JP2000057913A - Vacuum valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrict temperature rise while lowering the electrical resistance of a conducting part by providing a recessed part in each contact side end of a fixed rod and a movable rod, and fixing a coil reinforcement made of the non-magnetic material along the inner diametric surface of the recessed part so that the coil is worked at the ends of the fixed rod and the movable rod into a crack shape. SOLUTION: A coil part 20 is worked into a crank shape, and a tip thereof is bonded to a fixed contact 7A or a movable contact 7B. The electrifying current flows from a fixed rod 3A to a movable rod 3B through the coil part 20. A coil reinforcement 21 is made of the stainless steel having an electrical conductivity lower than that of the coil part 20. With this structure, the electrifying current hardly flows to the coil reinforcement 21. Consequently, when the arc is generated between the fixed contact 7A and the movable contact 7B, the current I flows like an allow, and a vertical magnetic field H is formed in a clearance 29. Ions and electrons of the arc are caught inside of an open clearance 29, and an arc spot is strongly moved so as to prevent the melting of the contacts 7A, 7B.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum valve having a built-in switching contact for a vacuum circuit breaker, and more particularly to a vacuum valve having a small temperature rise.

[0002]

2. Description of the Related Art FIG. 13 is a sectional view showing the structure of a conventional vacuum valve. The vacuum vessel 1 is formed of an insulating cylinder, and a cylindrical arc shield 4 is disposed inside the supporting cylinder via a support (not shown). Inside the arc shield 4, a fixed contact 7A and a movable contact 7B are arranged so as to be able to come and go. That is, the fixed contact 7A is joined to the fixed rod 3A via the coil portion 10, and the movable contact 7B
Is joined to the movable rod 3B via the coil section 10. The upper end of the fixed rod 3A is pulled out to the outside through the metal flange 2A in an airtight manner, and the lower end of the movable rod 3B is drawn out to the outside via the bellows 5 airtightly joined to the metal flange 2B. .

FIG. 13 shows a configuration in a case where the vacuum valve is in a cutoff state. The main circuit current is cut off or energized by interposing a movable rod 3B and a fixed rod 3A in a main circuit (not shown). By driving the movable rod 3B upward, the movable contact 7B and the fixed contact 7
A separation gap 29 with A is closed. The bellows 5 is formed in a bellows shape, and draws a current flowing through the movable rod 3B to the outside of the vacuum vessel 1 while keeping the movable rod 3B movable and airtight. Arc shield 4
Is made of metal, and is for preventing the inner wall of the vacuum vessel 1 from being stained by metal vapor generated at the time of opening and closing of current.
Further, the bellows cover 6 is formed in a cup shape, and protects the bellows 5 from metal vapor generated at the time of opening / closing of current, similarly to the arc shield 4. The inside of the vacuum vessel 1 is evacuated in advance, and is always kept at a high vacuum.

FIG. 14 is a cross-sectional view of a main part showing an internal configuration of the arc shield 4 of FIG. The fixed rod 3 </ b> A is joined to the coil part 10, and
1 is joined to the fixed contact 7A. On the other hand, the movable rod 3B is also joined to another coil part 10,
The protrusion 11 of the coil unit 10 is joined to the movable contact 7A. Further, metal coil reinforcements 8 are joined to the upper and lower coil portions 10 on the side opposite to the separation gap 29, respectively.

[0005] FIG. 15 is a perspective view of the fixed side coil unit 10 shown in FIG.
It is a top view which shows the structure of. The coil portion 10 has a hole 28A into which the end portion 28 (FIG. 13) of the fixed rod 3A fits, and the ring portion 1 formed on the outer periphery of the hole 28A.
3, four arm portions 14 extending from the ring portion 13 to the outer diameter side, an arc portion 12 extending counterclockwise from the tip of each of the arm portions 14, and a projection protruding downward from the arc portion 12. Each part is made of a conductor having good electric conductivity such as copper. Movable coil unit 10
14 are also formed in the same manner, except that the arc portion 12 extends clockwise from the tip of the arm portion 14 and the convex portion 11 projects upward when viewed in the plan view of FIG. The protrusions 11 are arranged so as to face the same position on the fixed side and the movable side as shown in FIG.

