JP3841589B2 - Electrode connection terminal and circuit breaker having the same - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electrode connection terminal fixed to an electrode of a vacuum valve incorporated in a circuit breaker for large current and a circuit breaker having the electrode connection terminal attached thereto.
[0002]
[Prior art]
The vacuum circuit breaker has a fixed electrode rod and a movable electrode rod arranged in a vacuum vessel adjusted to about 10 ⁻⁶ Torr, and these are connected to a conductor outside the vacuum vessel. The contact of the electrode rod is separated and the main circuit current is passed and cut off. Terminals are fixed to these electrode rods, and the terminals are connected to a conductor outside the vacuum vessel. FIG. 4 is a cross-sectional view showing the structure of a conventional electrode connection terminal. The split terminal 21 made of copper alloy is provided in a fitting hole into which the electrode rod 2 of the vacuum valve 2 is fitted, a split part 21d extending from the center to the edge side and extending in the both sides of the split part 21d. Bolt holes 21c. The bolt hole 21c is provided in such a manner that it passes through both the end faces of the split terminal 21 through the split portion 21d. The split terminal 21 is fixed to the electrode rod 2 by fitting the electrode rod 2 into the fitting hole, inserting the bolt 24 into the bolt hole 21c so as to penetrate the split portion 21d, and fastening with the nut 25.
[0003]
FIG. 5 is a plan view showing the structure of another conventional electrode connection terminal, which is a vacuum valve mounting device proposed in Japanese Utility Model Publication No. 49-2842. The external connection terminal 5 is connected to the split mold terminal 31 via the flexible conductor 6, and the split mold terminal 31 is fixed to the electrode rod (movable) 2. The split-type terminal 31 is made of a copper alloy, and screw holes are formed on both sides of the split portion 31a so as to penetrate the split portion 31a, and screw grooves are cut in the inner peripheral portion of the screw hole. Bolts 34 are inserted into the screw holes and screwed together, and the split portion 31 a is fastened to fix the split type terminal 31 to the electrode rod 2.
[0004]
[Problems to be solved by the invention]
The circuit breaker for large currents to which such an electrode connection terminal is attached opens and closes the electric circuit by moving the movable electrode bar forward and backward. For this reason, after continuous opening and closing thousands of times, the bolts that fasten the split-type terminals are loosened, and the contact resistance between the electrodes and the split-type terminals is increased. In addition, the split type terminal is becoming larger in order to cut off a large current, and accordingly, the mass and kinetic energy of the movable part increases, the impact energy and damping vibration during opening and closing operations increase, and the bolt further increases. There was a problem that it was easy to loosen.
[0005]
In order to prevent loosening of the bolt due to thousands of continuous opening / closing operations as described above without significantly changing the structure of the circuit breaker, the fastening force of the bolt may be increased. However, in order to prevent an increase in contact resistance due to the loosening of the bolt, a fastening torque that is 1.8 times the normal is required. The normal split type terminal 31 represented by Japanese Utility Model Publication No. 492841 shown in FIG. 5 is made of a copper alloy, and the screw groove of the screw hole is destroyed by fastening with high torque. was there.
[0006]
Further, since the head of the bolt 24 and the nut 25 are exposed from the end face of the split-type terminal 21, the split-type terminal 21 of the type shown in FIG. When the heat dissipating fins are provided in the peripheral portion of the fin, there is a problem that the mounting space for the fins is reduced.
[0007]
The present invention has been made in view of such circumstances, and by splitting a split terminal by screwing a fastening screw into a pin made of a material having a strength higher than that of the split terminal, the split terminal with a high fastening torque. It is an object of the present invention to provide an electrode connection terminal that can be fixed to an electrode and prevent loosening of a fastening screw and a circuit breaker including the electrode connection terminal. It is another object of the present invention to provide an electrode connection terminal capable of reducing a tool space during fastening by providing a screw groove into which a fastening screw is screwed, and a circuit breaker including the electrode connection terminal.
[0008]
[Means for Solving the Problems]
The electrode connection terminal according to the first aspect of the present invention is a fitting hole into which an electrode is fitted, a split portion connected to the fitting hole, and an insertion hole that is provided on both sides of the split portion and allows a fastening screw to pass through the split portion. And a pin hole that communicates with the insertion hole along the axial direction and into which a pin having a screw hole is inserted into the body portion.
[0009]
The electrode connection terminal according to a second aspect of the invention is characterized in that, in the first aspect of the invention, a fin for heat dissipation is further provided at least in the vicinity of the insertion hole.
