JPH0950738A - Insulated operating rod - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] It is an object to obtain an insulating operation rod having a small size, a light weight, and high strength. An insulating rod (4) having a female screw (4a) and having a first elastic coefficient, and a male screw (5) screw-engaged with the female screw (4a).
and a connection member 5 having a second elastic coefficient larger than the first elastic coefficient, and provided in association with the thread of the male thread 5a, the thread elasticity of the male thread 5a substantially corresponds to the axial elasticity with respect to the female thread 4a. Elastic increasing means 5b for increasing the difference between the internal thread 4a and the axial elasticity of the internal thread 4a.
The unevenness of the axial acting force of the a on the female screw 4a is alleviated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an insulating operating rod used for a charging section such as a power circuit breaker.

[0002]

2. Description of the Related Art FIG. 11 shows, for example, Japanese Utility Model Laid-Open No. 56-16743.
It is a front view which partially fractures | ruptures and shows the structure of the conventional insulating operation rod for circuit breakers shown by the 4th publication. In the figure, an insulating rod 1 having female threads 1a at both ends is formed by molding an insulating material such as glass fiber reinforced plastic, and the female thread 1a at both ends has a male thread 2a at one end. 2 is screwed. At the other end of the connecting fitting 2, a connecting portion (not shown) connected to an external mechanism is provided. The cap nut 3 having the circumferential protrusion 3a is
The protrusion 3 a is fitted to the end of the insulating rod 1 and fastened to the connection fitting 2. In order to prevent loosening of tightening, a screw engaging portion between the insulating rod 1 and the connecting fitting 2 and a contact surface between the insulating rod 1 and the cap nut 3 are fixed with an adhesive.

The insulating operation rod having such a structure transmits the force between the external mechanisms connected to the connecting portions of the connecting fittings 2 at both ends, and insulates both ends by the effect of the insulating rod 1.

The insulated operating rod receives not only an axial load but also a bending load depending on the use condition. The axial load is borne by the screw engaging portion between the insulating rod 1 and the connecting fitting 2. With respect to the load in the bending direction, the projection 3a of the cap nut 3 prevents the end portion of the insulating rod 1 from cracking, and constitutes an insulating operation rod that is strong against the bending load.

[0005]

Although the conventional insulated operating rod is constructed as described above, the electric operating device has a high voltage,
As the capacity increases, the load that the insulated operating rod bears also increases. In the structure of such a conventional insulated operating rod, the strength against the axial load depends on the screw engaging portion between the insulating rod 1 and the connecting fitting 2.

The insulating rod 1 and the connecting fitting 2 and the insulating rod 1 and the cap nut 3 are fixed by an adhesive, but the main purpose of these is to prevent the loosening of both, and it cannot be expected to increase the strength in the axial direction. This is because the adhesive surface may peel off when temperature changes are repeated due to shrinkage of the adhesive when it hardens and differences in the thermal expansion coefficients of the insulating rod 1, the connection fitting 2 and the cap nut 3. Because. In particular, when used in an electric device that requires high reliability, the strength in the axial direction cannot be increased by the adhesive.

Therefore, in the conventional method, in order to increase the strength in the axial direction, it is necessary to increase the screw diameter or the screw length to increase the contact area of the engaging screw threads. Therefore, when trying to obtain an insulating operation rod having increased strength in the axial direction while ensuring insulation performance, the overall length becomes long or the diameter becomes large, and therefore the weight increases. When the weight is increased, for example, when it is used for opening and closing an electrode of a circuit breaker, there are problems that the circuit breaker speed is reduced and the circuit breaker becomes large.

The present invention has been made to solve the above problems, and an object thereof is to obtain an insulating operating rod that is small in size, light in weight, and has high strength.

[0009]

According to another aspect of the present invention, there is provided an insulating operation rod, wherein an internal thread is formed, and an insulating rod having a first elastic coefficient and an external thread screw-engaged with the internal thread are provided.
And a connecting member having a second elastic coefficient larger than the elastic coefficient of the male thread and the thread of the male thread, and the axial elasticity of the thread of the male thread to the female thread is substantially increased to increase the axial elasticity of the female thread. And elasticity increasing means for reducing the difference between

In the insulated operating rod according to the second aspect, the elasticity increasing means is provided at the tip of the male screw.

According to another aspect of the insulation operating rod of the present invention, the elasticity increasing means is formed between the threads and extends along the threads.

In the insulated operating rod of the fourth aspect, the circumferential groove has a depth in the height direction of the screw thread, and substantially increases the height of the screw thread.

In the insulated operating rod of the fifth aspect, the circumferential groove has a depth in the width direction of the screw thread, and substantially reduces the width of the screw thread.