Returning to FIG. 14, the ring portions 13 (FIG. 15) of the upper and lower coil portions 10 are respectively joined to the fixed rods 3A or the movable rods 3B, and the convex portions 11 are respectively fixed rods 3A or the movable rods 3B. Is joined to. When the fixed contact 7A and the movable contact 7B are in contact with each other, an energizing current flows from the fixed rod 3A to the fixed contact 7A via the coil unit 10, and furthermore, the movable contact 7B passes through the coil unit 10 to the movable rod 3B. Flows to When the fixed contact 7A and the movable contact 7B are separated during energization, an arc is generated in the separation gap 29. The role of the vacuum valve is to extinguish this arc quickly. A place where an arc is generated from the fixed contact 7A or the movable contact 7B is called an arc spot. If this arc spot continues to be generated locally, the fixed heat 7A or the movable contact 7B
Melts locally. The coil section 10 is for preventing the arc spot from stopping locally. Coil section 1
With the zero interposition, a vertical magnetic field (in the direction of arrow H in FIG. 14) can be generated in the separation gap 29. The reason is,
In FIG. 15, a current I of the fixed-side coil portion 10 flows counterclockwise through the arc portion 12 from the ring portion 13 via the arm portion 14 as shown by an arrow I, and a convex portion protruding downward from the arc portion 12. It flows to the lower fixed contact (not shown) via 11. On the other hand, although not shown, the movable side coil portion 10 also flows counterclockwise through the arc portion 12 as shown by the arrow I. Therefore, a vertical magnetic field is formed in the separation gap 29 of FIG. 14, and the ions and electrons of the arc move in a spiral shape by the vertical magnetic field, and are trapped in the separation gap 29 where the vertical magnetic field is formed. Move violently without stopping locally at the fixed contact 7A and the movable contact 7, thereby preventing the fixed contact 7A and the movable contact 7B from melting due to arc heat.

FIG. 16 is a sectional view taken along the line AA of FIG.
FIG. 17 is a cross-sectional view taken along the line BB of FIG. 16, that is, a cross-sectional view of a portion where the arm portion 14 of the coil portion is not seen, and shows only a fixed-side contact configuration. In addition, FIG.
16 corresponds to a cross-sectional view taken along the line C-C in FIG. In FIG. 17, a coil reinforcement 8 is formed in a disk shape, and a hole 8 in the center of which a fixing rod 3A fits.
A is vacant. The lower surface of the coil reinforcement 8 is joined to the upper surface of the arm portion 14 of the coil portion 10 and the upper surface of the arc portion 12. Further, the contact reinforcement 9 is provided at the end of the cylindrical portion 16 with the flange portion 1.
5 has a shape attached to the outer diameter side, the upper end of the cylindrical portion 16 is joined to the end portion 28 of the fixed rod 3A, and the lower surface of the flange portion 15 is joined to the fixed contact 7A. Note that the configuration of the contact on the movable side is exactly the same as that in FIG. 17 and is inverted with respect to the separation gap 29 as shown in FIG.

[0008] Coil reinforcement 8 and contact reinforcement 9 of FIG.
Is for reinforcing the coil portion 10 and the fixed contact 7A (or the movable contact) so as not to be damaged by the contact pressure applied to the contacts at the time of closing or the impact pressure applied at the time of the opening / closing operation. The coil reinforcement 8 holds the coil portion 10 flat,
The contact reinforcement 9 presses the fixed contact 7A (or the movable contact) flat, and the fixed rod 3A (or the fixed contact 7A).
The force applied to the ring portion 13 of the coil portion 10 is reduced by receiving the force applied from the movable rod side). Coil reinforcement 8
The material of the contact reinforcement 9 is made of, for example, stainless steel, which is mechanically strong and has lower electrical conductivity than the coil portion 10 made of copper. This protects the coil portion 10 and the fixed contact 7A (or the movable contact), and allows most of the current to flow through the coil portion 10.

[0009]

However, in order to further increase the rated current of the conventional vacuum valve as described above, there is a problem that it is necessary to further reduce the electric resistance of the current-carrying part and reduce the temperature rise. there were. That is, the energizing path of the conventional vacuum valve is as follows: fixed rod → arm of fixed side coil → arc of fixed side coil → fixed contact → movable contact → arc of movable side coil → arm of movable side coil Part → movable rod, which is very long. As a result, the electric resistance of the current-carrying part of the vacuum valve increases, and it is difficult to further increase the rated current as it is.

It is an object of the present invention to reduce the electric resistance of a current-carrying part of a vacuum valve and further reduce the temperature rise.

