JPH0419930A - Operation system of vacuum circuit breaker - Google Patents

Abstract

PURPOSE:To make a vacuum circuit breaker small and light by carrying out contacting and parting operation of a plurality of vacuum circuit breakers driven through an axial circuit on one main shaft in the time order of each circuit breaker. CONSTITUTION:A vacuum circuit breaker is composed of a plurality of vacuum valves in, for example (a) phase, (b) phase, and (c) phase, and having a fixed contact 2 and a movable contact 3. The movable contact 3 comes into on and off states owing to reciprocal movement of an insulating rod 10A having a wipe spring 9. The insulating rod 10A moves reciprocally by a crank movement owing to the rotation of one main shaft 12 through a lever 11 installed in the main shaft 12. The length La, Lb, and Lc of each insulating rod are made longer in this order. The narrow angles alphaa, alphab, alphac between each lever and each insulating rod are made narrower in this order. Consequently, touching and parting the contacts 2, 3 are carried out successively in each vacuum valve and thus a load force for touching and parting becomes low and the circuit breaker is made small.

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) The present invention relates to an operating mechanism for a vacuum circuit breaker.

(Prior Art) In FIG. 5, which shows the operating mechanism of a conventional vacuum circuit breaker, three vacuum valves 1 are fixed horizontally in a row on the top of an insulating frame (not shown), and are connected to connecting conductors (not shown) at the upper ends. Fixed electrodes 2 are fixed to the lower ends of the fixed-side current-carrying shafts 4, respectively.

The upper end of the movable electrode 3, which is fixed to the upper end of the movable current-carrying shaft 5 that has passed through the bellows 1a at the lower end of the vacuum valve 1 in an airtight manner, is now in contact with the lower surface of the fixed electrode 2. Also,
The upper end of a clamp 7 to which a flexible conductor 7a is connected is connected to the lower end of the movable current-carrying shaft 5, and a conductor (not shown) connected to a load-side terminal (not shown) is connected to the flexible conductor 7a. . The lower end of the clamp 7 is connected to the upper end of an insulated operating rod 10 via a wipe spring 9.
The front end of a lever 11 is connected to the lower end of the lever 11 via a pin (not shown), and the rear end of the lever 11 is supported swingably as shown by arrow A by bearings (not shown) on both sides of the above-mentioned insulating frame. It is fixed to the main shaft 12. Furthermore,
A movable part of a tripping electromagnet (not shown) is connected to this main shaft 12, which drives the main shaft 12 in the counterclockwise direction of arrow A to close the vacuum valve 1 as shown in the figure.When the tripping electromagnet is activated, the main shaft An opening spring (not shown) that drives the switch 12 clockwise in the direction of arrow A is engaged.

The operating mechanism of the vacuum circuit breaker constructed as described above is provided in the vacuum circuit breaker.

All of the vacuum valve 1 to <-10 parts that make up the C phase are all common parts, and their mounting positions (for example, the vertical direction of the vacuum valve 1) and related positions (for example, the insulating rod 10 The angle formed by /<-11) is also assembled into each homologous -.

Therefore, in the operating mechanism of the vacuum circuit breaker configured in this way, when the vacuum valve 1 is opened by demagnetizing the closing electromagnet (not shown), all three phases swing by the same angle. , the wipe 1f spring 9 also returns to the same dimension, and the movable electrode 3 also opens one part at the same time, and the movable electrode 3 also swings at a predetermined angle determined by the stopper of the tripping electromagnet (not shown) connected to the main shaft. The pole is opened to a predetermined position.

Similarly, by excitation of a charging electromagnet (not shown), a vacuum is created < 1 lb.
When the main shaft 12 is turned on, the insulating rod 10 is moved upward by swinging in the counterclockwise direction of the arrow A according to /< -11, so that the movable electrode 3 that contacts the fixed electrode 2 also contacts the three phases at the same time. , the wipe amount of the wipe spring 9 that is subsequently compressed is also the same for all three phases.

FIG. 6 is a diagram showing the relationship between the load force of the operating mechanism of the vacuum circuit breaker configured as described above and the stroke of the movable contact.

In the same figure, the load force shown by the broken line increases linearly at a slope determined by the spring constant of the cutoff spring shown by the one-dot line until the point 98 of the instant when the movable electrode 3 makes contact with the fixed electrode 2; The mounting compressive strength of the wipe spring 9 increases, and when wiping starts, the compressive force due to the spring constant of the wipe spring is added and increases.

Therefore, in the conventional vacuum circuit breaker operating mechanism,
A closing spring with a closing operation force in the curved line shown in the figure corresponding to the load force shown in the broken line in the same figure is used.

FIG. 2(a) is a graph showing the relationship between the stroke of the insulating rod 10 for one phase and the load force for one phase of the operating mechanism of the vacuum circuit breaker configured as described above. Energy corresponding to the area surrounded by diagonal lines between 1/3 of the force of the spring and the contact opening of the load broken line by the wipe spring 9 drives the operating mechanism composed of the main shaft 12, the lever 11, the insulating rod 10, etc. consumed by energy. If the contact material is soft, such as a copper-chromium alloy, the welded contacts will be pulled apart by the breaking force when the wipe is 0, as shown in the figure.