In the insulated operating rod of the sixth aspect, the elasticity increasing means is an elastic body provided between the threads of the male screw and the threads of the female screw.

In the insulated operating rod of the present invention, the thread at the tip of the external thread is at least partially removed so as to form at least a partial gap between the thread of the external thread and the thread of the internal thread. A body is provided within the void.

In the insulated operating rod of the eighth aspect, the elastic body is an adhesive.

In the insulated operating rod of the ninth aspect, the elastic body is a spring member.

In the insulated operating rod according to claim 10,
The thread of the external thread has a spring groove on its bevel that extends along the thread, and a spring member is provided in the spring groove.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1. FIG. 1 is a partial cross-sectional side view showing an example of the insulated operating rod of the present invention. FIG. 2 schematically shows a load transmission amount at a screw engaging portion between a conventional connecting fitting and an insulating rod. FIG. 3 is an enlarged view of part A of FIG. 1 and is a cross-sectional view showing a screw engaging part. FIG. 4 is a diagram showing how the threads are deformed. FIG. 5 schematically shows the amount of load transmission at the screw engagement portion between the connection fitting and the insulating rod of the present invention.
The same or corresponding parts as those of the conventional insulated operating rod shown in FIG. 11 are designated by the same reference numerals, and the description thereof will be omitted. In the figure, the insulating rod 4 is, for example, a glass fiber impregnated with a thermosetting resin and molded into a cylinder, and female screws 4a are provided at both ends thereof. At both ends of the insulating rod 4, connection fittings 5 which are connection members each having a male screw 5a formed at one end thereof are fixed by being screwed into the female screw 4a. At the other end of the connection fitting 5, a connecting portion (not shown) that is connected to an external mechanism is provided.

FIG. 2 schematically shows a load transmission amount when a force acts in a direction in which the connection fitting 5 and the insulating rod 4 are pulled at a screw engaging portion between the conventional connection fitting 5 and the insulating rod 4. It is a thing. Since the insulating rod 4 is usually made of FRP or the like, it has a low elastic coefficient (first elastic coefficient). Also connection fitting 5
Is usually made of aluminum alloy or the like, and thus has a high elastic modulus (second elastic coefficient). Therefore, normally, the connection fitting 5
Is much higher than the rigidity of the insulating rod 4. When the insulating rod 4 having a low elastic coefficient and the connecting fitting 5 having a high elastic coefficient are screw-engaged with each other, since the connecting fitting 5 has high rigidity up to the tip end, the load is applied at the position 8 which is the tip of the male screw 5a of the connecting fitting 5. The transmission increases rapidly. Therefore, the amount of load transmission at the female screw engaging portion shows a very large distribution at the tip of the male screw 5a. If the axial force acts more than the allowable amount, the female screw 4a
Will be damaged.

In FIG. 3, a notch 5b, which is an elastic increasing means, extends in the circumferential direction along the screw thread in the direction perpendicular to the axis at the valley bottom of 1 to 3 rounds of the tip of the male screw 5a of the connection fitting 5. Is formed. That is, the notch 5b is a circumferential groove having a depth in the height direction of the thread. Notch 5
The crest 5c where b is provided has a deep trough, so when a force is applied in the axial direction, the crest 5c is deformed from the trough bottom and has less rigidity and elasticity than a normal crest without the cut 5b. ing. In addition, between the female screw 4a and the male screw 5a,
The adhesive 7 is filled.

FIG. 4 shows a cut 5b perpendicular to the axis at the bottom of the valley of 1 to 3 rounds of the tip of the male screw 5a of the connecting fitting 5.
FIG. 7 is a diagram showing a state of deformation of each thread when a force is applied to the one provided with in a direction in which the insulating rod 4 and the connection fitting 5 separate from each other. The amount of deformation of the thread without the cut 5b is the same as the amount of deformation of the thread 5c with the cut 5b. However, since the thread 5c has a deep valley, it can be seen that the thread 5c is gently deformed from the bottom. Although the adhesive 7 is not filled in FIG. 4, the deformation of each mountain is substantially the same as that of the adhesive 7 filled.

When the amount of deformation is the same, the load on the mountain having a small rigidity is small. When the rigidity is reduced as much as possible, the state becomes equivalent to that without the thread, and the load transmission amount of the thread at the tip position 9 of the thread without the notch 5b increases. That is, when the rigidity of the tip portion of the male screw 5a having a large load transmission amount is set to be smaller than the normal rigidity, the load transmission amount at that portion becomes small, and the load transmission amount becomes as shown in FIG. That is, by providing the notch 5b, the load that was being carried by the screw thread at the tip end is distributed to other threads, and the variation in the load that is carried by each screw thread of the female screw 4a of the insulating rod 4 is reduced. Since the maximum load applied to one mountain can be reduced, the axial strength of the insulated operating rod is improved.