[0011]

According to the present invention, in order to achieve the above object, both ends of an insulating vacuum vessel are joined by metal flanges, and fixed inside the vacuum vessel so as to be able to contact and separate from each other. The fixed contact and the movable contact are housed, and the fixed contact and the movable contact are respectively joined to one end of the fixed rod and the movable rod through a coil portion that allows current to flow in the circumferential direction, and the other end of the fixed rod hermetically seals the metal flange. In a vacuum valve which is pulled out to the outside and the other end of the movable rod is pulled out airtight through a bellows which is airtightly joined to a metal flange, a pot bottom is provided at a contact side end of the fixed rod and the movable rod. A concave portion is provided, and a coil reinforcement made of a non-magnetic material is fixed along the inner diameter surface of the concave portion, and the coil portion contacts the outer peripheral portion of the coil reinforcement. The end of the head and the movable rod may be so processed into the crank shape. As a result, the arm portion in the conventional coil portion is eliminated, and the length of the current-carrying portion is shortened, the electric resistance is reduced, and the temperature rise is reduced.

In such a configuration, a plurality of slits may be formed in the contact point in a radial direction.
As a result, the eddy current flowing through the contact due to the vertical magnetic field is eliminated, and the temperature rise in the current-carrying portion is reduced. In such a configuration, the coil reinforcement may have a cylindrical shape. In such a configuration, the coil reinforcement may have a cup shape, and the bottom of the cup may be directed to the contact side. Thereby, the coil reinforcement becomes mechanically strong.

[0013] In this configuration, the coil reinforcement may have a shape in which a flange portion protrudes from both ends in the axial direction of the cylinder toward the outer periphery in the radial direction. Thereby, even if the contact receives a large contact pressure, it can withstand it. In such a configuration, the rod, the coil portion, and the contact may be separately manufactured in advance and joined to each other by silver brazing. Thereby, the components on the movable side and the fixed side can be shared, and the coil portion can be easily processed.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments. FIG. 1 is a sectional view showing a configuration of a vacuum valve according to an embodiment of the present invention. Each of the coil portions 20 is formed at the ends of the fixed rod 3A and the movable rod 3B made of a conductor having good electric conductivity such as copper.
A non-magnetic cylindrical coil reinforcement 21 is fixed so as to be in contact with the inner peripheral side of the pot-bottomed concave portion provided on the inner diameter side of 0. The coil section 20 is formed into a crank shape as described later, and the tip thereof is fixed contact 7A or movable contact 7A.
B. The rest of FIG. 1 is the same as the conventional configuration of FIG. 13, and the same parts as those of the conventional configuration are denoted by the same reference numerals, and the detailed description is omitted.

FIG. 2 is a side view of a main part showing an internal configuration of the arc shield 4 of FIG. The coil portion 20 is processed into a crank shape, and the tip is joined to the fixed contact 7A or the movable contact 7B. The current flows from the fixed rod 3A to the fixed contact 7A via the coil section 20, and further flows from the movable contact 7B to the movable rod 3B via the coil section 20. The coil reinforcement 21 is made of a stainless material, for example, and has lower electric conductivity than the coil part 20 made of a copper material. Therefore, almost no current flows through the coil reinforcement 21. Therefore, when an arc is generated between the fixed contact 7A and the movable contact 7B, the current I flows as shown by an arrow, and a vertical magnetic field H is formed in the gap 29 between the fixed contact 7A and the movable contact 7B as in the case of FIG. Is done. As a result, the ions and electrons of the arc spirally move and are trapped in the separation gap 29 where the longitudinal magnetic field is formed, and the arc spot moves violently without stopping locally at the fixed contact 7A and the movable contact 7. In addition, the fixed contact 7A and the movable contact 7B can be prevented from being melted by the arc heat.

FIG. 3 is a plan view of the movable contact 7B of FIG. The movable contact 7B is formed with four slits 15 radially oriented in the same direction. The range 22 is a region where the crank-shaped tip of the coil section 20 is joined to the movable contact 7B, and the coil section 20 is joined immediately before each slit 15. The slit 15 is provided in the movable contact 7 by a vertical magnetic field.
This slit 15 is formed to eliminate the eddy current flowing through B, and the slit 15 can suppress the temperature rise of the movable contact 7B. Although the illustration of the plan view on the fixed contact side in FIG. 2 is omitted, the configuration is exactly the same as that in FIG.

