JPH0329958Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention relates to an abnormal tension buffer that is used, for example, to protect the drop-in line and the support points of the drop-in line when abnormal tension is applied to the overhead drop-in line for power distribution. It is something.

[Conventional technology]

Conventionally, the method of securing overhead lines for power distribution from the house side is to screw ring bolts to the gables or girders of the house, or to screw a ring coach, and to secure bindless insulators to the ring bolts or ring coach. The service line is kept in place. However, with this method, in snow-damaged areas, abnormal tension is applied to the drop-in wire due to the formation of a snow cap, and as a result, stress exceeding the limit load is applied to the retaining portion of the drop-in wire, causing the insulation coating of the wire to be destroyed. If left as is for a long period of time, the wire conductor may break due to stress corrosion, or may break due to abnormal tension, causing a short circuit between the phases and sparks between the phases, which may cause a fire. If a ring bolt or ring coach comes off, making it impossible to support the service line, or if the ring bolt or ring coach is supported by the wall of the house, such as a lath wall, the house may be damaged. In addition to snow damage, electrical wires were often broken due to slight wind vibrations and gear locking, often resulting in long power outages.

In order to address these problems, the applicant previously provided a buffer coil spring with a stopper disclosed in Japanese Utility Model Application No. 60-95240. This involves combining a pair of hooks that have a hook at one end in a link shape, connecting the two hooks in a variable manner within a certain dimension, and tightly wrapping the hooks so as to enclose this link. The coil spring is installed with a predetermined initial tension set, and the load-deflection characteristics of the coil spring have two characteristic displacement points: the initial tension setting point and the fixed point obtained by the locked state of the link part. For example, one hook part is moored to a ring coach on the side of a house, and the other hook part is moored to a bindless insulator holding a service line. As a result, it does not stretch under standard usage conditions and always maintains a certain degree of slack.
When abnormal tension is applied to the lead-in wire, the lead-in wire is deflected within the extension limit to quickly reach the fixed point, and its buffering action prevents breakage of the lead-in wire.

[Problem that the invention attempts to solve]

By the way, although the buffer coil spring with a stopper can buffer abnormal tension to a certain extent, when the span is long or when abnormal tension increases due to strong winds during a typhoon, it is difficult to deflect within the extension limit to reach the fixed point. There were cases in which the abnormal tension in service lines could not be sufficiently alleviated.

Therefore, the purpose of this invention is to deal with cases where abnormal tension is applied to service lines due to ice and snow, slight wind vibrations, gear locking, etc., as well as cases where high abnormal tension is applied to service lines due to strong winds during typhoons. To provide an abnormal tension buffer that can sufficiently buffer the abnormal tension to prevent breakage of service lines and damage to the wire sheathing, even when the cable length or span is long, and protect supporting points and supporting objects of a house from destruction. It is in.

[Means for solving problems]

In order to solve the above problems, this invention provides an abnormal tension buffer that operates in multiple stages depending on the degree of abnormal tension.

That is, a tightly wound coil spring is installed with a predetermined initial tension so as to enclose a pair of hooks having a hook at one end, and both ends are hooked in the axial direction as the coil spring expands. A mechanical or magnetic connection in which both hooks are locked when the parts are separated for a certain amount of time, and the locked state is released at a predetermined tensile load limit, that is, an abnormal tension exceeding a certain level. Alternatively, an adhesive connection portion is provided, and the coil spring has three characteristic displacement points: an initial tension setting point a, a locking point b, and a release point c in the load-deflection characteristics of the coil spring.

[Effect]

As mentioned above, the load-deflection characteristics of a coil spring include an initial tension setting point a, a locking point b, and a release point c.
When three characteristic displacement points are provided, firstly, if the initial tension setting point a is set above the tension of the lead-in wire in the standard usage state, it will not elongate below the predetermined tension and will always have a constant slack. If abnormal tension is applied to the service line due to snow or wind, it will quickly deflect within the extension limit to the anchoring point b to buffer the abnormal tension. When a high abnormal tension is applied to the service line due to strong winds, the locking state is released by the release point c and the deflection increases rapidly, so even these high abnormal tensions can be buffered. In addition to completely preventing disconnection of the lead-in wire and damage to the wire sheath,
Support points and supports of the house can also be protected.

〔Example〕

FIG. 1 shows an embodiment of the abnormal tension buffer according to this invention, and reference numerals 1 and 1' denote a pair of hooks having hooks 2 and 2' at one end.
The elliptical ring 3, which is bent into a substantially elliptical shape and has a small wire diameter and is combined in a link shape, allows the dimension ₂ between the two hooking parts ₁ and 1' in the axial direction to be increased within the dimension 1. are variably linked. Reference numeral 4 denotes a tightly wound coil spring which is installed by sequentially decreasing the coil diameter at both ends so as to enclose the pair of hooks 1 and 1', and is set to a predetermined initial tension.

