1.3D, the outermost loop 14y comes into contact with the outer case 2 before the optical cable 14 is sufficiently unwound, and it becomes difficult to unwind the optical cable 14 further. If the unwinding is forcibly performed in, the buckling occurs between the inner and outer circumferences of the optical cable.

Of course, if the optical cable 14 cannot be fully unwound,
The amount of relative rotation between the hollow shaft 11 and the outer case 12 cannot be increased.

When D ₁ ≧ 1.3D is satisfied in the present invention, the outer diameter D ₁ of the outer case 12 may be slightly larger than 1.3D,
Unnecessarily increasing the outer diameter D1 of the outer case 12 is uneconomical and also increases the size of the accumulator.

The reason for holding D ₂ ≦ 1.1 D in the present invention is to avoid the following situation.

That is, when the optical cable 14 is unwound so that D ₂ > 1.1D, the S-shaped curve described in FIG. 7 occurs in the inner layer of the optical cable 14 and the optical cable 14 buckles.

In order to maintain the above D ₂ ≦ 1.1D, for example, when the unwinding state of D ₂ = 1.1D is reached, a means for reversing the accumulator of the present invention from the unwinding rotation to the winding tightening rotation,
Or, the rotation amount from the tightened state to the unwound state of D ₂ = 1.1D is measured in advance, and when the rotation amount is reached, a means for stopping the relative rotation between the hollow shaft 11 and the outer case 12 is adopted. To be done.

The reversal may be achieved by switching the drive motor for the cable reel to which the accumulator of the present invention is attached from the normal rotation to the reverse rotation. Similarly, the braking may be performed by the braking means (for example, an electromagnetic brake) of the cable reel. The initial setting can be performed by a tachometer or the like.

Hereinafter, specific examples of the present invention and comparative examples thereof will be described.

Specific Examples 1 to 8 A hollow shaft 11 having an outer diameter of 70 mmφ was used, and an outer case 12 having an inner diameter D ₁ of 600 mmφ was used.

Therefore, the winding space 13 has a volume of 70 mmφ to 600 mmφ.

As the optical cable 14, a cable having 6 cores and a coating thickness of 1.2 mm by FRP was used.

The natural loop diameter D of this optical cable 14 is about 400 mmφ.
Is.

Therefore, the above D ₁ becomes 1.5D, and D ₁ ≧ 1.3D
Are satisfied.

Under the above conditions, the hollow shaft 11 is a non-rotating body and an outer case.
12 is a rotating body, and the length of the optical cable 14 is changed for each example to obtain the relative rotation amount of the hollow shaft 11 and the outer case 12, that is, the maximum rotation amount at which the optical cable 14 does not buckle, and the unrolled state The inner diameter D ₂ of the innermost loop 14x of the optical tape cable 14 was measured.

The results are shown in the table below.

D ₂ in each of the above specific examples satisfied D ₂ ≦ 1.1D.

Comparative Examples 1 to 4 For comparison, the maximum rotation amount in the specific example 2 is set to 48 times (comparative example 1), and the maximum rotation amount in the specific example 4 is 66 times.
(Comparative example 2), the maximum rotation amount in specific example 6 is 7
When the number of rotations was twice (Comparative Example 3) and the maximum amount of rotation was 76 times (Comparative Example 4) in Example 8, the optical cable 14 buckled in each Comparative Example.

By the way, D ₂ in these Comparative Examples 1 to 4 is D ₂ >.
It was 1.1D.

Concrete Example 9 In the same specifications as the concrete examples described above, D ₂ is set to 1.
075 times, that is, D ₂ <1.1D, the maximum rotation amount from the tightened state to the unwound state of the optical cable 14 was 65 times, and a rotation test was performed 500,000 times. The optical cable 14 endured the test without buckling. It was

Comparative Example 5 For comparison, in Example 9, D ₂ was set to 1.15 times D, that is, D ₂ > 1.1D, and the maximum rotation amount from the tightened state to the unwound state of the optical cable 14 was set to 65 times. As a result of a test, the rotational torque immediately before the winding-up state is changed to the unwinding state is increased, and the buckling frequency is extremely increased, and 5 cores among the 6 cores of the optical cable 14 are I have disconnected.

[Advantages of the Invention] As described above, in the present invention, in a given optical rotary rear cumulator, the inner diameter of the outer case is D ₁ , the natural loop diameter of the optical tape cable is D, and the innermost loop inner diameter of the optical tape cable in the unwound state. Is D ₂ ,
Since D ₁ ≧ 1.3D and D ₂ ≦ 1.1D are satisfied, a high rotation amount can be accumulated, and a long service life of the optical cable including buckling prevention can be secured.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of the optical rotary accumulator of the present invention, FIG. 2 is a sectional view taken along line II of FIG. 1 showing a state in which the optical cable is wound and tightened, and FIG. 3 is an optical cable. FIG. 1 is a cross-sectional view taken along the line I-I showing the unwound state, FIG. 4 is a cross-sectional view of the optical cable, FIG. 5 is an explanatory view showing the natural loop diameter of the optical cable, and FIGS. 6 and 7 are conventional. FIG. 3 is a cross-sectional view showing a wound state and an unwound state of an optical cable in the optical rotary rear cuumator. 11 …… Hollow shaft 12 …… Outer case 13 …… Winding space 14 …… Optical tape cable 14a …… Swirl winding start end 14b …… Swirl winding end 14x …… Innermost loop 14y …… Outermost loop

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Claims (1)

[Claims] 1. A hollow shaft and an outer case are rotatably assembled to each other with a winding space interposed between the inner and outer circumferences thereof, and an optical tape cable is spirally wound around the outer circumference of the hollow shaft in the winding space. Is wound into a spiral shape, and both ends of the spiral are hollow shafts,
In an optical rotary rear cumulator fixed to each outer case, the inner diameter of the outer case is D ₁ , the natural loop diameter of the optical tape cable is D, and the innermost loop inner diameter of the optical tape cable in the unwound state is D ₂ . In this case, the optical rotary rear cumulator is characterized by satisfying D ₁ ≧ 1.3D and D ₂ ≦ 1.1D.