FIG. 4 is a plan view showing the movable contact 7B shown in FIG. 3 except for the movable contact 7B. The coil part 20 is fixed so as to be in contact with the outer peripheral part of the coil reinforcement 21 and is mechanically reinforced. In this case also, the illustration of the plan view on the fixed contact side is omitted, but the configuration is exactly the same as that of FIG. FIG.
FIG. 5 is a side view showing a procedure for processing the coil unit 20 of FIG. 4. A pan bottom-shaped recess 16 is formed in advance at the end of the movable rod 3B. The coil reinforcement 21 is fitted into the recess 16, and the inner wall of the recess 16 and the coil reinforcement 21 are brazed by silver. In this state, the end of the movable rod 3B is machined into a crank shape to form the coil portion 20. In this case, the side view of the fixed contact is not shown, but the coil section 20 is formed in exactly the same manner as in FIG.

Returning to FIG. 2, the coil section 20 has no conventional arm section, and the length of the current-carrying section is shortened. As a result, the electric resistance of the coil section 20 decreases, the temperature rise becomes smaller than before, and it is possible to apply the present invention to a vacuum valve having a higher rated current. Further, as described above, the processing of the slits 15 eliminates the generation of eddy currents and reduces the temperature rise of the contacts. This can also increase the rated current of the vacuum valve.

FIG. 6 is a side view showing components of a vacuum valve according to another embodiment of the present invention. Movable contact 7B
After the coil part 20 to which the coil reinforcement 21 is joined and the movable rod 3B to which the bellows 5 and the bellows cover 6 are joined are separately manufactured, the same configuration as that of FIG. 2 is formed by silver brazing. Is done. On the other hand, although not shown, the fixed contact, its coil portion, and the fixed rod are separately manufactured, and then the same configuration as that of FIG. 2 is formed by silver brazing. Since the contact point and the coil portion are the same on the movable side and the fixed side, by manufacturing these parts separately, the parts on the movable side and the fixed side can be shared. In addition, since the coil section 20 can be processed without any contacts or rods, the work becomes easy and the processing becomes very easy. As a result, the manufacturing cost of the vacuum valve can be significantly reduced as compared with the related art.

FIG. 7 is a side view showing coil reinforcement of a vacuum valve according to still another embodiment of the present invention. The coil reinforcement 18 is formed in a cup shape. FIG. 8 is a plan view of the movable contact 7B in which the coil reinforcement 18 of FIG. 7 is fitted. The coil reinforcement 18 is silver brazed to the movable contact 7B. FIG. 9 is a side view showing a procedure for processing the coil unit 20 of FIG. A pan bottom-shaped recess 16 is formed in advance at the end of the movable rod 3B. The coil reinforcement 18 is fitted into the recess 16 with the bottom thereof facing upward, and the inner wall of the recess 16 and the coil reinforcement 18 are silver brazed. In this state, the end of the movable rod 3B is machined into a crank shape to form the coil portion 20. By making the coil reinforcement 18 into a cup shape, the coil reinforcement 18 itself becomes mechanically strong, and thereby the coil part 20 is also mechanically strengthened. Although FIGS. 7 to 9 show the configuration on the movable contact side, the coil unit 20 is mechanically reinforced by the same configuration on the fixed contact side.

FIG. 10 is a side view showing coil reinforcement of a vacuum valve according to still another embodiment of the present invention.
The coil reinforcement 19 includes a flange portion 19A that protrudes from both ends in the axial direction of the cylinder toward the outer periphery in the radial direction. FIG.
FIG. 11 is a plan view of a movable contact 7B in which the coil reinforcement 19 of FIG. 10 is fitted. The coil reinforcement 19 is silver brazed to the movable contact 7B.

FIG. 12 is a side view showing a procedure for processing the coil section 20 of FIG. A pan bottom-shaped recess 16 is formed in advance at the end of the movable rod 3B. The coil reinforcement 19 is fitted into the recess 16, and the inner wall of the recess 16 and the coil reinforcement 19 are brazed by silver. In that state, the movable rod 3B
Is machined into a crank shape to form a coil portion 20. By forming the coil reinforcement 19, the coil reinforcement 18 itself is resistant to a compressive force in the vertical direction, so that the movable contact can withstand a large contact pressure even if it receives a large contact pressure. Therefore, the contact pressure between the contacts can be further increased, and the contact state of the contacts can be kept better than before. Although FIGS. 10 to 12 show the configuration on the movable contact side, the configuration on the fixed contact side is completely the same so that the fixed contact can withstand a large contact pressure even if it receives a large contact pressure.