As described above, in the insulating operation rod of the present invention, the female screw 4a is formed, and the insulating rod 4 having the first elastic coefficient and the male screw 5a screw-engaged with the female screw 4a are provided. Is provided in association with the connection fitting 5 which is a connection member having a second elastic coefficient larger than the coefficient and the thread of the male screw 5a, and substantially increases the axial elasticity of the thread of the male screw 5a with respect to the female screw 4a. Since the unevenness of the axial acting force of the male screw 5a with respect to the female screw 4a is alleviated, the load is not concentrated on one place. , The axial strength is increased.

Further, in the insulated operating rod of the present invention, since the elasticity increasing means is provided at the tip of the male screw 5a, the load is not concentrated at one point at the tip of the male screw 5a, and the axial direction is increased. Strength increases.

Further, in the insulated operating rod of the present invention, the elasticity increasing means is the notch 5b which is a circumferential groove formed between threads and extending along the threads.
The male screw 5a has reduced rigidity and increased elasticity, and alleviates non-uniformity of the axial acting force, so that the strength in the axial direction increases.

Further, in the insulated operating rod of the present invention, since the circumferential groove has a depth in the height direction of the screw thread and substantially increases the height of the screw thread, elasticity is increased, Since the unevenness of the acting force in the axial direction is alleviated, the strength in the axial direction increases.

Embodiment 2 FIG. 6 is a sectional view of a screw engaging portion showing another embodiment of the insulated operating rod of the present invention. In the figure, the thread for 1 to 3 rounds from the tip of the male screw 5a of the connection fitting 5 is the thread 5d with the crest removed. In this embodiment, by removing the crest of the thread at the tip, a large amount of the adhesive 7, which is the elasticity increasing means, enters the gap in that portion. When a load is applied to each screw thread, the adhesive is likely to be deformed at the tip ridge, so that the rigidity of the thread is reduced, and the load is applied to the tip ridge.
Therefore, the load applied to the thread at the tip end is distributed to the other threads, and the variation in the load carried by each thread is reduced, and as a result, the strength of the insulating operation rod is improved.

As described above, in the insulated operating rod of the present invention, the elasticity increasing means is the adhesive 7 which is an elastic body provided between the threads of the male screw 5a and the threads of the female screw 4a.
Therefore, since the male screw 5a transmits a force to the female screw 4a via the adhesive 7 which is an elastic body, it becomes a state equivalent to that the rigidity of the screw thread is reduced, the elasticity is increased, and the axial action force is reduced. Since the uniformity is relaxed, the strength in the axial direction is increased.

Furthermore, in the insulated operating rod of the present invention, the thread at the tip of the external thread 5a is partially removed so as to form at least a partial gap with the thread of the internal thread 4a, Since the elastic body is provided in the gap and the male screw 4a transmits the force to the female screw via the elastic body, the state becomes equivalent to that the rigidity of the screw thread is reduced, and the non-uniformity of the axial acting force is eliminated. It relaxes and increases the axial strength.

Embodiment 3 FIG. 7 is a sectional view of a screw engaging portion showing another embodiment of the insulated operating rod of the present invention. In the figure, the thread of 1 to 3 turns from the tip of the male screw 5a of the connection fitting 5 is a thread 5e having a smaller thread diameter than the other threads. In this embodiment, by reducing the screw diameter of the screw thread at the tip end, a large amount of the adhesive agent 7 as an elastic body enters the gap in that portion, and the same effect as that of the second embodiment is obtained. Is. When a load is applied to each screw thread, the adhesive is likely to be deformed at the tip ridge, which is equivalent to a reduction in the rigidity of the thread and the load applied to the tip ridge is reduced. For this reason, the load applied to the ridge of the tip end is distributed to the other ridges, and the variation of the load carried by each ridge is reduced.

As described above, in the insulated operating rod of the present invention, since the elastic body is the adhesive 7, the elastic body also serves as an adhesive action between the male screw 5a and the female screw 4a.

Embodiment 4 FIG. FIG. 8 is a sectional view of a screw engaging portion showing another embodiment of the insulated operating rod of the present invention. In the present embodiment, a notch 5f is made in the axial direction at the bottom of the male screw 5a at the tip of the mountain for 1 to 3 rounds.
In the structure provided with the cuts 5f, the rigidity of the thread at that portion is reduced, and the structure is easily deformed under a low load. In the present embodiment, the rigidity of the thread at the tip of the screw, which bears a large share of the load, is reduced, so deformation occurs at a low load, the load at the tip is dispersed to other threads, and the variations in the load that each thread takes on are dispersed. Becomes smaller, and the strength of the insulated operating rod is improved.