In the above structure, when a load higher than the set initial tension is applied, the coil spring 4 expands and the hooks 2 and 2' at both ends separate, and the ring 3 separates by ₁ minute, as shown in Figure 2. After that, it becomes locked. As the load increases further, as shown in FIG. 3, the ring 3 breaks and the locked state is released, and the coil spring 4 rapidly expands. That is, the load-deflection characteristics of the coil spring 4 are provided with three characteristic displacement points: an initial tension setting point a, a locking point b, and a release point c, as shown in FIG. Note that the release point c can be arbitrarily set by selecting the material and wire diameter of the ring 3.

Fig. 5 shows an example of the use of the buffer, in which 5 is a ring coach screwed onto the wall of a house, one hook 2 of the buffer is moored, and the other hook 2' is moored. It is moored to a bindless insulator 6 that holds down an overhead power distribution lead-in line 7.

By the way, the wind pressure load on the service line is 100Kg/
Figure 6 shows how much load will be applied to the wire as abnormal tension when m ² is applied. Here, the wind pressure load of 100Kg/m ² refers to the Class A wind pressure load specified in Article 73 of the Electrical Equipment Technical Standards. The calculation conditions were for a single-phase three-wire system using IV3.2mm lead-in wires.

In the figure, curve A is for the case without a buffer, and curve B is for the case where there is no buffer.
The curve shown in the figure shows the case where the buffer coil spring with stopper of Utility Model Application No. 60-95240 shown in the conventional example is used, and C
The curve shown in FIG. 1 is obtained when the abnormal tension buffer according to this invention is used. Further, the load-deflection characteristic diagrams of B and C are shown in FIG. As can be seen from FIG. 6, in case B, the buffering effect is small in the long span, but the shock absorber C of this invention has a sufficient effect.
Furthermore, if the strength of the support point is known, damage to the support point can be prevented by appropriately setting the release point c.

Other embodiments will be described below. Note that the same parts as in the above embodiment are given the same reference numerals.

FIG. 8 shows one hook 1 of a pair of hooks 1a and 1a' having hooks 2 and 2' at one end.
Bend a' into a roughly oval shape and attach the other hook 1.
The wire diameter of the extended rear end part 8 of a is narrowed and bent into a hook shape, and the dimension ₄ between the two hooking parts 2 and 2' is variably connected within the dimension ₃ , and the dimension ₄ is approximately the minimum. In this state, a closely wound coil spring 4 is installed with a predetermined initial tension set so as to enclose the pair of hooks 1a and 1a' by successively decreasing the coil diameter at both ends.

Therefore, in this example, the locking point b is obtained by the locking state when both the locking parts 2 and 2' are separated by ₃ minutes, and the release point c is obtained by the locking state after the extension due to the increase in load. This is obtained by deforming and detaching the end portion 8. Therefore, the release point c can be arbitrarily set by adjusting the wire diameter of the extended rear end portion 8.

In short, the above embodiment is based on the coil spring 4
Both hooks are mechanically locked in a constant state of separation between both end hooks 2 and 2' in the axial direction with extension, and a predetermined tensile load limit exceeding this mechanical strength is applied. Although a mechanical connection portion is provided which releases the locking state when the locking state is reached, the same function can also be achieved by providing a magnetic connection portion.

FIG. 9 shows an example of this, in which a pair of hooks 1b, 1b' having hooks 2, 2' at one end are bent into a substantially oval shape, and the rear end of one hook 1b is permanently attached. The magnet 9 is fixed to the magnet 9, and another permanent magnet 9' that is magnetically fixed to the magnet 9 is attached to a substantially oval intermediate ring 10.
The intermediate ring 10 and the other hook 1b' are fixed to the rear end of the intermediate ring 10 and the other hook 1b' are combined into a link shape. Therefore, within dimension ₅ , both hooking parts 2,
The dimension ₆ between 2' is variably connected.

In this example, the locking point b is both the locking portions 2, 2'
The release point c is obtained by the mechanical locking state between the intermediate ring 10 and one hook 1b' and the magnetically connected state between the other hook 1b and the intermediate ring 10 after ₅ minutes of separation. permanent magnet 9,
This is obtained by separating the permanent magnets 9, 9' when the attraction force between them is exceeded. Therefore, setting the release point is
This can be carried out arbitrarily depending on the magnitude of the magnetic force of the permanent magnets 9, 9' or the magnitude of the attraction area.