[0023]

As described above, according to the present invention, a pot bottom-shaped recess is provided at the contact side end of the fixed rod and the movable rod, and a coil reinforcement made of a non-magnetic material is provided along the inner diameter surface of the recess. By fixing the ends of the fixed rod and the movable rod in which the coil portion is in contact with the outer peripheral portion of the coil reinforcement into a crank shape, the electric resistance of the current-carrying portion is reduced, the temperature rise is reduced, and a larger rated current Application to a vacuum valve becomes possible.

In this configuration, by forming a plurality of slits in the contact in the radial direction, the rise in the temperature of the contact can be reduced, and the rated current of the vacuum valve can be increased. In such a configuration, the coil reinforcement is cup-shaped, and the coil reinforcement is further mechanically strengthened by directing the bottom of the cup toward the contact.

In this configuration, the coil reinforcement has a shape in which the flange portion protrudes from both ends in the axial direction of the cylinder toward the outer periphery in the radial direction, so that the contact state between the contacts can be further favorably maintained. In such a configuration, the rod, the coil portion, and the contact are separately manufactured in advance and are joined to each other by silver brazing, so that the manufacturing cost of the vacuum valve can be significantly reduced as compared with the related art.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a configuration of a vacuum valve according to an embodiment of the present invention.

FIG. 2 is a side view of a main part showing an internal configuration of the arc shield of FIG. 1;

FIG. 3 is a plan view of the movable contact shown in FIG. 2;

FIG. 4 is a plan view excluding a movable contact in FIG. 3;

FIG. 5 is a side view showing a procedure for processing the coil part of FIG. 4;

FIG. 6 is a side view showing components of a vacuum valve according to another embodiment of the present invention.

FIG. 7 is a side view showing coil reinforcement of a vacuum valve according to still another embodiment of the present invention.

8 is a plan view of a movable contact into which the coil reinforcement of FIG. 7 is fitted.

FIG. 9 is a side view showing a procedure for processing the coil part of FIG. 8;

FIG. 10 is a side view showing coil reinforcement of a vacuum valve according to still another embodiment of the present invention.

11 is a plan view of the movable contact into which the coil reinforcement of FIG. 10 is fitted.

FIG. 12 is a side view showing a procedure for processing the coil part of FIG. 11;

FIG. 13 is a sectional view showing a configuration of a conventional vacuum valve.

14 is a side view of a main part showing an internal configuration of the arc shield of FIG. 13;

FIG. 15 is a plan view showing a configuration of a fixed-side coil unit in FIG. 14;

16 is a sectional view taken along line AA of FIG.

FIG. 17 is a sectional view taken along line BB of FIG. 16;

[Explanation of symbols]

1: vacuum vessel, 2A, 2B: metal flange, 3A: fixed rod, 3B: movable rod, 4: arc shield, 5:
Bellows, 6: Bellows cover, 7A: Fixed contact, 7
B: movable contact, 15: slit, 16: recess, 18,
19, 21: coil reinforcement, 19A: collar, 20: coil

Claims (6)

[Claims] An insulated vacuum vessel is joined at both ends by metal flanges, and a fixed contact and a movable contact which can be brought into contact with and separated from each other are housed inside the vacuum vessel, and the fixed contact and the movable contact are respectively arranged in a circumferential direction. The fixed rod and the movable rod are joined to one end of the fixed rod through a coil part that allows current to flow therethrough.The other end of the fixed rod is hermetically penetrated through the metal flange and pulled out, and the other end of the movable rod is hermetically sealed to the metal flange. In the vacuum valve which is drawn out airtight through a bellows joined to the base, a pot-bottomed concave portion is provided at the contact side end of the fixed rod and the movable rod, and the concave portion is formed along the inner diameter surface of the concave portion. The coil reinforcement made of a magnetic material is fixed, and the ends of the fixed rod and the movable rod that are in contact with the outer periphery of the coil reinforcement are formed into a crank shape. Vacuum valve, wherein the coil portion is formed. 2. The vacuum valve according to claim 1, wherein a plurality of radially oriented slits are formed in said contact point. 3. A vacuum valve according to claim 1, wherein said coil reinforcement has a cylindrical shape. 4. The vacuum valve according to claim 1, wherein the coil reinforcement has a cup shape,
A vacuum valve, wherein the bottom of the cup is directed toward the contact. 5. The vacuum valve according to claim 1, wherein the coil reinforcement has a shape in which a flange portion protrudes from both ends in the axial direction of the cylinder toward the outer periphery in the radial direction. valve. 6. The vacuum valve according to claim 1, wherein the rod, the coil portion, and the contact are separately manufactured in advance and are joined to each other by silver brazing.