As described above, in the insulated operating rod of the present invention, since the circumferential groove has a depth in the width direction of the screw thread and substantially reduces the width of the screw thread, elasticity is increased. , The non-uniformity of the acting force in the axial direction is alleviated and the strength in the axial direction is increased.

Embodiment 5 FIG. FIG. 9 is a sectional view of a screw engaging portion showing another embodiment of the insulated operating rod of the present invention. The thread of one to three rounds at the tip of the male screw 5a of the insulating rod 4 is made into a thread having a slightly small shape, and a cut 5g is made in the thread surface of the reduced thread, and a spiral material 11 made of a soft substance is included therein. For example, the rigidity of the load transmitting portion is reduced by inserting a material made of resin or a spiral spring member 12 having a spring shape by cutting a metal as shown in FIG. In the present embodiment, since there is a soft object between the threads of the tip portion where the load is large, the state becomes equivalent to that in which the rigidity of the male thread is reduced,
For this reason, the load of the tip portion is dispersed to other peaks, and the variation of the load carried by each peak is reduced, and the strength of the insulating operation rod is improved.

As described above, in the insulated operating rod of the present invention, since the elastic member is the spring member 12, the male screw 5a and the female screw 4a are in contact with each other through the spring member 12 at the tip portion, so that the screw thread This is equivalent to the reduction in rigidity, alleviating the non-uniformity of the acting force in the axial direction and increasing the strength in the axial direction.

Further, in the insulated operating rod of the present invention, the thread of the male screw 5a has a spring groove 5g extending along the thread on the slope thereof, and the spring member 12 is provided in the spring groove 5g. The spring is stably stored and reliability is improved.

[Brief description of drawings]

FIG. 1 is a side view with a partial cross section showing an example of an insulating operation rod of the present invention.

FIG. 2 is a diagram schematically showing a load transmission amount at a screw engaging portion between a conventional connecting fitting and an insulating rod.

FIG. 3 is a cross-sectional view showing a screw engaging portion in an enlarged view of portion A in FIG.

FIG. 4 is a diagram showing how a thread is deformed.

FIG. 5 is a schematic diagram showing a load transmission amount at a screw engaging portion between a connecting fitting and an insulating rod of the present invention.

FIG. 6 is a cross-sectional view of a screw engagement portion showing another embodiment of the insulated operating rod of the present invention.

FIG. 7 is a sectional view of a screw engaging portion showing another embodiment of the insulated operating rod of the present invention.

FIG. 8 is a sectional view of a screw engaging portion showing another embodiment of the insulated operating rod of the present invention.

FIG. 9 is a sectional view of a screw engagement portion showing another embodiment of the insulated operating rod of the present invention.

FIG. 10 is a sectional view of a screw engagement portion showing another embodiment of the insulated operating rod of the present invention.

FIG. 11 is a front view showing a partially broken structure of a conventional insulated operating rod.

[Explanation of symbols]

4 insulating rod, 4a female screw, 5 connecting metal (joint member), 5a male screw, 5b, 5f notch, 7 adhesive (elastic body), 12 spring member (elastic body).

Claims (10)

[Claims] 1. A connecting member having an internal thread and having an insulating rod having a first elastic coefficient and an external thread screw-engaged with the internal thread, and having a second elastic coefficient higher than the first elastic coefficient. And an elasticity increasing means which is provided in association with the thread of the male screw and which substantially increases the axial elasticity of the thread of the male screw with respect to the female screw to reduce the difference from the axial elasticity of the female screw. An insulating operating rod, which is provided with the non-uniformity of the axial acting force of the male screw on the female screw. 2. The insulated operating rod according to claim 1, wherein the elasticity increasing means is provided at a tip portion of the male screw. 3. The insulated operating rod according to claim 1, wherein the elasticity increasing means is a circumferential groove formed between the threads and extending along the threads. 4. The insulated operating rod according to claim 3, wherein the circumferential groove has a depth in the height direction of the screw thread and substantially increases the height of the screw thread. 5. The insulated operating rod according to claim 3, wherein the circumferential groove has a depth in the width direction of the thread, and the width of the thread is substantially reduced. 6. The insulated operating rod according to claim 1, wherein the elasticity increasing means is an elastic body provided between the threads of the male screw and the threads of the female screw. 7. A thread at the tip of the male thread is at least partially removed to form at least a partial void with the thread of the female thread, and the elastic body is within the void. The insulated operating rod according to claim 6, which is provided in the. 8. The insulated operating rod according to claim 7, wherein the elastic body is an adhesive. 9. The elastic body is a spring member.
Insulated operating rod as described. 10. The insulated operating rod according to claim 9, wherein the thread of the male screw has a spring groove extending along the thread on the slope thereof, and the spring member is provided in the spring groove.