[0010]
A circuit breaker according to a third aspect of the present invention is a pair of electrodes arranged in a vacuum vessel and electrically connected / cut off by relative movement thereof, and at least one or more electrode connection terminals fixed to one of the electrodes And a screw member for fixing the electrode connection terminal to the electrode. The electrode connection terminal includes a fitting hole into which the electrode is inserted, a split portion connected to the fitting hole, and both sides of the split portion. A through hole through which the fastening screw is inserted and a pin hole communicated with the insertion hole in the axial direction, and the screw member is screwed into the body portion. And a pin inserted into the pin hole and the fastening screw screwed into the screw hole of the pin.
[0011]
The circuit breaker according to a fourth invention is characterized in that, in the third invention, the pin is formed using a material having higher strength than the electrode connection terminal.
[0012]
The circuit breaker according to a fifth invention is characterized in that, in the third or fourth invention, the pin is made of stainless steel and the electrode connection terminal is made of a copper alloy.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be specifically described with reference to the drawings showing embodiments thereof.
FIG. 1 is a cross-sectional view showing the structure of the electrode connection terminal of the present embodiment, and FIG. 2 is a vertical cross-sectional view showing the main part of the circuit breaker to which the electrode connection terminal of FIG. 1 is attached. As shown in FIG. 2, the circuit breaker includes a vacuum vessel 7, and a movable electrode rod 2 and a fixed electrode rod 20 that pass through the vacuum vessel 7 and are coaxially disposed in the vacuum vessel 7. Split-type terminals 1 and 10 which are electrode connection terminals are fixed to the movable electrode bar 2 and the fixed electrode bar 20, respectively. The split type terminals 1 and 10 are connected to a conductor (not shown) outside the vacuum vessel 7 via a flexible conductor (not shown) connected thereto. In such a circuit breaker, by moving the movable electrode rod 2 forward and backward, the opposed end surfaces of the movable electrode rod 2 and the fixed electrode rod 20 are brought into contact with and separated from each other, and the main circuit current is passed and cut off.
[0014]
FIG. 1 shows a split-type terminal 1 fixed to a movable electrode rod (hereinafter referred to as an electrode rod) 2 side. The split type terminal 10 fixed to the fixed electrode rod 20 also has the same structure, and the description thereof is omitted. As shown in FIG. 1, the split terminal 1 made of a copper alloy has a substantially rectangular plate shape, has a fitting hole 2a for fitting the electrode rod 2 at a substantially center, and continues to the fitting hole 2a toward the peripheral side. It has a split part 1a that extends. Bolt holes 1c are provided in both side regions of the split part 1a so as to penetrate the split part 1a, and the opening part is formed to have a larger diameter than the bottom part side, and the head of the bolt 4 to be inserted is the bolt hole 1c. It is designed to be embedded inside. A pin hole 1b, which is a feature of the present invention, is communicated with the bottom of the bolt hole 1c. The pin hole 1b has an axial direction substantially parallel to the electrode rod 2, that is, the pin hole 1b and the bolt hole 1c. Are axially orthogonal to each other.
[0015]
A stainless steel holed pin 3 is inserted into the pin hole 1b. FIG. 3 is a perspective view showing a screw member for fixing the split type terminal of FIG. 1 to the electrode rod 2, and shows a screwed state of the holed pin 3 and the bolt 4. The holed pin 3 has a screw hole 3a penetrating perpendicularly to the body portion, and a screw groove (female screw) carved on the inner periphery of the screw hole 3a is a screw groove (male screw) on the outer periphery of the bolt 4. It has a dimension to be screwed. The holed pin 3 is inserted in a direction in which the axial direction of the screw hole 3a coincides with the axial direction of the bolt hole 1c (see FIG. 1), and the bolt 4 is inserted into the bolt hole 1c to the middle of the screw hole 3a. Screwed. The screw hole 3a is not limited to the through hole, and may be a screw hole having a bottom surface.
[0016]
.. Are provided at the peripheral end of the split terminal 1, and in particular, a large number of fins 8 are formed around the bolt hole 1c and the pin hole 1b. Since the pin 3 with the hole having the screw hole 3a to be screwed into the bolt 4 is inserted into the split type terminal 1, only the tool is mounted on the head of the bolt 4 when the bolt 4 is fastened. is there. Therefore, it is not necessary to secure a space for the tool around the screw hole 3a, and the fin 8 can be provided in that region.
[0017]
Since the split type terminal 1 having the above-described configuration is fastened by screwing the bolt 4 into the screw hole 3a of the stainless steel holed pin 3, the copper type split type terminal 1 can be tightened with a high fastening torque. Even when fastened to the electrode rod 2, the screw groove is not broken, and an increase in contact resistance due to loosening of the bolt 4 can be prevented. Further, as described above, the space required for the tool at the time of fastening can be reduced, and the heat radiation fins can be provided in that region, so that the heat radiation efficiency is increased.