Furthermore, instead of the permanent magnet, the release point can also be set by bonding rectangular or circular members having a specified cross-sectional area to each other with an adhesive or the like and using the adhesive strength.

Further, in each of the above examples, the mechanical, magnetic, or adhesive connection portion for releasing the locking state between the hooks is set inside the coil spring, but a system in which it is set outside the coil spring may also be adopted.

FIG. 10 shows such an example, in which a pair of hooks 1c, 1 have hooks 2, 2' at one end.
c' is provided with slide guides 11, 11', and the distal end of each slide guide is provided with locking parts 11a, 11a' that _loosely fit into the other slide guide. The dimension ₈ between 2 and 2' is variably connected. Similar to the other examples, a tightly wound coil spring 4 with a coil diameter successively smaller at both ends is installed with a predetermined initial tension set so as to enclose a pair of hooks. Locking point b
is obtained when the locking parts 11a and 11a' collide,
The release point c is obtained by breaking the locking portions 11a, 11a' or separating them from the slide guides 11, 11'.

In addition to the above, examples of externally installed mechanical connections include a small cylinder with an outwardly directed rim;
In combination with a large cylinder having inward projecting edges, a locking state can be obtained by the mutual projecting edges, and a release point c can also be set by dissociation due to deformation or destruction of the projecting edges.

Fig. 11 shows an example in which the connecting part is similarly set outside the coil spring, and shows an example having a magnetic connecting part, and shows a pair of hooks 1d and 1d' having hooking parts 2 and 2' at one end. A substantially U-shaped slide guide 12, 12' having a loop-shaped locking part 12a, 12a' at the tip is attached to each hook, and a slide guide 12, 12' having a loop-shaped locking part 13a, 13a' at one end, and another. In combination with intermediate members 13, 13' having permanent magnets 9, 9' fixed to their ends, the dimension ₁₀ between the two hooking parts 2, 2' is variably connected within the dimension ( ₉ x 2). . Note that the permanent magnets 9, 9' are not limited to square shapes, but may be ring-shaped surrounding the coil spring 4, and as in the previous embodiment, the release point c is set using the adhesive strength of an adhesive instead of the permanent magnets. You can also do that.

Among the above-mentioned embodiments, those having a magnetic connection part have the advantage that the tension can be returned to the initial tension setting point again after reaching the release point.

[Effect of idea]

As mentioned above, the abnormal tension buffer according to the present invention is particularly provided with a mechanical, magnetic or adhesive connection part that releases the locked state of both hooks at a predetermined tensile load limit, and reduces the load of the coil spring. -The structure has three characteristic displacement points: the initial tension setting point a, the locking point b, and the release point c for the deflection characteristics, so
It is extremely effective when used as a tie-down for service lines, as it can buffer not only snow damage but also abnormal tension caused by wind pressure, prevent service lines from breaking and coating damage, and protect supporting points and supports of houses. Of course, it can be widely applied to other anchored objects that require a mooring effect similar to that used for retaining service lines, and its practical value is high.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional view showing an embodiment of the abnormal tension buffer according to the invention, Fig. 2 is a longitudinal sectional view in the same locked state, and Fig. 3 shows the released of the same locked state. A vertical cross-sectional view, FIG. 4 is an explanatory diagram of load-deflection characteristics, FIG. 5 is an explanatory diagram showing an example of use for retaining a lead-in line, and FIG. 6 is a comparative explanatory diagram of tension-span characteristics. Fig. 7 is a comparative explanatory diagram of load-deflection characteristics, Fig. 8 is a longitudinal sectional view showing another example, and Fig. 9 is a
Longitudinal cross-sectional view of another example having a magnetic connection part, 1st
FIG. 0 is a longitudinal sectional view of another example in which the connecting portion is set outside of the coil spring, and FIG. 11 is a longitudinal sectional view of another example in which the connecting portion is set outside of the coil spring and connected with a magnet. 1, 1', 1a, 1a', 1b, 1b', 1c, 1
c', 1d, 1d'...futsuk. 2, 2'...Latching part,
4...Coil spring.

Claims (1)

[Scope of utility model registration request] A tightly wound coil spring is installed with a predetermined initial tension set so as to enclose a pair of hooks having a hook at one end, and as the coil spring expands, the distance between the hooks at both ends in the axial direction is A mechanical, magnetic, or adhesive connection is provided that keeps both hooks in a locked state when they are separated for a certain amount of time, and releases this locked state with a predetermined tensile load limit. An abnormal tension buffer characterized in that the deflection characteristics are provided with three characteristic displacement points: an initial tension setting point a, a locking point b, and a release point c.