On the other hand, if the contact material is hard, the impact force due to the inertia of the operating mechanism has a greater effect on the separation of the contacts, and depending on the opening speed and the inertia of the operating mechanism, it is generally 2 to 2 times the opening force. It will be tripled.

Therefore, if the ratio between the opening force and the impact force at the time of contact opening is set to l:2, which is the lower limit of the above ratio, and the ratio between the opening spring force and the wipe spring is set to 1, then the opening for three phases will be The relationship between the load force and the contact separation force is as shown in FIG. 3(a).

Here, the height of the impact force shown in the pulse-like curve on the right is
This corresponds to the energy due to the load force corresponding to the area surrounded by diagonal lines on the left, and the separation of the contact point is determined by the maximum value of the sum of this impact force and the opening force.

Therefore, if this sum is equally distributed to each phase, the relationship between the load force at the time of opening of the negative phase and the contact separation force is as shown in Figure (b), where the load force on the left side is The energy, impact force on the right side, and opening force are both 1/3 of that in Figure (a).

(Problem to be Solved by the Invention) However, as is well known, in the operation mechanism of a vacuum circuit breaker configured in this way, the closing/opening springs and electromagnets become larger due to instantaneous closing and closing operations, and the excitation Not only does the current increase, but the impact force due to stopping at the stopper when the contact is completed increases, and the components of the operating mechanism must be made stronger to withstand this. This increases inertia, creating a vicious cycle.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to obtain an operation mechanism for a vacuum circuit breaker that can reduce the size and weight of the vacuum circuit breaker.

[Structure of the invention]

(Means and Effects for Solving the Problems) In the present invention, one end of a lever is connected to an insulating rod that is connected to a plurality of vacuum valves via wipe springs, and the lever is oscillated by the other end of the lever. In the operating mechanism of a vacuum circuit breaker with a fixed moving main shaft, the included angle formed by the lever and insulating rod and the wipe amount of the wipe spring are set to different values to reduce the load force on the vacuum valve. This is a vacuum breaker operating mechanism that is smaller and lighter.

(Example) Hereinafter, one example of the operation mechanism of the vacuum circuit breaker of the present invention will be described with reference to the drawings. However, parts that overlap with FIGS. 5 and 6 are omitted.

FIG. 1 is a partial perspective view showing the operating mechanism of the vacuum circuit breaker of the present invention, and corresponds to FIG. 5.

In the same figure, the main shaft 12 and each insulating rod 10A, 10B, I
Each lever 11 between the OC and the OC has a mounting angle α8. αb, α0 is α8〉αb〉α. and different from each other.

Similarly, the length of the insulating rod 10A, IOB, and IOC is IOA>
10B) Unlike the IOC, as a result, in the same figure showing the contact and separation instants of the C-phase contacts, when the C-phase wipe is zero, the b-phase opens slightly (approximately 0,3 rm), and the C-phase It is further opened (approximately 0.6 nm).

That is, in the same figure, the length of each lever 11 for C phase, b phase, and C phase is 60 an and the same, but when the mounting angle is completed, C phase is α8 = 24.9 degrees, and b phase is α8 = 24.9 degrees. αb=21.
4', and C phase is α. = 15' and the rotation angle of the main shaft 12 is 26.66.

On the other hand, for the insulating rods 10A, IOB, and IOC, the C-phase insulating rod 10A has the longest length of Lnm, followed by the B-phase insulation rod Lnm.
The OB is L-3.4 mm, the shortest C phase is L-9.7 mm, and the upper ends of each insulating rod 10A, IOB, and IOC are at the same height.

In the operation mechanism of the vacuum circuit breaker configured in this way, when opening the main shaft 12, the main shaft 12 moves 26 clockwise as indicated by the arrow in FIG.
．． When oscillating 6", the contact gap opens by 24 degrees. Among these, the C phase is wiped by 2.9° oscillation, and the B phase is wiped by 3.Onn + minute movable electrode, and the B phase is 3.2° oscillating. The wipe descends 3.3 fields, and the C phase swings 3.5'' and wipes 3.6 m.
After descending by m minutes, from the C phase with the minimum wipe amount to the B phase.

The contacts open in the order of C phase.

On the other hand, when turning on, from the C phase with the maximum wipe amount to the b phase,
The contacts make contact in the order of C phase.

Next, the operation of the operating mechanism of the vacuum circuit breaker constructed in this way will be explained.

As described above, when the contacts of each phase open and close in order of a minute time, the full opening force acts between the contacts of each phase in order, as shown by 211ffi (b).

Therefore, if the contact material has low hardness (e.g. copper,
(chromium alloy), and when the only force acting on the welded contact is the opening force, the opening force at the opening position of the C-phase contact is equal to the opening force for one phase when the three phases are simultaneously opened, as shown in Figure (a). By setting it so that it exceeds, it is only possible to separate the gold phase.