[0018]
Note that the above-described split type terminal 1 has been described with a shape in which the fin 8 is provided at the peripheral end, but this is not a limitation, and even if the shape is not provided with a fin, it is caused by the looseness of the bolt 4. The increase in contact resistance can be prevented.
[0019]
Moreover, although the pin 3 with a hole inserted in the split type terminal 1 mentioned above has demonstrated the case made from stainless steel, it is not restricted to this, The material whose intensity | strength is higher than the material of the split type terminal 1 If it is formed with. Furthermore, although the case where the pin hole 1b described above is formed in a direction perpendicular to the bolt hole 1c is described, the present invention is not limited to this, and the pin 3 with a hole can be inserted in a direction in which the bolt 4 can be screwed. good. Furthermore, although the case where the screw hole 3a of the pin 3 with a hole mentioned above is a through-hole is demonstrated, it is not restricted to this, The screw hole which has a bottom part may be sufficient.
[0020]
Furthermore, although the split type terminal 1 mentioned above demonstrated the case where it fixed to the outer side of the vacuum vessel 7, it is not restricted to this, You may be fixed in the vacuum vessel 7.
[0021]
Furthermore, although the split type terminal 1 mentioned above has demonstrated the case where it has one split part 1a, it is not restricted to this, You may have a some split part. In this case, the pin 3 with a hole and the volt | bolt 4 are used according to the number of split parts.
[0022]
【The invention's effect】
As described above in detail, according to the first invention, the pin hole is provided in communication with the insertion hole through which the fastening screw passes, and therefore, a pin made of a material different from the electrode connection terminal is inserted into the pin hole. Can do. The body of the pin is provided with a screw hole with a screw groove, and the fastening screw is screwed into this screw hole. Therefore, if the pin is made of a material stronger than the electrode connection terminal, a high fastening torque Even if the fastening screw is tightened, the screw groove is not broken. Accordingly, it is possible to prevent an increase in contact resistance due to loosening of the bolt.
[0023]
According to the second aspect of the present invention, since the screw groove to be screwed into the fastening screw is inserted into the electrode connection terminal, there is no need for a tool space on the screw groove side at the time of fastening, and a space for attaching the heat radiation fin is provided. Sufficiently secured.
[0024]
According to the third and fourth aspects of the present invention, the electrode connection terminal has a pin hole in a direction intersecting with the insertion hole through which the fastening screw passes, and a pin having a screw hole in the body portion is inserted into the pin hole. A fastening screw is screwed into this screw hole. Therefore, if the pin is made of a material stronger than the electrode connection terminal, the screw groove will not be destroyed even if the fastening screw is fastened with a high fastening torque, and the contact resistance is increased due to the loosening of the bolt. Can be prevented.
[0025]
In the fifth invention, since the pin is made of stainless steel having higher strength than the electrode connection terminal made of copper alloy, the screw groove can withstand high fastening torque.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing the structure of an electrode connection terminal according to the present embodiment.
FIG. 2 is a longitudinal sectional view showing a main part of a circuit breaker to which the electrode connection terminal of FIG. 1 is attached.
3 is a perspective view showing a screwed state of a screw member for fixing the split terminal of FIG. 1 to an electrode rod. FIG.
FIG. 4 is a cross-sectional view showing the structure of a conventional electrode connection terminal.
FIG. 5 is a plan view showing the structure of a conventional vacuum valve mounting device.
[Explanation of symbols]
1 split type terminal, 1a split part, 1b pin hole, 1c bolt hole, 2 electrode rod 2a fitting hole, 3 holed pin, 3a screw hole, 4 bolt, 7 vacuum container.

Claims (5)

A fitting hole into which the electrode is inserted, a split part connected to the fitting hole, an insertion hole provided on both sides of the split part, through which the fastening screw is inserted, and the insertion hole crossing the axial direction And a pin hole into which a pin having a screw hole in the body portion is to be inserted. The electrode connection terminal according to claim 1, further comprising a fin for heat dissipation in the vicinity of at least the insertion hole. A pair of electrodes arranged in a vacuum vessel and electrically connected / cut off by relative movement thereof, at least one or more electrode connecting terminals fixed to one of the electrodes, and the electrode connecting terminals connected to the electrodes A screw member for fixing the electrode, and the electrode connection terminal is provided in a fitting hole into which the electrode is inserted, a split portion connected to the fitting hole, and on both sides of the split portion, and passes through the split portion. And a pin hole communicating with the insertion hole in the axial direction, and the screw member has a screw hole in the body portion and is inserted into the pin hole. A circuit breaker comprising: a pin that is formed, and the fastening screw that is screwed into a screw hole of the pin. 4. The circuit breaker according to claim 3, wherein the pin is formed using a material having higher strength than the electrode connection terminal. The circuit breaker according to claim 3 or 4, wherein the pin is made of stainless steel and the electrode connection terminal is made of a copper alloy.

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