That is, by slightly shifting the opening time of each phase, the total opening force and the total bellows vacuum force can be applied to the opening force of each phase, as shown in Fig. 2(b). The opening force can be reduced to approximately 1/2 of the conventional force.

Second, if the contact material is hard and the impact force is large, the opening force can be reduced by about two-thirds, as detailed below.

In other words, as shown in Figure 3 (C), which corresponds to Figure 3 (A), if the opening spring force is set to 2/3 of the conventional one, and the spring constant is also set to 2/3, first, the C phase contact The C phase is opened by the additional force of the opening spring force equivalent to 2/3 as well as the impact force equivalent to 5/6 shown in the pulse-like curve diagram on the right side of the figure (a).

In addition, in the b phase, as shown in Figure (d), the energy required to open the contact from the impact force in Figure (c) (i.e., equivalent to 1/3 of the shaded area in Figure (a)) The value obtained by subtracting the energy) is added to the opening spring force to open the circuit.

Furthermore, in the C phase, as shown in the same figure (e), the same figure (d)
The value obtained by subtracting the above-mentioned energy from the impact force is added to the circuit-opening spring force, and the circuit is opened with a force equal to the sum of the impact force and the circuit-opening force shown in FIG.

Therefore, in this case, it is possible to open the circuit with about 2/3 of the opening force as compared to the case shown in FIG.

Next, FIG. 4 shows another embodiment of the vacuum circuit breaker operating mechanism of the present invention.

In the same figure, the vacuum valves 1 have different mounting heights in the axial direction, with the C phase being the highest, followed by the b phase, and the C phase.
They are arranged in order of phase, and the difference is 0.3m.

In addition, wipe spring 9, insulating rod 10 and operation lever 1
1 is the same as before.

In this case, the gap when the contacts are fully open will be slightly different for each phase, but all you need to do is change the mounting position of the vacuum valve 1.
It has the advantage of being easy to manufacture.

In the above embodiment, the difference in the amount of wipe between the a, b, and C phase contacts is approximately 0.3 mm. However, depending on the amount of wipe, the closing/opening speed, and the application conditions of the circuit breaker, The included angle between the lever 11 and the insulating rods 10A, IOB, and IOC may be increased, for example, to about 3+nm. Also, for example, when the throwing speed is 1m71 seconds, the difference in throwing time can be reduced by 2 kites or less by setting it within 2 kites. /1000 seconds or less.

Furthermore, in the above embodiment, the installation length of the wipe spring 9 is b
The phase is 0.3 aa shorter than the C phase, and the C phase may be further shortened by 0.3 m to make the contact pressure at the completion of charging the same.

Further, a third link may be provided between the insulating operating shaft and the wipe spring 9, or a pin joint may be provided to smooth the movement of the movable energizing shaft 5.

〔Effect of the invention〕

As described above, according to the present invention, one end of the lever is connected to each insulating rod connected to a plurality of vacuum valves via wipe springs, and a main shaft for swinging the lever is fixed to the other end of the lever. In the operating mechanism of a vacuum circuit breaker,
By setting the included angle formed by the lever and insulating rod and the wipe amount of the wipe spring to different values, we have reduced the load force on the contacts of the vacuum valve, making it possible to make the vacuum circuit breaker smaller and lighter. It is possible to obtain a vacuum circuit breaker operating mechanism that can be used.

[Brief explanation of the drawing]

FIG. 1 is a partial perspective view showing one embodiment of the vacuum circuit breaker operating mechanism of the present invention, and FIGS. 2 and 3 are diagrams illustrating the operation of the vacuum circuit breaker operating mechanism of the present invention. Figure (a) is a graph showing the relationship between the contact gap and the load force for one phase during three-phase simultaneous operation of a conventional vacuum circuit breaker, and Figure (b) is a graph showing the contact points of the operating mechanism of the vacuum circuit breaker of the present invention. Graphs showing the relationship between the gap and the load force for three phases, Figures 3(a) and 3(b) are graphs showing the contact separation force of the operating mechanism of a conventional vacuum circuit breaker, and Figure 3(c)
, (d) and (e) are graphs showing the contact separation force of the operating mechanism of the vacuum circuit breaker of the present invention, FIG. 4 is a diagram showing another embodiment of the operating mechanism of the vacuum circuit breaker of the present invention, and FIG. FIG. 5 is a partial perspective view showing the operating mechanism of a conventional vacuum circuit breaker, and FIG. 6 is a graph showing the operation of the operating mechanism of a conventional vacuum circuit breaker. 1 Vacuum valve 9 Wipe spring 10 Insulation rod 1] Lever 12 Main shaft

Claims (1)

[Claims] A vacuum cutoff in which one end of a lever is connected to an insulating rod that is connected to a plurality of vacuum valves via wipe springs, and a main shaft for swinging the lever is fixed to the other end of the lever. An operating mechanism for a vacuum circuit breaker, characterized in that an included angle formed by the lever and the insulating rod and a wipe amount of the wipe spring are set to different values.